1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Facilitate override of interface linkage and calling conventions.
47** Be aware that these macros may not be used within this particular
48** translation of the amalgamation and its associated header file.
49**
50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51** compiler that the target identifier should have external linkage.
52**
53** The SQLITE_CDECL macro is used to set the calling convention for
54** public functions that accept a variable number of arguments.
55**
56** The SQLITE_APICALL macro is used to set the calling convention for
57** public functions that accept a fixed number of arguments.
58**
59** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60**
61** The SQLITE_CALLBACK macro is used to set the calling convention for
62** function pointers.
63**
64** The SQLITE_SYSAPI macro is used to set the calling convention for
65** functions provided by the operating system.
66**
67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68** SQLITE_SYSAPI macros are used only when building for environments
69** that require non-default calling conventions.
70*/
71#ifndef SQLITE_EXTERN
72# define SQLITE_EXTERN extern
73#endif
74#ifndef SQLITE_API
75# define SQLITE_API
76#endif
77#ifndef SQLITE_CDECL
78# define SQLITE_CDECL
79#endif
80#ifndef SQLITE_APICALL
81# define SQLITE_APICALL
82#endif
83#ifndef SQLITE_STDCALL
84# define SQLITE_STDCALL SQLITE_APICALL
85#endif
86#ifndef SQLITE_CALLBACK
87# define SQLITE_CALLBACK
88#endif
89#ifndef SQLITE_SYSAPI
90# define SQLITE_SYSAPI
91#endif
92
93/*
94** These no-op macros are used in front of interfaces to mark those
95** interfaces as either deprecated or experimental. New applications
96** should not use deprecated interfaces - they are supported for backwards
97** compatibility only. Application writers should be aware that
98** experimental interfaces are subject to change in point releases.
99**
100** These macros used to resolve to various kinds of compiler magic that
101** would generate warning messages when they were used. But that
102** compiler magic ended up generating such a flurry of bug reports
103** that we have taken it all out and gone back to using simple
104** noop macros.
105*/
106#define SQLITE_DEPRECATED
107#define SQLITE_EXPERIMENTAL
108
109/*
110** Ensure these symbols were not defined by some previous header file.
111*/
112#ifdef SQLITE_VERSION
113# undef SQLITE_VERSION
114#endif
115#ifdef SQLITE_VERSION_NUMBER
116# undef SQLITE_VERSION_NUMBER
117#endif
118
119/*
120** CAPI3REF: Compile-Time Library Version Numbers
121**
122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123** evaluates to a string literal that is the SQLite version in the
124** format "X.Y.Z" where X is the major version number (always 3 for
125** SQLite3) and Y is the minor version number and Z is the release number.)^
126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128** numbers used in [SQLITE_VERSION].)^
129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130** be larger than the release from which it is derived. Either Y will
131** be held constant and Z will be incremented or else Y will be incremented
132** and Z will be reset to zero.
133**
134** Since [version 3.6.18] ([dateof:3.6.18]),
135** SQLite source code has been stored in the
136** <a href="http://www.fossil-scm.org/">Fossil configuration management
137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138** a string which identifies a particular check-in of SQLite
139** within its configuration management system. ^The SQLITE_SOURCE_ID
140** string contains the date and time of the check-in (UTC) and a SHA1
141** or SHA3-256 hash of the entire source tree. If the source code has
142** been edited in any way since it was last checked in, then the last
143** four hexadecimal digits of the hash may be modified.
144**
145** See also: [sqlite3_libversion()],
146** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147** [sqlite_version()] and [sqlite_source_id()].
148*/
149#define SQLITE_VERSION "3.40.1"
150#define SQLITE_VERSION_NUMBER 3040001
151#define SQLITE_SOURCE_ID "2022-12-28 14:03:47 df5c253c0b3dd24916e4ec7cf77d3db5294cc9fd45ae7b9c5e82ad8197f38a24"
152
153/*
154** CAPI3REF: Run-Time Library Version Numbers
155** KEYWORDS: sqlite3_version sqlite3_sourceid
156**
157** These interfaces provide the same information as the [SQLITE_VERSION],
158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159** but are associated with the library instead of the header file. ^(Cautious
160** programmers might include assert() statements in their application to
161** verify that values returned by these interfaces match the macros in
162** the header, and thus ensure that the application is
163** compiled with matching library and header files.
164**
165** <blockquote><pre>
166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169** </pre></blockquote>)^
170**
171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172** macro. ^The sqlite3_libversion() function returns a pointer to the
173** to the sqlite3_version[] string constant. The sqlite3_libversion()
174** function is provided for use in DLLs since DLL users usually do not have
175** direct access to string constants within the DLL. ^The
176** sqlite3_libversion_number() function returns an integer equal to
177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178** a pointer to a string constant whose value is the same as the
179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180** using an edited copy of [the amalgamation], then the last four characters
181** of the hash might be different from [SQLITE_SOURCE_ID].)^
182**
183** See also: [sqlite_version()] and [sqlite_source_id()].
184*/
185SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186SQLITE_API const char *sqlite3_libversion(void);
187SQLITE_API const char *sqlite3_sourceid(void);
188SQLITE_API int sqlite3_libversion_number(void);
189
190/*
191** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192**
193** ^The sqlite3_compileoption_used() function returns 0 or 1
194** indicating whether the specified option was defined at
195** compile time. ^The SQLITE_ prefix may be omitted from the
196** option name passed to sqlite3_compileoption_used().
197**
198** ^The sqlite3_compileoption_get() function allows iterating
199** over the list of options that were defined at compile time by
200** returning the N-th compile time option string. ^If N is out of range,
201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202** prefix is omitted from any strings returned by
203** sqlite3_compileoption_get().
204**
205** ^Support for the diagnostic functions sqlite3_compileoption_used()
206** and sqlite3_compileoption_get() may be omitted by specifying the
207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208**
209** See also: SQL functions [sqlite_compileoption_used()] and
210** [sqlite_compileoption_get()] and the [compile_options pragma].
211*/
212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214SQLITE_API const char *sqlite3_compileoption_get(int N);
215#else
216# define sqlite3_compileoption_used(X) 0
217# define sqlite3_compileoption_get(X) ((void*)0)
218#endif
219
220/*
221** CAPI3REF: Test To See If The Library Is Threadsafe
222**
223** ^The sqlite3_threadsafe() function returns zero if and only if
224** SQLite was compiled with mutexing code omitted due to the
225** [SQLITE_THREADSAFE] compile-time option being set to 0.
226**
227** SQLite can be compiled with or without mutexes. When
228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229** are enabled and SQLite is threadsafe. When the
230** [SQLITE_THREADSAFE] macro is 0,
231** the mutexes are omitted. Without the mutexes, it is not safe
232** to use SQLite concurrently from more than one thread.
233**
234** Enabling mutexes incurs a measurable performance penalty.
235** So if speed is of utmost importance, it makes sense to disable
236** the mutexes. But for maximum safety, mutexes should be enabled.
237** ^The default behavior is for mutexes to be enabled.
238**
239** This interface can be used by an application to make sure that the
240** version of SQLite that it is linking against was compiled with
241** the desired setting of the [SQLITE_THREADSAFE] macro.
242**
243** This interface only reports on the compile-time mutex setting
244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246** can be fully or partially disabled using a call to [sqlite3_config()]
247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249** sqlite3_threadsafe() function shows only the compile-time setting of
250** thread safety, not any run-time changes to that setting made by
251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252** is unchanged by calls to sqlite3_config().)^
253**
254** See the [threading mode] documentation for additional information.
255*/
256SQLITE_API int sqlite3_threadsafe(void);
257
258/*
259** CAPI3REF: Database Connection Handle
260** KEYWORDS: {database connection} {database connections}
261**
262** Each open SQLite database is represented by a pointer to an instance of
263** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266** and [sqlite3_close_v2()] are its destructors. There are many other
267** interfaces (such as
268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269** [sqlite3_busy_timeout()] to name but three) that are methods on an
270** sqlite3 object.
271*/
272typedef struct sqlite3 sqlite3;
273
274/*
275** CAPI3REF: 64-Bit Integer Types
276** KEYWORDS: sqlite_int64 sqlite_uint64
277**
278** Because there is no cross-platform way to specify 64-bit integer types
279** SQLite includes typedefs for 64-bit signed and unsigned integers.
280**
281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283** compatibility only.
284**
285** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287** sqlite3_uint64 and sqlite_uint64 types can store integer values
288** between 0 and +18446744073709551615 inclusive.
289*/
290#ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292# ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294# else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296# endif
297#elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300#else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303#endif
304typedef sqlite_int64 sqlite3_int64;
305typedef sqlite_uint64 sqlite3_uint64;
306
307/*
308** If compiling for a processor that lacks floating point support,
309** substitute integer for floating-point.
310*/
311#ifdef SQLITE_OMIT_FLOATING_POINT
312# define double sqlite3_int64
313#endif
314
315/*
316** CAPI3REF: Closing A Database Connection
317** DESTRUCTOR: sqlite3
318**
319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320** for the [sqlite3] object.
321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322** the [sqlite3] object is successfully destroyed and all associated
323** resources are deallocated.
324**
325** Ideally, applications should [sqlite3_finalize | finalize] all
326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328** with the [sqlite3] object prior to attempting to close the object.
329** ^If the database connection is associated with unfinalized prepared
330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331** sqlite3_close() will leave the database connection open and return
332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335** connection immediately, it marks the database connection as an unusable
336** "zombie" and makes arrangements to automatically deallocate the database
337** connection after all prepared statements are finalized, all BLOB handles
338** are closed, and all backups have finished. The sqlite3_close_v2() interface
339** is intended for use with host languages that are garbage collected, and
340** where the order in which destructors are called is arbitrary.
341**
342** ^If an [sqlite3] object is destroyed while a transaction is open,
343** the transaction is automatically rolled back.
344**
345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346** must be either a NULL
347** pointer or an [sqlite3] object pointer obtained
348** from [sqlite3_open()], [sqlite3_open16()], or
349** [sqlite3_open_v2()], and not previously closed.
350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351** argument is a harmless no-op.
352*/
353SQLITE_API int sqlite3_close(sqlite3*);
354SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356/*
357** The type for a callback function.
358** This is legacy and deprecated. It is included for historical
359** compatibility and is not documented.
360*/
361typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363/*
364** CAPI3REF: One-Step Query Execution Interface
365** METHOD: sqlite3
366**
367** The sqlite3_exec() interface is a convenience wrapper around
368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369** that allows an application to run multiple statements of SQL
370** without having to use a lot of C code.
371**
372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373** semicolon-separate SQL statements passed into its 2nd argument,
374** in the context of the [database connection] passed in as its 1st
375** argument. ^If the callback function of the 3rd argument to
376** sqlite3_exec() is not NULL, then it is invoked for each result row
377** coming out of the evaluated SQL statements. ^The 4th argument to
378** sqlite3_exec() is relayed through to the 1st argument of each
379** callback invocation. ^If the callback pointer to sqlite3_exec()
380** is NULL, then no callback is ever invoked and result rows are
381** ignored.
382**
383** ^If an error occurs while evaluating the SQL statements passed into
384** sqlite3_exec(), then execution of the current statement stops and
385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386** is not NULL then any error message is written into memory obtained
387** from [sqlite3_malloc()] and passed back through the 5th parameter.
388** To avoid memory leaks, the application should invoke [sqlite3_free()]
389** on error message strings returned through the 5th parameter of
390** sqlite3_exec() after the error message string is no longer needed.
391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393** NULL before returning.
394**
395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396** routine returns SQLITE_ABORT without invoking the callback again and
397** without running any subsequent SQL statements.
398**
399** ^The 2nd argument to the sqlite3_exec() callback function is the
400** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401** callback is an array of pointers to strings obtained as if from
402** [sqlite3_column_text()], one for each column. ^If an element of a
403** result row is NULL then the corresponding string pointer for the
404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405** sqlite3_exec() callback is an array of pointers to strings where each
406** entry represents the name of corresponding result column as obtained
407** from [sqlite3_column_name()].
408**
409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410** to an empty string, or a pointer that contains only whitespace and/or
411** SQL comments, then no SQL statements are evaluated and the database
412** is not changed.
413**
414** Restrictions:
415**
416** <ul>
417** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418** is a valid and open [database connection].
419** <li> The application must not close the [database connection] specified by
420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421** <li> The application must not modify the SQL statement text passed into
422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423** </ul>
424*/
425SQLITE_API int sqlite3_exec(
426 sqlite3*, /* An open database */
427 const char *sql, /* SQL to be evaluated */
428 int (*callback)(void*,int,char**,char**), /* Callback function */
429 void *, /* 1st argument to callback */
430 char **errmsg /* Error msg written here */
431);
432
433/*
434** CAPI3REF: Result Codes
435** KEYWORDS: {result code definitions}
436**
437** Many SQLite functions return an integer result code from the set shown
438** here in order to indicate success or failure.
439**
440** New error codes may be added in future versions of SQLite.
441**
442** See also: [extended result code definitions]
443*/
444#define SQLITE_OK 0 /* Successful result */
445/* beginning-of-error-codes */
446#define SQLITE_ERROR 1 /* Generic error */
447#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
448#define SQLITE_PERM 3 /* Access permission denied */
449#define SQLITE_ABORT 4 /* Callback routine requested an abort */
450#define SQLITE_BUSY 5 /* The database file is locked */
451#define SQLITE_LOCKED 6 /* A table in the database is locked */
452#define SQLITE_NOMEM 7 /* A malloc() failed */
453#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
454#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
455#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
456#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
457#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
458#define SQLITE_FULL 13 /* Insertion failed because database is full */
459#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
460#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
461#define SQLITE_EMPTY 16 /* Internal use only */
462#define SQLITE_SCHEMA 17 /* The database schema changed */
463#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
464#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
465#define SQLITE_MISMATCH 20 /* Data type mismatch */
466#define SQLITE_MISUSE 21 /* Library used incorrectly */
467#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
468#define SQLITE_AUTH 23 /* Authorization denied */
469#define SQLITE_FORMAT 24 /* Not used */
470#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
471#define SQLITE_NOTADB 26 /* File opened that is not a database file */
472#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
473#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
474#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
475#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
476/* end-of-error-codes */
477
478/*
479** CAPI3REF: Extended Result Codes
480** KEYWORDS: {extended result code definitions}
481**
482** In its default configuration, SQLite API routines return one of 30 integer
483** [result codes]. However, experience has shown that many of
484** these result codes are too coarse-grained. They do not provide as
485** much information about problems as programmers might like. In an effort to
486** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
487** and later) include
488** support for additional result codes that provide more detailed information
489** about errors. These [extended result codes] are enabled or disabled
490** on a per database connection basis using the
491** [sqlite3_extended_result_codes()] API. Or, the extended code for
492** the most recent error can be obtained using
493** [sqlite3_extended_errcode()].
494*/
495#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
496#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
497#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
498#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
499#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
500#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
501#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
502#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
503#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
504#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
505#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
506#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
507#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
508#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
509#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
510#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
511#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
512#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
513#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
514#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
515#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
516#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
517#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
518#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
519#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
520#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
521#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
522#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
523#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
524#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
525#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
526#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
527#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
528#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
529#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
530#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
531#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
532#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
533#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
534#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
535#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
536#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
537#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
538#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
539#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
540#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
541#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
542#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
543#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
544#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
545#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
546#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
547#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
548#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
549#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
550#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
551#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
552#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
553#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
554#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
555#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
556#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
557#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
558#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
559#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
560#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
561#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
562#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
563#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
564#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
565#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
566#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
567#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
568#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
569#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
570
571/*
572** CAPI3REF: Flags For File Open Operations
573**
574** These bit values are intended for use in the
575** 3rd parameter to the [sqlite3_open_v2()] interface and
576** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
577**
578** Only those flags marked as "Ok for sqlite3_open_v2()" may be
579** used as the third argument to the [sqlite3_open_v2()] interface.
580** The other flags have historically been ignored by sqlite3_open_v2(),
581** though future versions of SQLite might change so that an error is
582** raised if any of the disallowed bits are passed into sqlite3_open_v2().
583** Applications should not depend on the historical behavior.
584**
585** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
586** [sqlite3_open_v2()] does *not* cause the underlying database file
587** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
588** [sqlite3_open_v2()] has historically be a no-op and might become an
589** error in future versions of SQLite.
590*/
591#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
592#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
593#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
594#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
595#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
596#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
597#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
598#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
599#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
600#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
601#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
602#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
603#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
604#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
605#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
606#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
607#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
608#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
609#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
610#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
611#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
613
614/* Reserved: 0x00F00000 */
615/* Legacy compatibility: */
616#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
617
618
619/*
620** CAPI3REF: Device Characteristics
621**
622** The xDeviceCharacteristics method of the [sqlite3_io_methods]
623** object returns an integer which is a vector of these
624** bit values expressing I/O characteristics of the mass storage
625** device that holds the file that the [sqlite3_io_methods]
626** refers to.
627**
628** The SQLITE_IOCAP_ATOMIC property means that all writes of
629** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
630** mean that writes of blocks that are nnn bytes in size and
631** are aligned to an address which is an integer multiple of
632** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
633** that when data is appended to a file, the data is appended
634** first then the size of the file is extended, never the other
635** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
636** information is written to disk in the same order as calls
637** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
638** after reboot following a crash or power loss, the only bytes in a
639** file that were written at the application level might have changed
640** and that adjacent bytes, even bytes within the same sector are
641** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
642** flag indicates that a file cannot be deleted when open. The
643** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
644** read-only media and cannot be changed even by processes with
645** elevated privileges.
646**
647** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
648** filesystem supports doing multiple write operations atomically when those
649** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
650** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
651*/
652#define SQLITE_IOCAP_ATOMIC 0x00000001
653#define SQLITE_IOCAP_ATOMIC512 0x00000002
654#define SQLITE_IOCAP_ATOMIC1K 0x00000004
655#define SQLITE_IOCAP_ATOMIC2K 0x00000008
656#define SQLITE_IOCAP_ATOMIC4K 0x00000010
657#define SQLITE_IOCAP_ATOMIC8K 0x00000020
658#define SQLITE_IOCAP_ATOMIC16K 0x00000040
659#define SQLITE_IOCAP_ATOMIC32K 0x00000080
660#define SQLITE_IOCAP_ATOMIC64K 0x00000100
661#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
662#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
663#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
664#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
665#define SQLITE_IOCAP_IMMUTABLE 0x00002000
666#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
667
668/*
669** CAPI3REF: File Locking Levels
670**
671** SQLite uses one of these integer values as the second
672** argument to calls it makes to the xLock() and xUnlock() methods
673** of an [sqlite3_io_methods] object. These values are ordered from
674** lest restrictive to most restrictive.
675**
676** The argument to xLock() is always SHARED or higher. The argument to
677** xUnlock is either SHARED or NONE.
678*/
679#define SQLITE_LOCK_NONE 0 /* xUnlock() only */
680#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
681#define SQLITE_LOCK_RESERVED 2 /* xLock() only */
682#define SQLITE_LOCK_PENDING 3 /* xLock() only */
683#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
684
685/*
686** CAPI3REF: Synchronization Type Flags
687**
688** When SQLite invokes the xSync() method of an
689** [sqlite3_io_methods] object it uses a combination of
690** these integer values as the second argument.
691**
692** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
693** sync operation only needs to flush data to mass storage. Inode
694** information need not be flushed. If the lower four bits of the flag
695** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
696** If the lower four bits equal SQLITE_SYNC_FULL, that means
697** to use Mac OS X style fullsync instead of fsync().
698**
699** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
700** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
701** settings. The [synchronous pragma] determines when calls to the
702** xSync VFS method occur and applies uniformly across all platforms.
703** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
704** energetic or rigorous or forceful the sync operations are and
705** only make a difference on Mac OSX for the default SQLite code.
706** (Third-party VFS implementations might also make the distinction
707** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
708** operating systems natively supported by SQLite, only Mac OSX
709** cares about the difference.)
710*/
711#define SQLITE_SYNC_NORMAL 0x00002
712#define SQLITE_SYNC_FULL 0x00003
713#define SQLITE_SYNC_DATAONLY 0x00010
714
715/*
716** CAPI3REF: OS Interface Open File Handle
717**
718** An [sqlite3_file] object represents an open file in the
719** [sqlite3_vfs | OS interface layer]. Individual OS interface
720** implementations will
721** want to subclass this object by appending additional fields
722** for their own use. The pMethods entry is a pointer to an
723** [sqlite3_io_methods] object that defines methods for performing
724** I/O operations on the open file.
725*/
726typedef struct sqlite3_file sqlite3_file;
727struct sqlite3_file {
728 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
729};
730
731/*
732** CAPI3REF: OS Interface File Virtual Methods Object
733**
734** Every file opened by the [sqlite3_vfs.xOpen] method populates an
735** [sqlite3_file] object (or, more commonly, a subclass of the
736** [sqlite3_file] object) with a pointer to an instance of this object.
737** This object defines the methods used to perform various operations
738** against the open file represented by the [sqlite3_file] object.
739**
740** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
741** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
742** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
743** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
744** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
745** to NULL.
746**
747** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
748** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
749** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
750** flag may be ORed in to indicate that only the data of the file
751** and not its inode needs to be synced.
752**
753** The integer values to xLock() and xUnlock() are one of
754** <ul>
755** <li> [SQLITE_LOCK_NONE],
756** <li> [SQLITE_LOCK_SHARED],
757** <li> [SQLITE_LOCK_RESERVED],
758** <li> [SQLITE_LOCK_PENDING], or
759** <li> [SQLITE_LOCK_EXCLUSIVE].
760** </ul>
761** xLock() upgrades the database file lock. In other words, xLock() moves the
762** database file lock in the direction NONE toward EXCLUSIVE. The argument to
763** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
764** SQLITE_LOCK_NONE. If the database file lock is already at or above the
765** requested lock, then the call to xLock() is a no-op.
766** xUnlock() downgrades the database file lock to either SHARED or NONE.
767* If the lock is already at or below the requested lock state, then the call
768** to xUnlock() is a no-op.
769** The xCheckReservedLock() method checks whether any database connection,
770** either in this process or in some other process, is holding a RESERVED,
771** PENDING, or EXCLUSIVE lock on the file. It returns true
772** if such a lock exists and false otherwise.
773**
774** The xFileControl() method is a generic interface that allows custom
775** VFS implementations to directly control an open file using the
776** [sqlite3_file_control()] interface. The second "op" argument is an
777** integer opcode. The third argument is a generic pointer intended to
778** point to a structure that may contain arguments or space in which to
779** write return values. Potential uses for xFileControl() might be
780** functions to enable blocking locks with timeouts, to change the
781** locking strategy (for example to use dot-file locks), to inquire
782** about the status of a lock, or to break stale locks. The SQLite
783** core reserves all opcodes less than 100 for its own use.
784** A [file control opcodes | list of opcodes] less than 100 is available.
785** Applications that define a custom xFileControl method should use opcodes
786** greater than 100 to avoid conflicts. VFS implementations should
787** return [SQLITE_NOTFOUND] for file control opcodes that they do not
788** recognize.
789**
790** The xSectorSize() method returns the sector size of the
791** device that underlies the file. The sector size is the
792** minimum write that can be performed without disturbing
793** other bytes in the file. The xDeviceCharacteristics()
794** method returns a bit vector describing behaviors of the
795** underlying device:
796**
797** <ul>
798** <li> [SQLITE_IOCAP_ATOMIC]
799** <li> [SQLITE_IOCAP_ATOMIC512]
800** <li> [SQLITE_IOCAP_ATOMIC1K]
801** <li> [SQLITE_IOCAP_ATOMIC2K]
802** <li> [SQLITE_IOCAP_ATOMIC4K]
803** <li> [SQLITE_IOCAP_ATOMIC8K]
804** <li> [SQLITE_IOCAP_ATOMIC16K]
805** <li> [SQLITE_IOCAP_ATOMIC32K]
806** <li> [SQLITE_IOCAP_ATOMIC64K]
807** <li> [SQLITE_IOCAP_SAFE_APPEND]
808** <li> [SQLITE_IOCAP_SEQUENTIAL]
809** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
810** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
811** <li> [SQLITE_IOCAP_IMMUTABLE]
812** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
813** </ul>
814**
815** The SQLITE_IOCAP_ATOMIC property means that all writes of
816** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
817** mean that writes of blocks that are nnn bytes in size and
818** are aligned to an address which is an integer multiple of
819** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
820** that when data is appended to a file, the data is appended
821** first then the size of the file is extended, never the other
822** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
823** information is written to disk in the same order as calls
824** to xWrite().
825**
826** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
827** in the unread portions of the buffer with zeros. A VFS that
828** fails to zero-fill short reads might seem to work. However,
829** failure to zero-fill short reads will eventually lead to
830** database corruption.
831*/
832typedef struct sqlite3_io_methods sqlite3_io_methods;
833struct sqlite3_io_methods {
834 int iVersion;
835 int (*xClose)(sqlite3_file*);
836 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
837 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
838 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
839 int (*xSync)(sqlite3_file*, int flags);
840 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
841 int (*xLock)(sqlite3_file*, int);
842 int (*xUnlock)(sqlite3_file*, int);
843 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
844 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
845 int (*xSectorSize)(sqlite3_file*);
846 int (*xDeviceCharacteristics)(sqlite3_file*);
847 /* Methods above are valid for version 1 */
848 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
849 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
850 void (*xShmBarrier)(sqlite3_file*);
851 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
852 /* Methods above are valid for version 2 */
853 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
854 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
855 /* Methods above are valid for version 3 */
856 /* Additional methods may be added in future releases */
857};
858
859/*
860** CAPI3REF: Standard File Control Opcodes
861** KEYWORDS: {file control opcodes} {file control opcode}
862**
863** These integer constants are opcodes for the xFileControl method
864** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
865** interface.
866**
867** <ul>
868** <li>[[SQLITE_FCNTL_LOCKSTATE]]
869** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
870** opcode causes the xFileControl method to write the current state of
871** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
872** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
873** into an integer that the pArg argument points to.
874** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
875**
876** <li>[[SQLITE_FCNTL_SIZE_HINT]]
877** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
878** layer a hint of how large the database file will grow to be during the
879** current transaction. This hint is not guaranteed to be accurate but it
880** is often close. The underlying VFS might choose to preallocate database
881** file space based on this hint in order to help writes to the database
882** file run faster.
883**
884** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
885** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
886** implements [sqlite3_deserialize()] to set an upper bound on the size
887** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
888** If the integer pointed to is negative, then it is filled in with the
889** current limit. Otherwise the limit is set to the larger of the value
890** of the integer pointed to and the current database size. The integer
891** pointed to is set to the new limit.
892**
893** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
894** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
895** extends and truncates the database file in chunks of a size specified
896** by the user. The fourth argument to [sqlite3_file_control()] should
897** point to an integer (type int) containing the new chunk-size to use
898** for the nominated database. Allocating database file space in large
899** chunks (say 1MB at a time), may reduce file-system fragmentation and
900** improve performance on some systems.
901**
902** <li>[[SQLITE_FCNTL_FILE_POINTER]]
903** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
904** to the [sqlite3_file] object associated with a particular database
905** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
906**
907** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
908** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
909** to the [sqlite3_file] object associated with the journal file (either
910** the [rollback journal] or the [write-ahead log]) for a particular database
911** connection. See also [SQLITE_FCNTL_FILE_POINTER].
912**
913** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
914** No longer in use.
915**
916** <li>[[SQLITE_FCNTL_SYNC]]
917** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
918** sent to the VFS immediately before the xSync method is invoked on a
919** database file descriptor. Or, if the xSync method is not invoked
920** because the user has configured SQLite with
921** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
922** of the xSync method. In most cases, the pointer argument passed with
923** this file-control is NULL. However, if the database file is being synced
924** as part of a multi-database commit, the argument points to a nul-terminated
925** string containing the transactions super-journal file name. VFSes that
926** do not need this signal should silently ignore this opcode. Applications
927** should not call [sqlite3_file_control()] with this opcode as doing so may
928** disrupt the operation of the specialized VFSes that do require it.
929**
930** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
931** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
932** and sent to the VFS after a transaction has been committed immediately
933** but before the database is unlocked. VFSes that do not need this signal
934** should silently ignore this opcode. Applications should not call
935** [sqlite3_file_control()] with this opcode as doing so may disrupt the
936** operation of the specialized VFSes that do require it.
937**
938** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
939** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
940** retry counts and intervals for certain disk I/O operations for the
941** windows [VFS] in order to provide robustness in the presence of
942** anti-virus programs. By default, the windows VFS will retry file read,
943** file write, and file delete operations up to 10 times, with a delay
944** of 25 milliseconds before the first retry and with the delay increasing
945** by an additional 25 milliseconds with each subsequent retry. This
946** opcode allows these two values (10 retries and 25 milliseconds of delay)
947** to be adjusted. The values are changed for all database connections
948** within the same process. The argument is a pointer to an array of two
949** integers where the first integer is the new retry count and the second
950** integer is the delay. If either integer is negative, then the setting
951** is not changed but instead the prior value of that setting is written
952** into the array entry, allowing the current retry settings to be
953** interrogated. The zDbName parameter is ignored.
954**
955** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
956** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
957** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
958** write ahead log ([WAL file]) and shared memory
959** files used for transaction control
960** are automatically deleted when the latest connection to the database
961** closes. Setting persistent WAL mode causes those files to persist after
962** close. Persisting the files is useful when other processes that do not
963** have write permission on the directory containing the database file want
964** to read the database file, as the WAL and shared memory files must exist
965** in order for the database to be readable. The fourth parameter to
966** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
967** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
968** WAL mode. If the integer is -1, then it is overwritten with the current
969** WAL persistence setting.
970**
971** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
972** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
973** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
974** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
975** xDeviceCharacteristics methods. The fourth parameter to
976** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
977** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
978** mode. If the integer is -1, then it is overwritten with the current
979** zero-damage mode setting.
980**
981** <li>[[SQLITE_FCNTL_OVERWRITE]]
982** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
983** a write transaction to indicate that, unless it is rolled back for some
984** reason, the entire database file will be overwritten by the current
985** transaction. This is used by VACUUM operations.
986**
987** <li>[[SQLITE_FCNTL_VFSNAME]]
988** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
989** all [VFSes] in the VFS stack. The names are of all VFS shims and the
990** final bottom-level VFS are written into memory obtained from
991** [sqlite3_malloc()] and the result is stored in the char* variable
992** that the fourth parameter of [sqlite3_file_control()] points to.
993** The caller is responsible for freeing the memory when done. As with
994** all file-control actions, there is no guarantee that this will actually
995** do anything. Callers should initialize the char* variable to a NULL
996** pointer in case this file-control is not implemented. This file-control
997** is intended for diagnostic use only.
998**
999** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1000** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1001** [VFSes] currently in use. ^(The argument X in
1002** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1003** of type "[sqlite3_vfs] **". This opcodes will set *X
1004** to a pointer to the top-level VFS.)^
1005** ^When there are multiple VFS shims in the stack, this opcode finds the
1006** upper-most shim only.
1007**
1008** <li>[[SQLITE_FCNTL_PRAGMA]]
1009** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1010** file control is sent to the open [sqlite3_file] object corresponding
1011** to the database file to which the pragma statement refers. ^The argument
1012** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1013** pointers to strings (char**) in which the second element of the array
1014** is the name of the pragma and the third element is the argument to the
1015** pragma or NULL if the pragma has no argument. ^The handler for an
1016** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1017** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1018** or the equivalent and that string will become the result of the pragma or
1019** the error message if the pragma fails. ^If the
1020** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1021** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1022** file control returns [SQLITE_OK], then the parser assumes that the
1023** VFS has handled the PRAGMA itself and the parser generates a no-op
1024** prepared statement if result string is NULL, or that returns a copy
1025** of the result string if the string is non-NULL.
1026** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1027** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1028** that the VFS encountered an error while handling the [PRAGMA] and the
1029** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1030** file control occurs at the beginning of pragma statement analysis and so
1031** it is able to override built-in [PRAGMA] statements.
1032**
1033** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1034** ^The [SQLITE_FCNTL_BUSYHANDLER]
1035** file-control may be invoked by SQLite on the database file handle
1036** shortly after it is opened in order to provide a custom VFS with access
1037** to the connection's busy-handler callback. The argument is of type (void**)
1038** - an array of two (void *) values. The first (void *) actually points
1039** to a function of type (int (*)(void *)). In order to invoke the connection's
1040** busy-handler, this function should be invoked with the second (void *) in
1041** the array as the only argument. If it returns non-zero, then the operation
1042** should be retried. If it returns zero, the custom VFS should abandon the
1043** current operation.
1044**
1045** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1046** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1047** to have SQLite generate a
1048** temporary filename using the same algorithm that is followed to generate
1049** temporary filenames for TEMP tables and other internal uses. The
1050** argument should be a char** which will be filled with the filename
1051** written into memory obtained from [sqlite3_malloc()]. The caller should
1052** invoke [sqlite3_free()] on the result to avoid a memory leak.
1053**
1054** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1055** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1056** maximum number of bytes that will be used for memory-mapped I/O.
1057** The argument is a pointer to a value of type sqlite3_int64 that
1058** is an advisory maximum number of bytes in the file to memory map. The
1059** pointer is overwritten with the old value. The limit is not changed if
1060** the value originally pointed to is negative, and so the current limit
1061** can be queried by passing in a pointer to a negative number. This
1062** file-control is used internally to implement [PRAGMA mmap_size].
1063**
1064** <li>[[SQLITE_FCNTL_TRACE]]
1065** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1066** to the VFS about what the higher layers of the SQLite stack are doing.
1067** This file control is used by some VFS activity tracing [shims].
1068** The argument is a zero-terminated string. Higher layers in the
1069** SQLite stack may generate instances of this file control if
1070** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1071**
1072** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1073** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1074** pointer to an integer and it writes a boolean into that integer depending
1075** on whether or not the file has been renamed, moved, or deleted since it
1076** was first opened.
1077**
1078** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1079** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1080** underlying native file handle associated with a file handle. This file
1081** control interprets its argument as a pointer to a native file handle and
1082** writes the resulting value there.
1083**
1084** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1085** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1086** opcode causes the xFileControl method to swap the file handle with the one
1087** pointed to by the pArg argument. This capability is used during testing
1088** and only needs to be supported when SQLITE_TEST is defined.
1089**
1090** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1091** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1092** be advantageous to block on the next WAL lock if the lock is not immediately
1093** available. The WAL subsystem issues this signal during rare
1094** circumstances in order to fix a problem with priority inversion.
1095** Applications should <em>not</em> use this file-control.
1096**
1097** <li>[[SQLITE_FCNTL_ZIPVFS]]
1098** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1099** VFS should return SQLITE_NOTFOUND for this opcode.
1100**
1101** <li>[[SQLITE_FCNTL_RBU]]
1102** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1103** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1104** this opcode.
1105**
1106** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1107** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1108** the file descriptor is placed in "batch write mode", which
1109** means all subsequent write operations will be deferred and done
1110** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1111** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1112** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1113** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1114** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1115** no VFS interface calls on the same [sqlite3_file] file descriptor
1116** except for calls to the xWrite method and the xFileControl method
1117** with [SQLITE_FCNTL_SIZE_HINT].
1118**
1119** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1120** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1121** operations since the previous successful call to
1122** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1123** This file control returns [SQLITE_OK] if and only if the writes were
1124** all performed successfully and have been committed to persistent storage.
1125** ^Regardless of whether or not it is successful, this file control takes
1126** the file descriptor out of batch write mode so that all subsequent
1127** write operations are independent.
1128** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1129** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1130**
1131** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1132** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1133** operations since the previous successful call to
1134** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1135** ^This file control takes the file descriptor out of batch write mode
1136** so that all subsequent write operations are independent.
1137** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1138** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1139**
1140** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1141** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1142** to block for up to M milliseconds before failing when attempting to
1143** obtain a file lock using the xLock or xShmLock methods of the VFS.
1144** The parameter is a pointer to a 32-bit signed integer that contains
1145** the value that M is to be set to. Before returning, the 32-bit signed
1146** integer is overwritten with the previous value of M.
1147**
1148** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1149** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1150** a database file. The argument is a pointer to a 32-bit unsigned integer.
1151** The "data version" for the pager is written into the pointer. The
1152** "data version" changes whenever any change occurs to the corresponding
1153** database file, either through SQL statements on the same database
1154** connection or through transactions committed by separate database
1155** connections possibly in other processes. The [sqlite3_total_changes()]
1156** interface can be used to find if any database on the connection has changed,
1157** but that interface responds to changes on TEMP as well as MAIN and does
1158** not provide a mechanism to detect changes to MAIN only. Also, the
1159** [sqlite3_total_changes()] interface responds to internal changes only and
1160** omits changes made by other database connections. The
1161** [PRAGMA data_version] command provides a mechanism to detect changes to
1162** a single attached database that occur due to other database connections,
1163** but omits changes implemented by the database connection on which it is
1164** called. This file control is the only mechanism to detect changes that
1165** happen either internally or externally and that are associated with
1166** a particular attached database.
1167**
1168** <li>[[SQLITE_FCNTL_CKPT_START]]
1169** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1170** in wal mode before the client starts to copy pages from the wal
1171** file to the database file.
1172**
1173** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1174** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1175** in wal mode after the client has finished copying pages from the wal
1176** file to the database file, but before the *-shm file is updated to
1177** record the fact that the pages have been checkpointed.
1178** </ul>
1179**
1180** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1181** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1182** whether or not there is a database client in another process with a wal-mode
1183** transaction open on the database or not. It is only available on unix.The
1184** (void*) argument passed with this file-control should be a pointer to a
1185** value of type (int). The integer value is set to 1 if the database is a wal
1186** mode database and there exists at least one client in another process that
1187** currently has an SQL transaction open on the database. It is set to 0 if
1188** the database is not a wal-mode db, or if there is no such connection in any
1189** other process. This opcode cannot be used to detect transactions opened
1190** by clients within the current process, only within other processes.
1191** </ul>
1192**
1193** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1194** Used by the cksmvfs VFS module only.
1195**
1196** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1197** If there is currently no transaction open on the database, and the
1198** database is not a temp db, then this file-control purges the contents
1199** of the in-memory page cache. If there is an open transaction, or if
1200** the db is a temp-db, it is a no-op, not an error.
1201** </ul>
1202*/
1203#define SQLITE_FCNTL_LOCKSTATE 1
1204#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1205#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1206#define SQLITE_FCNTL_LAST_ERRNO 4
1207#define SQLITE_FCNTL_SIZE_HINT 5
1208#define SQLITE_FCNTL_CHUNK_SIZE 6
1209#define SQLITE_FCNTL_FILE_POINTER 7
1210#define SQLITE_FCNTL_SYNC_OMITTED 8
1211#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1212#define SQLITE_FCNTL_PERSIST_WAL 10
1213#define SQLITE_FCNTL_OVERWRITE 11
1214#define SQLITE_FCNTL_VFSNAME 12
1215#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1216#define SQLITE_FCNTL_PRAGMA 14
1217#define SQLITE_FCNTL_BUSYHANDLER 15
1218#define SQLITE_FCNTL_TEMPFILENAME 16
1219#define SQLITE_FCNTL_MMAP_SIZE 18
1220#define SQLITE_FCNTL_TRACE 19
1221#define SQLITE_FCNTL_HAS_MOVED 20
1222#define SQLITE_FCNTL_SYNC 21
1223#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1224#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1225#define SQLITE_FCNTL_WAL_BLOCK 24
1226#define SQLITE_FCNTL_ZIPVFS 25
1227#define SQLITE_FCNTL_RBU 26
1228#define SQLITE_FCNTL_VFS_POINTER 27
1229#define SQLITE_FCNTL_JOURNAL_POINTER 28
1230#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1231#define SQLITE_FCNTL_PDB 30
1232#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1233#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1234#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1235#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1236#define SQLITE_FCNTL_DATA_VERSION 35
1237#define SQLITE_FCNTL_SIZE_LIMIT 36
1238#define SQLITE_FCNTL_CKPT_DONE 37
1239#define SQLITE_FCNTL_RESERVE_BYTES 38
1240#define SQLITE_FCNTL_CKPT_START 39
1241#define SQLITE_FCNTL_EXTERNAL_READER 40
1242#define SQLITE_FCNTL_CKSM_FILE 41
1243#define SQLITE_FCNTL_RESET_CACHE 42
1244
1245/* deprecated names */
1246#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1247#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1248#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1249
1250
1251/*
1252** CAPI3REF: Mutex Handle
1253**
1254** The mutex module within SQLite defines [sqlite3_mutex] to be an
1255** abstract type for a mutex object. The SQLite core never looks
1256** at the internal representation of an [sqlite3_mutex]. It only
1257** deals with pointers to the [sqlite3_mutex] object.
1258**
1259** Mutexes are created using [sqlite3_mutex_alloc()].
1260*/
1261typedef struct sqlite3_mutex sqlite3_mutex;
1262
1263/*
1264** CAPI3REF: Loadable Extension Thunk
1265**
1266** A pointer to the opaque sqlite3_api_routines structure is passed as
1267** the third parameter to entry points of [loadable extensions]. This
1268** structure must be typedefed in order to work around compiler warnings
1269** on some platforms.
1270*/
1271typedef struct sqlite3_api_routines sqlite3_api_routines;
1272
1273/*
1274** CAPI3REF: File Name
1275**
1276** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1277** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1278** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1279** may also be passed to special APIs such as:
1280**
1281** <ul>
1282** <li> sqlite3_filename_database()
1283** <li> sqlite3_filename_journal()
1284** <li> sqlite3_filename_wal()
1285** <li> sqlite3_uri_parameter()
1286** <li> sqlite3_uri_boolean()
1287** <li> sqlite3_uri_int64()
1288** <li> sqlite3_uri_key()
1289** </ul>
1290*/
1291typedef const char *sqlite3_filename;
1292
1293/*
1294** CAPI3REF: OS Interface Object
1295**
1296** An instance of the sqlite3_vfs object defines the interface between
1297** the SQLite core and the underlying operating system. The "vfs"
1298** in the name of the object stands for "virtual file system". See
1299** the [VFS | VFS documentation] for further information.
1300**
1301** The VFS interface is sometimes extended by adding new methods onto
1302** the end. Each time such an extension occurs, the iVersion field
1303** is incremented. The iVersion value started out as 1 in
1304** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1305** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1306** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1307** may be appended to the sqlite3_vfs object and the iVersion value
1308** may increase again in future versions of SQLite.
1309** Note that due to an oversight, the structure
1310** of the sqlite3_vfs object changed in the transition from
1311** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1312** and yet the iVersion field was not increased.
1313**
1314** The szOsFile field is the size of the subclassed [sqlite3_file]
1315** structure used by this VFS. mxPathname is the maximum length of
1316** a pathname in this VFS.
1317**
1318** Registered sqlite3_vfs objects are kept on a linked list formed by
1319** the pNext pointer. The [sqlite3_vfs_register()]
1320** and [sqlite3_vfs_unregister()] interfaces manage this list
1321** in a thread-safe way. The [sqlite3_vfs_find()] interface
1322** searches the list. Neither the application code nor the VFS
1323** implementation should use the pNext pointer.
1324**
1325** The pNext field is the only field in the sqlite3_vfs
1326** structure that SQLite will ever modify. SQLite will only access
1327** or modify this field while holding a particular static mutex.
1328** The application should never modify anything within the sqlite3_vfs
1329** object once the object has been registered.
1330**
1331** The zName field holds the name of the VFS module. The name must
1332** be unique across all VFS modules.
1333**
1334** [[sqlite3_vfs.xOpen]]
1335** ^SQLite guarantees that the zFilename parameter to xOpen
1336** is either a NULL pointer or string obtained
1337** from xFullPathname() with an optional suffix added.
1338** ^If a suffix is added to the zFilename parameter, it will
1339** consist of a single "-" character followed by no more than
1340** 11 alphanumeric and/or "-" characters.
1341** ^SQLite further guarantees that
1342** the string will be valid and unchanged until xClose() is
1343** called. Because of the previous sentence,
1344** the [sqlite3_file] can safely store a pointer to the
1345** filename if it needs to remember the filename for some reason.
1346** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1347** must invent its own temporary name for the file. ^Whenever the
1348** xFilename parameter is NULL it will also be the case that the
1349** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1350**
1351** The flags argument to xOpen() includes all bits set in
1352** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1353** or [sqlite3_open16()] is used, then flags includes at least
1354** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1355** If xOpen() opens a file read-only then it sets *pOutFlags to
1356** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1357**
1358** ^(SQLite will also add one of the following flags to the xOpen()
1359** call, depending on the object being opened:
1360**
1361** <ul>
1362** <li> [SQLITE_OPEN_MAIN_DB]
1363** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1364** <li> [SQLITE_OPEN_TEMP_DB]
1365** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1366** <li> [SQLITE_OPEN_TRANSIENT_DB]
1367** <li> [SQLITE_OPEN_SUBJOURNAL]
1368** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1369** <li> [SQLITE_OPEN_WAL]
1370** </ul>)^
1371**
1372** The file I/O implementation can use the object type flags to
1373** change the way it deals with files. For example, an application
1374** that does not care about crash recovery or rollback might make
1375** the open of a journal file a no-op. Writes to this journal would
1376** also be no-ops, and any attempt to read the journal would return
1377** SQLITE_IOERR. Or the implementation might recognize that a database
1378** file will be doing page-aligned sector reads and writes in a random
1379** order and set up its I/O subsystem accordingly.
1380**
1381** SQLite might also add one of the following flags to the xOpen method:
1382**
1383** <ul>
1384** <li> [SQLITE_OPEN_DELETEONCLOSE]
1385** <li> [SQLITE_OPEN_EXCLUSIVE]
1386** </ul>
1387**
1388** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1389** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1390** will be set for TEMP databases and their journals, transient
1391** databases, and subjournals.
1392**
1393** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1394** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1395** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1396** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1397** SQLITE_OPEN_CREATE, is used to indicate that file should always
1398** be created, and that it is an error if it already exists.
1399** It is <i>not</i> used to indicate the file should be opened
1400** for exclusive access.
1401**
1402** ^At least szOsFile bytes of memory are allocated by SQLite
1403** to hold the [sqlite3_file] structure passed as the third
1404** argument to xOpen. The xOpen method does not have to
1405** allocate the structure; it should just fill it in. Note that
1406** the xOpen method must set the sqlite3_file.pMethods to either
1407** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1408** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1409** element will be valid after xOpen returns regardless of the success
1410** or failure of the xOpen call.
1411**
1412** [[sqlite3_vfs.xAccess]]
1413** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1414** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1415** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1416** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1417** flag is never actually used and is not implemented in the built-in
1418** VFSes of SQLite. The file is named by the second argument and can be a
1419** directory. The xAccess method returns [SQLITE_OK] on success or some
1420** non-zero error code if there is an I/O error or if the name of
1421** the file given in the second argument is illegal. If SQLITE_OK
1422** is returned, then non-zero or zero is written into *pResOut to indicate
1423** whether or not the file is accessible.
1424**
1425** ^SQLite will always allocate at least mxPathname+1 bytes for the
1426** output buffer xFullPathname. The exact size of the output buffer
1427** is also passed as a parameter to both methods. If the output buffer
1428** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1429** handled as a fatal error by SQLite, vfs implementations should endeavor
1430** to prevent this by setting mxPathname to a sufficiently large value.
1431**
1432** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1433** interfaces are not strictly a part of the filesystem, but they are
1434** included in the VFS structure for completeness.
1435** The xRandomness() function attempts to return nBytes bytes
1436** of good-quality randomness into zOut. The return value is
1437** the actual number of bytes of randomness obtained.
1438** The xSleep() method causes the calling thread to sleep for at
1439** least the number of microseconds given. ^The xCurrentTime()
1440** method returns a Julian Day Number for the current date and time as
1441** a floating point value.
1442** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1443** Day Number multiplied by 86400000 (the number of milliseconds in
1444** a 24-hour day).
1445** ^SQLite will use the xCurrentTimeInt64() method to get the current
1446** date and time if that method is available (if iVersion is 2 or
1447** greater and the function pointer is not NULL) and will fall back
1448** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1449**
1450** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1451** are not used by the SQLite core. These optional interfaces are provided
1452** by some VFSes to facilitate testing of the VFS code. By overriding
1453** system calls with functions under its control, a test program can
1454** simulate faults and error conditions that would otherwise be difficult
1455** or impossible to induce. The set of system calls that can be overridden
1456** varies from one VFS to another, and from one version of the same VFS to the
1457** next. Applications that use these interfaces must be prepared for any
1458** or all of these interfaces to be NULL or for their behavior to change
1459** from one release to the next. Applications must not attempt to access
1460** any of these methods if the iVersion of the VFS is less than 3.
1461*/
1462typedef struct sqlite3_vfs sqlite3_vfs;
1463typedef void (*sqlite3_syscall_ptr)(void);
1464struct sqlite3_vfs {
1465 int iVersion; /* Structure version number (currently 3) */
1466 int szOsFile; /* Size of subclassed sqlite3_file */
1467 int mxPathname; /* Maximum file pathname length */
1468 sqlite3_vfs *pNext; /* Next registered VFS */
1469 const char *zName; /* Name of this virtual file system */
1470 void *pAppData; /* Pointer to application-specific data */
1471 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1472 int flags, int *pOutFlags);
1473 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1474 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1475 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1476 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1477 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1478 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1479 void (*xDlClose)(sqlite3_vfs*, void*);
1480 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1481 int (*xSleep)(sqlite3_vfs*, int microseconds);
1482 int (*xCurrentTime)(sqlite3_vfs*, double*);
1483 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1484 /*
1485 ** The methods above are in version 1 of the sqlite_vfs object
1486 ** definition. Those that follow are added in version 2 or later
1487 */
1488 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1489 /*
1490 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1491 ** Those below are for version 3 and greater.
1492 */
1493 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1494 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1495 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1496 /*
1497 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1498 ** New fields may be appended in future versions. The iVersion
1499 ** value will increment whenever this happens.
1500 */
1501};
1502
1503/*
1504** CAPI3REF: Flags for the xAccess VFS method
1505**
1506** These integer constants can be used as the third parameter to
1507** the xAccess method of an [sqlite3_vfs] object. They determine
1508** what kind of permissions the xAccess method is looking for.
1509** With SQLITE_ACCESS_EXISTS, the xAccess method
1510** simply checks whether the file exists.
1511** With SQLITE_ACCESS_READWRITE, the xAccess method
1512** checks whether the named directory is both readable and writable
1513** (in other words, if files can be added, removed, and renamed within
1514** the directory).
1515** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1516** [temp_store_directory pragma], though this could change in a future
1517** release of SQLite.
1518** With SQLITE_ACCESS_READ, the xAccess method
1519** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1520** currently unused, though it might be used in a future release of
1521** SQLite.
1522*/
1523#define SQLITE_ACCESS_EXISTS 0
1524#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1525#define SQLITE_ACCESS_READ 2 /* Unused */
1526
1527/*
1528** CAPI3REF: Flags for the xShmLock VFS method
1529**
1530** These integer constants define the various locking operations
1531** allowed by the xShmLock method of [sqlite3_io_methods]. The
1532** following are the only legal combinations of flags to the
1533** xShmLock method:
1534**
1535** <ul>
1536** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1537** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1538** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1539** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1540** </ul>
1541**
1542** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1543** was given on the corresponding lock.
1544**
1545** The xShmLock method can transition between unlocked and SHARED or
1546** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1547** and EXCLUSIVE.
1548*/
1549#define SQLITE_SHM_UNLOCK 1
1550#define SQLITE_SHM_LOCK 2
1551#define SQLITE_SHM_SHARED 4
1552#define SQLITE_SHM_EXCLUSIVE 8
1553
1554/*
1555** CAPI3REF: Maximum xShmLock index
1556**
1557** The xShmLock method on [sqlite3_io_methods] may use values
1558** between 0 and this upper bound as its "offset" argument.
1559** The SQLite core will never attempt to acquire or release a
1560** lock outside of this range
1561*/
1562#define SQLITE_SHM_NLOCK 8
1563
1564
1565/*
1566** CAPI3REF: Initialize The SQLite Library
1567**
1568** ^The sqlite3_initialize() routine initializes the
1569** SQLite library. ^The sqlite3_shutdown() routine
1570** deallocates any resources that were allocated by sqlite3_initialize().
1571** These routines are designed to aid in process initialization and
1572** shutdown on embedded systems. Workstation applications using
1573** SQLite normally do not need to invoke either of these routines.
1574**
1575** A call to sqlite3_initialize() is an "effective" call if it is
1576** the first time sqlite3_initialize() is invoked during the lifetime of
1577** the process, or if it is the first time sqlite3_initialize() is invoked
1578** following a call to sqlite3_shutdown(). ^(Only an effective call
1579** of sqlite3_initialize() does any initialization. All other calls
1580** are harmless no-ops.)^
1581**
1582** A call to sqlite3_shutdown() is an "effective" call if it is the first
1583** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1584** an effective call to sqlite3_shutdown() does any deinitialization.
1585** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1586**
1587** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1588** is not. The sqlite3_shutdown() interface must only be called from a
1589** single thread. All open [database connections] must be closed and all
1590** other SQLite resources must be deallocated prior to invoking
1591** sqlite3_shutdown().
1592**
1593** Among other things, ^sqlite3_initialize() will invoke
1594** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1595** will invoke sqlite3_os_end().
1596**
1597** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1598** ^If for some reason, sqlite3_initialize() is unable to initialize
1599** the library (perhaps it is unable to allocate a needed resource such
1600** as a mutex) it returns an [error code] other than [SQLITE_OK].
1601**
1602** ^The sqlite3_initialize() routine is called internally by many other
1603** SQLite interfaces so that an application usually does not need to
1604** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1605** calls sqlite3_initialize() so the SQLite library will be automatically
1606** initialized when [sqlite3_open()] is called if it has not be initialized
1607** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1608** compile-time option, then the automatic calls to sqlite3_initialize()
1609** are omitted and the application must call sqlite3_initialize() directly
1610** prior to using any other SQLite interface. For maximum portability,
1611** it is recommended that applications always invoke sqlite3_initialize()
1612** directly prior to using any other SQLite interface. Future releases
1613** of SQLite may require this. In other words, the behavior exhibited
1614** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1615** default behavior in some future release of SQLite.
1616**
1617** The sqlite3_os_init() routine does operating-system specific
1618** initialization of the SQLite library. The sqlite3_os_end()
1619** routine undoes the effect of sqlite3_os_init(). Typical tasks
1620** performed by these routines include allocation or deallocation
1621** of static resources, initialization of global variables,
1622** setting up a default [sqlite3_vfs] module, or setting up
1623** a default configuration using [sqlite3_config()].
1624**
1625** The application should never invoke either sqlite3_os_init()
1626** or sqlite3_os_end() directly. The application should only invoke
1627** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1628** interface is called automatically by sqlite3_initialize() and
1629** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1630** implementations for sqlite3_os_init() and sqlite3_os_end()
1631** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1632** When [custom builds | built for other platforms]
1633** (using the [SQLITE_OS_OTHER=1] compile-time
1634** option) the application must supply a suitable implementation for
1635** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1636** implementation of sqlite3_os_init() or sqlite3_os_end()
1637** must return [SQLITE_OK] on success and some other [error code] upon
1638** failure.
1639*/
1640SQLITE_API int sqlite3_initialize(void);
1641SQLITE_API int sqlite3_shutdown(void);
1642SQLITE_API int sqlite3_os_init(void);
1643SQLITE_API int sqlite3_os_end(void);
1644
1645/*
1646** CAPI3REF: Configuring The SQLite Library
1647**
1648** The sqlite3_config() interface is used to make global configuration
1649** changes to SQLite in order to tune SQLite to the specific needs of
1650** the application. The default configuration is recommended for most
1651** applications and so this routine is usually not necessary. It is
1652** provided to support rare applications with unusual needs.
1653**
1654** <b>The sqlite3_config() interface is not threadsafe. The application
1655** must ensure that no other SQLite interfaces are invoked by other
1656** threads while sqlite3_config() is running.</b>
1657**
1658** The sqlite3_config() interface
1659** may only be invoked prior to library initialization using
1660** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1661** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1662** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1663** Note, however, that ^sqlite3_config() can be called as part of the
1664** implementation of an application-defined [sqlite3_os_init()].
1665**
1666** The first argument to sqlite3_config() is an integer
1667** [configuration option] that determines
1668** what property of SQLite is to be configured. Subsequent arguments
1669** vary depending on the [configuration option]
1670** in the first argument.
1671**
1672** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1673** ^If the option is unknown or SQLite is unable to set the option
1674** then this routine returns a non-zero [error code].
1675*/
1676SQLITE_API int sqlite3_config(int, ...);
1677
1678/*
1679** CAPI3REF: Configure database connections
1680** METHOD: sqlite3
1681**
1682** The sqlite3_db_config() interface is used to make configuration
1683** changes to a [database connection]. The interface is similar to
1684** [sqlite3_config()] except that the changes apply to a single
1685** [database connection] (specified in the first argument).
1686**
1687** The second argument to sqlite3_db_config(D,V,...) is the
1688** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1689** that indicates what aspect of the [database connection] is being configured.
1690** Subsequent arguments vary depending on the configuration verb.
1691**
1692** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1693** the call is considered successful.
1694*/
1695SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1696
1697/*
1698** CAPI3REF: Memory Allocation Routines
1699**
1700** An instance of this object defines the interface between SQLite
1701** and low-level memory allocation routines.
1702**
1703** This object is used in only one place in the SQLite interface.
1704** A pointer to an instance of this object is the argument to
1705** [sqlite3_config()] when the configuration option is
1706** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1707** By creating an instance of this object
1708** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1709** during configuration, an application can specify an alternative
1710** memory allocation subsystem for SQLite to use for all of its
1711** dynamic memory needs.
1712**
1713** Note that SQLite comes with several [built-in memory allocators]
1714** that are perfectly adequate for the overwhelming majority of applications
1715** and that this object is only useful to a tiny minority of applications
1716** with specialized memory allocation requirements. This object is
1717** also used during testing of SQLite in order to specify an alternative
1718** memory allocator that simulates memory out-of-memory conditions in
1719** order to verify that SQLite recovers gracefully from such
1720** conditions.
1721**
1722** The xMalloc, xRealloc, and xFree methods must work like the
1723** malloc(), realloc() and free() functions from the standard C library.
1724** ^SQLite guarantees that the second argument to
1725** xRealloc is always a value returned by a prior call to xRoundup.
1726**
1727** xSize should return the allocated size of a memory allocation
1728** previously obtained from xMalloc or xRealloc. The allocated size
1729** is always at least as big as the requested size but may be larger.
1730**
1731** The xRoundup method returns what would be the allocated size of
1732** a memory allocation given a particular requested size. Most memory
1733** allocators round up memory allocations at least to the next multiple
1734** of 8. Some allocators round up to a larger multiple or to a power of 2.
1735** Every memory allocation request coming in through [sqlite3_malloc()]
1736** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1737** that causes the corresponding memory allocation to fail.
1738**
1739** The xInit method initializes the memory allocator. For example,
1740** it might allocate any required mutexes or initialize internal data
1741** structures. The xShutdown method is invoked (indirectly) by
1742** [sqlite3_shutdown()] and should deallocate any resources acquired
1743** by xInit. The pAppData pointer is used as the only parameter to
1744** xInit and xShutdown.
1745**
1746** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1747** the xInit method, so the xInit method need not be threadsafe. The
1748** xShutdown method is only called from [sqlite3_shutdown()] so it does
1749** not need to be threadsafe either. For all other methods, SQLite
1750** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1751** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1752** it is by default) and so the methods are automatically serialized.
1753** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1754** methods must be threadsafe or else make their own arrangements for
1755** serialization.
1756**
1757** SQLite will never invoke xInit() more than once without an intervening
1758** call to xShutdown().
1759*/
1760typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1761struct sqlite3_mem_methods {
1762 void *(*xMalloc)(int); /* Memory allocation function */
1763 void (*xFree)(void*); /* Free a prior allocation */
1764 void *(*xRealloc)(void*,int); /* Resize an allocation */
1765 int (*xSize)(void*); /* Return the size of an allocation */
1766 int (*xRoundup)(int); /* Round up request size to allocation size */
1767 int (*xInit)(void*); /* Initialize the memory allocator */
1768 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1769 void *pAppData; /* Argument to xInit() and xShutdown() */
1770};
1771
1772/*
1773** CAPI3REF: Configuration Options
1774** KEYWORDS: {configuration option}
1775**
1776** These constants are the available integer configuration options that
1777** can be passed as the first argument to the [sqlite3_config()] interface.
1778**
1779** New configuration options may be added in future releases of SQLite.
1780** Existing configuration options might be discontinued. Applications
1781** should check the return code from [sqlite3_config()] to make sure that
1782** the call worked. The [sqlite3_config()] interface will return a
1783** non-zero [error code] if a discontinued or unsupported configuration option
1784** is invoked.
1785**
1786** <dl>
1787** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1788** <dd>There are no arguments to this option. ^This option sets the
1789** [threading mode] to Single-thread. In other words, it disables
1790** all mutexing and puts SQLite into a mode where it can only be used
1791** by a single thread. ^If SQLite is compiled with
1792** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1793** it is not possible to change the [threading mode] from its default
1794** value of Single-thread and so [sqlite3_config()] will return
1795** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1796** configuration option.</dd>
1797**
1798** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1799** <dd>There are no arguments to this option. ^This option sets the
1800** [threading mode] to Multi-thread. In other words, it disables
1801** mutexing on [database connection] and [prepared statement] objects.
1802** The application is responsible for serializing access to
1803** [database connections] and [prepared statements]. But other mutexes
1804** are enabled so that SQLite will be safe to use in a multi-threaded
1805** environment as long as no two threads attempt to use the same
1806** [database connection] at the same time. ^If SQLite is compiled with
1807** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1808** it is not possible to set the Multi-thread [threading mode] and
1809** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1810** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1811**
1812** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1813** <dd>There are no arguments to this option. ^This option sets the
1814** [threading mode] to Serialized. In other words, this option enables
1815** all mutexes including the recursive
1816** mutexes on [database connection] and [prepared statement] objects.
1817** In this mode (which is the default when SQLite is compiled with
1818** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1819** to [database connections] and [prepared statements] so that the
1820** application is free to use the same [database connection] or the
1821** same [prepared statement] in different threads at the same time.
1822** ^If SQLite is compiled with
1823** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1824** it is not possible to set the Serialized [threading mode] and
1825** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1826** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1827**
1828** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1829** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1830** a pointer to an instance of the [sqlite3_mem_methods] structure.
1831** The argument specifies
1832** alternative low-level memory allocation routines to be used in place of
1833** the memory allocation routines built into SQLite.)^ ^SQLite makes
1834** its own private copy of the content of the [sqlite3_mem_methods] structure
1835** before the [sqlite3_config()] call returns.</dd>
1836**
1837** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1838** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1839** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1840** The [sqlite3_mem_methods]
1841** structure is filled with the currently defined memory allocation routines.)^
1842** This option can be used to overload the default memory allocation
1843** routines with a wrapper that simulations memory allocation failure or
1844** tracks memory usage, for example. </dd>
1845**
1846** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1847** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1848** type int, interpreted as a boolean, which if true provides a hint to
1849** SQLite that it should avoid large memory allocations if possible.
1850** SQLite will run faster if it is free to make large memory allocations,
1851** but some application might prefer to run slower in exchange for
1852** guarantees about memory fragmentation that are possible if large
1853** allocations are avoided. This hint is normally off.
1854** </dd>
1855**
1856** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1857** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1858** interpreted as a boolean, which enables or disables the collection of
1859** memory allocation statistics. ^(When memory allocation statistics are
1860** disabled, the following SQLite interfaces become non-operational:
1861** <ul>
1862** <li> [sqlite3_hard_heap_limit64()]
1863** <li> [sqlite3_memory_used()]
1864** <li> [sqlite3_memory_highwater()]
1865** <li> [sqlite3_soft_heap_limit64()]
1866** <li> [sqlite3_status64()]
1867** </ul>)^
1868** ^Memory allocation statistics are enabled by default unless SQLite is
1869** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1870** allocation statistics are disabled by default.
1871** </dd>
1872**
1873** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1874** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1875** </dd>
1876**
1877** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1878** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1879** that SQLite can use for the database page cache with the default page
1880** cache implementation.
1881** This configuration option is a no-op if an application-defined page
1882** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1883** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1884** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1885** and the number of cache lines (N).
1886** The sz argument should be the size of the largest database page
1887** (a power of two between 512 and 65536) plus some extra bytes for each
1888** page header. ^The number of extra bytes needed by the page header
1889** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1890** ^It is harmless, apart from the wasted memory,
1891** for the sz parameter to be larger than necessary. The pMem
1892** argument must be either a NULL pointer or a pointer to an 8-byte
1893** aligned block of memory of at least sz*N bytes, otherwise
1894** subsequent behavior is undefined.
1895** ^When pMem is not NULL, SQLite will strive to use the memory provided
1896** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1897** a page cache line is larger than sz bytes or if all of the pMem buffer
1898** is exhausted.
1899** ^If pMem is NULL and N is non-zero, then each database connection
1900** does an initial bulk allocation for page cache memory
1901** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1902** of -1024*N bytes if N is negative, . ^If additional
1903** page cache memory is needed beyond what is provided by the initial
1904** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1905** additional cache line. </dd>
1906**
1907** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1908** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1909** that SQLite will use for all of its dynamic memory allocation needs
1910** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1911** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1912** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1913** [SQLITE_ERROR] if invoked otherwise.
1914** ^There are three arguments to SQLITE_CONFIG_HEAP:
1915** An 8-byte aligned pointer to the memory,
1916** the number of bytes in the memory buffer, and the minimum allocation size.
1917** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1918** to using its default memory allocator (the system malloc() implementation),
1919** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1920** memory pointer is not NULL then the alternative memory
1921** allocator is engaged to handle all of SQLites memory allocation needs.
1922** The first pointer (the memory pointer) must be aligned to an 8-byte
1923** boundary or subsequent behavior of SQLite will be undefined.
1924** The minimum allocation size is capped at 2**12. Reasonable values
1925** for the minimum allocation size are 2**5 through 2**8.</dd>
1926**
1927** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1928** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1929** pointer to an instance of the [sqlite3_mutex_methods] structure.
1930** The argument specifies alternative low-level mutex routines to be used
1931** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1932** the content of the [sqlite3_mutex_methods] structure before the call to
1933** [sqlite3_config()] returns. ^If SQLite is compiled with
1934** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1935** the entire mutexing subsystem is omitted from the build and hence calls to
1936** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1937** return [SQLITE_ERROR].</dd>
1938**
1939** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1940** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1941** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1942** [sqlite3_mutex_methods]
1943** structure is filled with the currently defined mutex routines.)^
1944** This option can be used to overload the default mutex allocation
1945** routines with a wrapper used to track mutex usage for performance
1946** profiling or testing, for example. ^If SQLite is compiled with
1947** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1948** the entire mutexing subsystem is omitted from the build and hence calls to
1949** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1950** return [SQLITE_ERROR].</dd>
1951**
1952** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1953** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1954** the default size of lookaside memory on each [database connection].
1955** The first argument is the
1956** size of each lookaside buffer slot and the second is the number of
1957** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1958** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1959** option to [sqlite3_db_config()] can be used to change the lookaside
1960** configuration on individual connections.)^ </dd>
1961**
1962** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1963** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1964** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1965** the interface to a custom page cache implementation.)^
1966** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1967**
1968** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1969** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1970** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1971** the current page cache implementation into that object.)^ </dd>
1972**
1973** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1974** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1975** global [error log].
1976** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1977** function with a call signature of void(*)(void*,int,const char*),
1978** and a pointer to void. ^If the function pointer is not NULL, it is
1979** invoked by [sqlite3_log()] to process each logging event. ^If the
1980** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1981** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1982** passed through as the first parameter to the application-defined logger
1983** function whenever that function is invoked. ^The second parameter to
1984** the logger function is a copy of the first parameter to the corresponding
1985** [sqlite3_log()] call and is intended to be a [result code] or an
1986** [extended result code]. ^The third parameter passed to the logger is
1987** log message after formatting via [sqlite3_snprintf()].
1988** The SQLite logging interface is not reentrant; the logger function
1989** supplied by the application must not invoke any SQLite interface.
1990** In a multi-threaded application, the application-defined logger
1991** function must be threadsafe. </dd>
1992**
1993** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1994** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1995** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1996** then URI handling is globally disabled.)^ ^If URI handling is globally
1997** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1998** [sqlite3_open16()] or
1999** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2000** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2001** connection is opened. ^If it is globally disabled, filenames are
2002** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2003** database connection is opened. ^(By default, URI handling is globally
2004** disabled. The default value may be changed by compiling with the
2005** [SQLITE_USE_URI] symbol defined.)^
2006**
2007** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2008** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2009** argument which is interpreted as a boolean in order to enable or disable
2010** the use of covering indices for full table scans in the query optimizer.
2011** ^The default setting is determined
2012** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2013** if that compile-time option is omitted.
2014** The ability to disable the use of covering indices for full table scans
2015** is because some incorrectly coded legacy applications might malfunction
2016** when the optimization is enabled. Providing the ability to
2017** disable the optimization allows the older, buggy application code to work
2018** without change even with newer versions of SQLite.
2019**
2020** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2021** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2022** <dd> These options are obsolete and should not be used by new code.
2023** They are retained for backwards compatibility but are now no-ops.
2024** </dd>
2025**
2026** [[SQLITE_CONFIG_SQLLOG]]
2027** <dt>SQLITE_CONFIG_SQLLOG
2028** <dd>This option is only available if sqlite is compiled with the
2029** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2030** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2031** The second should be of type (void*). The callback is invoked by the library
2032** in three separate circumstances, identified by the value passed as the
2033** fourth parameter. If the fourth parameter is 0, then the database connection
2034** passed as the second argument has just been opened. The third argument
2035** points to a buffer containing the name of the main database file. If the
2036** fourth parameter is 1, then the SQL statement that the third parameter
2037** points to has just been executed. Or, if the fourth parameter is 2, then
2038** the connection being passed as the second parameter is being closed. The
2039** third parameter is passed NULL In this case. An example of using this
2040** configuration option can be seen in the "test_sqllog.c" source file in
2041** the canonical SQLite source tree.</dd>
2042**
2043** [[SQLITE_CONFIG_MMAP_SIZE]]
2044** <dt>SQLITE_CONFIG_MMAP_SIZE
2045** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2046** that are the default mmap size limit (the default setting for
2047** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2048** ^The default setting can be overridden by each database connection using
2049** either the [PRAGMA mmap_size] command, or by using the
2050** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2051** will be silently truncated if necessary so that it does not exceed the
2052** compile-time maximum mmap size set by the
2053** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2054** ^If either argument to this option is negative, then that argument is
2055** changed to its compile-time default.
2056**
2057** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2058** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2059** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2060** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2061** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2062** that specifies the maximum size of the created heap.
2063**
2064** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2065** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2066** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2067** is a pointer to an integer and writes into that integer the number of extra
2068** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2069** The amount of extra space required can change depending on the compiler,
2070** target platform, and SQLite version.
2071**
2072** [[SQLITE_CONFIG_PMASZ]]
2073** <dt>SQLITE_CONFIG_PMASZ
2074** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2075** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2076** sorter to that integer. The default minimum PMA Size is set by the
2077** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2078** to help with sort operations when multithreaded sorting
2079** is enabled (using the [PRAGMA threads] command) and the amount of content
2080** to be sorted exceeds the page size times the minimum of the
2081** [PRAGMA cache_size] setting and this value.
2082**
2083** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2084** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2085** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2086** becomes the [statement journal] spill-to-disk threshold.
2087** [Statement journals] are held in memory until their size (in bytes)
2088** exceeds this threshold, at which point they are written to disk.
2089** Or if the threshold is -1, statement journals are always held
2090** exclusively in memory.
2091** Since many statement journals never become large, setting the spill
2092** threshold to a value such as 64KiB can greatly reduce the amount of
2093** I/O required to support statement rollback.
2094** The default value for this setting is controlled by the
2095** [SQLITE_STMTJRNL_SPILL] compile-time option.
2096**
2097** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2098** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2099** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2100** of type (int) - the new value of the sorter-reference size threshold.
2101** Usually, when SQLite uses an external sort to order records according
2102** to an ORDER BY clause, all fields required by the caller are present in the
2103** sorted records. However, if SQLite determines based on the declared type
2104** of a table column that its values are likely to be very large - larger
2105** than the configured sorter-reference size threshold - then a reference
2106** is stored in each sorted record and the required column values loaded
2107** from the database as records are returned in sorted order. The default
2108** value for this option is to never use this optimization. Specifying a
2109** negative value for this option restores the default behaviour.
2110** This option is only available if SQLite is compiled with the
2111** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2112**
2113** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2114** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2115** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2116** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2117** database created using [sqlite3_deserialize()]. This default maximum
2118** size can be adjusted up or down for individual databases using the
2119** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2120** configuration setting is never used, then the default maximum is determined
2121** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2122** compile-time option is not set, then the default maximum is 1073741824.
2123** </dl>
2124*/
2125#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2126#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2127#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2128#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2129#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2130#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2131#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2132#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2133#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2134#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2135#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2136/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2137#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2138#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2139#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2140#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2141#define SQLITE_CONFIG_URI 17 /* int */
2142#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2143#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2144#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2145#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2146#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2147#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2148#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2149#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2150#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2151#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2152#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2153#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2154
2155/*
2156** CAPI3REF: Database Connection Configuration Options
2157**
2158** These constants are the available integer configuration options that
2159** can be passed as the second argument to the [sqlite3_db_config()] interface.
2160**
2161** New configuration options may be added in future releases of SQLite.
2162** Existing configuration options might be discontinued. Applications
2163** should check the return code from [sqlite3_db_config()] to make sure that
2164** the call worked. ^The [sqlite3_db_config()] interface will return a
2165** non-zero [error code] if a discontinued or unsupported configuration option
2166** is invoked.
2167**
2168** <dl>
2169** [[SQLITE_DBCONFIG_LOOKASIDE]]
2170** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2171** <dd> ^This option takes three additional arguments that determine the
2172** [lookaside memory allocator] configuration for the [database connection].
2173** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2174** pointer to a memory buffer to use for lookaside memory.
2175** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2176** may be NULL in which case SQLite will allocate the
2177** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2178** size of each lookaside buffer slot. ^The third argument is the number of
2179** slots. The size of the buffer in the first argument must be greater than
2180** or equal to the product of the second and third arguments. The buffer
2181** must be aligned to an 8-byte boundary. ^If the second argument to
2182** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2183** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2184** configuration for a database connection can only be changed when that
2185** connection is not currently using lookaside memory, or in other words
2186** when the "current value" returned by
2187** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2188** Any attempt to change the lookaside memory configuration when lookaside
2189** memory is in use leaves the configuration unchanged and returns
2190** [SQLITE_BUSY].)^</dd>
2191**
2192** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2193** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2194** <dd> ^This option is used to enable or disable the enforcement of
2195** [foreign key constraints]. There should be two additional arguments.
2196** The first argument is an integer which is 0 to disable FK enforcement,
2197** positive to enable FK enforcement or negative to leave FK enforcement
2198** unchanged. The second parameter is a pointer to an integer into which
2199** is written 0 or 1 to indicate whether FK enforcement is off or on
2200** following this call. The second parameter may be a NULL pointer, in
2201** which case the FK enforcement setting is not reported back. </dd>
2202**
2203** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2204** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2205** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2206** There should be two additional arguments.
2207** The first argument is an integer which is 0 to disable triggers,
2208** positive to enable triggers or negative to leave the setting unchanged.
2209** The second parameter is a pointer to an integer into which
2210** is written 0 or 1 to indicate whether triggers are disabled or enabled
2211** following this call. The second parameter may be a NULL pointer, in
2212** which case the trigger setting is not reported back.
2213**
2214** <p>Originally this option disabled all triggers. ^(However, since
2215** SQLite version 3.35.0, TEMP triggers are still allowed even if
2216** this option is off. So, in other words, this option now only disables
2217** triggers in the main database schema or in the schemas of ATTACH-ed
2218** databases.)^ </dd>
2219**
2220** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2221** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2222** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2223** There should be two additional arguments.
2224** The first argument is an integer which is 0 to disable views,
2225** positive to enable views or negative to leave the setting unchanged.
2226** The second parameter is a pointer to an integer into which
2227** is written 0 or 1 to indicate whether views are disabled or enabled
2228** following this call. The second parameter may be a NULL pointer, in
2229** which case the view setting is not reported back.
2230**
2231** <p>Originally this option disabled all views. ^(However, since
2232** SQLite version 3.35.0, TEMP views are still allowed even if
2233** this option is off. So, in other words, this option now only disables
2234** views in the main database schema or in the schemas of ATTACH-ed
2235** databases.)^ </dd>
2236**
2237** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2238** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2239** <dd> ^This option is used to enable or disable the
2240** [fts3_tokenizer()] function which is part of the
2241** [FTS3] full-text search engine extension.
2242** There should be two additional arguments.
2243** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2244** positive to enable fts3_tokenizer() or negative to leave the setting
2245** unchanged.
2246** The second parameter is a pointer to an integer into which
2247** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2248** following this call. The second parameter may be a NULL pointer, in
2249** which case the new setting is not reported back. </dd>
2250**
2251** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2252** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2253** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2254** interface independently of the [load_extension()] SQL function.
2255** The [sqlite3_enable_load_extension()] API enables or disables both the
2256** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2257** There should be two additional arguments.
2258** When the first argument to this interface is 1, then only the C-API is
2259** enabled and the SQL function remains disabled. If the first argument to
2260** this interface is 0, then both the C-API and the SQL function are disabled.
2261** If the first argument is -1, then no changes are made to state of either the
2262** C-API or the SQL function.
2263** The second parameter is a pointer to an integer into which
2264** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2265** is disabled or enabled following this call. The second parameter may
2266** be a NULL pointer, in which case the new setting is not reported back.
2267** </dd>
2268**
2269** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2270** <dd> ^This option is used to change the name of the "main" database
2271** schema. ^The sole argument is a pointer to a constant UTF8 string
2272** which will become the new schema name in place of "main". ^SQLite
2273** does not make a copy of the new main schema name string, so the application
2274** must ensure that the argument passed into this DBCONFIG option is unchanged
2275** until after the database connection closes.
2276** </dd>
2277**
2278** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2279** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2280** <dd> Usually, when a database in wal mode is closed or detached from a
2281** database handle, SQLite checks if this will mean that there are now no
2282** connections at all to the database. If so, it performs a checkpoint
2283** operation before closing the connection. This option may be used to
2284** override this behaviour. The first parameter passed to this operation
2285** is an integer - positive to disable checkpoints-on-close, or zero (the
2286** default) to enable them, and negative to leave the setting unchanged.
2287** The second parameter is a pointer to an integer
2288** into which is written 0 or 1 to indicate whether checkpoints-on-close
2289** have been disabled - 0 if they are not disabled, 1 if they are.
2290** </dd>
2291**
2292** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2293** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2294** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2295** a single SQL query statement will always use the same algorithm regardless
2296** of values of [bound parameters].)^ The QPSG disables some query optimizations
2297** that look at the values of bound parameters, which can make some queries
2298** slower. But the QPSG has the advantage of more predictable behavior. With
2299** the QPSG active, SQLite will always use the same query plan in the field as
2300** was used during testing in the lab.
2301** The first argument to this setting is an integer which is 0 to disable
2302** the QPSG, positive to enable QPSG, or negative to leave the setting
2303** unchanged. The second parameter is a pointer to an integer into which
2304** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2305** following this call.
2306** </dd>
2307**
2308** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2309** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2310** include output for any operations performed by trigger programs. This
2311** option is used to set or clear (the default) a flag that governs this
2312** behavior. The first parameter passed to this operation is an integer -
2313** positive to enable output for trigger programs, or zero to disable it,
2314** or negative to leave the setting unchanged.
2315** The second parameter is a pointer to an integer into which is written
2316** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2317** it is not disabled, 1 if it is.
2318** </dd>
2319**
2320** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2321** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2322** [VACUUM] in order to reset a database back to an empty database
2323** with no schema and no content. The following process works even for
2324** a badly corrupted database file:
2325** <ol>
2326** <li> If the database connection is newly opened, make sure it has read the
2327** database schema by preparing then discarding some query against the
2328** database, or calling sqlite3_table_column_metadata(), ignoring any
2329** errors. This step is only necessary if the application desires to keep
2330** the database in WAL mode after the reset if it was in WAL mode before
2331** the reset.
2332** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2333** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2334** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2335** </ol>
2336** Because resetting a database is destructive and irreversible, the
2337** process requires the use of this obscure API and multiple steps to help
2338** ensure that it does not happen by accident.
2339**
2340** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2341** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2342** "defensive" flag for a database connection. When the defensive
2343** flag is enabled, language features that allow ordinary SQL to
2344** deliberately corrupt the database file are disabled. The disabled
2345** features include but are not limited to the following:
2346** <ul>
2347** <li> The [PRAGMA writable_schema=ON] statement.
2348** <li> The [PRAGMA journal_mode=OFF] statement.
2349** <li> The [PRAGMA schema_version=N] statement.
2350** <li> Writes to the [sqlite_dbpage] virtual table.
2351** <li> Direct writes to [shadow tables].
2352** </ul>
2353** </dd>
2354**
2355** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2356** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2357** "writable_schema" flag. This has the same effect and is logically equivalent
2358** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2359** The first argument to this setting is an integer which is 0 to disable
2360** the writable_schema, positive to enable writable_schema, or negative to
2361** leave the setting unchanged. The second parameter is a pointer to an
2362** integer into which is written 0 or 1 to indicate whether the writable_schema
2363** is enabled or disabled following this call.
2364** </dd>
2365**
2366** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2367** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2368** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2369** the legacy behavior of the [ALTER TABLE RENAME] command such it
2370** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2371** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2372** additional information. This feature can also be turned on and off
2373** using the [PRAGMA legacy_alter_table] statement.
2374** </dd>
2375**
2376** [[SQLITE_DBCONFIG_DQS_DML]]
2377** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2378** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2379** the legacy [double-quoted string literal] misfeature for DML statements
2380** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2381** default value of this setting is determined by the [-DSQLITE_DQS]
2382** compile-time option.
2383** </dd>
2384**
2385** [[SQLITE_DBCONFIG_DQS_DDL]]
2386** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2387** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2388** the legacy [double-quoted string literal] misfeature for DDL statements,
2389** such as CREATE TABLE and CREATE INDEX. The
2390** default value of this setting is determined by the [-DSQLITE_DQS]
2391** compile-time option.
2392** </dd>
2393**
2394** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2395** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2396** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2397** assume that database schemas are untainted by malicious content.
2398** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2399** takes additional defensive steps to protect the application from harm
2400** including:
2401** <ul>
2402** <li> Prohibit the use of SQL functions inside triggers, views,
2403** CHECK constraints, DEFAULT clauses, expression indexes,
2404** partial indexes, or generated columns
2405** unless those functions are tagged with [SQLITE_INNOCUOUS].
2406** <li> Prohibit the use of virtual tables inside of triggers or views
2407** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2408** </ul>
2409** This setting defaults to "on" for legacy compatibility, however
2410** all applications are advised to turn it off if possible. This setting
2411** can also be controlled using the [PRAGMA trusted_schema] statement.
2412** </dd>
2413**
2414** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2415** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2416** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2417** the legacy file format flag. When activated, this flag causes all newly
2418** created database file to have a schema format version number (the 4-byte
2419** integer found at offset 44 into the database header) of 1. This in turn
2420** means that the resulting database file will be readable and writable by
2421** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2422** newly created databases are generally not understandable by SQLite versions
2423** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2424** is now scarcely any need to generated database files that are compatible
2425** all the way back to version 3.0.0, and so this setting is of little
2426** practical use, but is provided so that SQLite can continue to claim the
2427** ability to generate new database files that are compatible with version
2428** 3.0.0.
2429** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2430** the [VACUUM] command will fail with an obscure error when attempting to
2431** process a table with generated columns and a descending index. This is
2432** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2433** either generated columns or decending indexes.
2434** </dd>
2435** </dl>
2436*/
2437#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2438#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2439#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2440#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2441#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2442#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2443#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2444#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2445#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2446#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2447#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2448#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2449#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2450#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2451#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2452#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2453#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2454#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2455#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
2456
2457/*
2458** CAPI3REF: Enable Or Disable Extended Result Codes
2459** METHOD: sqlite3
2460**
2461** ^The sqlite3_extended_result_codes() routine enables or disables the
2462** [extended result codes] feature of SQLite. ^The extended result
2463** codes are disabled by default for historical compatibility.
2464*/
2465SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2466
2467/*
2468** CAPI3REF: Last Insert Rowid
2469** METHOD: sqlite3
2470**
2471** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2472** has a unique 64-bit signed
2473** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2474** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2475** names are not also used by explicitly declared columns. ^If
2476** the table has a column of type [INTEGER PRIMARY KEY] then that column
2477** is another alias for the rowid.
2478**
2479** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2480** the most recent successful [INSERT] into a rowid table or [virtual table]
2481** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2482** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2483** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2484** zero.
2485**
2486** As well as being set automatically as rows are inserted into database
2487** tables, the value returned by this function may be set explicitly by
2488** [sqlite3_set_last_insert_rowid()]
2489**
2490** Some virtual table implementations may INSERT rows into rowid tables as
2491** part of committing a transaction (e.g. to flush data accumulated in memory
2492** to disk). In this case subsequent calls to this function return the rowid
2493** associated with these internal INSERT operations, which leads to
2494** unintuitive results. Virtual table implementations that do write to rowid
2495** tables in this way can avoid this problem by restoring the original
2496** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2497** control to the user.
2498**
2499** ^(If an [INSERT] occurs within a trigger then this routine will
2500** return the [rowid] of the inserted row as long as the trigger is
2501** running. Once the trigger program ends, the value returned
2502** by this routine reverts to what it was before the trigger was fired.)^
2503**
2504** ^An [INSERT] that fails due to a constraint violation is not a
2505** successful [INSERT] and does not change the value returned by this
2506** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2507** and INSERT OR ABORT make no changes to the return value of this
2508** routine when their insertion fails. ^(When INSERT OR REPLACE
2509** encounters a constraint violation, it does not fail. The
2510** INSERT continues to completion after deleting rows that caused
2511** the constraint problem so INSERT OR REPLACE will always change
2512** the return value of this interface.)^
2513**
2514** ^For the purposes of this routine, an [INSERT] is considered to
2515** be successful even if it is subsequently rolled back.
2516**
2517** This function is accessible to SQL statements via the
2518** [last_insert_rowid() SQL function].
2519**
2520** If a separate thread performs a new [INSERT] on the same
2521** database connection while the [sqlite3_last_insert_rowid()]
2522** function is running and thus changes the last insert [rowid],
2523** then the value returned by [sqlite3_last_insert_rowid()] is
2524** unpredictable and might not equal either the old or the new
2525** last insert [rowid].
2526*/
2527SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2528
2529/*
2530** CAPI3REF: Set the Last Insert Rowid value.
2531** METHOD: sqlite3
2532**
2533** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2534** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2535** without inserting a row into the database.
2536*/
2537SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2538
2539/*
2540** CAPI3REF: Count The Number Of Rows Modified
2541** METHOD: sqlite3
2542**
2543** ^These functions return the number of rows modified, inserted or
2544** deleted by the most recently completed INSERT, UPDATE or DELETE
2545** statement on the database connection specified by the only parameter.
2546** The two functions are identical except for the type of the return value
2547** and that if the number of rows modified by the most recent INSERT, UPDATE
2548** or DELETE is greater than the maximum value supported by type "int", then
2549** the return value of sqlite3_changes() is undefined. ^Executing any other
2550** type of SQL statement does not modify the value returned by these functions.
2551**
2552** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2553** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2554** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2555**
2556** Changes to a view that are intercepted by
2557** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2558** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2559** DELETE statement run on a view is always zero. Only changes made to real
2560** tables are counted.
2561**
2562** Things are more complicated if the sqlite3_changes() function is
2563** executed while a trigger program is running. This may happen if the
2564** program uses the [changes() SQL function], or if some other callback
2565** function invokes sqlite3_changes() directly. Essentially:
2566**
2567** <ul>
2568** <li> ^(Before entering a trigger program the value returned by
2569** sqlite3_changes() function is saved. After the trigger program
2570** has finished, the original value is restored.)^
2571**
2572** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2573** statement sets the value returned by sqlite3_changes()
2574** upon completion as normal. Of course, this value will not include
2575** any changes performed by sub-triggers, as the sqlite3_changes()
2576** value will be saved and restored after each sub-trigger has run.)^
2577** </ul>
2578**
2579** ^This means that if the changes() SQL function (or similar) is used
2580** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2581** returns the value as set when the calling statement began executing.
2582** ^If it is used by the second or subsequent such statement within a trigger
2583** program, the value returned reflects the number of rows modified by the
2584** previous INSERT, UPDATE or DELETE statement within the same trigger.
2585**
2586** If a separate thread makes changes on the same database connection
2587** while [sqlite3_changes()] is running then the value returned
2588** is unpredictable and not meaningful.
2589**
2590** See also:
2591** <ul>
2592** <li> the [sqlite3_total_changes()] interface
2593** <li> the [count_changes pragma]
2594** <li> the [changes() SQL function]
2595** <li> the [data_version pragma]
2596** </ul>
2597*/
2598SQLITE_API int sqlite3_changes(sqlite3*);
2599SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2600
2601/*
2602** CAPI3REF: Total Number Of Rows Modified
2603** METHOD: sqlite3
2604**
2605** ^These functions return the total number of rows inserted, modified or
2606** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2607** since the database connection was opened, including those executed as
2608** part of trigger programs. The two functions are identical except for the
2609** type of the return value and that if the number of rows modified by the
2610** connection exceeds the maximum value supported by type "int", then
2611** the return value of sqlite3_total_changes() is undefined. ^Executing
2612** any other type of SQL statement does not affect the value returned by
2613** sqlite3_total_changes().
2614**
2615** ^Changes made as part of [foreign key actions] are included in the
2616** count, but those made as part of REPLACE constraint resolution are
2617** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2618** are not counted.
2619**
2620** The [sqlite3_total_changes(D)] interface only reports the number
2621** of rows that changed due to SQL statement run against database
2622** connection D. Any changes by other database connections are ignored.
2623** To detect changes against a database file from other database
2624** connections use the [PRAGMA data_version] command or the
2625** [SQLITE_FCNTL_DATA_VERSION] [file control].
2626**
2627** If a separate thread makes changes on the same database connection
2628** while [sqlite3_total_changes()] is running then the value
2629** returned is unpredictable and not meaningful.
2630**
2631** See also:
2632** <ul>
2633** <li> the [sqlite3_changes()] interface
2634** <li> the [count_changes pragma]
2635** <li> the [changes() SQL function]
2636** <li> the [data_version pragma]
2637** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2638** </ul>
2639*/
2640SQLITE_API int sqlite3_total_changes(sqlite3*);
2641SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2642
2643/*
2644** CAPI3REF: Interrupt A Long-Running Query
2645** METHOD: sqlite3
2646**
2647** ^This function causes any pending database operation to abort and
2648** return at its earliest opportunity. This routine is typically
2649** called in response to a user action such as pressing "Cancel"
2650** or Ctrl-C where the user wants a long query operation to halt
2651** immediately.
2652**
2653** ^It is safe to call this routine from a thread different from the
2654** thread that is currently running the database operation. But it
2655** is not safe to call this routine with a [database connection] that
2656** is closed or might close before sqlite3_interrupt() returns.
2657**
2658** ^If an SQL operation is very nearly finished at the time when
2659** sqlite3_interrupt() is called, then it might not have an opportunity
2660** to be interrupted and might continue to completion.
2661**
2662** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2663** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2664** that is inside an explicit transaction, then the entire transaction
2665** will be rolled back automatically.
2666**
2667** ^The sqlite3_interrupt(D) call is in effect until all currently running
2668** SQL statements on [database connection] D complete. ^Any new SQL statements
2669** that are started after the sqlite3_interrupt() call and before the
2670** running statement count reaches zero are interrupted as if they had been
2671** running prior to the sqlite3_interrupt() call. ^New SQL statements
2672** that are started after the running statement count reaches zero are
2673** not effected by the sqlite3_interrupt().
2674** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2675** SQL statements is a no-op and has no effect on SQL statements
2676** that are started after the sqlite3_interrupt() call returns.
2677*/
2678SQLITE_API void sqlite3_interrupt(sqlite3*);
2679
2680/*
2681** CAPI3REF: Determine If An SQL Statement Is Complete
2682**
2683** These routines are useful during command-line input to determine if the
2684** currently entered text seems to form a complete SQL statement or
2685** if additional input is needed before sending the text into
2686** SQLite for parsing. ^These routines return 1 if the input string
2687** appears to be a complete SQL statement. ^A statement is judged to be
2688** complete if it ends with a semicolon token and is not a prefix of a
2689** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2690** string literals or quoted identifier names or comments are not
2691** independent tokens (they are part of the token in which they are
2692** embedded) and thus do not count as a statement terminator. ^Whitespace
2693** and comments that follow the final semicolon are ignored.
2694**
2695** ^These routines return 0 if the statement is incomplete. ^If a
2696** memory allocation fails, then SQLITE_NOMEM is returned.
2697**
2698** ^These routines do not parse the SQL statements thus
2699** will not detect syntactically incorrect SQL.
2700**
2701** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2702** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2703** automatically by sqlite3_complete16(). If that initialization fails,
2704** then the return value from sqlite3_complete16() will be non-zero
2705** regardless of whether or not the input SQL is complete.)^
2706**
2707** The input to [sqlite3_complete()] must be a zero-terminated
2708** UTF-8 string.
2709**
2710** The input to [sqlite3_complete16()] must be a zero-terminated
2711** UTF-16 string in native byte order.
2712*/
2713SQLITE_API int sqlite3_complete(const char *sql);
2714SQLITE_API int sqlite3_complete16(const void *sql);
2715
2716/*
2717** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2718** KEYWORDS: {busy-handler callback} {busy handler}
2719** METHOD: sqlite3
2720**
2721** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2722** that might be invoked with argument P whenever
2723** an attempt is made to access a database table associated with
2724** [database connection] D when another thread
2725** or process has the table locked.
2726** The sqlite3_busy_handler() interface is used to implement
2727** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2728**
2729** ^If the busy callback is NULL, then [SQLITE_BUSY]
2730** is returned immediately upon encountering the lock. ^If the busy callback
2731** is not NULL, then the callback might be invoked with two arguments.
2732**
2733** ^The first argument to the busy handler is a copy of the void* pointer which
2734** is the third argument to sqlite3_busy_handler(). ^The second argument to
2735** the busy handler callback is the number of times that the busy handler has
2736** been invoked previously for the same locking event. ^If the
2737** busy callback returns 0, then no additional attempts are made to
2738** access the database and [SQLITE_BUSY] is returned
2739** to the application.
2740** ^If the callback returns non-zero, then another attempt
2741** is made to access the database and the cycle repeats.
2742**
2743** The presence of a busy handler does not guarantee that it will be invoked
2744** when there is lock contention. ^If SQLite determines that invoking the busy
2745** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2746** to the application instead of invoking the
2747** busy handler.
2748** Consider a scenario where one process is holding a read lock that
2749** it is trying to promote to a reserved lock and
2750** a second process is holding a reserved lock that it is trying
2751** to promote to an exclusive lock. The first process cannot proceed
2752** because it is blocked by the second and the second process cannot
2753** proceed because it is blocked by the first. If both processes
2754** invoke the busy handlers, neither will make any progress. Therefore,
2755** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2756** will induce the first process to release its read lock and allow
2757** the second process to proceed.
2758**
2759** ^The default busy callback is NULL.
2760**
2761** ^(There can only be a single busy handler defined for each
2762** [database connection]. Setting a new busy handler clears any
2763** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2764** or evaluating [PRAGMA busy_timeout=N] will change the
2765** busy handler and thus clear any previously set busy handler.
2766**
2767** The busy callback should not take any actions which modify the
2768** database connection that invoked the busy handler. In other words,
2769** the busy handler is not reentrant. Any such actions
2770** result in undefined behavior.
2771**
2772** A busy handler must not close the database connection
2773** or [prepared statement] that invoked the busy handler.
2774*/
2775SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2776
2777/*
2778** CAPI3REF: Set A Busy Timeout
2779** METHOD: sqlite3
2780**
2781** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2782** for a specified amount of time when a table is locked. ^The handler
2783** will sleep multiple times until at least "ms" milliseconds of sleeping
2784** have accumulated. ^After at least "ms" milliseconds of sleeping,
2785** the handler returns 0 which causes [sqlite3_step()] to return
2786** [SQLITE_BUSY].
2787**
2788** ^Calling this routine with an argument less than or equal to zero
2789** turns off all busy handlers.
2790**
2791** ^(There can only be a single busy handler for a particular
2792** [database connection] at any given moment. If another busy handler
2793** was defined (using [sqlite3_busy_handler()]) prior to calling
2794** this routine, that other busy handler is cleared.)^
2795**
2796** See also: [PRAGMA busy_timeout]
2797*/
2798SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2799
2800/*
2801** CAPI3REF: Convenience Routines For Running Queries
2802** METHOD: sqlite3
2803**
2804** This is a legacy interface that is preserved for backwards compatibility.
2805** Use of this interface is not recommended.
2806**
2807** Definition: A <b>result table</b> is memory data structure created by the
2808** [sqlite3_get_table()] interface. A result table records the
2809** complete query results from one or more queries.
2810**
2811** The table conceptually has a number of rows and columns. But
2812** these numbers are not part of the result table itself. These
2813** numbers are obtained separately. Let N be the number of rows
2814** and M be the number of columns.
2815**
2816** A result table is an array of pointers to zero-terminated UTF-8 strings.
2817** There are (N+1)*M elements in the array. The first M pointers point
2818** to zero-terminated strings that contain the names of the columns.
2819** The remaining entries all point to query results. NULL values result
2820** in NULL pointers. All other values are in their UTF-8 zero-terminated
2821** string representation as returned by [sqlite3_column_text()].
2822**
2823** A result table might consist of one or more memory allocations.
2824** It is not safe to pass a result table directly to [sqlite3_free()].
2825** A result table should be deallocated using [sqlite3_free_table()].
2826**
2827** ^(As an example of the result table format, suppose a query result
2828** is as follows:
2829**
2830** <blockquote><pre>
2831** Name | Age
2832** -----------------------
2833** Alice | 43
2834** Bob | 28
2835** Cindy | 21
2836** </pre></blockquote>
2837**
2838** There are two columns (M==2) and three rows (N==3). Thus the
2839** result table has 8 entries. Suppose the result table is stored
2840** in an array named azResult. Then azResult holds this content:
2841**
2842** <blockquote><pre>
2843** azResult&#91;0] = "Name";
2844** azResult&#91;1] = "Age";
2845** azResult&#91;2] = "Alice";
2846** azResult&#91;3] = "43";
2847** azResult&#91;4] = "Bob";
2848** azResult&#91;5] = "28";
2849** azResult&#91;6] = "Cindy";
2850** azResult&#91;7] = "21";
2851** </pre></blockquote>)^
2852**
2853** ^The sqlite3_get_table() function evaluates one or more
2854** semicolon-separated SQL statements in the zero-terminated UTF-8
2855** string of its 2nd parameter and returns a result table to the
2856** pointer given in its 3rd parameter.
2857**
2858** After the application has finished with the result from sqlite3_get_table(),
2859** it must pass the result table pointer to sqlite3_free_table() in order to
2860** release the memory that was malloced. Because of the way the
2861** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2862** function must not try to call [sqlite3_free()] directly. Only
2863** [sqlite3_free_table()] is able to release the memory properly and safely.
2864**
2865** The sqlite3_get_table() interface is implemented as a wrapper around
2866** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2867** to any internal data structures of SQLite. It uses only the public
2868** interface defined here. As a consequence, errors that occur in the
2869** wrapper layer outside of the internal [sqlite3_exec()] call are not
2870** reflected in subsequent calls to [sqlite3_errcode()] or
2871** [sqlite3_errmsg()].
2872*/
2873SQLITE_API int sqlite3_get_table(
2874 sqlite3 *db, /* An open database */
2875 const char *zSql, /* SQL to be evaluated */
2876 char ***pazResult, /* Results of the query */
2877 int *pnRow, /* Number of result rows written here */
2878 int *pnColumn, /* Number of result columns written here */
2879 char **pzErrmsg /* Error msg written here */
2880);
2881SQLITE_API void sqlite3_free_table(char **result);
2882
2883/*
2884** CAPI3REF: Formatted String Printing Functions
2885**
2886** These routines are work-alikes of the "printf()" family of functions
2887** from the standard C library.
2888** These routines understand most of the common formatting options from
2889** the standard library printf()
2890** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2891** See the [built-in printf()] documentation for details.
2892**
2893** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2894** results into memory obtained from [sqlite3_malloc64()].
2895** The strings returned by these two routines should be
2896** released by [sqlite3_free()]. ^Both routines return a
2897** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2898** memory to hold the resulting string.
2899**
2900** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2901** the standard C library. The result is written into the
2902** buffer supplied as the second parameter whose size is given by
2903** the first parameter. Note that the order of the
2904** first two parameters is reversed from snprintf().)^ This is an
2905** historical accident that cannot be fixed without breaking
2906** backwards compatibility. ^(Note also that sqlite3_snprintf()
2907** returns a pointer to its buffer instead of the number of
2908** characters actually written into the buffer.)^ We admit that
2909** the number of characters written would be a more useful return
2910** value but we cannot change the implementation of sqlite3_snprintf()
2911** now without breaking compatibility.
2912**
2913** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2914** guarantees that the buffer is always zero-terminated. ^The first
2915** parameter "n" is the total size of the buffer, including space for
2916** the zero terminator. So the longest string that can be completely
2917** written will be n-1 characters.
2918**
2919** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2920**
2921** See also: [built-in printf()], [printf() SQL function]
2922*/
2923SQLITE_API char *sqlite3_mprintf(const char*,...);
2924SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2925SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2926SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2927
2928/*
2929** CAPI3REF: Memory Allocation Subsystem
2930**
2931** The SQLite core uses these three routines for all of its own
2932** internal memory allocation needs. "Core" in the previous sentence
2933** does not include operating-system specific [VFS] implementation. The
2934** Windows VFS uses native malloc() and free() for some operations.
2935**
2936** ^The sqlite3_malloc() routine returns a pointer to a block
2937** of memory at least N bytes in length, where N is the parameter.
2938** ^If sqlite3_malloc() is unable to obtain sufficient free
2939** memory, it returns a NULL pointer. ^If the parameter N to
2940** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2941** a NULL pointer.
2942**
2943** ^The sqlite3_malloc64(N) routine works just like
2944** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2945** of a signed 32-bit integer.
2946**
2947** ^Calling sqlite3_free() with a pointer previously returned
2948** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2949** that it might be reused. ^The sqlite3_free() routine is
2950** a no-op if is called with a NULL pointer. Passing a NULL pointer
2951** to sqlite3_free() is harmless. After being freed, memory
2952** should neither be read nor written. Even reading previously freed
2953** memory might result in a segmentation fault or other severe error.
2954** Memory corruption, a segmentation fault, or other severe error
2955** might result if sqlite3_free() is called with a non-NULL pointer that
2956** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2957**
2958** ^The sqlite3_realloc(X,N) interface attempts to resize a
2959** prior memory allocation X to be at least N bytes.
2960** ^If the X parameter to sqlite3_realloc(X,N)
2961** is a NULL pointer then its behavior is identical to calling
2962** sqlite3_malloc(N).
2963** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2964** negative then the behavior is exactly the same as calling
2965** sqlite3_free(X).
2966** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2967** of at least N bytes in size or NULL if insufficient memory is available.
2968** ^If M is the size of the prior allocation, then min(N,M) bytes
2969** of the prior allocation are copied into the beginning of buffer returned
2970** by sqlite3_realloc(X,N) and the prior allocation is freed.
2971** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2972** prior allocation is not freed.
2973**
2974** ^The sqlite3_realloc64(X,N) interfaces works the same as
2975** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2976** of a 32-bit signed integer.
2977**
2978** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2979** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2980** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2981** ^The value returned by sqlite3_msize(X) might be larger than the number
2982** of bytes requested when X was allocated. ^If X is a NULL pointer then
2983** sqlite3_msize(X) returns zero. If X points to something that is not
2984** the beginning of memory allocation, or if it points to a formerly
2985** valid memory allocation that has now been freed, then the behavior
2986** of sqlite3_msize(X) is undefined and possibly harmful.
2987**
2988** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2989** sqlite3_malloc64(), and sqlite3_realloc64()
2990** is always aligned to at least an 8 byte boundary, or to a
2991** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2992** option is used.
2993**
2994** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2995** must be either NULL or else pointers obtained from a prior
2996** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2997** not yet been released.
2998**
2999** The application must not read or write any part of
3000** a block of memory after it has been released using
3001** [sqlite3_free()] or [sqlite3_realloc()].
3002*/
3003SQLITE_API void *sqlite3_malloc(int);
3004SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3005SQLITE_API void *sqlite3_realloc(void*, int);
3006SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3007SQLITE_API void sqlite3_free(void*);
3008SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3009
3010/*
3011** CAPI3REF: Memory Allocator Statistics
3012**
3013** SQLite provides these two interfaces for reporting on the status
3014** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3015** routines, which form the built-in memory allocation subsystem.
3016**
3017** ^The [sqlite3_memory_used()] routine returns the number of bytes
3018** of memory currently outstanding (malloced but not freed).
3019** ^The [sqlite3_memory_highwater()] routine returns the maximum
3020** value of [sqlite3_memory_used()] since the high-water mark
3021** was last reset. ^The values returned by [sqlite3_memory_used()] and
3022** [sqlite3_memory_highwater()] include any overhead
3023** added by SQLite in its implementation of [sqlite3_malloc()],
3024** but not overhead added by the any underlying system library
3025** routines that [sqlite3_malloc()] may call.
3026**
3027** ^The memory high-water mark is reset to the current value of
3028** [sqlite3_memory_used()] if and only if the parameter to
3029** [sqlite3_memory_highwater()] is true. ^The value returned
3030** by [sqlite3_memory_highwater(1)] is the high-water mark
3031** prior to the reset.
3032*/
3033SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3034SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3035
3036/*
3037** CAPI3REF: Pseudo-Random Number Generator
3038**
3039** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3040** select random [ROWID | ROWIDs] when inserting new records into a table that
3041** already uses the largest possible [ROWID]. The PRNG is also used for
3042** the built-in random() and randomblob() SQL functions. This interface allows
3043** applications to access the same PRNG for other purposes.
3044**
3045** ^A call to this routine stores N bytes of randomness into buffer P.
3046** ^The P parameter can be a NULL pointer.
3047**
3048** ^If this routine has not been previously called or if the previous
3049** call had N less than one or a NULL pointer for P, then the PRNG is
3050** seeded using randomness obtained from the xRandomness method of
3051** the default [sqlite3_vfs] object.
3052** ^If the previous call to this routine had an N of 1 or more and a
3053** non-NULL P then the pseudo-randomness is generated
3054** internally and without recourse to the [sqlite3_vfs] xRandomness
3055** method.
3056*/
3057SQLITE_API void sqlite3_randomness(int N, void *P);
3058
3059/*
3060** CAPI3REF: Compile-Time Authorization Callbacks
3061** METHOD: sqlite3
3062** KEYWORDS: {authorizer callback}
3063**
3064** ^This routine registers an authorizer callback with a particular
3065** [database connection], supplied in the first argument.
3066** ^The authorizer callback is invoked as SQL statements are being compiled
3067** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3068** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3069** and [sqlite3_prepare16_v3()]. ^At various
3070** points during the compilation process, as logic is being created
3071** to perform various actions, the authorizer callback is invoked to
3072** see if those actions are allowed. ^The authorizer callback should
3073** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3074** specific action but allow the SQL statement to continue to be
3075** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3076** rejected with an error. ^If the authorizer callback returns
3077** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3078** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3079** the authorizer will fail with an error message.
3080**
3081** When the callback returns [SQLITE_OK], that means the operation
3082** requested is ok. ^When the callback returns [SQLITE_DENY], the
3083** [sqlite3_prepare_v2()] or equivalent call that triggered the
3084** authorizer will fail with an error message explaining that
3085** access is denied.
3086**
3087** ^The first parameter to the authorizer callback is a copy of the third
3088** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3089** to the callback is an integer [SQLITE_COPY | action code] that specifies
3090** the particular action to be authorized. ^The third through sixth parameters
3091** to the callback are either NULL pointers or zero-terminated strings
3092** that contain additional details about the action to be authorized.
3093** Applications must always be prepared to encounter a NULL pointer in any
3094** of the third through the sixth parameters of the authorization callback.
3095**
3096** ^If the action code is [SQLITE_READ]
3097** and the callback returns [SQLITE_IGNORE] then the
3098** [prepared statement] statement is constructed to substitute
3099** a NULL value in place of the table column that would have
3100** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3101** return can be used to deny an untrusted user access to individual
3102** columns of a table.
3103** ^When a table is referenced by a [SELECT] but no column values are
3104** extracted from that table (for example in a query like
3105** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3106** is invoked once for that table with a column name that is an empty string.
3107** ^If the action code is [SQLITE_DELETE] and the callback returns
3108** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3109** [truncate optimization] is disabled and all rows are deleted individually.
3110**
3111** An authorizer is used when [sqlite3_prepare | preparing]
3112** SQL statements from an untrusted source, to ensure that the SQL statements
3113** do not try to access data they are not allowed to see, or that they do not
3114** try to execute malicious statements that damage the database. For
3115** example, an application may allow a user to enter arbitrary
3116** SQL queries for evaluation by a database. But the application does
3117** not want the user to be able to make arbitrary changes to the
3118** database. An authorizer could then be put in place while the
3119** user-entered SQL is being [sqlite3_prepare | prepared] that
3120** disallows everything except [SELECT] statements.
3121**
3122** Applications that need to process SQL from untrusted sources
3123** might also consider lowering resource limits using [sqlite3_limit()]
3124** and limiting database size using the [max_page_count] [PRAGMA]
3125** in addition to using an authorizer.
3126**
3127** ^(Only a single authorizer can be in place on a database connection
3128** at a time. Each call to sqlite3_set_authorizer overrides the
3129** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3130** The authorizer is disabled by default.
3131**
3132** The authorizer callback must not do anything that will modify
3133** the database connection that invoked the authorizer callback.
3134** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3135** database connections for the meaning of "modify" in this paragraph.
3136**
3137** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3138** statement might be re-prepared during [sqlite3_step()] due to a
3139** schema change. Hence, the application should ensure that the
3140** correct authorizer callback remains in place during the [sqlite3_step()].
3141**
3142** ^Note that the authorizer callback is invoked only during
3143** [sqlite3_prepare()] or its variants. Authorization is not
3144** performed during statement evaluation in [sqlite3_step()], unless
3145** as stated in the previous paragraph, sqlite3_step() invokes
3146** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3147*/
3148SQLITE_API int sqlite3_set_authorizer(
3149 sqlite3*,
3150 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3151 void *pUserData
3152);
3153
3154/*
3155** CAPI3REF: Authorizer Return Codes
3156**
3157** The [sqlite3_set_authorizer | authorizer callback function] must
3158** return either [SQLITE_OK] or one of these two constants in order
3159** to signal SQLite whether or not the action is permitted. See the
3160** [sqlite3_set_authorizer | authorizer documentation] for additional
3161** information.
3162**
3163** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3164** returned from the [sqlite3_vtab_on_conflict()] interface.
3165*/
3166#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3167#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3168
3169/*
3170** CAPI3REF: Authorizer Action Codes
3171**
3172** The [sqlite3_set_authorizer()] interface registers a callback function
3173** that is invoked to authorize certain SQL statement actions. The
3174** second parameter to the callback is an integer code that specifies
3175** what action is being authorized. These are the integer action codes that
3176** the authorizer callback may be passed.
3177**
3178** These action code values signify what kind of operation is to be
3179** authorized. The 3rd and 4th parameters to the authorization
3180** callback function will be parameters or NULL depending on which of these
3181** codes is used as the second parameter. ^(The 5th parameter to the
3182** authorizer callback is the name of the database ("main", "temp",
3183** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3184** is the name of the inner-most trigger or view that is responsible for
3185** the access attempt or NULL if this access attempt is directly from
3186** top-level SQL code.
3187*/
3188/******************************************* 3rd ************ 4th ***********/
3189#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3190#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3191#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3192#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3193#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3194#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3195#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3196#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3197#define SQLITE_DELETE 9 /* Table Name NULL */
3198#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3199#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3200#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3201#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3202#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3203#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3204#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3205#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3206#define SQLITE_INSERT 18 /* Table Name NULL */
3207#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3208#define SQLITE_READ 20 /* Table Name Column Name */
3209#define SQLITE_SELECT 21 /* NULL NULL */
3210#define SQLITE_TRANSACTION 22 /* Operation NULL */
3211#define SQLITE_UPDATE 23 /* Table Name Column Name */
3212#define SQLITE_ATTACH 24 /* Filename NULL */
3213#define SQLITE_DETACH 25 /* Database Name NULL */
3214#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3215#define SQLITE_REINDEX 27 /* Index Name NULL */
3216#define SQLITE_ANALYZE 28 /* Table Name NULL */
3217#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3218#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3219#define SQLITE_FUNCTION 31 /* NULL Function Name */
3220#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3221#define SQLITE_COPY 0 /* No longer used */
3222#define SQLITE_RECURSIVE 33 /* NULL NULL */
3223
3224/*
3225** CAPI3REF: Tracing And Profiling Functions
3226** METHOD: sqlite3
3227**
3228** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3229** instead of the routines described here.
3230**
3231** These routines register callback functions that can be used for
3232** tracing and profiling the execution of SQL statements.
3233**
3234** ^The callback function registered by sqlite3_trace() is invoked at
3235** various times when an SQL statement is being run by [sqlite3_step()].
3236** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3237** SQL statement text as the statement first begins executing.
3238** ^(Additional sqlite3_trace() callbacks might occur
3239** as each triggered subprogram is entered. The callbacks for triggers
3240** contain a UTF-8 SQL comment that identifies the trigger.)^
3241**
3242** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3243** the length of [bound parameter] expansion in the output of sqlite3_trace().
3244**
3245** ^The callback function registered by sqlite3_profile() is invoked
3246** as each SQL statement finishes. ^The profile callback contains
3247** the original statement text and an estimate of wall-clock time
3248** of how long that statement took to run. ^The profile callback
3249** time is in units of nanoseconds, however the current implementation
3250** is only capable of millisecond resolution so the six least significant
3251** digits in the time are meaningless. Future versions of SQLite
3252** might provide greater resolution on the profiler callback. Invoking
3253** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3254** profile callback.
3255*/
3256SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3257 void(*xTrace)(void*,const char*), void*);
3258SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3259 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3260
3261/*
3262** CAPI3REF: SQL Trace Event Codes
3263** KEYWORDS: SQLITE_TRACE
3264**
3265** These constants identify classes of events that can be monitored
3266** using the [sqlite3_trace_v2()] tracing logic. The M argument
3267** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3268** the following constants. ^The first argument to the trace callback
3269** is one of the following constants.
3270**
3271** New tracing constants may be added in future releases.
3272**
3273** ^A trace callback has four arguments: xCallback(T,C,P,X).
3274** ^The T argument is one of the integer type codes above.
3275** ^The C argument is a copy of the context pointer passed in as the
3276** fourth argument to [sqlite3_trace_v2()].
3277** The P and X arguments are pointers whose meanings depend on T.
3278**
3279** <dl>
3280** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3281** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3282** first begins running and possibly at other times during the
3283** execution of the prepared statement, such as at the start of each
3284** trigger subprogram. ^The P argument is a pointer to the
3285** [prepared statement]. ^The X argument is a pointer to a string which
3286** is the unexpanded SQL text of the prepared statement or an SQL comment
3287** that indicates the invocation of a trigger. ^The callback can compute
3288** the same text that would have been returned by the legacy [sqlite3_trace()]
3289** interface by using the X argument when X begins with "--" and invoking
3290** [sqlite3_expanded_sql(P)] otherwise.
3291**
3292** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3293** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3294** information as is provided by the [sqlite3_profile()] callback.
3295** ^The P argument is a pointer to the [prepared statement] and the
3296** X argument points to a 64-bit integer which is the estimated of
3297** the number of nanosecond that the prepared statement took to run.
3298** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3299**
3300** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3301** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3302** statement generates a single row of result.
3303** ^The P argument is a pointer to the [prepared statement] and the
3304** X argument is unused.
3305**
3306** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3307** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3308** connection closes.
3309** ^The P argument is a pointer to the [database connection] object
3310** and the X argument is unused.
3311** </dl>
3312*/
3313#define SQLITE_TRACE_STMT 0x01
3314#define SQLITE_TRACE_PROFILE 0x02
3315#define SQLITE_TRACE_ROW 0x04
3316#define SQLITE_TRACE_CLOSE 0x08
3317
3318/*
3319** CAPI3REF: SQL Trace Hook
3320** METHOD: sqlite3
3321**
3322** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3323** function X against [database connection] D, using property mask M
3324** and context pointer P. ^If the X callback is
3325** NULL or if the M mask is zero, then tracing is disabled. The
3326** M argument should be the bitwise OR-ed combination of
3327** zero or more [SQLITE_TRACE] constants.
3328**
3329** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3330** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3331**
3332** ^The X callback is invoked whenever any of the events identified by
3333** mask M occur. ^The integer return value from the callback is currently
3334** ignored, though this may change in future releases. Callback
3335** implementations should return zero to ensure future compatibility.
3336**
3337** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3338** ^The T argument is one of the [SQLITE_TRACE]
3339** constants to indicate why the callback was invoked.
3340** ^The C argument is a copy of the context pointer.
3341** The P and X arguments are pointers whose meanings depend on T.
3342**
3343** The sqlite3_trace_v2() interface is intended to replace the legacy
3344** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3345** are deprecated.
3346*/
3347SQLITE_API int sqlite3_trace_v2(
3348 sqlite3*,
3349 unsigned uMask,
3350 int(*xCallback)(unsigned,void*,void*,void*),
3351 void *pCtx
3352);
3353
3354/*
3355** CAPI3REF: Query Progress Callbacks
3356** METHOD: sqlite3
3357**
3358** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3359** function X to be invoked periodically during long running calls to
3360** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3361** database connection D. An example use for this
3362** interface is to keep a GUI updated during a large query.
3363**
3364** ^The parameter P is passed through as the only parameter to the
3365** callback function X. ^The parameter N is the approximate number of
3366** [virtual machine instructions] that are evaluated between successive
3367** invocations of the callback X. ^If N is less than one then the progress
3368** handler is disabled.
3369**
3370** ^Only a single progress handler may be defined at one time per
3371** [database connection]; setting a new progress handler cancels the
3372** old one. ^Setting parameter X to NULL disables the progress handler.
3373** ^The progress handler is also disabled by setting N to a value less
3374** than 1.
3375**
3376** ^If the progress callback returns non-zero, the operation is
3377** interrupted. This feature can be used to implement a
3378** "Cancel" button on a GUI progress dialog box.
3379**
3380** The progress handler callback must not do anything that will modify
3381** the database connection that invoked the progress handler.
3382** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3383** database connections for the meaning of "modify" in this paragraph.
3384**
3385*/
3386SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3387
3388/*
3389** CAPI3REF: Opening A New Database Connection
3390** CONSTRUCTOR: sqlite3
3391**
3392** ^These routines open an SQLite database file as specified by the
3393** filename argument. ^The filename argument is interpreted as UTF-8 for
3394** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3395** order for sqlite3_open16(). ^(A [database connection] handle is usually
3396** returned in *ppDb, even if an error occurs. The only exception is that
3397** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3398** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3399** object.)^ ^(If the database is opened (and/or created) successfully, then
3400** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3401** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3402** an English language description of the error following a failure of any
3403** of the sqlite3_open() routines.
3404**
3405** ^The default encoding will be UTF-8 for databases created using
3406** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3407** created using sqlite3_open16() will be UTF-16 in the native byte order.
3408**
3409** Whether or not an error occurs when it is opened, resources
3410** associated with the [database connection] handle should be released by
3411** passing it to [sqlite3_close()] when it is no longer required.
3412**
3413** The sqlite3_open_v2() interface works like sqlite3_open()
3414** except that it accepts two additional parameters for additional control
3415** over the new database connection. ^(The flags parameter to
3416** sqlite3_open_v2() must include, at a minimum, one of the following
3417** three flag combinations:)^
3418**
3419** <dl>
3420** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3421** <dd>The database is opened in read-only mode. If the database does not
3422** already exist, an error is returned.</dd>)^
3423**
3424** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3425** <dd>The database is opened for reading and writing if possible, or reading
3426** only if the file is write protected by the operating system. In either
3427** case the database must already exist, otherwise an error is returned.</dd>)^
3428**
3429** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3430** <dd>The database is opened for reading and writing, and is created if
3431** it does not already exist. This is the behavior that is always used for
3432** sqlite3_open() and sqlite3_open16().</dd>)^
3433** </dl>
3434**
3435** In addition to the required flags, the following optional flags are
3436** also supported:
3437**
3438** <dl>
3439** ^(<dt>[SQLITE_OPEN_URI]</dt>
3440** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3441**
3442** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3443** <dd>The database will be opened as an in-memory database. The database
3444** is named by the "filename" argument for the purposes of cache-sharing,
3445** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3446** </dd>)^
3447**
3448** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3449** <dd>The new database connection will use the "multi-thread"
3450** [threading mode].)^ This means that separate threads are allowed
3451** to use SQLite at the same time, as long as each thread is using
3452** a different [database connection].
3453**
3454** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3455** <dd>The new database connection will use the "serialized"
3456** [threading mode].)^ This means the multiple threads can safely
3457** attempt to use the same database connection at the same time.
3458** (Mutexes will block any actual concurrency, but in this mode
3459** there is no harm in trying.)
3460**
3461** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3462** <dd>The database is opened [shared cache] enabled, overriding
3463** the default shared cache setting provided by
3464** [sqlite3_enable_shared_cache()].)^
3465** The [use of shared cache mode is discouraged] and hence shared cache
3466** capabilities may be omitted from many builds of SQLite. In such cases,
3467** this option is a no-op.
3468**
3469** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3470** <dd>The database is opened [shared cache] disabled, overriding
3471** the default shared cache setting provided by
3472** [sqlite3_enable_shared_cache()].)^
3473**
3474** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3475** <dd>The database connection comes up in "extended result code mode".
3476** In other words, the database behaves has if
3477** [sqlite3_extended_result_codes(db,1)] where called on the database
3478** connection as soon as the connection is created. In addition to setting
3479** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3480** to return an extended result code.</dd>
3481**
3482** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3483** <dd>The database filename is not allowed to contain a symbolic link</dd>
3484** </dl>)^
3485**
3486** If the 3rd parameter to sqlite3_open_v2() is not one of the
3487** required combinations shown above optionally combined with other
3488** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3489** then the behavior is undefined. Historic versions of SQLite
3490** have silently ignored surplus bits in the flags parameter to
3491** sqlite3_open_v2(), however that behavior might not be carried through
3492** into future versions of SQLite and so applications should not rely
3493** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3494** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3495** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3496** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3497** by sqlite3_open_v2().
3498**
3499** ^The fourth parameter to sqlite3_open_v2() is the name of the
3500** [sqlite3_vfs] object that defines the operating system interface that
3501** the new database connection should use. ^If the fourth parameter is
3502** a NULL pointer then the default [sqlite3_vfs] object is used.
3503**
3504** ^If the filename is ":memory:", then a private, temporary in-memory database
3505** is created for the connection. ^This in-memory database will vanish when
3506** the database connection is closed. Future versions of SQLite might
3507** make use of additional special filenames that begin with the ":" character.
3508** It is recommended that when a database filename actually does begin with
3509** a ":" character you should prefix the filename with a pathname such as
3510** "./" to avoid ambiguity.
3511**
3512** ^If the filename is an empty string, then a private, temporary
3513** on-disk database will be created. ^This private database will be
3514** automatically deleted as soon as the database connection is closed.
3515**
3516** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3517**
3518** ^If [URI filename] interpretation is enabled, and the filename argument
3519** begins with "file:", then the filename is interpreted as a URI. ^URI
3520** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3521** set in the third argument to sqlite3_open_v2(), or if it has
3522** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3523** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3524** URI filename interpretation is turned off
3525** by default, but future releases of SQLite might enable URI filename
3526** interpretation by default. See "[URI filenames]" for additional
3527** information.
3528**
3529** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3530** authority, then it must be either an empty string or the string
3531** "localhost". ^If the authority is not an empty string or "localhost", an
3532** error is returned to the caller. ^The fragment component of a URI, if
3533** present, is ignored.
3534**
3535** ^SQLite uses the path component of the URI as the name of the disk file
3536** which contains the database. ^If the path begins with a '/' character,
3537** then it is interpreted as an absolute path. ^If the path does not begin
3538** with a '/' (meaning that the authority section is omitted from the URI)
3539** then the path is interpreted as a relative path.
3540** ^(On windows, the first component of an absolute path
3541** is a drive specification (e.g. "C:").)^
3542**
3543** [[core URI query parameters]]
3544** The query component of a URI may contain parameters that are interpreted
3545** either by SQLite itself, or by a [VFS | custom VFS implementation].
3546** SQLite and its built-in [VFSes] interpret the
3547** following query parameters:
3548**
3549** <ul>
3550** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3551** a VFS object that provides the operating system interface that should
3552** be used to access the database file on disk. ^If this option is set to
3553** an empty string the default VFS object is used. ^Specifying an unknown
3554** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3555** present, then the VFS specified by the option takes precedence over
3556** the value passed as the fourth parameter to sqlite3_open_v2().
3557**
3558** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3559** "rwc", or "memory". Attempting to set it to any other value is
3560** an error)^.
3561** ^If "ro" is specified, then the database is opened for read-only
3562** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3563** third argument to sqlite3_open_v2(). ^If the mode option is set to
3564** "rw", then the database is opened for read-write (but not create)
3565** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3566** been set. ^Value "rwc" is equivalent to setting both
3567** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3568** set to "memory" then a pure [in-memory database] that never reads
3569** or writes from disk is used. ^It is an error to specify a value for
3570** the mode parameter that is less restrictive than that specified by
3571** the flags passed in the third parameter to sqlite3_open_v2().
3572**
3573** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3574** "private". ^Setting it to "shared" is equivalent to setting the
3575** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3576** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3577** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3578** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3579** a URI filename, its value overrides any behavior requested by setting
3580** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3581**
3582** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3583** [powersafe overwrite] property does or does not apply to the
3584** storage media on which the database file resides.
3585**
3586** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3587** which if set disables file locking in rollback journal modes. This
3588** is useful for accessing a database on a filesystem that does not
3589** support locking. Caution: Database corruption might result if two
3590** or more processes write to the same database and any one of those
3591** processes uses nolock=1.
3592**
3593** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3594** parameter that indicates that the database file is stored on
3595** read-only media. ^When immutable is set, SQLite assumes that the
3596** database file cannot be changed, even by a process with higher
3597** privilege, and so the database is opened read-only and all locking
3598** and change detection is disabled. Caution: Setting the immutable
3599** property on a database file that does in fact change can result
3600** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3601** See also: [SQLITE_IOCAP_IMMUTABLE].
3602**
3603** </ul>
3604**
3605** ^Specifying an unknown parameter in the query component of a URI is not an
3606** error. Future versions of SQLite might understand additional query
3607** parameters. See "[query parameters with special meaning to SQLite]" for
3608** additional information.
3609**
3610** [[URI filename examples]] <h3>URI filename examples</h3>
3611**
3612** <table border="1" align=center cellpadding=5>
3613** <tr><th> URI filenames <th> Results
3614** <tr><td> file:data.db <td>
3615** Open the file "data.db" in the current directory.
3616** <tr><td> file:/home/fred/data.db<br>
3617** file:///home/fred/data.db <br>
3618** file://localhost/home/fred/data.db <br> <td>
3619** Open the database file "/home/fred/data.db".
3620** <tr><td> file://darkstar/home/fred/data.db <td>
3621** An error. "darkstar" is not a recognized authority.
3622** <tr><td style="white-space:nowrap">
3623** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3624** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3625** C:. Note that the %20 escaping in this example is not strictly
3626** necessary - space characters can be used literally
3627** in URI filenames.
3628** <tr><td> file:data.db?mode=ro&cache=private <td>
3629** Open file "data.db" in the current directory for read-only access.
3630** Regardless of whether or not shared-cache mode is enabled by
3631** default, use a private cache.
3632** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3633** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3634** that uses dot-files in place of posix advisory locking.
3635** <tr><td> file:data.db?mode=readonly <td>
3636** An error. "readonly" is not a valid option for the "mode" parameter.
3637** Use "ro" instead: "file:data.db?mode=ro".
3638** </table>
3639**
3640** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3641** query components of a URI. A hexadecimal escape sequence consists of a
3642** percent sign - "%" - followed by exactly two hexadecimal digits
3643** specifying an octet value. ^Before the path or query components of a
3644** URI filename are interpreted, they are encoded using UTF-8 and all
3645** hexadecimal escape sequences replaced by a single byte containing the
3646** corresponding octet. If this process generates an invalid UTF-8 encoding,
3647** the results are undefined.
3648**
3649** <b>Note to Windows users:</b> The encoding used for the filename argument
3650** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3651** codepage is currently defined. Filenames containing international
3652** characters must be converted to UTF-8 prior to passing them into
3653** sqlite3_open() or sqlite3_open_v2().
3654**
3655** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3656** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3657** features that require the use of temporary files may fail.
3658**
3659** See also: [sqlite3_temp_directory]
3660*/
3661SQLITE_API int sqlite3_open(
3662 const char *filename, /* Database filename (UTF-8) */
3663 sqlite3 **ppDb /* OUT: SQLite db handle */
3664);
3665SQLITE_API int sqlite3_open16(
3666 const void *filename, /* Database filename (UTF-16) */
3667 sqlite3 **ppDb /* OUT: SQLite db handle */
3668);
3669SQLITE_API int sqlite3_open_v2(
3670 const char *filename, /* Database filename (UTF-8) */
3671 sqlite3 **ppDb, /* OUT: SQLite db handle */
3672 int flags, /* Flags */
3673 const char *zVfs /* Name of VFS module to use */
3674);
3675
3676/*
3677** CAPI3REF: Obtain Values For URI Parameters
3678**
3679** These are utility routines, useful to [VFS|custom VFS implementations],
3680** that check if a database file was a URI that contained a specific query
3681** parameter, and if so obtains the value of that query parameter.
3682**
3683** The first parameter to these interfaces (hereafter referred to
3684** as F) must be one of:
3685** <ul>
3686** <li> A database filename pointer created by the SQLite core and
3687** passed into the xOpen() method of a VFS implemention, or
3688** <li> A filename obtained from [sqlite3_db_filename()], or
3689** <li> A new filename constructed using [sqlite3_create_filename()].
3690** </ul>
3691** If the F parameter is not one of the above, then the behavior is
3692** undefined and probably undesirable. Older versions of SQLite were
3693** more tolerant of invalid F parameters than newer versions.
3694**
3695** If F is a suitable filename (as described in the previous paragraph)
3696** and if P is the name of the query parameter, then
3697** sqlite3_uri_parameter(F,P) returns the value of the P
3698** parameter if it exists or a NULL pointer if P does not appear as a
3699** query parameter on F. If P is a query parameter of F and it
3700** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3701** a pointer to an empty string.
3702**
3703** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3704** parameter and returns true (1) or false (0) according to the value
3705** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3706** value of query parameter P is one of "yes", "true", or "on" in any
3707** case or if the value begins with a non-zero number. The
3708** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3709** query parameter P is one of "no", "false", or "off" in any case or
3710** if the value begins with a numeric zero. If P is not a query
3711** parameter on F or if the value of P does not match any of the
3712** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3713**
3714** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3715** 64-bit signed integer and returns that integer, or D if P does not
3716** exist. If the value of P is something other than an integer, then
3717** zero is returned.
3718**
3719** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3720** the value) of the N-th query parameter for filename F, or a NULL
3721** pointer if N is less than zero or greater than the number of query
3722** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3723** the name of the first query parameter, 1 for the second parameter, and
3724** so forth.
3725**
3726** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3727** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3728** is not a database file pathname pointer that the SQLite core passed
3729** into the xOpen VFS method, then the behavior of this routine is undefined
3730** and probably undesirable.
3731**
3732** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3733** parameter can also be the name of a rollback journal file or WAL file
3734** in addition to the main database file. Prior to version 3.31.0, these
3735** routines would only work if F was the name of the main database file.
3736** When the F parameter is the name of the rollback journal or WAL file,
3737** it has access to all the same query parameters as were found on the
3738** main database file.
3739**
3740** See the [URI filename] documentation for additional information.
3741*/
3742SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
3743SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
3744SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
3745SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
3746
3747/*
3748** CAPI3REF: Translate filenames
3749**
3750** These routines are available to [VFS|custom VFS implementations] for
3751** translating filenames between the main database file, the journal file,
3752** and the WAL file.
3753**
3754** If F is the name of an sqlite database file, journal file, or WAL file
3755** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3756** returns the name of the corresponding database file.
3757**
3758** If F is the name of an sqlite database file, journal file, or WAL file
3759** passed by the SQLite core into the VFS, or if F is a database filename
3760** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3761** returns the name of the corresponding rollback journal file.
3762**
3763** If F is the name of an sqlite database file, journal file, or WAL file
3764** that was passed by the SQLite core into the VFS, or if F is a database
3765** filename obtained from [sqlite3_db_filename()], then
3766** sqlite3_filename_wal(F) returns the name of the corresponding
3767** WAL file.
3768**
3769** In all of the above, if F is not the name of a database, journal or WAL
3770** filename passed into the VFS from the SQLite core and F is not the
3771** return value from [sqlite3_db_filename()], then the result is
3772** undefined and is likely a memory access violation.
3773*/
3774SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
3775SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
3776SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
3777
3778/*
3779** CAPI3REF: Database File Corresponding To A Journal
3780**
3781** ^If X is the name of a rollback or WAL-mode journal file that is
3782** passed into the xOpen method of [sqlite3_vfs], then
3783** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3784** object that represents the main database file.
3785**
3786** This routine is intended for use in custom [VFS] implementations
3787** only. It is not a general-purpose interface.
3788** The argument sqlite3_file_object(X) must be a filename pointer that
3789** has been passed into [sqlite3_vfs].xOpen method where the
3790** flags parameter to xOpen contains one of the bits
3791** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3792** of this routine results in undefined and probably undesirable
3793** behavior.
3794*/
3795SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3796
3797/*
3798** CAPI3REF: Create and Destroy VFS Filenames
3799**
3800** These interfces are provided for use by [VFS shim] implementations and
3801** are not useful outside of that context.
3802**
3803** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3804** database filename D with corresponding journal file J and WAL file W and
3805** with N URI parameters key/values pairs in the array P. The result from
3806** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3807** is safe to pass to routines like:
3808** <ul>
3809** <li> [sqlite3_uri_parameter()],
3810** <li> [sqlite3_uri_boolean()],
3811** <li> [sqlite3_uri_int64()],
3812** <li> [sqlite3_uri_key()],
3813** <li> [sqlite3_filename_database()],
3814** <li> [sqlite3_filename_journal()], or
3815** <li> [sqlite3_filename_wal()].
3816** </ul>
3817** If a memory allocation error occurs, sqlite3_create_filename() might
3818** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3819** must be released by a corresponding call to sqlite3_free_filename(Y).
3820**
3821** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3822** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3823** to a key and value for a query parameter. The P parameter may be a NULL
3824** pointer if N is zero. None of the 2*N pointers in the P array may be
3825** NULL pointers and key pointers should not be empty strings.
3826** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3827** be NULL pointers, though they can be empty strings.
3828**
3829** The sqlite3_free_filename(Y) routine releases a memory allocation
3830** previously obtained from sqlite3_create_filename(). Invoking
3831** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3832**
3833** If the Y parameter to sqlite3_free_filename(Y) is anything other
3834** than a NULL pointer or a pointer previously acquired from
3835** sqlite3_create_filename(), then bad things such as heap
3836** corruption or segfaults may occur. The value Y should not be
3837** used again after sqlite3_free_filename(Y) has been called. This means
3838** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3839** then the corresponding [sqlite3_module.xClose() method should also be
3840** invoked prior to calling sqlite3_free_filename(Y).
3841*/
3842SQLITE_API sqlite3_filename sqlite3_create_filename(
3843 const char *zDatabase,
3844 const char *zJournal,
3845 const char *zWal,
3846 int nParam,
3847 const char **azParam
3848);
3849SQLITE_API void sqlite3_free_filename(sqlite3_filename);
3850
3851/*
3852** CAPI3REF: Error Codes And Messages
3853** METHOD: sqlite3
3854**
3855** ^If the most recent sqlite3_* API call associated with
3856** [database connection] D failed, then the sqlite3_errcode(D) interface
3857** returns the numeric [result code] or [extended result code] for that
3858** API call.
3859** ^The sqlite3_extended_errcode()
3860** interface is the same except that it always returns the
3861** [extended result code] even when extended result codes are
3862** disabled.
3863**
3864** The values returned by sqlite3_errcode() and/or
3865** sqlite3_extended_errcode() might change with each API call.
3866** Except, there are some interfaces that are guaranteed to never
3867** change the value of the error code. The error-code preserving
3868** interfaces include the following:
3869**
3870** <ul>
3871** <li> sqlite3_errcode()
3872** <li> sqlite3_extended_errcode()
3873** <li> sqlite3_errmsg()
3874** <li> sqlite3_errmsg16()
3875** <li> sqlite3_error_offset()
3876** </ul>
3877**
3878** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3879** text that describes the error, as either UTF-8 or UTF-16 respectively.
3880** ^(Memory to hold the error message string is managed internally.
3881** The application does not need to worry about freeing the result.
3882** However, the error string might be overwritten or deallocated by
3883** subsequent calls to other SQLite interface functions.)^
3884**
3885** ^The sqlite3_errstr() interface returns the English-language text
3886** that describes the [result code], as UTF-8.
3887** ^(Memory to hold the error message string is managed internally
3888** and must not be freed by the application)^.
3889**
3890** ^If the most recent error references a specific token in the input
3891** SQL, the sqlite3_error_offset() interface returns the byte offset
3892** of the start of that token. ^The byte offset returned by
3893** sqlite3_error_offset() assumes that the input SQL is UTF8.
3894** ^If the most recent error does not reference a specific token in the input
3895** SQL, then the sqlite3_error_offset() function returns -1.
3896**
3897** When the serialized [threading mode] is in use, it might be the
3898** case that a second error occurs on a separate thread in between
3899** the time of the first error and the call to these interfaces.
3900** When that happens, the second error will be reported since these
3901** interfaces always report the most recent result. To avoid
3902** this, each thread can obtain exclusive use of the [database connection] D
3903** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3904** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3905** all calls to the interfaces listed here are completed.
3906**
3907** If an interface fails with SQLITE_MISUSE, that means the interface
3908** was invoked incorrectly by the application. In that case, the
3909** error code and message may or may not be set.
3910*/
3911SQLITE_API int sqlite3_errcode(sqlite3 *db);
3912SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3913SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3914SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3915SQLITE_API const char *sqlite3_errstr(int);
3916SQLITE_API int sqlite3_error_offset(sqlite3 *db);
3917
3918/*
3919** CAPI3REF: Prepared Statement Object
3920** KEYWORDS: {prepared statement} {prepared statements}
3921**
3922** An instance of this object represents a single SQL statement that
3923** has been compiled into binary form and is ready to be evaluated.
3924**
3925** Think of each SQL statement as a separate computer program. The
3926** original SQL text is source code. A prepared statement object
3927** is the compiled object code. All SQL must be converted into a
3928** prepared statement before it can be run.
3929**
3930** The life-cycle of a prepared statement object usually goes like this:
3931**
3932** <ol>
3933** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3934** <li> Bind values to [parameters] using the sqlite3_bind_*()
3935** interfaces.
3936** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3937** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3938** to step 2. Do this zero or more times.
3939** <li> Destroy the object using [sqlite3_finalize()].
3940** </ol>
3941*/
3942typedef struct sqlite3_stmt sqlite3_stmt;
3943
3944/*
3945** CAPI3REF: Run-time Limits
3946** METHOD: sqlite3
3947**
3948** ^(This interface allows the size of various constructs to be limited
3949** on a connection by connection basis. The first parameter is the
3950** [database connection] whose limit is to be set or queried. The
3951** second parameter is one of the [limit categories] that define a
3952** class of constructs to be size limited. The third parameter is the
3953** new limit for that construct.)^
3954**
3955** ^If the new limit is a negative number, the limit is unchanged.
3956** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3957** [limits | hard upper bound]
3958** set at compile-time by a C preprocessor macro called
3959** [limits | SQLITE_MAX_<i>NAME</i>].
3960** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3961** ^Attempts to increase a limit above its hard upper bound are
3962** silently truncated to the hard upper bound.
3963**
3964** ^Regardless of whether or not the limit was changed, the
3965** [sqlite3_limit()] interface returns the prior value of the limit.
3966** ^Hence, to find the current value of a limit without changing it,
3967** simply invoke this interface with the third parameter set to -1.
3968**
3969** Run-time limits are intended for use in applications that manage
3970** both their own internal database and also databases that are controlled
3971** by untrusted external sources. An example application might be a
3972** web browser that has its own databases for storing history and
3973** separate databases controlled by JavaScript applications downloaded
3974** off the Internet. The internal databases can be given the
3975** large, default limits. Databases managed by external sources can
3976** be given much smaller limits designed to prevent a denial of service
3977** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3978** interface to further control untrusted SQL. The size of the database
3979** created by an untrusted script can be contained using the
3980** [max_page_count] [PRAGMA].
3981**
3982** New run-time limit categories may be added in future releases.
3983*/
3984SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3985
3986/*
3987** CAPI3REF: Run-Time Limit Categories
3988** KEYWORDS: {limit category} {*limit categories}
3989**
3990** These constants define various performance limits
3991** that can be lowered at run-time using [sqlite3_limit()].
3992** The synopsis of the meanings of the various limits is shown below.
3993** Additional information is available at [limits | Limits in SQLite].
3994**
3995** <dl>
3996** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3997** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3998**
3999** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4000** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4001**
4002** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4003** <dd>The maximum number of columns in a table definition or in the
4004** result set of a [SELECT] or the maximum number of columns in an index
4005** or in an ORDER BY or GROUP BY clause.</dd>)^
4006**
4007** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4008** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4009**
4010** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4011** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4012**
4013** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4014** <dd>The maximum number of instructions in a virtual machine program
4015** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4016** the equivalent tries to allocate space for more than this many opcodes
4017** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4018**
4019** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4020** <dd>The maximum number of arguments on a function.</dd>)^
4021**
4022** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4023** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4024**
4025** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4026** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4027** <dd>The maximum length of the pattern argument to the [LIKE] or
4028** [GLOB] operators.</dd>)^
4029**
4030** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4031** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4032** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4033**
4034** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4035** <dd>The maximum depth of recursion for triggers.</dd>)^
4036**
4037** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4038** <dd>The maximum number of auxiliary worker threads that a single
4039** [prepared statement] may start.</dd>)^
4040** </dl>
4041*/
4042#define SQLITE_LIMIT_LENGTH 0
4043#define SQLITE_LIMIT_SQL_LENGTH 1
4044#define SQLITE_LIMIT_COLUMN 2
4045#define SQLITE_LIMIT_EXPR_DEPTH 3
4046#define SQLITE_LIMIT_COMPOUND_SELECT 4
4047#define SQLITE_LIMIT_VDBE_OP 5
4048#define SQLITE_LIMIT_FUNCTION_ARG 6
4049#define SQLITE_LIMIT_ATTACHED 7
4050#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4051#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4052#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4053#define SQLITE_LIMIT_WORKER_THREADS 11
4054
4055/*
4056** CAPI3REF: Prepare Flags
4057**
4058** These constants define various flags that can be passed into
4059** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4060** [sqlite3_prepare16_v3()] interfaces.
4061**
4062** New flags may be added in future releases of SQLite.
4063**
4064** <dl>
4065** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4066** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4067** that the prepared statement will be retained for a long time and
4068** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4069** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4070** be used just once or at most a few times and then destroyed using
4071** [sqlite3_finalize()] relatively soon. The current implementation acts
4072** on this hint by avoiding the use of [lookaside memory] so as not to
4073** deplete the limited store of lookaside memory. Future versions of
4074** SQLite may act on this hint differently.
4075**
4076** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4077** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4078** to be required for any prepared statement that wanted to use the
4079** [sqlite3_normalized_sql()] interface. However, the
4080** [sqlite3_normalized_sql()] interface is now available to all
4081** prepared statements, regardless of whether or not they use this
4082** flag.
4083**
4084** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4085** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4086** to return an error (error code SQLITE_ERROR) if the statement uses
4087** any virtual tables.
4088** </dl>
4089*/
4090#define SQLITE_PREPARE_PERSISTENT 0x01
4091#define SQLITE_PREPARE_NORMALIZE 0x02
4092#define SQLITE_PREPARE_NO_VTAB 0x04
4093
4094/*
4095** CAPI3REF: Compiling An SQL Statement
4096** KEYWORDS: {SQL statement compiler}
4097** METHOD: sqlite3
4098** CONSTRUCTOR: sqlite3_stmt
4099**
4100** To execute an SQL statement, it must first be compiled into a byte-code
4101** program using one of these routines. Or, in other words, these routines
4102** are constructors for the [prepared statement] object.
4103**
4104** The preferred routine to use is [sqlite3_prepare_v2()]. The
4105** [sqlite3_prepare()] interface is legacy and should be avoided.
4106** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4107** for special purposes.
4108**
4109** The use of the UTF-8 interfaces is preferred, as SQLite currently
4110** does all parsing using UTF-8. The UTF-16 interfaces are provided
4111** as a convenience. The UTF-16 interfaces work by converting the
4112** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4113**
4114** The first argument, "db", is a [database connection] obtained from a
4115** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4116** [sqlite3_open16()]. The database connection must not have been closed.
4117**
4118** The second argument, "zSql", is the statement to be compiled, encoded
4119** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4120** and sqlite3_prepare_v3()
4121** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4122** and sqlite3_prepare16_v3() use UTF-16.
4123**
4124** ^If the nByte argument is negative, then zSql is read up to the
4125** first zero terminator. ^If nByte is positive, then it is the
4126** number of bytes read from zSql. ^If nByte is zero, then no prepared
4127** statement is generated.
4128** If the caller knows that the supplied string is nul-terminated, then
4129** there is a small performance advantage to passing an nByte parameter that
4130** is the number of bytes in the input string <i>including</i>
4131** the nul-terminator.
4132**
4133** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4134** past the end of the first SQL statement in zSql. These routines only
4135** compile the first statement in zSql, so *pzTail is left pointing to
4136** what remains uncompiled.
4137**
4138** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4139** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4140** to NULL. ^If the input text contains no SQL (if the input is an empty
4141** string or a comment) then *ppStmt is set to NULL.
4142** The calling procedure is responsible for deleting the compiled
4143** SQL statement using [sqlite3_finalize()] after it has finished with it.
4144** ppStmt may not be NULL.
4145**
4146** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4147** otherwise an [error code] is returned.
4148**
4149** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4150** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4151** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4152** are retained for backwards compatibility, but their use is discouraged.
4153** ^In the "vX" interfaces, the prepared statement
4154** that is returned (the [sqlite3_stmt] object) contains a copy of the
4155** original SQL text. This causes the [sqlite3_step()] interface to
4156** behave differently in three ways:
4157**
4158** <ol>
4159** <li>
4160** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4161** always used to do, [sqlite3_step()] will automatically recompile the SQL
4162** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4163** retries will occur before sqlite3_step() gives up and returns an error.
4164** </li>
4165**
4166** <li>
4167** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4168** [error codes] or [extended error codes]. ^The legacy behavior was that
4169** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4170** and the application would have to make a second call to [sqlite3_reset()]
4171** in order to find the underlying cause of the problem. With the "v2" prepare
4172** interfaces, the underlying reason for the error is returned immediately.
4173** </li>
4174**
4175** <li>
4176** ^If the specific value bound to a [parameter | host parameter] in the
4177** WHERE clause might influence the choice of query plan for a statement,
4178** then the statement will be automatically recompiled, as if there had been
4179** a schema change, on the first [sqlite3_step()] call following any change
4180** to the [sqlite3_bind_text | bindings] of that [parameter].
4181** ^The specific value of a WHERE-clause [parameter] might influence the
4182** choice of query plan if the parameter is the left-hand side of a [LIKE]
4183** or [GLOB] operator or if the parameter is compared to an indexed column
4184** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4185** </li>
4186** </ol>
4187**
4188** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4189** the extra prepFlags parameter, which is a bit array consisting of zero or
4190** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4191** sqlite3_prepare_v2() interface works exactly the same as
4192** sqlite3_prepare_v3() with a zero prepFlags parameter.
4193*/
4194SQLITE_API int sqlite3_prepare(
4195 sqlite3 *db, /* Database handle */
4196 const char *zSql, /* SQL statement, UTF-8 encoded */
4197 int nByte, /* Maximum length of zSql in bytes. */
4198 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4199 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4200);
4201SQLITE_API int sqlite3_prepare_v2(
4202 sqlite3 *db, /* Database handle */
4203 const char *zSql, /* SQL statement, UTF-8 encoded */
4204 int nByte, /* Maximum length of zSql in bytes. */
4205 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4206 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4207);
4208SQLITE_API int sqlite3_prepare_v3(
4209 sqlite3 *db, /* Database handle */
4210 const char *zSql, /* SQL statement, UTF-8 encoded */
4211 int nByte, /* Maximum length of zSql in bytes. */
4212 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4213 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4214 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4215);
4216SQLITE_API int sqlite3_prepare16(
4217 sqlite3 *db, /* Database handle */
4218 const void *zSql, /* SQL statement, UTF-16 encoded */
4219 int nByte, /* Maximum length of zSql in bytes. */
4220 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4221 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4222);
4223SQLITE_API int sqlite3_prepare16_v2(
4224 sqlite3 *db, /* Database handle */
4225 const void *zSql, /* SQL statement, UTF-16 encoded */
4226 int nByte, /* Maximum length of zSql in bytes. */
4227 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4228 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4229);
4230SQLITE_API int sqlite3_prepare16_v3(
4231 sqlite3 *db, /* Database handle */
4232 const void *zSql, /* SQL statement, UTF-16 encoded */
4233 int nByte, /* Maximum length of zSql in bytes. */
4234 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4235 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4236 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4237);
4238
4239/*
4240** CAPI3REF: Retrieving Statement SQL
4241** METHOD: sqlite3_stmt
4242**
4243** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4244** SQL text used to create [prepared statement] P if P was
4245** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4246** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4247** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4248** string containing the SQL text of prepared statement P with
4249** [bound parameters] expanded.
4250** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4251** string containing the normalized SQL text of prepared statement P. The
4252** semantics used to normalize a SQL statement are unspecified and subject
4253** to change. At a minimum, literal values will be replaced with suitable
4254** placeholders.
4255**
4256** ^(For example, if a prepared statement is created using the SQL
4257** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4258** and parameter :xyz is unbound, then sqlite3_sql() will return
4259** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4260** will return "SELECT 2345,NULL".)^
4261**
4262** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4263** is available to hold the result, or if the result would exceed the
4264** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4265**
4266** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4267** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4268** option causes sqlite3_expanded_sql() to always return NULL.
4269**
4270** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4271** are managed by SQLite and are automatically freed when the prepared
4272** statement is finalized.
4273** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4274** is obtained from [sqlite3_malloc()] and must be freed by the application
4275** by passing it to [sqlite3_free()].
4276**
4277** ^The sqlite3_normalized_sql() interface is only available if
4278** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4279*/
4280SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4281SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4282#ifdef SQLITE_ENABLE_NORMALIZE
4283SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4284#endif
4285
4286/*
4287** CAPI3REF: Determine If An SQL Statement Writes The Database
4288** METHOD: sqlite3_stmt
4289**
4290** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4291** and only if the [prepared statement] X makes no direct changes to
4292** the content of the database file.
4293**
4294** Note that [application-defined SQL functions] or
4295** [virtual tables] might change the database indirectly as a side effect.
4296** ^(For example, if an application defines a function "eval()" that
4297** calls [sqlite3_exec()], then the following SQL statement would
4298** change the database file through side-effects:
4299**
4300** <blockquote><pre>
4301** SELECT eval('DELETE FROM t1') FROM t2;
4302** </pre></blockquote>
4303**
4304** But because the [SELECT] statement does not change the database file
4305** directly, sqlite3_stmt_readonly() would still return true.)^
4306**
4307** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4308** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4309** since the statements themselves do not actually modify the database but
4310** rather they control the timing of when other statements modify the
4311** database. ^The [ATTACH] and [DETACH] statements also cause
4312** sqlite3_stmt_readonly() to return true since, while those statements
4313** change the configuration of a database connection, they do not make
4314** changes to the content of the database files on disk.
4315** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4316** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4317** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4318** sqlite3_stmt_readonly() returns false for those commands.
4319**
4320** ^This routine returns false if there is any possibility that the
4321** statement might change the database file. ^A false return does
4322** not guarantee that the statement will change the database file.
4323** ^For example, an UPDATE statement might have a WHERE clause that
4324** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4325** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4326** read-only no-op if the table already exists, but
4327** sqlite3_stmt_readonly() still returns false for such a statement.
4328**
4329** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4330** statement, then sqlite3_stmt_readonly(X) returns the same value as
4331** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4332*/
4333SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4334
4335/*
4336** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4337** METHOD: sqlite3_stmt
4338**
4339** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4340** prepared statement S is an EXPLAIN statement, or 2 if the
4341** statement S is an EXPLAIN QUERY PLAN.
4342** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4343** an ordinary statement or a NULL pointer.
4344*/
4345SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4346
4347/*
4348** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4349** METHOD: sqlite3_stmt
4350**
4351** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4352** [prepared statement] S has been stepped at least once using
4353** [sqlite3_step(S)] but has neither run to completion (returned
4354** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4355** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4356** interface returns false if S is a NULL pointer. If S is not a
4357** NULL pointer and is not a pointer to a valid [prepared statement]
4358** object, then the behavior is undefined and probably undesirable.
4359**
4360** This interface can be used in combination [sqlite3_next_stmt()]
4361** to locate all prepared statements associated with a database
4362** connection that are in need of being reset. This can be used,
4363** for example, in diagnostic routines to search for prepared
4364** statements that are holding a transaction open.
4365*/
4366SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4367
4368/*
4369** CAPI3REF: Dynamically Typed Value Object
4370** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4371**
4372** SQLite uses the sqlite3_value object to represent all values
4373** that can be stored in a database table. SQLite uses dynamic typing
4374** for the values it stores. ^Values stored in sqlite3_value objects
4375** can be integers, floating point values, strings, BLOBs, or NULL.
4376**
4377** An sqlite3_value object may be either "protected" or "unprotected".
4378** Some interfaces require a protected sqlite3_value. Other interfaces
4379** will accept either a protected or an unprotected sqlite3_value.
4380** Every interface that accepts sqlite3_value arguments specifies
4381** whether or not it requires a protected sqlite3_value. The
4382** [sqlite3_value_dup()] interface can be used to construct a new
4383** protected sqlite3_value from an unprotected sqlite3_value.
4384**
4385** The terms "protected" and "unprotected" refer to whether or not
4386** a mutex is held. An internal mutex is held for a protected
4387** sqlite3_value object but no mutex is held for an unprotected
4388** sqlite3_value object. If SQLite is compiled to be single-threaded
4389** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4390** or if SQLite is run in one of reduced mutex modes
4391** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4392** then there is no distinction between protected and unprotected
4393** sqlite3_value objects and they can be used interchangeably. However,
4394** for maximum code portability it is recommended that applications
4395** still make the distinction between protected and unprotected
4396** sqlite3_value objects even when not strictly required.
4397**
4398** ^The sqlite3_value objects that are passed as parameters into the
4399** implementation of [application-defined SQL functions] are protected.
4400** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4401** are protected.
4402** ^The sqlite3_value object returned by
4403** [sqlite3_column_value()] is unprotected.
4404** Unprotected sqlite3_value objects may only be used as arguments
4405** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4406** [sqlite3_value_dup()].
4407** The [sqlite3_value_blob | sqlite3_value_type()] family of
4408** interfaces require protected sqlite3_value objects.
4409*/
4410typedef struct sqlite3_value sqlite3_value;
4411
4412/*
4413** CAPI3REF: SQL Function Context Object
4414**
4415** The context in which an SQL function executes is stored in an
4416** sqlite3_context object. ^A pointer to an sqlite3_context object
4417** is always first parameter to [application-defined SQL functions].
4418** The application-defined SQL function implementation will pass this
4419** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4420** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4421** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4422** and/or [sqlite3_set_auxdata()].
4423*/
4424typedef struct sqlite3_context sqlite3_context;
4425
4426/*
4427** CAPI3REF: Binding Values To Prepared Statements
4428** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4429** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4430** METHOD: sqlite3_stmt
4431**
4432** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4433** literals may be replaced by a [parameter] that matches one of following
4434** templates:
4435**
4436** <ul>
4437** <li> ?
4438** <li> ?NNN
4439** <li> :VVV
4440** <li> @VVV
4441** <li> $VVV
4442** </ul>
4443**
4444** In the templates above, NNN represents an integer literal,
4445** and VVV represents an alphanumeric identifier.)^ ^The values of these
4446** parameters (also called "host parameter names" or "SQL parameters")
4447** can be set using the sqlite3_bind_*() routines defined here.
4448**
4449** ^The first argument to the sqlite3_bind_*() routines is always
4450** a pointer to the [sqlite3_stmt] object returned from
4451** [sqlite3_prepare_v2()] or its variants.
4452**
4453** ^The second argument is the index of the SQL parameter to be set.
4454** ^The leftmost SQL parameter has an index of 1. ^When the same named
4455** SQL parameter is used more than once, second and subsequent
4456** occurrences have the same index as the first occurrence.
4457** ^The index for named parameters can be looked up using the
4458** [sqlite3_bind_parameter_index()] API if desired. ^The index
4459** for "?NNN" parameters is the value of NNN.
4460** ^The NNN value must be between 1 and the [sqlite3_limit()]
4461** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4462**
4463** ^The third argument is the value to bind to the parameter.
4464** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4465** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4466** is ignored and the end result is the same as sqlite3_bind_null().
4467** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4468** it should be a pointer to well-formed UTF8 text.
4469** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4470** it should be a pointer to well-formed UTF16 text.
4471** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4472** it should be a pointer to a well-formed unicode string that is
4473** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4474** otherwise.
4475**
4476** [[byte-order determination rules]] ^The byte-order of
4477** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4478** found in first character, which is removed, or in the absence of a BOM
4479** the byte order is the native byte order of the host
4480** machine for sqlite3_bind_text16() or the byte order specified in
4481** the 6th parameter for sqlite3_bind_text64().)^
4482** ^If UTF16 input text contains invalid unicode
4483** characters, then SQLite might change those invalid characters
4484** into the unicode replacement character: U+FFFD.
4485**
4486** ^(In those routines that have a fourth argument, its value is the
4487** number of bytes in the parameter. To be clear: the value is the
4488** number of <u>bytes</u> in the value, not the number of characters.)^
4489** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4490** is negative, then the length of the string is
4491** the number of bytes up to the first zero terminator.
4492** If the fourth parameter to sqlite3_bind_blob() is negative, then
4493** the behavior is undefined.
4494** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4495** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4496** that parameter must be the byte offset
4497** where the NUL terminator would occur assuming the string were NUL
4498** terminated. If any NUL characters occurs at byte offsets less than
4499** the value of the fourth parameter then the resulting string value will
4500** contain embedded NULs. The result of expressions involving strings
4501** with embedded NULs is undefined.
4502**
4503** ^The fifth argument to the BLOB and string binding interfaces controls
4504** or indicates the lifetime of the object referenced by the third parameter.
4505** These three options exist:
4506** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4507** with it may be passed. ^It is called to dispose of the BLOB or string even
4508** if the call to the bind API fails, except the destructor is not called if
4509** the third parameter is a NULL pointer or the fourth parameter is negative.
4510** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that
4511** the application remains responsible for disposing of the object. ^In this
4512** case, the object and the provided pointer to it must remain valid until
4513** either the prepared statement is finalized or the same SQL parameter is
4514** bound to something else, whichever occurs sooner.
4515** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4516** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4517** object and pointer to it must remain valid until then. ^SQLite will then
4518** manage the lifetime of its private copy.
4519**
4520** ^The sixth argument to sqlite3_bind_text64() must be one of
4521** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4522** to specify the encoding of the text in the third parameter. If
4523** the sixth argument to sqlite3_bind_text64() is not one of the
4524** allowed values shown above, or if the text encoding is different
4525** from the encoding specified by the sixth parameter, then the behavior
4526** is undefined.
4527**
4528** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4529** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4530** (just an integer to hold its size) while it is being processed.
4531** Zeroblobs are intended to serve as placeholders for BLOBs whose
4532** content is later written using
4533** [sqlite3_blob_open | incremental BLOB I/O] routines.
4534** ^A negative value for the zeroblob results in a zero-length BLOB.
4535**
4536** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4537** [prepared statement] S to have an SQL value of NULL, but to also be
4538** associated with the pointer P of type T. ^D is either a NULL pointer or
4539** a pointer to a destructor function for P. ^SQLite will invoke the
4540** destructor D with a single argument of P when it is finished using
4541** P. The T parameter should be a static string, preferably a string
4542** literal. The sqlite3_bind_pointer() routine is part of the
4543** [pointer passing interface] added for SQLite 3.20.0.
4544**
4545** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4546** for the [prepared statement] or with a prepared statement for which
4547** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4548** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4549** routine is passed a [prepared statement] that has been finalized, the
4550** result is undefined and probably harmful.
4551**
4552** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4553** ^Unbound parameters are interpreted as NULL.
4554**
4555** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4556** [error code] if anything goes wrong.
4557** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4558** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4559** [SQLITE_MAX_LENGTH].
4560** ^[SQLITE_RANGE] is returned if the parameter
4561** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4562**
4563** See also: [sqlite3_bind_parameter_count()],
4564** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4565*/
4566SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4567SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4568 void(*)(void*));
4569SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4570SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4571SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4572SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4573SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4574SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4575SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4576 void(*)(void*), unsigned char encoding);
4577SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4578SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4579SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4580SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4581
4582/*
4583** CAPI3REF: Number Of SQL Parameters
4584** METHOD: sqlite3_stmt
4585**
4586** ^This routine can be used to find the number of [SQL parameters]
4587** in a [prepared statement]. SQL parameters are tokens of the
4588** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4589** placeholders for values that are [sqlite3_bind_blob | bound]
4590** to the parameters at a later time.
4591**
4592** ^(This routine actually returns the index of the largest (rightmost)
4593** parameter. For all forms except ?NNN, this will correspond to the
4594** number of unique parameters. If parameters of the ?NNN form are used,
4595** there may be gaps in the list.)^
4596**
4597** See also: [sqlite3_bind_blob|sqlite3_bind()],
4598** [sqlite3_bind_parameter_name()], and
4599** [sqlite3_bind_parameter_index()].
4600*/
4601SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4602
4603/*
4604** CAPI3REF: Name Of A Host Parameter
4605** METHOD: sqlite3_stmt
4606**
4607** ^The sqlite3_bind_parameter_name(P,N) interface returns
4608** the name of the N-th [SQL parameter] in the [prepared statement] P.
4609** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4610** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4611** respectively.
4612** In other words, the initial ":" or "$" or "@" or "?"
4613** is included as part of the name.)^
4614** ^Parameters of the form "?" without a following integer have no name
4615** and are referred to as "nameless" or "anonymous parameters".
4616**
4617** ^The first host parameter has an index of 1, not 0.
4618**
4619** ^If the value N is out of range or if the N-th parameter is
4620** nameless, then NULL is returned. ^The returned string is
4621** always in UTF-8 encoding even if the named parameter was
4622** originally specified as UTF-16 in [sqlite3_prepare16()],
4623** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4624**
4625** See also: [sqlite3_bind_blob|sqlite3_bind()],
4626** [sqlite3_bind_parameter_count()], and
4627** [sqlite3_bind_parameter_index()].
4628*/
4629SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4630
4631/*
4632** CAPI3REF: Index Of A Parameter With A Given Name
4633** METHOD: sqlite3_stmt
4634**
4635** ^Return the index of an SQL parameter given its name. ^The
4636** index value returned is suitable for use as the second
4637** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4638** is returned if no matching parameter is found. ^The parameter
4639** name must be given in UTF-8 even if the original statement
4640** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4641** [sqlite3_prepare16_v3()].
4642**
4643** See also: [sqlite3_bind_blob|sqlite3_bind()],
4644** [sqlite3_bind_parameter_count()], and
4645** [sqlite3_bind_parameter_name()].
4646*/
4647SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4648
4649/*
4650** CAPI3REF: Reset All Bindings On A Prepared Statement
4651** METHOD: sqlite3_stmt
4652**
4653** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4654** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4655** ^Use this routine to reset all host parameters to NULL.
4656*/
4657SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4658
4659/*
4660** CAPI3REF: Number Of Columns In A Result Set
4661** METHOD: sqlite3_stmt
4662**
4663** ^Return the number of columns in the result set returned by the
4664** [prepared statement]. ^If this routine returns 0, that means the
4665** [prepared statement] returns no data (for example an [UPDATE]).
4666** ^However, just because this routine returns a positive number does not
4667** mean that one or more rows of data will be returned. ^A SELECT statement
4668** will always have a positive sqlite3_column_count() but depending on the
4669** WHERE clause constraints and the table content, it might return no rows.
4670**
4671** See also: [sqlite3_data_count()]
4672*/
4673SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4674
4675/*
4676** CAPI3REF: Column Names In A Result Set
4677** METHOD: sqlite3_stmt
4678**
4679** ^These routines return the name assigned to a particular column
4680** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4681** interface returns a pointer to a zero-terminated UTF-8 string
4682** and sqlite3_column_name16() returns a pointer to a zero-terminated
4683** UTF-16 string. ^The first parameter is the [prepared statement]
4684** that implements the [SELECT] statement. ^The second parameter is the
4685** column number. ^The leftmost column is number 0.
4686**
4687** ^The returned string pointer is valid until either the [prepared statement]
4688** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4689** reprepared by the first call to [sqlite3_step()] for a particular run
4690** or until the next call to
4691** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4692**
4693** ^If sqlite3_malloc() fails during the processing of either routine
4694** (for example during a conversion from UTF-8 to UTF-16) then a
4695** NULL pointer is returned.
4696**
4697** ^The name of a result column is the value of the "AS" clause for
4698** that column, if there is an AS clause. If there is no AS clause
4699** then the name of the column is unspecified and may change from
4700** one release of SQLite to the next.
4701*/
4702SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4703SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4704
4705/*
4706** CAPI3REF: Source Of Data In A Query Result
4707** METHOD: sqlite3_stmt
4708**
4709** ^These routines provide a means to determine the database, table, and
4710** table column that is the origin of a particular result column in
4711** [SELECT] statement.
4712** ^The name of the database or table or column can be returned as
4713** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4714** the database name, the _table_ routines return the table name, and
4715** the origin_ routines return the column name.
4716** ^The returned string is valid until the [prepared statement] is destroyed
4717** using [sqlite3_finalize()] or until the statement is automatically
4718** reprepared by the first call to [sqlite3_step()] for a particular run
4719** or until the same information is requested
4720** again in a different encoding.
4721**
4722** ^The names returned are the original un-aliased names of the
4723** database, table, and column.
4724**
4725** ^The first argument to these interfaces is a [prepared statement].
4726** ^These functions return information about the Nth result column returned by
4727** the statement, where N is the second function argument.
4728** ^The left-most column is column 0 for these routines.
4729**
4730** ^If the Nth column returned by the statement is an expression or
4731** subquery and is not a column value, then all of these functions return
4732** NULL. ^These routines might also return NULL if a memory allocation error
4733** occurs. ^Otherwise, they return the name of the attached database, table,
4734** or column that query result column was extracted from.
4735**
4736** ^As with all other SQLite APIs, those whose names end with "16" return
4737** UTF-16 encoded strings and the other functions return UTF-8.
4738**
4739** ^These APIs are only available if the library was compiled with the
4740** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4741**
4742** If two or more threads call one or more
4743** [sqlite3_column_database_name | column metadata interfaces]
4744** for the same [prepared statement] and result column
4745** at the same time then the results are undefined.
4746*/
4747SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4748SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4749SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4750SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4751SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4752SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4753
4754/*
4755** CAPI3REF: Declared Datatype Of A Query Result
4756** METHOD: sqlite3_stmt
4757**
4758** ^(The first parameter is a [prepared statement].
4759** If this statement is a [SELECT] statement and the Nth column of the
4760** returned result set of that [SELECT] is a table column (not an
4761** expression or subquery) then the declared type of the table
4762** column is returned.)^ ^If the Nth column of the result set is an
4763** expression or subquery, then a NULL pointer is returned.
4764** ^The returned string is always UTF-8 encoded.
4765**
4766** ^(For example, given the database schema:
4767**
4768** CREATE TABLE t1(c1 VARIANT);
4769**
4770** and the following statement to be compiled:
4771**
4772** SELECT c1 + 1, c1 FROM t1;
4773**
4774** this routine would return the string "VARIANT" for the second result
4775** column (i==1), and a NULL pointer for the first result column (i==0).)^
4776**
4777** ^SQLite uses dynamic run-time typing. ^So just because a column
4778** is declared to contain a particular type does not mean that the
4779** data stored in that column is of the declared type. SQLite is
4780** strongly typed, but the typing is dynamic not static. ^Type
4781** is associated with individual values, not with the containers
4782** used to hold those values.
4783*/
4784SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4785SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4786
4787/*
4788** CAPI3REF: Evaluate An SQL Statement
4789** METHOD: sqlite3_stmt
4790**
4791** After a [prepared statement] has been prepared using any of
4792** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4793** or [sqlite3_prepare16_v3()] or one of the legacy
4794** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4795** must be called one or more times to evaluate the statement.
4796**
4797** The details of the behavior of the sqlite3_step() interface depend
4798** on whether the statement was prepared using the newer "vX" interfaces
4799** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4800** [sqlite3_prepare16_v2()] or the older legacy
4801** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4802** new "vX" interface is recommended for new applications but the legacy
4803** interface will continue to be supported.
4804**
4805** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4806** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4807** ^With the "v2" interface, any of the other [result codes] or
4808** [extended result codes] might be returned as well.
4809**
4810** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4811** database locks it needs to do its job. ^If the statement is a [COMMIT]
4812** or occurs outside of an explicit transaction, then you can retry the
4813** statement. If the statement is not a [COMMIT] and occurs within an
4814** explicit transaction then you should rollback the transaction before
4815** continuing.
4816**
4817** ^[SQLITE_DONE] means that the statement has finished executing
4818** successfully. sqlite3_step() should not be called again on this virtual
4819** machine without first calling [sqlite3_reset()] to reset the virtual
4820** machine back to its initial state.
4821**
4822** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4823** is returned each time a new row of data is ready for processing by the
4824** caller. The values may be accessed using the [column access functions].
4825** sqlite3_step() is called again to retrieve the next row of data.
4826**
4827** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4828** violation) has occurred. sqlite3_step() should not be called again on
4829** the VM. More information may be found by calling [sqlite3_errmsg()].
4830** ^With the legacy interface, a more specific error code (for example,
4831** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4832** can be obtained by calling [sqlite3_reset()] on the
4833** [prepared statement]. ^In the "v2" interface,
4834** the more specific error code is returned directly by sqlite3_step().
4835**
4836** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4837** Perhaps it was called on a [prepared statement] that has
4838** already been [sqlite3_finalize | finalized] or on one that had
4839** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4840** be the case that the same database connection is being used by two or
4841** more threads at the same moment in time.
4842**
4843** For all versions of SQLite up to and including 3.6.23.1, a call to
4844** [sqlite3_reset()] was required after sqlite3_step() returned anything
4845** other than [SQLITE_ROW] before any subsequent invocation of
4846** sqlite3_step(). Failure to reset the prepared statement using
4847** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4848** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4849** sqlite3_step() began
4850** calling [sqlite3_reset()] automatically in this circumstance rather
4851** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4852** break because any application that ever receives an SQLITE_MISUSE error
4853** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4854** can be used to restore the legacy behavior.
4855**
4856** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4857** API always returns a generic error code, [SQLITE_ERROR], following any
4858** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4859** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4860** specific [error codes] that better describes the error.
4861** We admit that this is a goofy design. The problem has been fixed
4862** with the "v2" interface. If you prepare all of your SQL statements
4863** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4864** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4865** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4866** then the more specific [error codes] are returned directly
4867** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4868*/
4869SQLITE_API int sqlite3_step(sqlite3_stmt*);
4870
4871/*
4872** CAPI3REF: Number of columns in a result set
4873** METHOD: sqlite3_stmt
4874**
4875** ^The sqlite3_data_count(P) interface returns the number of columns in the
4876** current row of the result set of [prepared statement] P.
4877** ^If prepared statement P does not have results ready to return
4878** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4879** interfaces) then sqlite3_data_count(P) returns 0.
4880** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4881** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4882** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4883** will return non-zero if previous call to [sqlite3_step](P) returned
4884** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4885** where it always returns zero since each step of that multi-step
4886** pragma returns 0 columns of data.
4887**
4888** See also: [sqlite3_column_count()]
4889*/
4890SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4891
4892/*
4893** CAPI3REF: Fundamental Datatypes
4894** KEYWORDS: SQLITE_TEXT
4895**
4896** ^(Every value in SQLite has one of five fundamental datatypes:
4897**
4898** <ul>
4899** <li> 64-bit signed integer
4900** <li> 64-bit IEEE floating point number
4901** <li> string
4902** <li> BLOB
4903** <li> NULL
4904** </ul>)^
4905**
4906** These constants are codes for each of those types.
4907**
4908** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4909** for a completely different meaning. Software that links against both
4910** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4911** SQLITE_TEXT.
4912*/
4913#define SQLITE_INTEGER 1
4914#define SQLITE_FLOAT 2
4915#define SQLITE_BLOB 4
4916#define SQLITE_NULL 5
4917#ifdef SQLITE_TEXT
4918# undef SQLITE_TEXT
4919#else
4920# define SQLITE_TEXT 3
4921#endif
4922#define SQLITE3_TEXT 3
4923
4924/*
4925** CAPI3REF: Result Values From A Query
4926** KEYWORDS: {column access functions}
4927** METHOD: sqlite3_stmt
4928**
4929** <b>Summary:</b>
4930** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4931** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4932** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4933** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4934** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4935** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4936** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4937** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4938** [sqlite3_value|unprotected sqlite3_value] object.
4939** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4940** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4941** or a UTF-8 TEXT result in bytes
4942** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4943** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4944** TEXT in bytes
4945** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4946** datatype of the result
4947** </table></blockquote>
4948**
4949** <b>Details:</b>
4950**
4951** ^These routines return information about a single column of the current
4952** result row of a query. ^In every case the first argument is a pointer
4953** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4954** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4955** and the second argument is the index of the column for which information
4956** should be returned. ^The leftmost column of the result set has the index 0.
4957** ^The number of columns in the result can be determined using
4958** [sqlite3_column_count()].
4959**
4960** If the SQL statement does not currently point to a valid row, or if the
4961** column index is out of range, the result is undefined.
4962** These routines may only be called when the most recent call to
4963** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4964** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4965** If any of these routines are called after [sqlite3_reset()] or
4966** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4967** something other than [SQLITE_ROW], the results are undefined.
4968** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4969** are called from a different thread while any of these routines
4970** are pending, then the results are undefined.
4971**
4972** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4973** each return the value of a result column in a specific data format. If
4974** the result column is not initially in the requested format (for example,
4975** if the query returns an integer but the sqlite3_column_text() interface
4976** is used to extract the value) then an automatic type conversion is performed.
4977**
4978** ^The sqlite3_column_type() routine returns the
4979** [SQLITE_INTEGER | datatype code] for the initial data type
4980** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4981** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4982** The return value of sqlite3_column_type() can be used to decide which
4983** of the first six interface should be used to extract the column value.
4984** The value returned by sqlite3_column_type() is only meaningful if no
4985** automatic type conversions have occurred for the value in question.
4986** After a type conversion, the result of calling sqlite3_column_type()
4987** is undefined, though harmless. Future
4988** versions of SQLite may change the behavior of sqlite3_column_type()
4989** following a type conversion.
4990**
4991** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4992** or sqlite3_column_bytes16() interfaces can be used to determine the size
4993** of that BLOB or string.
4994**
4995** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4996** routine returns the number of bytes in that BLOB or string.
4997** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4998** the string to UTF-8 and then returns the number of bytes.
4999** ^If the result is a numeric value then sqlite3_column_bytes() uses
5000** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5001** the number of bytes in that string.
5002** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5003**
5004** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5005** routine returns the number of bytes in that BLOB or string.
5006** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5007** the string to UTF-16 and then returns the number of bytes.
5008** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5009** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5010** the number of bytes in that string.
5011** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5012**
5013** ^The values returned by [sqlite3_column_bytes()] and
5014** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5015** of the string. ^For clarity: the values returned by
5016** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5017** bytes in the string, not the number of characters.
5018**
5019** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5020** even empty strings, are always zero-terminated. ^The return
5021** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5022**
5023** ^Strings returned by sqlite3_column_text16() always have the endianness
5024** which is native to the platform, regardless of the text encoding set
5025** for the database.
5026**
5027** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5028** [unprotected sqlite3_value] object. In a multithreaded environment,
5029** an unprotected sqlite3_value object may only be used safely with
5030** [sqlite3_bind_value()] and [sqlite3_result_value()].
5031** If the [unprotected sqlite3_value] object returned by
5032** [sqlite3_column_value()] is used in any other way, including calls
5033** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5034** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5035** Hence, the sqlite3_column_value() interface
5036** is normally only useful within the implementation of
5037** [application-defined SQL functions] or [virtual tables], not within
5038** top-level application code.
5039**
5040** These routines may attempt to convert the datatype of the result.
5041** ^For example, if the internal representation is FLOAT and a text result
5042** is requested, [sqlite3_snprintf()] is used internally to perform the
5043** conversion automatically. ^(The following table details the conversions
5044** that are applied:
5045**
5046** <blockquote>
5047** <table border="1">
5048** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5049**
5050** <tr><td> NULL <td> INTEGER <td> Result is 0
5051** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5052** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5053** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5054** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5055** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5056** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5057** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5058** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5059** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5060** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5061** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5062** <tr><td> TEXT <td> BLOB <td> No change
5063** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5064** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5065** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5066** </table>
5067** </blockquote>)^
5068**
5069** Note that when type conversions occur, pointers returned by prior
5070** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5071** sqlite3_column_text16() may be invalidated.
5072** Type conversions and pointer invalidations might occur
5073** in the following cases:
5074**
5075** <ul>
5076** <li> The initial content is a BLOB and sqlite3_column_text() or
5077** sqlite3_column_text16() is called. A zero-terminator might
5078** need to be added to the string.</li>
5079** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5080** sqlite3_column_text16() is called. The content must be converted
5081** to UTF-16.</li>
5082** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5083** sqlite3_column_text() is called. The content must be converted
5084** to UTF-8.</li>
5085** </ul>
5086**
5087** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5088** not invalidate a prior pointer, though of course the content of the buffer
5089** that the prior pointer references will have been modified. Other kinds
5090** of conversion are done in place when it is possible, but sometimes they
5091** are not possible and in those cases prior pointers are invalidated.
5092**
5093** The safest policy is to invoke these routines
5094** in one of the following ways:
5095**
5096** <ul>
5097** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5098** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5099** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5100** </ul>
5101**
5102** In other words, you should call sqlite3_column_text(),
5103** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5104** into the desired format, then invoke sqlite3_column_bytes() or
5105** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5106** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5107** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5108** with calls to sqlite3_column_bytes().
5109**
5110** ^The pointers returned are valid until a type conversion occurs as
5111** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5112** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5113** and BLOBs is freed automatically. Do not pass the pointers returned
5114** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5115** [sqlite3_free()].
5116**
5117** As long as the input parameters are correct, these routines will only
5118** fail if an out-of-memory error occurs during a format conversion.
5119** Only the following subset of interfaces are subject to out-of-memory
5120** errors:
5121**
5122** <ul>
5123** <li> sqlite3_column_blob()
5124** <li> sqlite3_column_text()
5125** <li> sqlite3_column_text16()
5126** <li> sqlite3_column_bytes()
5127** <li> sqlite3_column_bytes16()
5128** </ul>
5129**
5130** If an out-of-memory error occurs, then the return value from these
5131** routines is the same as if the column had contained an SQL NULL value.
5132** Valid SQL NULL returns can be distinguished from out-of-memory errors
5133** by invoking the [sqlite3_errcode()] immediately after the suspect
5134** return value is obtained and before any
5135** other SQLite interface is called on the same [database connection].
5136*/
5137SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5138SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5139SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5140SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5141SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5142SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5143SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5144SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5145SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5146SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5147
5148/*
5149** CAPI3REF: Destroy A Prepared Statement Object
5150** DESTRUCTOR: sqlite3_stmt
5151**
5152** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5153** ^If the most recent evaluation of the statement encountered no errors
5154** or if the statement is never been evaluated, then sqlite3_finalize() returns
5155** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5156** sqlite3_finalize(S) returns the appropriate [error code] or
5157** [extended error code].
5158**
5159** ^The sqlite3_finalize(S) routine can be called at any point during
5160** the life cycle of [prepared statement] S:
5161** before statement S is ever evaluated, after
5162** one or more calls to [sqlite3_reset()], or after any call
5163** to [sqlite3_step()] regardless of whether or not the statement has
5164** completed execution.
5165**
5166** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5167**
5168** The application must finalize every [prepared statement] in order to avoid
5169** resource leaks. It is a grievous error for the application to try to use
5170** a prepared statement after it has been finalized. Any use of a prepared
5171** statement after it has been finalized can result in undefined and
5172** undesirable behavior such as segfaults and heap corruption.
5173*/
5174SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5175
5176/*
5177** CAPI3REF: Reset A Prepared Statement Object
5178** METHOD: sqlite3_stmt
5179**
5180** The sqlite3_reset() function is called to reset a [prepared statement]
5181** object back to its initial state, ready to be re-executed.
5182** ^Any SQL statement variables that had values bound to them using
5183** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5184** Use [sqlite3_clear_bindings()] to reset the bindings.
5185**
5186** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5187** back to the beginning of its program.
5188**
5189** ^If the most recent call to [sqlite3_step(S)] for the
5190** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5191** or if [sqlite3_step(S)] has never before been called on S,
5192** then [sqlite3_reset(S)] returns [SQLITE_OK].
5193**
5194** ^If the most recent call to [sqlite3_step(S)] for the
5195** [prepared statement] S indicated an error, then
5196** [sqlite3_reset(S)] returns an appropriate [error code].
5197**
5198** ^The [sqlite3_reset(S)] interface does not change the values
5199** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5200*/
5201SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5202
5203/*
5204** CAPI3REF: Create Or Redefine SQL Functions
5205** KEYWORDS: {function creation routines}
5206** METHOD: sqlite3
5207**
5208** ^These functions (collectively known as "function creation routines")
5209** are used to add SQL functions or aggregates or to redefine the behavior
5210** of existing SQL functions or aggregates. The only differences between
5211** the three "sqlite3_create_function*" routines are the text encoding
5212** expected for the second parameter (the name of the function being
5213** created) and the presence or absence of a destructor callback for
5214** the application data pointer. Function sqlite3_create_window_function()
5215** is similar, but allows the user to supply the extra callback functions
5216** needed by [aggregate window functions].
5217**
5218** ^The first parameter is the [database connection] to which the SQL
5219** function is to be added. ^If an application uses more than one database
5220** connection then application-defined SQL functions must be added
5221** to each database connection separately.
5222**
5223** ^The second parameter is the name of the SQL function to be created or
5224** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5225** representation, exclusive of the zero-terminator. ^Note that the name
5226** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5227** ^Any attempt to create a function with a longer name
5228** will result in [SQLITE_MISUSE] being returned.
5229**
5230** ^The third parameter (nArg)
5231** is the number of arguments that the SQL function or
5232** aggregate takes. ^If this parameter is -1, then the SQL function or
5233** aggregate may take any number of arguments between 0 and the limit
5234** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5235** parameter is less than -1 or greater than 127 then the behavior is
5236** undefined.
5237**
5238** ^The fourth parameter, eTextRep, specifies what
5239** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5240** its parameters. The application should set this parameter to
5241** [SQLITE_UTF16LE] if the function implementation invokes
5242** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5243** implementation invokes [sqlite3_value_text16be()] on an input, or
5244** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5245** otherwise. ^The same SQL function may be registered multiple times using
5246** different preferred text encodings, with different implementations for
5247** each encoding.
5248** ^When multiple implementations of the same function are available, SQLite
5249** will pick the one that involves the least amount of data conversion.
5250**
5251** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5252** to signal that the function will always return the same result given
5253** the same inputs within a single SQL statement. Most SQL functions are
5254** deterministic. The built-in [random()] SQL function is an example of a
5255** function that is not deterministic. The SQLite query planner is able to
5256** perform additional optimizations on deterministic functions, so use
5257** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5258**
5259** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5260** flag, which if present prevents the function from being invoked from
5261** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5262** index expressions, or the WHERE clause of partial indexes.
5263**
5264** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5265** all application-defined SQL functions that do not need to be
5266** used inside of triggers, view, CHECK constraints, or other elements of
5267** the database schema. This flags is especially recommended for SQL
5268** functions that have side effects or reveal internal application state.
5269** Without this flag, an attacker might be able to modify the schema of
5270** a database file to include invocations of the function with parameters
5271** chosen by the attacker, which the application will then execute when
5272** the database file is opened and read.
5273**
5274** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5275** function can gain access to this pointer using [sqlite3_user_data()].)^
5276**
5277** ^The sixth, seventh and eighth parameters passed to the three
5278** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5279** pointers to C-language functions that implement the SQL function or
5280** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5281** callback only; NULL pointers must be passed as the xStep and xFinal
5282** parameters. ^An aggregate SQL function requires an implementation of xStep
5283** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5284** SQL function or aggregate, pass NULL pointers for all three function
5285** callbacks.
5286**
5287** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5288** and xInverse) passed to sqlite3_create_window_function are pointers to
5289** C-language callbacks that implement the new function. xStep and xFinal
5290** must both be non-NULL. xValue and xInverse may either both be NULL, in
5291** which case a regular aggregate function is created, or must both be
5292** non-NULL, in which case the new function may be used as either an aggregate
5293** or aggregate window function. More details regarding the implementation
5294** of aggregate window functions are
5295** [user-defined window functions|available here].
5296**
5297** ^(If the final parameter to sqlite3_create_function_v2() or
5298** sqlite3_create_window_function() is not NULL, then it is destructor for
5299** the application data pointer. The destructor is invoked when the function
5300** is deleted, either by being overloaded or when the database connection
5301** closes.)^ ^The destructor is also invoked if the call to
5302** sqlite3_create_function_v2() fails. ^When the destructor callback is
5303** invoked, it is passed a single argument which is a copy of the application
5304** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5305**
5306** ^It is permitted to register multiple implementations of the same
5307** functions with the same name but with either differing numbers of
5308** arguments or differing preferred text encodings. ^SQLite will use
5309** the implementation that most closely matches the way in which the
5310** SQL function is used. ^A function implementation with a non-negative
5311** nArg parameter is a better match than a function implementation with
5312** a negative nArg. ^A function where the preferred text encoding
5313** matches the database encoding is a better
5314** match than a function where the encoding is different.
5315** ^A function where the encoding difference is between UTF16le and UTF16be
5316** is a closer match than a function where the encoding difference is
5317** between UTF8 and UTF16.
5318**
5319** ^Built-in functions may be overloaded by new application-defined functions.
5320**
5321** ^An application-defined function is permitted to call other
5322** SQLite interfaces. However, such calls must not
5323** close the database connection nor finalize or reset the prepared
5324** statement in which the function is running.
5325*/
5326SQLITE_API int sqlite3_create_function(
5327 sqlite3 *db,
5328 const char *zFunctionName,
5329 int nArg,
5330 int eTextRep,
5331 void *pApp,
5332 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5333 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5334 void (*xFinal)(sqlite3_context*)
5335);
5336SQLITE_API int sqlite3_create_function16(
5337 sqlite3 *db,
5338 const void *zFunctionName,
5339 int nArg,
5340 int eTextRep,
5341 void *pApp,
5342 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5343 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5344 void (*xFinal)(sqlite3_context*)
5345);
5346SQLITE_API int sqlite3_create_function_v2(
5347 sqlite3 *db,
5348 const char *zFunctionName,
5349 int nArg,
5350 int eTextRep,
5351 void *pApp,
5352 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5353 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5354 void (*xFinal)(sqlite3_context*),
5355 void(*xDestroy)(void*)
5356);
5357SQLITE_API int sqlite3_create_window_function(
5358 sqlite3 *db,
5359 const char *zFunctionName,
5360 int nArg,
5361 int eTextRep,
5362 void *pApp,
5363 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5364 void (*xFinal)(sqlite3_context*),
5365 void (*xValue)(sqlite3_context*),
5366 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5367 void(*xDestroy)(void*)
5368);
5369
5370/*
5371** CAPI3REF: Text Encodings
5372**
5373** These constant define integer codes that represent the various
5374** text encodings supported by SQLite.
5375*/
5376#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5377#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5378#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5379#define SQLITE_UTF16 4 /* Use native byte order */
5380#define SQLITE_ANY 5 /* Deprecated */
5381#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5382
5383/*
5384** CAPI3REF: Function Flags
5385**
5386** These constants may be ORed together with the
5387** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5388** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5389** [sqlite3_create_function_v2()].
5390**
5391** <dl>
5392** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5393** The SQLITE_DETERMINISTIC flag means that the new function always gives
5394** the same output when the input parameters are the same.
5395** The [abs|abs() function] is deterministic, for example, but
5396** [randomblob|randomblob()] is not. Functions must
5397** be deterministic in order to be used in certain contexts such as
5398** with the WHERE clause of [partial indexes] or in [generated columns].
5399** SQLite might also optimize deterministic functions by factoring them
5400** out of inner loops.
5401** </dd>
5402**
5403** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5404** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5405** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5406** schema structures such as [CHECK constraints], [DEFAULT clauses],
5407** [expression indexes], [partial indexes], or [generated columns].
5408** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5409** for all [application-defined SQL functions], and especially for functions
5410** that have side-effects or that could potentially leak sensitive
5411** information.
5412** </dd>
5413**
5414** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5415** The SQLITE_INNOCUOUS flag means that the function is unlikely
5416** to cause problems even if misused. An innocuous function should have
5417** no side effects and should not depend on any values other than its
5418** input parameters. The [abs|abs() function] is an example of an
5419** innocuous function.
5420** The [load_extension() SQL function] is not innocuous because of its
5421** side effects.
5422** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5423** exactly the same. The [random|random() function] is an example of a
5424** function that is innocuous but not deterministic.
5425** <p>Some heightened security settings
5426** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5427** disable the use of SQL functions inside views and triggers and in
5428** schema structures such as [CHECK constraints], [DEFAULT clauses],
5429** [expression indexes], [partial indexes], and [generated columns] unless
5430** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5431** are innocuous. Developers are advised to avoid using the
5432** SQLITE_INNOCUOUS flag for application-defined functions unless the
5433** function has been carefully audited and found to be free of potentially
5434** security-adverse side-effects and information-leaks.
5435** </dd>
5436**
5437** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5438** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5439** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5440** Specifying this flag makes no difference for scalar or aggregate user
5441** functions. However, if it is not specified for a user-defined window
5442** function, then any sub-types belonging to arguments passed to the window
5443** function may be discarded before the window function is called (i.e.
5444** sqlite3_value_subtype() will always return 0).
5445** </dd>
5446** </dl>
5447*/
5448#define SQLITE_DETERMINISTIC 0x000000800
5449#define SQLITE_DIRECTONLY 0x000080000
5450#define SQLITE_SUBTYPE 0x000100000
5451#define SQLITE_INNOCUOUS 0x000200000
5452
5453/*
5454** CAPI3REF: Deprecated Functions
5455** DEPRECATED
5456**
5457** These functions are [deprecated]. In order to maintain
5458** backwards compatibility with older code, these functions continue
5459** to be supported. However, new applications should avoid
5460** the use of these functions. To encourage programmers to avoid
5461** these functions, we will not explain what they do.
5462*/
5463#ifndef SQLITE_OMIT_DEPRECATED
5464SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5465SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5466SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5467SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5468SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5469SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5470 void*,sqlite3_int64);
5471#endif
5472
5473/*
5474** CAPI3REF: Obtaining SQL Values
5475** METHOD: sqlite3_value
5476**
5477** <b>Summary:</b>
5478** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5479** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5480** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5481** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5482** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5483** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5484** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5485** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5486** the native byteorder
5487** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5488** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5489** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5490** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5491** or a UTF-8 TEXT in bytes
5492** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5493** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5494** TEXT in bytes
5495** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5496** datatype of the value
5497** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5498** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5499** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5500** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5501** against a virtual table.
5502** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5503** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5504** </table></blockquote>
5505**
5506** <b>Details:</b>
5507**
5508** These routines extract type, size, and content information from
5509** [protected sqlite3_value] objects. Protected sqlite3_value objects
5510** are used to pass parameter information into the functions that
5511** implement [application-defined SQL functions] and [virtual tables].
5512**
5513** These routines work only with [protected sqlite3_value] objects.
5514** Any attempt to use these routines on an [unprotected sqlite3_value]
5515** is not threadsafe.
5516**
5517** ^These routines work just like the corresponding [column access functions]
5518** except that these routines take a single [protected sqlite3_value] object
5519** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5520**
5521** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5522** in the native byte-order of the host machine. ^The
5523** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5524** extract UTF-16 strings as big-endian and little-endian respectively.
5525**
5526** ^If [sqlite3_value] object V was initialized
5527** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5528** and if X and Y are strings that compare equal according to strcmp(X,Y),
5529** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5530** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5531** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5532**
5533** ^(The sqlite3_value_type(V) interface returns the
5534** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5535** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5536** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5537** Other interfaces might change the datatype for an sqlite3_value object.
5538** For example, if the datatype is initially SQLITE_INTEGER and
5539** sqlite3_value_text(V) is called to extract a text value for that
5540** integer, then subsequent calls to sqlite3_value_type(V) might return
5541** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5542** occurs is undefined and may change from one release of SQLite to the next.
5543**
5544** ^(The sqlite3_value_numeric_type() interface attempts to apply
5545** numeric affinity to the value. This means that an attempt is
5546** made to convert the value to an integer or floating point. If
5547** such a conversion is possible without loss of information (in other
5548** words, if the value is a string that looks like a number)
5549** then the conversion is performed. Otherwise no conversion occurs.
5550** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5551**
5552** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
5553** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current encoding
5554** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
5555** returns something other than SQLITE_TEXT, then the return value from
5556** sqlite3_value_encoding(X) is meaningless. ^Calls to
5557** sqlite3_value_text(X), sqlite3_value_text16(X), sqlite3_value_text16be(X),
5558** sqlite3_value_text16le(X), sqlite3_value_bytes(X), or
5559** sqlite3_value_bytes16(X) might change the encoding of the value X and
5560** thus change the return from subsequent calls to sqlite3_value_encoding(X).
5561**
5562** ^Within the [xUpdate] method of a [virtual table], the
5563** sqlite3_value_nochange(X) interface returns true if and only if
5564** the column corresponding to X is unchanged by the UPDATE operation
5565** that the xUpdate method call was invoked to implement and if
5566** and the prior [xColumn] method call that was invoked to extracted
5567** the value for that column returned without setting a result (probably
5568** because it queried [sqlite3_vtab_nochange()] and found that the column
5569** was unchanging). ^Within an [xUpdate] method, any value for which
5570** sqlite3_value_nochange(X) is true will in all other respects appear
5571** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5572** than within an [xUpdate] method call for an UPDATE statement, then
5573** the return value is arbitrary and meaningless.
5574**
5575** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5576** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5577** interfaces. ^If X comes from an SQL literal value, or a table column,
5578** or an expression, then sqlite3_value_frombind(X) returns zero.
5579**
5580** Please pay particular attention to the fact that the pointer returned
5581** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5582** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5583** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5584** or [sqlite3_value_text16()].
5585**
5586** These routines must be called from the same thread as
5587** the SQL function that supplied the [sqlite3_value*] parameters.
5588**
5589** As long as the input parameter is correct, these routines can only
5590** fail if an out-of-memory error occurs during a format conversion.
5591** Only the following subset of interfaces are subject to out-of-memory
5592** errors:
5593**
5594** <ul>
5595** <li> sqlite3_value_blob()
5596** <li> sqlite3_value_text()
5597** <li> sqlite3_value_text16()
5598** <li> sqlite3_value_text16le()
5599** <li> sqlite3_value_text16be()
5600** <li> sqlite3_value_bytes()
5601** <li> sqlite3_value_bytes16()
5602** </ul>
5603**
5604** If an out-of-memory error occurs, then the return value from these
5605** routines is the same as if the column had contained an SQL NULL value.
5606** Valid SQL NULL returns can be distinguished from out-of-memory errors
5607** by invoking the [sqlite3_errcode()] immediately after the suspect
5608** return value is obtained and before any
5609** other SQLite interface is called on the same [database connection].
5610*/
5611SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5612SQLITE_API double sqlite3_value_double(sqlite3_value*);
5613SQLITE_API int sqlite3_value_int(sqlite3_value*);
5614SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5615SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5616SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5617SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5618SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5619SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5620SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5621SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5622SQLITE_API int sqlite3_value_type(sqlite3_value*);
5623SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5624SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5625SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5626SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
5627
5628/*
5629** CAPI3REF: Finding The Subtype Of SQL Values
5630** METHOD: sqlite3_value
5631**
5632** The sqlite3_value_subtype(V) function returns the subtype for
5633** an [application-defined SQL function] argument V. The subtype
5634** information can be used to pass a limited amount of context from
5635** one SQL function to another. Use the [sqlite3_result_subtype()]
5636** routine to set the subtype for the return value of an SQL function.
5637*/
5638SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5639
5640/*
5641** CAPI3REF: Copy And Free SQL Values
5642** METHOD: sqlite3_value
5643**
5644** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5645** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5646** is a [protected sqlite3_value] object even if the input is not.
5647** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5648** memory allocation fails. ^If V is a [pointer value], then the result
5649** of sqlite3_value_dup(V) is a NULL value.
5650**
5651** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5652** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5653** then sqlite3_value_free(V) is a harmless no-op.
5654*/
5655SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5656SQLITE_API void sqlite3_value_free(sqlite3_value*);
5657
5658/*
5659** CAPI3REF: Obtain Aggregate Function Context
5660** METHOD: sqlite3_context
5661**
5662** Implementations of aggregate SQL functions use this
5663** routine to allocate memory for storing their state.
5664**
5665** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5666** for a particular aggregate function, SQLite allocates
5667** N bytes of memory, zeroes out that memory, and returns a pointer
5668** to the new memory. ^On second and subsequent calls to
5669** sqlite3_aggregate_context() for the same aggregate function instance,
5670** the same buffer is returned. Sqlite3_aggregate_context() is normally
5671** called once for each invocation of the xStep callback and then one
5672** last time when the xFinal callback is invoked. ^(When no rows match
5673** an aggregate query, the xStep() callback of the aggregate function
5674** implementation is never called and xFinal() is called exactly once.
5675** In those cases, sqlite3_aggregate_context() might be called for the
5676** first time from within xFinal().)^
5677**
5678** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5679** when first called if N is less than or equal to zero or if a memory
5680** allocation error occurs.
5681**
5682** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5683** determined by the N parameter on first successful call. Changing the
5684** value of N in any subsequent call to sqlite3_aggregate_context() within
5685** the same aggregate function instance will not resize the memory
5686** allocation.)^ Within the xFinal callback, it is customary to set
5687** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5688** pointless memory allocations occur.
5689**
5690** ^SQLite automatically frees the memory allocated by
5691** sqlite3_aggregate_context() when the aggregate query concludes.
5692**
5693** The first parameter must be a copy of the
5694** [sqlite3_context | SQL function context] that is the first parameter
5695** to the xStep or xFinal callback routine that implements the aggregate
5696** function.
5697**
5698** This routine must be called from the same thread in which
5699** the aggregate SQL function is running.
5700*/
5701SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5702
5703/*
5704** CAPI3REF: User Data For Functions
5705** METHOD: sqlite3_context
5706**
5707** ^The sqlite3_user_data() interface returns a copy of
5708** the pointer that was the pUserData parameter (the 5th parameter)
5709** of the [sqlite3_create_function()]
5710** and [sqlite3_create_function16()] routines that originally
5711** registered the application defined function.
5712**
5713** This routine must be called from the same thread in which
5714** the application-defined function is running.
5715*/
5716SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5717
5718/*
5719** CAPI3REF: Database Connection For Functions
5720** METHOD: sqlite3_context
5721**
5722** ^The sqlite3_context_db_handle() interface returns a copy of
5723** the pointer to the [database connection] (the 1st parameter)
5724** of the [sqlite3_create_function()]
5725** and [sqlite3_create_function16()] routines that originally
5726** registered the application defined function.
5727*/
5728SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5729
5730/*
5731** CAPI3REF: Function Auxiliary Data
5732** METHOD: sqlite3_context
5733**
5734** These functions may be used by (non-aggregate) SQL functions to
5735** associate metadata with argument values. If the same value is passed to
5736** multiple invocations of the same SQL function during query execution, under
5737** some circumstances the associated metadata may be preserved. An example
5738** of where this might be useful is in a regular-expression matching
5739** function. The compiled version of the regular expression can be stored as
5740** metadata associated with the pattern string.
5741** Then as long as the pattern string remains the same,
5742** the compiled regular expression can be reused on multiple
5743** invocations of the same function.
5744**
5745** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5746** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5747** value to the application-defined function. ^N is zero for the left-most
5748** function argument. ^If there is no metadata
5749** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5750** returns a NULL pointer.
5751**
5752** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5753** argument of the application-defined function. ^Subsequent
5754** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5755** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5756** NULL if the metadata has been discarded.
5757** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5758** SQLite will invoke the destructor function X with parameter P exactly
5759** once, when the metadata is discarded.
5760** SQLite is free to discard the metadata at any time, including: <ul>
5761** <li> ^(when the corresponding function parameter changes)^, or
5762** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5763** SQL statement)^, or
5764** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5765** parameter)^, or
5766** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5767** allocation error occurs.)^ </ul>
5768**
5769** Note the last bullet in particular. The destructor X in
5770** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5771** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5772** should be called near the end of the function implementation and the
5773** function implementation should not make any use of P after
5774** sqlite3_set_auxdata() has been called.
5775**
5776** ^(In practice, metadata is preserved between function calls for
5777** function parameters that are compile-time constants, including literal
5778** values and [parameters] and expressions composed from the same.)^
5779**
5780** The value of the N parameter to these interfaces should be non-negative.
5781** Future enhancements may make use of negative N values to define new
5782** kinds of function caching behavior.
5783**
5784** These routines must be called from the same thread in which
5785** the SQL function is running.
5786*/
5787SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5788SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5789
5790
5791/*
5792** CAPI3REF: Constants Defining Special Destructor Behavior
5793**
5794** These are special values for the destructor that is passed in as the
5795** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5796** argument is SQLITE_STATIC, it means that the content pointer is constant
5797** and will never change. It does not need to be destroyed. ^The
5798** SQLITE_TRANSIENT value means that the content will likely change in
5799** the near future and that SQLite should make its own private copy of
5800** the content before returning.
5801**
5802** The typedef is necessary to work around problems in certain
5803** C++ compilers.
5804*/
5805typedef void (*sqlite3_destructor_type)(void*);
5806#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5807#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5808
5809/*
5810** CAPI3REF: Setting The Result Of An SQL Function
5811** METHOD: sqlite3_context
5812**
5813** These routines are used by the xFunc or xFinal callbacks that
5814** implement SQL functions and aggregates. See
5815** [sqlite3_create_function()] and [sqlite3_create_function16()]
5816** for additional information.
5817**
5818** These functions work very much like the [parameter binding] family of
5819** functions used to bind values to host parameters in prepared statements.
5820** Refer to the [SQL parameter] documentation for additional information.
5821**
5822** ^The sqlite3_result_blob() interface sets the result from
5823** an application-defined function to be the BLOB whose content is pointed
5824** to by the second parameter and which is N bytes long where N is the
5825** third parameter.
5826**
5827** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5828** interfaces set the result of the application-defined function to be
5829** a BLOB containing all zero bytes and N bytes in size.
5830**
5831** ^The sqlite3_result_double() interface sets the result from
5832** an application-defined function to be a floating point value specified
5833** by its 2nd argument.
5834**
5835** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5836** cause the implemented SQL function to throw an exception.
5837** ^SQLite uses the string pointed to by the
5838** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5839** as the text of an error message. ^SQLite interprets the error
5840** message string from sqlite3_result_error() as UTF-8. ^SQLite
5841** interprets the string from sqlite3_result_error16() as UTF-16 using
5842** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5843** ^If the third parameter to sqlite3_result_error()
5844** or sqlite3_result_error16() is negative then SQLite takes as the error
5845** message all text up through the first zero character.
5846** ^If the third parameter to sqlite3_result_error() or
5847** sqlite3_result_error16() is non-negative then SQLite takes that many
5848** bytes (not characters) from the 2nd parameter as the error message.
5849** ^The sqlite3_result_error() and sqlite3_result_error16()
5850** routines make a private copy of the error message text before
5851** they return. Hence, the calling function can deallocate or
5852** modify the text after they return without harm.
5853** ^The sqlite3_result_error_code() function changes the error code
5854** returned by SQLite as a result of an error in a function. ^By default,
5855** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5856** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5857**
5858** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5859** error indicating that a string or BLOB is too long to represent.
5860**
5861** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5862** error indicating that a memory allocation failed.
5863**
5864** ^The sqlite3_result_int() interface sets the return value
5865** of the application-defined function to be the 32-bit signed integer
5866** value given in the 2nd argument.
5867** ^The sqlite3_result_int64() interface sets the return value
5868** of the application-defined function to be the 64-bit signed integer
5869** value given in the 2nd argument.
5870**
5871** ^The sqlite3_result_null() interface sets the return value
5872** of the application-defined function to be NULL.
5873**
5874** ^The sqlite3_result_text(), sqlite3_result_text16(),
5875** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5876** set the return value of the application-defined function to be
5877** a text string which is represented as UTF-8, UTF-16 native byte order,
5878** UTF-16 little endian, or UTF-16 big endian, respectively.
5879** ^The sqlite3_result_text64() interface sets the return value of an
5880** application-defined function to be a text string in an encoding
5881** specified by the fifth (and last) parameter, which must be one
5882** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5883** ^SQLite takes the text result from the application from
5884** the 2nd parameter of the sqlite3_result_text* interfaces.
5885** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
5886** other than sqlite3_result_text64() is negative, then SQLite computes
5887** the string length itself by searching the 2nd parameter for the first
5888** zero character.
5889** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5890** is non-negative, then as many bytes (not characters) of the text
5891** pointed to by the 2nd parameter are taken as the application-defined
5892** function result. If the 3rd parameter is non-negative, then it
5893** must be the byte offset into the string where the NUL terminator would
5894** appear if the string where NUL terminated. If any NUL characters occur
5895** in the string at a byte offset that is less than the value of the 3rd
5896** parameter, then the resulting string will contain embedded NULs and the
5897** result of expressions operating on strings with embedded NULs is undefined.
5898** ^If the 4th parameter to the sqlite3_result_text* interfaces
5899** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5900** function as the destructor on the text or BLOB result when it has
5901** finished using that result.
5902** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5903** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5904** assumes that the text or BLOB result is in constant space and does not
5905** copy the content of the parameter nor call a destructor on the content
5906** when it has finished using that result.
5907** ^If the 4th parameter to the sqlite3_result_text* interfaces
5908** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5909** then SQLite makes a copy of the result into space obtained
5910** from [sqlite3_malloc()] before it returns.
5911**
5912** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5913** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5914** when the encoding is not UTF8, if the input UTF16 begins with a
5915** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5916** string and the rest of the string is interpreted according to the
5917** byte-order specified by the BOM. ^The byte-order specified by
5918** the BOM at the beginning of the text overrides the byte-order
5919** specified by the interface procedure. ^So, for example, if
5920** sqlite3_result_text16le() is invoked with text that begins
5921** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5922** first two bytes of input are skipped and the remaining input
5923** is interpreted as UTF16BE text.
5924**
5925** ^For UTF16 input text to the sqlite3_result_text16(),
5926** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5927** sqlite3_result_text64() routines, if the text contains invalid
5928** UTF16 characters, the invalid characters might be converted
5929** into the unicode replacement character, U+FFFD.
5930**
5931** ^The sqlite3_result_value() interface sets the result of
5932** the application-defined function to be a copy of the
5933** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5934** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5935** so that the [sqlite3_value] specified in the parameter may change or
5936** be deallocated after sqlite3_result_value() returns without harm.
5937** ^A [protected sqlite3_value] object may always be used where an
5938** [unprotected sqlite3_value] object is required, so either
5939** kind of [sqlite3_value] object can be used with this interface.
5940**
5941** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5942** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5943** also associates the host-language pointer P or type T with that
5944** NULL value such that the pointer can be retrieved within an
5945** [application-defined SQL function] using [sqlite3_value_pointer()].
5946** ^If the D parameter is not NULL, then it is a pointer to a destructor
5947** for the P parameter. ^SQLite invokes D with P as its only argument
5948** when SQLite is finished with P. The T parameter should be a static
5949** string and preferably a string literal. The sqlite3_result_pointer()
5950** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5951**
5952** If these routines are called from within the different thread
5953** than the one containing the application-defined function that received
5954** the [sqlite3_context] pointer, the results are undefined.
5955*/
5956SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5957SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5958 sqlite3_uint64,void(*)(void*));
5959SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5960SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5961SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5962SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5963SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5964SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5965SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5966SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5967SQLITE_API void sqlite3_result_null(sqlite3_context*);
5968SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5969SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5970 void(*)(void*), unsigned char encoding);
5971SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5972SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5973SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5974SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5975SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5976SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5977SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5978
5979
5980/*
5981** CAPI3REF: Setting The Subtype Of An SQL Function
5982** METHOD: sqlite3_context
5983**
5984** The sqlite3_result_subtype(C,T) function causes the subtype of
5985** the result from the [application-defined SQL function] with
5986** [sqlite3_context] C to be the value T. Only the lower 8 bits
5987** of the subtype T are preserved in current versions of SQLite;
5988** higher order bits are discarded.
5989** The number of subtype bytes preserved by SQLite might increase
5990** in future releases of SQLite.
5991*/
5992SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5993
5994/*
5995** CAPI3REF: Define New Collating Sequences
5996** METHOD: sqlite3
5997**
5998** ^These functions add, remove, or modify a [collation] associated
5999** with the [database connection] specified as the first argument.
6000**
6001** ^The name of the collation is a UTF-8 string
6002** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6003** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6004** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6005** considered to be the same name.
6006**
6007** ^(The third argument (eTextRep) must be one of the constants:
6008** <ul>
6009** <li> [SQLITE_UTF8],
6010** <li> [SQLITE_UTF16LE],
6011** <li> [SQLITE_UTF16BE],
6012** <li> [SQLITE_UTF16], or
6013** <li> [SQLITE_UTF16_ALIGNED].
6014** </ul>)^
6015** ^The eTextRep argument determines the encoding of strings passed
6016** to the collating function callback, xCompare.
6017** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6018** force strings to be UTF16 with native byte order.
6019** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6020** on an even byte address.
6021**
6022** ^The fourth argument, pArg, is an application data pointer that is passed
6023** through as the first argument to the collating function callback.
6024**
6025** ^The fifth argument, xCompare, is a pointer to the collating function.
6026** ^Multiple collating functions can be registered using the same name but
6027** with different eTextRep parameters and SQLite will use whichever
6028** function requires the least amount of data transformation.
6029** ^If the xCompare argument is NULL then the collating function is
6030** deleted. ^When all collating functions having the same name are deleted,
6031** that collation is no longer usable.
6032**
6033** ^The collating function callback is invoked with a copy of the pArg
6034** application data pointer and with two strings in the encoding specified
6035** by the eTextRep argument. The two integer parameters to the collating
6036** function callback are the length of the two strings, in bytes. The collating
6037** function must return an integer that is negative, zero, or positive
6038** if the first string is less than, equal to, or greater than the second,
6039** respectively. A collating function must always return the same answer
6040** given the same inputs. If two or more collating functions are registered
6041** to the same collation name (using different eTextRep values) then all
6042** must give an equivalent answer when invoked with equivalent strings.
6043** The collating function must obey the following properties for all
6044** strings A, B, and C:
6045**
6046** <ol>
6047** <li> If A==B then B==A.
6048** <li> If A==B and B==C then A==C.
6049** <li> If A&lt;B THEN B&gt;A.
6050** <li> If A&lt;B and B&lt;C then A&lt;C.
6051** </ol>
6052**
6053** If a collating function fails any of the above constraints and that
6054** collating function is registered and used, then the behavior of SQLite
6055** is undefined.
6056**
6057** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6058** with the addition that the xDestroy callback is invoked on pArg when
6059** the collating function is deleted.
6060** ^Collating functions are deleted when they are overridden by later
6061** calls to the collation creation functions or when the
6062** [database connection] is closed using [sqlite3_close()].
6063**
6064** ^The xDestroy callback is <u>not</u> called if the
6065** sqlite3_create_collation_v2() function fails. Applications that invoke
6066** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6067** check the return code and dispose of the application data pointer
6068** themselves rather than expecting SQLite to deal with it for them.
6069** This is different from every other SQLite interface. The inconsistency
6070** is unfortunate but cannot be changed without breaking backwards
6071** compatibility.
6072**
6073** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6074*/
6075SQLITE_API int sqlite3_create_collation(
6076 sqlite3*,
6077 const char *zName,
6078 int eTextRep,
6079 void *pArg,
6080 int(*xCompare)(void*,int,const void*,int,const void*)
6081);
6082SQLITE_API int sqlite3_create_collation_v2(
6083 sqlite3*,
6084 const char *zName,
6085 int eTextRep,
6086 void *pArg,
6087 int(*xCompare)(void*,int,const void*,int,const void*),
6088 void(*xDestroy)(void*)
6089);
6090SQLITE_API int sqlite3_create_collation16(
6091 sqlite3*,
6092 const void *zName,
6093 int eTextRep,
6094 void *pArg,
6095 int(*xCompare)(void*,int,const void*,int,const void*)
6096);
6097
6098/*
6099** CAPI3REF: Collation Needed Callbacks
6100** METHOD: sqlite3
6101**
6102** ^To avoid having to register all collation sequences before a database
6103** can be used, a single callback function may be registered with the
6104** [database connection] to be invoked whenever an undefined collation
6105** sequence is required.
6106**
6107** ^If the function is registered using the sqlite3_collation_needed() API,
6108** then it is passed the names of undefined collation sequences as strings
6109** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6110** the names are passed as UTF-16 in machine native byte order.
6111** ^A call to either function replaces the existing collation-needed callback.
6112**
6113** ^(When the callback is invoked, the first argument passed is a copy
6114** of the second argument to sqlite3_collation_needed() or
6115** sqlite3_collation_needed16(). The second argument is the database
6116** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6117** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6118** sequence function required. The fourth parameter is the name of the
6119** required collation sequence.)^
6120**
6121** The callback function should register the desired collation using
6122** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6123** [sqlite3_create_collation_v2()].
6124*/
6125SQLITE_API int sqlite3_collation_needed(
6126 sqlite3*,
6127 void*,
6128 void(*)(void*,sqlite3*,int eTextRep,const char*)
6129);
6130SQLITE_API int sqlite3_collation_needed16(
6131 sqlite3*,
6132 void*,
6133 void(*)(void*,sqlite3*,int eTextRep,const void*)
6134);
6135
6136#ifdef SQLITE_ENABLE_CEROD
6137/*
6138** Specify the activation key for a CEROD database. Unless
6139** activated, none of the CEROD routines will work.
6140*/
6141SQLITE_API void sqlite3_activate_cerod(
6142 const char *zPassPhrase /* Activation phrase */
6143);
6144#endif
6145
6146/*
6147** CAPI3REF: Suspend Execution For A Short Time
6148**
6149** The sqlite3_sleep() function causes the current thread to suspend execution
6150** for at least a number of milliseconds specified in its parameter.
6151**
6152** If the operating system does not support sleep requests with
6153** millisecond time resolution, then the time will be rounded up to
6154** the nearest second. The number of milliseconds of sleep actually
6155** requested from the operating system is returned.
6156**
6157** ^SQLite implements this interface by calling the xSleep()
6158** method of the default [sqlite3_vfs] object. If the xSleep() method
6159** of the default VFS is not implemented correctly, or not implemented at
6160** all, then the behavior of sqlite3_sleep() may deviate from the description
6161** in the previous paragraphs.
6162*/
6163SQLITE_API int sqlite3_sleep(int);
6164
6165/*
6166** CAPI3REF: Name Of The Folder Holding Temporary Files
6167**
6168** ^(If this global variable is made to point to a string which is
6169** the name of a folder (a.k.a. directory), then all temporary files
6170** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6171** will be placed in that directory.)^ ^If this variable
6172** is a NULL pointer, then SQLite performs a search for an appropriate
6173** temporary file directory.
6174**
6175** Applications are strongly discouraged from using this global variable.
6176** It is required to set a temporary folder on Windows Runtime (WinRT).
6177** But for all other platforms, it is highly recommended that applications
6178** neither read nor write this variable. This global variable is a relic
6179** that exists for backwards compatibility of legacy applications and should
6180** be avoided in new projects.
6181**
6182** It is not safe to read or modify this variable in more than one
6183** thread at a time. It is not safe to read or modify this variable
6184** if a [database connection] is being used at the same time in a separate
6185** thread.
6186** It is intended that this variable be set once
6187** as part of process initialization and before any SQLite interface
6188** routines have been called and that this variable remain unchanged
6189** thereafter.
6190**
6191** ^The [temp_store_directory pragma] may modify this variable and cause
6192** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6193** the [temp_store_directory pragma] always assumes that any string
6194** that this variable points to is held in memory obtained from
6195** [sqlite3_malloc] and the pragma may attempt to free that memory
6196** using [sqlite3_free].
6197** Hence, if this variable is modified directly, either it should be
6198** made NULL or made to point to memory obtained from [sqlite3_malloc]
6199** or else the use of the [temp_store_directory pragma] should be avoided.
6200** Except when requested by the [temp_store_directory pragma], SQLite
6201** does not free the memory that sqlite3_temp_directory points to. If
6202** the application wants that memory to be freed, it must do
6203** so itself, taking care to only do so after all [database connection]
6204** objects have been destroyed.
6205**
6206** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6207** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6208** features that require the use of temporary files may fail. Here is an
6209** example of how to do this using C++ with the Windows Runtime:
6210**
6211** <blockquote><pre>
6212** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6213** &nbsp; TemporaryFolder->Path->Data();
6214** char zPathBuf&#91;MAX_PATH + 1&#93;;
6215** memset(zPathBuf, 0, sizeof(zPathBuf));
6216** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6217** &nbsp; NULL, NULL);
6218** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6219** </pre></blockquote>
6220*/
6221SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6222
6223/*
6224** CAPI3REF: Name Of The Folder Holding Database Files
6225**
6226** ^(If this global variable is made to point to a string which is
6227** the name of a folder (a.k.a. directory), then all database files
6228** specified with a relative pathname and created or accessed by
6229** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6230** to be relative to that directory.)^ ^If this variable is a NULL
6231** pointer, then SQLite assumes that all database files specified
6232** with a relative pathname are relative to the current directory
6233** for the process. Only the windows VFS makes use of this global
6234** variable; it is ignored by the unix VFS.
6235**
6236** Changing the value of this variable while a database connection is
6237** open can result in a corrupt database.
6238**
6239** It is not safe to read or modify this variable in more than one
6240** thread at a time. It is not safe to read or modify this variable
6241** if a [database connection] is being used at the same time in a separate
6242** thread.
6243** It is intended that this variable be set once
6244** as part of process initialization and before any SQLite interface
6245** routines have been called and that this variable remain unchanged
6246** thereafter.
6247**
6248** ^The [data_store_directory pragma] may modify this variable and cause
6249** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6250** the [data_store_directory pragma] always assumes that any string
6251** that this variable points to is held in memory obtained from
6252** [sqlite3_malloc] and the pragma may attempt to free that memory
6253** using [sqlite3_free].
6254** Hence, if this variable is modified directly, either it should be
6255** made NULL or made to point to memory obtained from [sqlite3_malloc]
6256** or else the use of the [data_store_directory pragma] should be avoided.
6257*/
6258SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6259
6260/*
6261** CAPI3REF: Win32 Specific Interface
6262**
6263** These interfaces are available only on Windows. The
6264** [sqlite3_win32_set_directory] interface is used to set the value associated
6265** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6266** zValue, depending on the value of the type parameter. The zValue parameter
6267** should be NULL to cause the previous value to be freed via [sqlite3_free];
6268** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6269** prior to being used. The [sqlite3_win32_set_directory] interface returns
6270** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6271** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6272** [sqlite3_data_directory] variable is intended to act as a replacement for
6273** the current directory on the sub-platforms of Win32 where that concept is
6274** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6275** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6276** sqlite3_win32_set_directory interface except the string parameter must be
6277** UTF-8 or UTF-16, respectively.
6278*/
6279SQLITE_API int sqlite3_win32_set_directory(
6280 unsigned long type, /* Identifier for directory being set or reset */
6281 void *zValue /* New value for directory being set or reset */
6282);
6283SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6284SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6285
6286/*
6287** CAPI3REF: Win32 Directory Types
6288**
6289** These macros are only available on Windows. They define the allowed values
6290** for the type argument to the [sqlite3_win32_set_directory] interface.
6291*/
6292#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6293#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6294
6295/*
6296** CAPI3REF: Test For Auto-Commit Mode
6297** KEYWORDS: {autocommit mode}
6298** METHOD: sqlite3
6299**
6300** ^The sqlite3_get_autocommit() interface returns non-zero or
6301** zero if the given database connection is or is not in autocommit mode,
6302** respectively. ^Autocommit mode is on by default.
6303** ^Autocommit mode is disabled by a [BEGIN] statement.
6304** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6305**
6306** If certain kinds of errors occur on a statement within a multi-statement
6307** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6308** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6309** transaction might be rolled back automatically. The only way to
6310** find out whether SQLite automatically rolled back the transaction after
6311** an error is to use this function.
6312**
6313** If another thread changes the autocommit status of the database
6314** connection while this routine is running, then the return value
6315** is undefined.
6316*/
6317SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6318
6319/*
6320** CAPI3REF: Find The Database Handle Of A Prepared Statement
6321** METHOD: sqlite3_stmt
6322**
6323** ^The sqlite3_db_handle interface returns the [database connection] handle
6324** to which a [prepared statement] belongs. ^The [database connection]
6325** returned by sqlite3_db_handle is the same [database connection]
6326** that was the first argument
6327** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6328** create the statement in the first place.
6329*/
6330SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6331
6332/*
6333** CAPI3REF: Return The Schema Name For A Database Connection
6334** METHOD: sqlite3
6335**
6336** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6337** for the N-th database on database connection D, or a NULL pointer of N is
6338** out of range. An N value of 0 means the main database file. An N of 1 is
6339** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6340** databases.
6341**
6342** Space to hold the string that is returned by sqlite3_db_name() is managed
6343** by SQLite itself. The string might be deallocated by any operation that
6344** changes the schema, including [ATTACH] or [DETACH] or calls to
6345** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6346** occur on a different thread. Applications that need to
6347** remember the string long-term should make their own copy. Applications that
6348** are accessing the same database connection simultaneously on multiple
6349** threads should mutex-protect calls to this API and should make their own
6350** private copy of the result prior to releasing the mutex.
6351*/
6352SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6353
6354/*
6355** CAPI3REF: Return The Filename For A Database Connection
6356** METHOD: sqlite3
6357**
6358** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6359** associated with database N of connection D.
6360** ^If there is no attached database N on the database
6361** connection D, or if database N is a temporary or in-memory database, then
6362** this function will return either a NULL pointer or an empty string.
6363**
6364** ^The string value returned by this routine is owned and managed by
6365** the database connection. ^The value will be valid until the database N
6366** is [DETACH]-ed or until the database connection closes.
6367**
6368** ^The filename returned by this function is the output of the
6369** xFullPathname method of the [VFS]. ^In other words, the filename
6370** will be an absolute pathname, even if the filename used
6371** to open the database originally was a URI or relative pathname.
6372**
6373** If the filename pointer returned by this routine is not NULL, then it
6374** can be used as the filename input parameter to these routines:
6375** <ul>
6376** <li> [sqlite3_uri_parameter()]
6377** <li> [sqlite3_uri_boolean()]
6378** <li> [sqlite3_uri_int64()]
6379** <li> [sqlite3_filename_database()]
6380** <li> [sqlite3_filename_journal()]
6381** <li> [sqlite3_filename_wal()]
6382** </ul>
6383*/
6384SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6385
6386/*
6387** CAPI3REF: Determine if a database is read-only
6388** METHOD: sqlite3
6389**
6390** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6391** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6392** the name of a database on connection D.
6393*/
6394SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6395
6396/*
6397** CAPI3REF: Determine the transaction state of a database
6398** METHOD: sqlite3
6399**
6400** ^The sqlite3_txn_state(D,S) interface returns the current
6401** [transaction state] of schema S in database connection D. ^If S is NULL,
6402** then the highest transaction state of any schema on database connection D
6403** is returned. Transaction states are (in order of lowest to highest):
6404** <ol>
6405** <li value="0"> SQLITE_TXN_NONE
6406** <li value="1"> SQLITE_TXN_READ
6407** <li value="2"> SQLITE_TXN_WRITE
6408** </ol>
6409** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6410** a valid schema, then -1 is returned.
6411*/
6412SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6413
6414/*
6415** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6416** KEYWORDS: {transaction state}
6417**
6418** These constants define the current transaction state of a database file.
6419** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6420** constants in order to describe the transaction state of schema S
6421** in [database connection] D.
6422**
6423** <dl>
6424** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6425** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6426** pending.</dd>
6427**
6428** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6429** <dd>The SQLITE_TXN_READ state means that the database is currently
6430** in a read transaction. Content has been read from the database file
6431** but nothing in the database file has changed. The transaction state
6432** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6433** no other conflicting concurrent write transactions. The transaction
6434** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6435** [COMMIT].</dd>
6436**
6437** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6438** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6439** in a write transaction. Content has been written to the database file
6440** but has not yet committed. The transaction state will change to
6441** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6442*/
6443#define SQLITE_TXN_NONE 0
6444#define SQLITE_TXN_READ 1
6445#define SQLITE_TXN_WRITE 2
6446
6447/*
6448** CAPI3REF: Find the next prepared statement
6449** METHOD: sqlite3
6450**
6451** ^This interface returns a pointer to the next [prepared statement] after
6452** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6453** then this interface returns a pointer to the first prepared statement
6454** associated with the database connection pDb. ^If no prepared statement
6455** satisfies the conditions of this routine, it returns NULL.
6456**
6457** The [database connection] pointer D in a call to
6458** [sqlite3_next_stmt(D,S)] must refer to an open database
6459** connection and in particular must not be a NULL pointer.
6460*/
6461SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6462
6463/*
6464** CAPI3REF: Commit And Rollback Notification Callbacks
6465** METHOD: sqlite3
6466**
6467** ^The sqlite3_commit_hook() interface registers a callback
6468** function to be invoked whenever a transaction is [COMMIT | committed].
6469** ^Any callback set by a previous call to sqlite3_commit_hook()
6470** for the same database connection is overridden.
6471** ^The sqlite3_rollback_hook() interface registers a callback
6472** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6473** ^Any callback set by a previous call to sqlite3_rollback_hook()
6474** for the same database connection is overridden.
6475** ^The pArg argument is passed through to the callback.
6476** ^If the callback on a commit hook function returns non-zero,
6477** then the commit is converted into a rollback.
6478**
6479** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6480** return the P argument from the previous call of the same function
6481** on the same [database connection] D, or NULL for
6482** the first call for each function on D.
6483**
6484** The commit and rollback hook callbacks are not reentrant.
6485** The callback implementation must not do anything that will modify
6486** the database connection that invoked the callback. Any actions
6487** to modify the database connection must be deferred until after the
6488** completion of the [sqlite3_step()] call that triggered the commit
6489** or rollback hook in the first place.
6490** Note that running any other SQL statements, including SELECT statements,
6491** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6492** the database connections for the meaning of "modify" in this paragraph.
6493**
6494** ^Registering a NULL function disables the callback.
6495**
6496** ^When the commit hook callback routine returns zero, the [COMMIT]
6497** operation is allowed to continue normally. ^If the commit hook
6498** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6499** ^The rollback hook is invoked on a rollback that results from a commit
6500** hook returning non-zero, just as it would be with any other rollback.
6501**
6502** ^For the purposes of this API, a transaction is said to have been
6503** rolled back if an explicit "ROLLBACK" statement is executed, or
6504** an error or constraint causes an implicit rollback to occur.
6505** ^The rollback callback is not invoked if a transaction is
6506** automatically rolled back because the database connection is closed.
6507**
6508** See also the [sqlite3_update_hook()] interface.
6509*/
6510SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6511SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6512
6513/*
6514** CAPI3REF: Autovacuum Compaction Amount Callback
6515** METHOD: sqlite3
6516**
6517** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6518** function C that is invoked prior to each autovacuum of the database
6519** file. ^The callback is passed a copy of the generic data pointer (P),
6520** the schema-name of the attached database that is being autovacuumed,
6521** the size of the database file in pages, the number of free pages,
6522** and the number of bytes per page, respectively. The callback should
6523** return the number of free pages that should be removed by the
6524** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6525** ^If the value returned is greater than or equal to the number of
6526** free pages, then a complete autovacuum happens.
6527**
6528** <p>^If there are multiple ATTACH-ed database files that are being
6529** modified as part of a transaction commit, then the autovacuum pages
6530** callback is invoked separately for each file.
6531**
6532** <p><b>The callback is not reentrant.</b> The callback function should
6533** not attempt to invoke any other SQLite interface. If it does, bad
6534** things may happen, including segmentation faults and corrupt database
6535** files. The callback function should be a simple function that
6536** does some arithmetic on its input parameters and returns a result.
6537**
6538** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6539** destructor for the P parameter. ^If X is not NULL, then X(P) is
6540** invoked whenever the database connection closes or when the callback
6541** is overwritten by another invocation of sqlite3_autovacuum_pages().
6542**
6543** <p>^There is only one autovacuum pages callback per database connection.
6544** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6545** previous invocations for that database connection. ^If the callback
6546** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6547** then the autovacuum steps callback is cancelled. The return value
6548** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6549** be some other error code if something goes wrong. The current
6550** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6551** return codes might be added in future releases.
6552**
6553** <p>If no autovacuum pages callback is specified (the usual case) or
6554** a NULL pointer is provided for the callback,
6555** then the default behavior is to vacuum all free pages. So, in other
6556** words, the default behavior is the same as if the callback function
6557** were something like this:
6558**
6559** <blockquote><pre>
6560** &nbsp; unsigned int demonstration_autovac_pages_callback(
6561** &nbsp; void *pClientData,
6562** &nbsp; const char *zSchema,
6563** &nbsp; unsigned int nDbPage,
6564** &nbsp; unsigned int nFreePage,
6565** &nbsp; unsigned int nBytePerPage
6566** &nbsp; ){
6567** &nbsp; return nFreePage;
6568** &nbsp; }
6569** </pre></blockquote>
6570*/
6571SQLITE_API int sqlite3_autovacuum_pages(
6572 sqlite3 *db,
6573 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6574 void*,
6575 void(*)(void*)
6576);
6577
6578
6579/*
6580** CAPI3REF: Data Change Notification Callbacks
6581** METHOD: sqlite3
6582**
6583** ^The sqlite3_update_hook() interface registers a callback function
6584** with the [database connection] identified by the first argument
6585** to be invoked whenever a row is updated, inserted or deleted in
6586** a [rowid table].
6587** ^Any callback set by a previous call to this function
6588** for the same database connection is overridden.
6589**
6590** ^The second argument is a pointer to the function to invoke when a
6591** row is updated, inserted or deleted in a rowid table.
6592** ^The first argument to the callback is a copy of the third argument
6593** to sqlite3_update_hook().
6594** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6595** or [SQLITE_UPDATE], depending on the operation that caused the callback
6596** to be invoked.
6597** ^The third and fourth arguments to the callback contain pointers to the
6598** database and table name containing the affected row.
6599** ^The final callback parameter is the [rowid] of the row.
6600** ^In the case of an update, this is the [rowid] after the update takes place.
6601**
6602** ^(The update hook is not invoked when internal system tables are
6603** modified (i.e. sqlite_sequence).)^
6604** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6605**
6606** ^In the current implementation, the update hook
6607** is not invoked when conflicting rows are deleted because of an
6608** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6609** invoked when rows are deleted using the [truncate optimization].
6610** The exceptions defined in this paragraph might change in a future
6611** release of SQLite.
6612**
6613** The update hook implementation must not do anything that will modify
6614** the database connection that invoked the update hook. Any actions
6615** to modify the database connection must be deferred until after the
6616** completion of the [sqlite3_step()] call that triggered the update hook.
6617** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6618** database connections for the meaning of "modify" in this paragraph.
6619**
6620** ^The sqlite3_update_hook(D,C,P) function
6621** returns the P argument from the previous call
6622** on the same [database connection] D, or NULL for
6623** the first call on D.
6624**
6625** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6626** and [sqlite3_preupdate_hook()] interfaces.
6627*/
6628SQLITE_API void *sqlite3_update_hook(
6629 sqlite3*,
6630 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6631 void*
6632);
6633
6634/*
6635** CAPI3REF: Enable Or Disable Shared Pager Cache
6636**
6637** ^(This routine enables or disables the sharing of the database cache
6638** and schema data structures between [database connection | connections]
6639** to the same database. Sharing is enabled if the argument is true
6640** and disabled if the argument is false.)^
6641**
6642** This interface is omitted if SQLite is compiled with
6643** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
6644** compile-time option is recommended because the
6645** [use of shared cache mode is discouraged].
6646**
6647** ^Cache sharing is enabled and disabled for an entire process.
6648** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6649** In prior versions of SQLite,
6650** sharing was enabled or disabled for each thread separately.
6651**
6652** ^(The cache sharing mode set by this interface effects all subsequent
6653** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6654** Existing database connections continue to use the sharing mode
6655** that was in effect at the time they were opened.)^
6656**
6657** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6658** successfully. An [error code] is returned otherwise.)^
6659**
6660** ^Shared cache is disabled by default. It is recommended that it stay
6661** that way. In other words, do not use this routine. This interface
6662** continues to be provided for historical compatibility, but its use is
6663** discouraged. Any use of shared cache is discouraged. If shared cache
6664** must be used, it is recommended that shared cache only be enabled for
6665** individual database connections using the [sqlite3_open_v2()] interface
6666** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6667**
6668** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6669** and will always return SQLITE_MISUSE. On those systems,
6670** shared cache mode should be enabled per-database connection via
6671** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6672**
6673** This interface is threadsafe on processors where writing a
6674** 32-bit integer is atomic.
6675**
6676** See Also: [SQLite Shared-Cache Mode]
6677*/
6678SQLITE_API int sqlite3_enable_shared_cache(int);
6679
6680/*
6681** CAPI3REF: Attempt To Free Heap Memory
6682**
6683** ^The sqlite3_release_memory() interface attempts to free N bytes
6684** of heap memory by deallocating non-essential memory allocations
6685** held by the database library. Memory used to cache database
6686** pages to improve performance is an example of non-essential memory.
6687** ^sqlite3_release_memory() returns the number of bytes actually freed,
6688** which might be more or less than the amount requested.
6689** ^The sqlite3_release_memory() routine is a no-op returning zero
6690** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6691**
6692** See also: [sqlite3_db_release_memory()]
6693*/
6694SQLITE_API int sqlite3_release_memory(int);
6695
6696/*
6697** CAPI3REF: Free Memory Used By A Database Connection
6698** METHOD: sqlite3
6699**
6700** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6701** memory as possible from database connection D. Unlike the
6702** [sqlite3_release_memory()] interface, this interface is in effect even
6703** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6704** omitted.
6705**
6706** See also: [sqlite3_release_memory()]
6707*/
6708SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6709
6710/*
6711** CAPI3REF: Impose A Limit On Heap Size
6712**
6713** These interfaces impose limits on the amount of heap memory that will be
6714** by all database connections within a single process.
6715**
6716** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6717** soft limit on the amount of heap memory that may be allocated by SQLite.
6718** ^SQLite strives to keep heap memory utilization below the soft heap
6719** limit by reducing the number of pages held in the page cache
6720** as heap memory usages approaches the limit.
6721** ^The soft heap limit is "soft" because even though SQLite strives to stay
6722** below the limit, it will exceed the limit rather than generate
6723** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6724** is advisory only.
6725**
6726** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6727** N bytes on the amount of memory that will be allocated. ^The
6728** sqlite3_hard_heap_limit64(N) interface is similar to
6729** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6730** when the hard heap limit is reached.
6731**
6732** ^The return value from both sqlite3_soft_heap_limit64() and
6733** sqlite3_hard_heap_limit64() is the size of
6734** the heap limit prior to the call, or negative in the case of an
6735** error. ^If the argument N is negative
6736** then no change is made to the heap limit. Hence, the current
6737** size of heap limits can be determined by invoking
6738** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6739**
6740** ^Setting the heap limits to zero disables the heap limiter mechanism.
6741**
6742** ^The soft heap limit may not be greater than the hard heap limit.
6743** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6744** is invoked with a value of N that is greater than the hard heap limit,
6745** the soft heap limit is set to the value of the hard heap limit.
6746** ^The soft heap limit is automatically enabled whenever the hard heap
6747** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6748** the soft heap limit is outside the range of 1..N, then the soft heap
6749** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6750** hard heap limit is enabled makes the soft heap limit equal to the
6751** hard heap limit.
6752**
6753** The memory allocation limits can also be adjusted using
6754** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6755**
6756** ^(The heap limits are not enforced in the current implementation
6757** if one or more of following conditions are true:
6758**
6759** <ul>
6760** <li> The limit value is set to zero.
6761** <li> Memory accounting is disabled using a combination of the
6762** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6763** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6764** <li> An alternative page cache implementation is specified using
6765** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6766** <li> The page cache allocates from its own memory pool supplied
6767** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6768** from the heap.
6769** </ul>)^
6770**
6771** The circumstances under which SQLite will enforce the heap limits may
6772** changes in future releases of SQLite.
6773*/
6774SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6775SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6776
6777/*
6778** CAPI3REF: Deprecated Soft Heap Limit Interface
6779** DEPRECATED
6780**
6781** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6782** interface. This routine is provided for historical compatibility
6783** only. All new applications should use the
6784** [sqlite3_soft_heap_limit64()] interface rather than this one.
6785*/
6786SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6787
6788
6789/*
6790** CAPI3REF: Extract Metadata About A Column Of A Table
6791** METHOD: sqlite3
6792**
6793** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6794** information about column C of table T in database D
6795** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6796** interface returns SQLITE_OK and fills in the non-NULL pointers in
6797** the final five arguments with appropriate values if the specified
6798** column exists. ^The sqlite3_table_column_metadata() interface returns
6799** SQLITE_ERROR if the specified column does not exist.
6800** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6801** NULL pointer, then this routine simply checks for the existence of the
6802** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6803** does not. If the table name parameter T in a call to
6804** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6805** undefined behavior.
6806**
6807** ^The column is identified by the second, third and fourth parameters to
6808** this function. ^(The second parameter is either the name of the database
6809** (i.e. "main", "temp", or an attached database) containing the specified
6810** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6811** for the table using the same algorithm used by the database engine to
6812** resolve unqualified table references.
6813**
6814** ^The third and fourth parameters to this function are the table and column
6815** name of the desired column, respectively.
6816**
6817** ^Metadata is returned by writing to the memory locations passed as the 5th
6818** and subsequent parameters to this function. ^Any of these arguments may be
6819** NULL, in which case the corresponding element of metadata is omitted.
6820**
6821** ^(<blockquote>
6822** <table border="1">
6823** <tr><th> Parameter <th> Output<br>Type <th> Description
6824**
6825** <tr><td> 5th <td> const char* <td> Data type
6826** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6827** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6828** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6829** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6830** </table>
6831** </blockquote>)^
6832**
6833** ^The memory pointed to by the character pointers returned for the
6834** declaration type and collation sequence is valid until the next
6835** call to any SQLite API function.
6836**
6837** ^If the specified table is actually a view, an [error code] is returned.
6838**
6839** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6840** is not a [WITHOUT ROWID] table and an
6841** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6842** parameters are set for the explicitly declared column. ^(If there is no
6843** [INTEGER PRIMARY KEY] column, then the outputs
6844** for the [rowid] are set as follows:
6845**
6846** <pre>
6847** data type: "INTEGER"
6848** collation sequence: "BINARY"
6849** not null: 0
6850** primary key: 1
6851** auto increment: 0
6852** </pre>)^
6853**
6854** ^This function causes all database schemas to be read from disk and
6855** parsed, if that has not already been done, and returns an error if
6856** any errors are encountered while loading the schema.
6857*/
6858SQLITE_API int sqlite3_table_column_metadata(
6859 sqlite3 *db, /* Connection handle */
6860 const char *zDbName, /* Database name or NULL */
6861 const char *zTableName, /* Table name */
6862 const char *zColumnName, /* Column name */
6863 char const **pzDataType, /* OUTPUT: Declared data type */
6864 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6865 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6866 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6867 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6868);
6869
6870/*
6871** CAPI3REF: Load An Extension
6872** METHOD: sqlite3
6873**
6874** ^This interface loads an SQLite extension library from the named file.
6875**
6876** ^The sqlite3_load_extension() interface attempts to load an
6877** [SQLite extension] library contained in the file zFile. If
6878** the file cannot be loaded directly, attempts are made to load
6879** with various operating-system specific extensions added.
6880** So for example, if "samplelib" cannot be loaded, then names like
6881** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6882** be tried also.
6883**
6884** ^The entry point is zProc.
6885** ^(zProc may be 0, in which case SQLite will try to come up with an
6886** entry point name on its own. It first tries "sqlite3_extension_init".
6887** If that does not work, it constructs a name "sqlite3_X_init" where the
6888** X is consists of the lower-case equivalent of all ASCII alphabetic
6889** characters in the filename from the last "/" to the first following
6890** "." and omitting any initial "lib".)^
6891** ^The sqlite3_load_extension() interface returns
6892** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6893** ^If an error occurs and pzErrMsg is not 0, then the
6894** [sqlite3_load_extension()] interface shall attempt to
6895** fill *pzErrMsg with error message text stored in memory
6896** obtained from [sqlite3_malloc()]. The calling function
6897** should free this memory by calling [sqlite3_free()].
6898**
6899** ^Extension loading must be enabled using
6900** [sqlite3_enable_load_extension()] or
6901** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6902** prior to calling this API,
6903** otherwise an error will be returned.
6904**
6905** <b>Security warning:</b> It is recommended that the
6906** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6907** interface. The use of the [sqlite3_enable_load_extension()] interface
6908** should be avoided. This will keep the SQL function [load_extension()]
6909** disabled and prevent SQL injections from giving attackers
6910** access to extension loading capabilities.
6911**
6912** See also the [load_extension() SQL function].
6913*/
6914SQLITE_API int sqlite3_load_extension(
6915 sqlite3 *db, /* Load the extension into this database connection */
6916 const char *zFile, /* Name of the shared library containing extension */
6917 const char *zProc, /* Entry point. Derived from zFile if 0 */
6918 char **pzErrMsg /* Put error message here if not 0 */
6919);
6920
6921/*
6922** CAPI3REF: Enable Or Disable Extension Loading
6923** METHOD: sqlite3
6924**
6925** ^So as not to open security holes in older applications that are
6926** unprepared to deal with [extension loading], and as a means of disabling
6927** [extension loading] while evaluating user-entered SQL, the following API
6928** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6929**
6930** ^Extension loading is off by default.
6931** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6932** to turn extension loading on and call it with onoff==0 to turn
6933** it back off again.
6934**
6935** ^This interface enables or disables both the C-API
6936** [sqlite3_load_extension()] and the SQL function [load_extension()].
6937** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6938** to enable or disable only the C-API.)^
6939**
6940** <b>Security warning:</b> It is recommended that extension loading
6941** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6942** rather than this interface, so the [load_extension()] SQL function
6943** remains disabled. This will prevent SQL injections from giving attackers
6944** access to extension loading capabilities.
6945*/
6946SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6947
6948/*
6949** CAPI3REF: Automatically Load Statically Linked Extensions
6950**
6951** ^This interface causes the xEntryPoint() function to be invoked for
6952** each new [database connection] that is created. The idea here is that
6953** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6954** that is to be automatically loaded into all new database connections.
6955**
6956** ^(Even though the function prototype shows that xEntryPoint() takes
6957** no arguments and returns void, SQLite invokes xEntryPoint() with three
6958** arguments and expects an integer result as if the signature of the
6959** entry point where as follows:
6960**
6961** <blockquote><pre>
6962** &nbsp; int xEntryPoint(
6963** &nbsp; sqlite3 *db,
6964** &nbsp; const char **pzErrMsg,
6965** &nbsp; const struct sqlite3_api_routines *pThunk
6966** &nbsp; );
6967** </pre></blockquote>)^
6968**
6969** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6970** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6971** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6972** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6973** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6974** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6975** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6976**
6977** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6978** on the list of automatic extensions is a harmless no-op. ^No entry point
6979** will be called more than once for each database connection that is opened.
6980**
6981** See also: [sqlite3_reset_auto_extension()]
6982** and [sqlite3_cancel_auto_extension()]
6983*/
6984SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6985
6986/*
6987** CAPI3REF: Cancel Automatic Extension Loading
6988**
6989** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6990** initialization routine X that was registered using a prior call to
6991** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6992** routine returns 1 if initialization routine X was successfully
6993** unregistered and it returns 0 if X was not on the list of initialization
6994** routines.
6995*/
6996SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6997
6998/*
6999** CAPI3REF: Reset Automatic Extension Loading
7000**
7001** ^This interface disables all automatic extensions previously
7002** registered using [sqlite3_auto_extension()].
7003*/
7004SQLITE_API void sqlite3_reset_auto_extension(void);
7005
7006/*
7007** The interface to the virtual-table mechanism is currently considered
7008** to be experimental. The interface might change in incompatible ways.
7009** If this is a problem for you, do not use the interface at this time.
7010**
7011** When the virtual-table mechanism stabilizes, we will declare the
7012** interface fixed, support it indefinitely, and remove this comment.
7013*/
7014
7015/*
7016** Structures used by the virtual table interface
7017*/
7018typedef struct sqlite3_vtab sqlite3_vtab;
7019typedef struct sqlite3_index_info sqlite3_index_info;
7020typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7021typedef struct sqlite3_module sqlite3_module;
7022
7023/*
7024** CAPI3REF: Virtual Table Object
7025** KEYWORDS: sqlite3_module {virtual table module}
7026**
7027** This structure, sometimes called a "virtual table module",
7028** defines the implementation of a [virtual table].
7029** This structure consists mostly of methods for the module.
7030**
7031** ^A virtual table module is created by filling in a persistent
7032** instance of this structure and passing a pointer to that instance
7033** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7034** ^The registration remains valid until it is replaced by a different
7035** module or until the [database connection] closes. The content
7036** of this structure must not change while it is registered with
7037** any database connection.
7038*/
7039struct sqlite3_module {
7040 int iVersion;
7041 int (*xCreate)(sqlite3*, void *pAux,
7042 int argc, const char *const*argv,
7043 sqlite3_vtab **ppVTab, char**);
7044 int (*xConnect)(sqlite3*, void *pAux,
7045 int argc, const char *const*argv,
7046 sqlite3_vtab **ppVTab, char**);
7047 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7048 int (*xDisconnect)(sqlite3_vtab *pVTab);
7049 int (*xDestroy)(sqlite3_vtab *pVTab);
7050 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7051 int (*xClose)(sqlite3_vtab_cursor*);
7052 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7053 int argc, sqlite3_value **argv);
7054 int (*xNext)(sqlite3_vtab_cursor*);
7055 int (*xEof)(sqlite3_vtab_cursor*);
7056 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7057 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7058 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7059 int (*xBegin)(sqlite3_vtab *pVTab);
7060 int (*xSync)(sqlite3_vtab *pVTab);
7061 int (*xCommit)(sqlite3_vtab *pVTab);
7062 int (*xRollback)(sqlite3_vtab *pVTab);
7063 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7064 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7065 void **ppArg);
7066 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7067 /* The methods above are in version 1 of the sqlite_module object. Those
7068 ** below are for version 2 and greater. */
7069 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7070 int (*xRelease)(sqlite3_vtab *pVTab, int);
7071 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7072 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7073 ** Those below are for version 3 and greater. */
7074 int (*xShadowName)(const char*);
7075};
7076
7077/*
7078** CAPI3REF: Virtual Table Indexing Information
7079** KEYWORDS: sqlite3_index_info
7080**
7081** The sqlite3_index_info structure and its substructures is used as part
7082** of the [virtual table] interface to
7083** pass information into and receive the reply from the [xBestIndex]
7084** method of a [virtual table module]. The fields under **Inputs** are the
7085** inputs to xBestIndex and are read-only. xBestIndex inserts its
7086** results into the **Outputs** fields.
7087**
7088** ^(The aConstraint[] array records WHERE clause constraints of the form:
7089**
7090** <blockquote>column OP expr</blockquote>
7091**
7092** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7093** stored in aConstraint[].op using one of the
7094** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7095** ^(The index of the column is stored in
7096** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7097** expr on the right-hand side can be evaluated (and thus the constraint
7098** is usable) and false if it cannot.)^
7099**
7100** ^The optimizer automatically inverts terms of the form "expr OP column"
7101** and makes other simplifications to the WHERE clause in an attempt to
7102** get as many WHERE clause terms into the form shown above as possible.
7103** ^The aConstraint[] array only reports WHERE clause terms that are
7104** relevant to the particular virtual table being queried.
7105**
7106** ^Information about the ORDER BY clause is stored in aOrderBy[].
7107** ^Each term of aOrderBy records a column of the ORDER BY clause.
7108**
7109** The colUsed field indicates which columns of the virtual table may be
7110** required by the current scan. Virtual table columns are numbered from
7111** zero in the order in which they appear within the CREATE TABLE statement
7112** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7113** the corresponding bit is set within the colUsed mask if the column may be
7114** required by SQLite. If the table has at least 64 columns and any column
7115** to the right of the first 63 is required, then bit 63 of colUsed is also
7116** set. In other words, column iCol may be required if the expression
7117** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7118** non-zero.
7119**
7120** The [xBestIndex] method must fill aConstraintUsage[] with information
7121** about what parameters to pass to xFilter. ^If argvIndex>0 then
7122** the right-hand side of the corresponding aConstraint[] is evaluated
7123** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7124** is true, then the constraint is assumed to be fully handled by the
7125** virtual table and might not be checked again by the byte code.)^ ^(The
7126** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7127** is left in its default setting of false, the constraint will always be
7128** checked separately in byte code. If the omit flag is change to true, then
7129** the constraint may or may not be checked in byte code. In other words,
7130** when the omit flag is true there is no guarantee that the constraint will
7131** not be checked again using byte code.)^
7132**
7133** ^The idxNum and idxPtr values are recorded and passed into the
7134** [xFilter] method.
7135** ^[sqlite3_free()] is used to free idxPtr if and only if
7136** needToFreeIdxPtr is true.
7137**
7138** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7139** the correct order to satisfy the ORDER BY clause so that no separate
7140** sorting step is required.
7141**
7142** ^The estimatedCost value is an estimate of the cost of a particular
7143** strategy. A cost of N indicates that the cost of the strategy is similar
7144** to a linear scan of an SQLite table with N rows. A cost of log(N)
7145** indicates that the expense of the operation is similar to that of a
7146** binary search on a unique indexed field of an SQLite table with N rows.
7147**
7148** ^The estimatedRows value is an estimate of the number of rows that
7149** will be returned by the strategy.
7150**
7151** The xBestIndex method may optionally populate the idxFlags field with a
7152** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7153** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7154** assumes that the strategy may visit at most one row.
7155**
7156** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7157** SQLite also assumes that if a call to the xUpdate() method is made as
7158** part of the same statement to delete or update a virtual table row and the
7159** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7160** any database changes. In other words, if the xUpdate() returns
7161** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7162** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7163** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7164** the xUpdate method are automatically rolled back by SQLite.
7165**
7166** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7167** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7168** If a virtual table extension is
7169** used with an SQLite version earlier than 3.8.2, the results of attempting
7170** to read or write the estimatedRows field are undefined (but are likely
7171** to include crashing the application). The estimatedRows field should
7172** therefore only be used if [sqlite3_libversion_number()] returns a
7173** value greater than or equal to 3008002. Similarly, the idxFlags field
7174** was added for [version 3.9.0] ([dateof:3.9.0]).
7175** It may therefore only be used if
7176** sqlite3_libversion_number() returns a value greater than or equal to
7177** 3009000.
7178*/
7179struct sqlite3_index_info {
7180 /* Inputs */
7181 int nConstraint; /* Number of entries in aConstraint */
7182 struct sqlite3_index_constraint {
7183 int iColumn; /* Column constrained. -1 for ROWID */
7184 unsigned char op; /* Constraint operator */
7185 unsigned char usable; /* True if this constraint is usable */
7186 int iTermOffset; /* Used internally - xBestIndex should ignore */
7187 } *aConstraint; /* Table of WHERE clause constraints */
7188 int nOrderBy; /* Number of terms in the ORDER BY clause */
7189 struct sqlite3_index_orderby {
7190 int iColumn; /* Column number */
7191 unsigned char desc; /* True for DESC. False for ASC. */
7192 } *aOrderBy; /* The ORDER BY clause */
7193 /* Outputs */
7194 struct sqlite3_index_constraint_usage {
7195 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7196 unsigned char omit; /* Do not code a test for this constraint */
7197 } *aConstraintUsage;
7198 int idxNum; /* Number used to identify the index */
7199 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7200 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7201 int orderByConsumed; /* True if output is already ordered */
7202 double estimatedCost; /* Estimated cost of using this index */
7203 /* Fields below are only available in SQLite 3.8.2 and later */
7204 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7205 /* Fields below are only available in SQLite 3.9.0 and later */
7206 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7207 /* Fields below are only available in SQLite 3.10.0 and later */
7208 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7209};
7210
7211/*
7212** CAPI3REF: Virtual Table Scan Flags
7213**
7214** Virtual table implementations are allowed to set the
7215** [sqlite3_index_info].idxFlags field to some combination of
7216** these bits.
7217*/
7218#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7219
7220/*
7221** CAPI3REF: Virtual Table Constraint Operator Codes
7222**
7223** These macros define the allowed values for the
7224** [sqlite3_index_info].aConstraint[].op field. Each value represents
7225** an operator that is part of a constraint term in the WHERE clause of
7226** a query that uses a [virtual table].
7227**
7228** ^The left-hand operand of the operator is given by the corresponding
7229** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7230** operand is the rowid.
7231** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7232** operators have no left-hand operand, and so for those operators the
7233** corresponding aConstraint[].iColumn is meaningless and should not be
7234** used.
7235**
7236** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7237** value 255 are reserved to represent functions that are overloaded
7238** by the [xFindFunction|xFindFunction method] of the virtual table
7239** implementation.
7240**
7241** The right-hand operands for each constraint might be accessible using
7242** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7243** operand is only available if it appears as a single constant literal
7244** in the input SQL. If the right-hand operand is another column or an
7245** expression (even a constant expression) or a parameter, then the
7246** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7247** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7248** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7249** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7250** always return SQLITE_NOTFOUND.
7251**
7252** The collating sequence to be used for comparison can be found using
7253** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7254** tables, the collating sequence of constraints does not matter (for example
7255** because the constraints are numeric) and so the sqlite3_vtab_collation()
7256** interface is no commonly needed.
7257*/
7258#define SQLITE_INDEX_CONSTRAINT_EQ 2
7259#define SQLITE_INDEX_CONSTRAINT_GT 4
7260#define SQLITE_INDEX_CONSTRAINT_LE 8
7261#define SQLITE_INDEX_CONSTRAINT_LT 16
7262#define SQLITE_INDEX_CONSTRAINT_GE 32
7263#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7264#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7265#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7266#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7267#define SQLITE_INDEX_CONSTRAINT_NE 68
7268#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7269#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7270#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7271#define SQLITE_INDEX_CONSTRAINT_IS 72
7272#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7273#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7274#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7275
7276/*
7277** CAPI3REF: Register A Virtual Table Implementation
7278** METHOD: sqlite3
7279**
7280** ^These routines are used to register a new [virtual table module] name.
7281** ^Module names must be registered before
7282** creating a new [virtual table] using the module and before using a
7283** preexisting [virtual table] for the module.
7284**
7285** ^The module name is registered on the [database connection] specified
7286** by the first parameter. ^The name of the module is given by the
7287** second parameter. ^The third parameter is a pointer to
7288** the implementation of the [virtual table module]. ^The fourth
7289** parameter is an arbitrary client data pointer that is passed through
7290** into the [xCreate] and [xConnect] methods of the virtual table module
7291** when a new virtual table is be being created or reinitialized.
7292**
7293** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7294** is a pointer to a destructor for the pClientData. ^SQLite will
7295** invoke the destructor function (if it is not NULL) when SQLite
7296** no longer needs the pClientData pointer. ^The destructor will also
7297** be invoked if the call to sqlite3_create_module_v2() fails.
7298** ^The sqlite3_create_module()
7299** interface is equivalent to sqlite3_create_module_v2() with a NULL
7300** destructor.
7301**
7302** ^If the third parameter (the pointer to the sqlite3_module object) is
7303** NULL then no new module is created and any existing modules with the
7304** same name are dropped.
7305**
7306** See also: [sqlite3_drop_modules()]
7307*/
7308SQLITE_API int sqlite3_create_module(
7309 sqlite3 *db, /* SQLite connection to register module with */
7310 const char *zName, /* Name of the module */
7311 const sqlite3_module *p, /* Methods for the module */
7312 void *pClientData /* Client data for xCreate/xConnect */
7313);
7314SQLITE_API int sqlite3_create_module_v2(
7315 sqlite3 *db, /* SQLite connection to register module with */
7316 const char *zName, /* Name of the module */
7317 const sqlite3_module *p, /* Methods for the module */
7318 void *pClientData, /* Client data for xCreate/xConnect */
7319 void(*xDestroy)(void*) /* Module destructor function */
7320);
7321
7322/*
7323** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7324** METHOD: sqlite3
7325**
7326** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7327** table modules from database connection D except those named on list L.
7328** The L parameter must be either NULL or a pointer to an array of pointers
7329** to strings where the array is terminated by a single NULL pointer.
7330** ^If the L parameter is NULL, then all virtual table modules are removed.
7331**
7332** See also: [sqlite3_create_module()]
7333*/
7334SQLITE_API int sqlite3_drop_modules(
7335 sqlite3 *db, /* Remove modules from this connection */
7336 const char **azKeep /* Except, do not remove the ones named here */
7337);
7338
7339/*
7340** CAPI3REF: Virtual Table Instance Object
7341** KEYWORDS: sqlite3_vtab
7342**
7343** Every [virtual table module] implementation uses a subclass
7344** of this object to describe a particular instance
7345** of the [virtual table]. Each subclass will
7346** be tailored to the specific needs of the module implementation.
7347** The purpose of this superclass is to define certain fields that are
7348** common to all module implementations.
7349**
7350** ^Virtual tables methods can set an error message by assigning a
7351** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7352** take care that any prior string is freed by a call to [sqlite3_free()]
7353** prior to assigning a new string to zErrMsg. ^After the error message
7354** is delivered up to the client application, the string will be automatically
7355** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7356*/
7357struct sqlite3_vtab {
7358 const sqlite3_module *pModule; /* The module for this virtual table */
7359 int nRef; /* Number of open cursors */
7360 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7361 /* Virtual table implementations will typically add additional fields */
7362};
7363
7364/*
7365** CAPI3REF: Virtual Table Cursor Object
7366** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7367**
7368** Every [virtual table module] implementation uses a subclass of the
7369** following structure to describe cursors that point into the
7370** [virtual table] and are used
7371** to loop through the virtual table. Cursors are created using the
7372** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7373** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7374** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7375** of the module. Each module implementation will define
7376** the content of a cursor structure to suit its own needs.
7377**
7378** This superclass exists in order to define fields of the cursor that
7379** are common to all implementations.
7380*/
7381struct sqlite3_vtab_cursor {
7382 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7383 /* Virtual table implementations will typically add additional fields */
7384};
7385
7386/*
7387** CAPI3REF: Declare The Schema Of A Virtual Table
7388**
7389** ^The [xCreate] and [xConnect] methods of a
7390** [virtual table module] call this interface
7391** to declare the format (the names and datatypes of the columns) of
7392** the virtual tables they implement.
7393*/
7394SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7395
7396/*
7397** CAPI3REF: Overload A Function For A Virtual Table
7398** METHOD: sqlite3
7399**
7400** ^(Virtual tables can provide alternative implementations of functions
7401** using the [xFindFunction] method of the [virtual table module].
7402** But global versions of those functions
7403** must exist in order to be overloaded.)^
7404**
7405** ^(This API makes sure a global version of a function with a particular
7406** name and number of parameters exists. If no such function exists
7407** before this API is called, a new function is created.)^ ^The implementation
7408** of the new function always causes an exception to be thrown. So
7409** the new function is not good for anything by itself. Its only
7410** purpose is to be a placeholder function that can be overloaded
7411** by a [virtual table].
7412*/
7413SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7414
7415/*
7416** The interface to the virtual-table mechanism defined above (back up
7417** to a comment remarkably similar to this one) is currently considered
7418** to be experimental. The interface might change in incompatible ways.
7419** If this is a problem for you, do not use the interface at this time.
7420**
7421** When the virtual-table mechanism stabilizes, we will declare the
7422** interface fixed, support it indefinitely, and remove this comment.
7423*/
7424
7425/*
7426** CAPI3REF: A Handle To An Open BLOB
7427** KEYWORDS: {BLOB handle} {BLOB handles}
7428**
7429** An instance of this object represents an open BLOB on which
7430** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7431** ^Objects of this type are created by [sqlite3_blob_open()]
7432** and destroyed by [sqlite3_blob_close()].
7433** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7434** can be used to read or write small subsections of the BLOB.
7435** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7436*/
7437typedef struct sqlite3_blob sqlite3_blob;
7438
7439/*
7440** CAPI3REF: Open A BLOB For Incremental I/O
7441** METHOD: sqlite3
7442** CONSTRUCTOR: sqlite3_blob
7443**
7444** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7445** in row iRow, column zColumn, table zTable in database zDb;
7446** in other words, the same BLOB that would be selected by:
7447**
7448** <pre>
7449** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7450** </pre>)^
7451**
7452** ^(Parameter zDb is not the filename that contains the database, but
7453** rather the symbolic name of the database. For attached databases, this is
7454** the name that appears after the AS keyword in the [ATTACH] statement.
7455** For the main database file, the database name is "main". For TEMP
7456** tables, the database name is "temp".)^
7457**
7458** ^If the flags parameter is non-zero, then the BLOB is opened for read
7459** and write access. ^If the flags parameter is zero, the BLOB is opened for
7460** read-only access.
7461**
7462** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7463** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7464** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7465** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7466** on *ppBlob after this function it returns.
7467**
7468** This function fails with SQLITE_ERROR if any of the following are true:
7469** <ul>
7470** <li> ^(Database zDb does not exist)^,
7471** <li> ^(Table zTable does not exist within database zDb)^,
7472** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7473** <li> ^(Column zColumn does not exist)^,
7474** <li> ^(Row iRow is not present in the table)^,
7475** <li> ^(The specified column of row iRow contains a value that is not
7476** a TEXT or BLOB value)^,
7477** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7478** constraint and the blob is being opened for read/write access)^,
7479** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7480** column zColumn is part of a [child key] definition and the blob is
7481** being opened for read/write access)^.
7482** </ul>
7483**
7484** ^Unless it returns SQLITE_MISUSE, this function sets the
7485** [database connection] error code and message accessible via
7486** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7487**
7488** A BLOB referenced by sqlite3_blob_open() may be read using the
7489** [sqlite3_blob_read()] interface and modified by using
7490** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7491** different row of the same table using the [sqlite3_blob_reopen()]
7492** interface. However, the column, table, or database of a [BLOB handle]
7493** cannot be changed after the [BLOB handle] is opened.
7494**
7495** ^(If the row that a BLOB handle points to is modified by an
7496** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7497** then the BLOB handle is marked as "expired".
7498** This is true if any column of the row is changed, even a column
7499** other than the one the BLOB handle is open on.)^
7500** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7501** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7502** ^(Changes written into a BLOB prior to the BLOB expiring are not
7503** rolled back by the expiration of the BLOB. Such changes will eventually
7504** commit if the transaction continues to completion.)^
7505**
7506** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7507** the opened blob. ^The size of a blob may not be changed by this
7508** interface. Use the [UPDATE] SQL command to change the size of a
7509** blob.
7510**
7511** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7512** and the built-in [zeroblob] SQL function may be used to create a
7513** zero-filled blob to read or write using the incremental-blob interface.
7514**
7515** To avoid a resource leak, every open [BLOB handle] should eventually
7516** be released by a call to [sqlite3_blob_close()].
7517**
7518** See also: [sqlite3_blob_close()],
7519** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7520** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7521*/
7522SQLITE_API int sqlite3_blob_open(
7523 sqlite3*,
7524 const char *zDb,
7525 const char *zTable,
7526 const char *zColumn,
7527 sqlite3_int64 iRow,
7528 int flags,
7529 sqlite3_blob **ppBlob
7530);
7531
7532/*
7533** CAPI3REF: Move a BLOB Handle to a New Row
7534** METHOD: sqlite3_blob
7535**
7536** ^This function is used to move an existing [BLOB handle] so that it points
7537** to a different row of the same database table. ^The new row is identified
7538** by the rowid value passed as the second argument. Only the row can be
7539** changed. ^The database, table and column on which the blob handle is open
7540** remain the same. Moving an existing [BLOB handle] to a new row is
7541** faster than closing the existing handle and opening a new one.
7542**
7543** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7544** it must exist and there must be either a blob or text value stored in
7545** the nominated column.)^ ^If the new row is not present in the table, or if
7546** it does not contain a blob or text value, or if another error occurs, an
7547** SQLite error code is returned and the blob handle is considered aborted.
7548** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7549** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7550** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7551** always returns zero.
7552**
7553** ^This function sets the database handle error code and message.
7554*/
7555SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7556
7557/*
7558** CAPI3REF: Close A BLOB Handle
7559** DESTRUCTOR: sqlite3_blob
7560**
7561** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7562** unconditionally. Even if this routine returns an error code, the
7563** handle is still closed.)^
7564**
7565** ^If the blob handle being closed was opened for read-write access, and if
7566** the database is in auto-commit mode and there are no other open read-write
7567** blob handles or active write statements, the current transaction is
7568** committed. ^If an error occurs while committing the transaction, an error
7569** code is returned and the transaction rolled back.
7570**
7571** Calling this function with an argument that is not a NULL pointer or an
7572** open blob handle results in undefined behaviour. ^Calling this routine
7573** with a null pointer (such as would be returned by a failed call to
7574** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7575** is passed a valid open blob handle, the values returned by the
7576** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7577*/
7578SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7579
7580/*
7581** CAPI3REF: Return The Size Of An Open BLOB
7582** METHOD: sqlite3_blob
7583**
7584** ^Returns the size in bytes of the BLOB accessible via the
7585** successfully opened [BLOB handle] in its only argument. ^The
7586** incremental blob I/O routines can only read or overwriting existing
7587** blob content; they cannot change the size of a blob.
7588**
7589** This routine only works on a [BLOB handle] which has been created
7590** by a prior successful call to [sqlite3_blob_open()] and which has not
7591** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7592** to this routine results in undefined and probably undesirable behavior.
7593*/
7594SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7595
7596/*
7597** CAPI3REF: Read Data From A BLOB Incrementally
7598** METHOD: sqlite3_blob
7599**
7600** ^(This function is used to read data from an open [BLOB handle] into a
7601** caller-supplied buffer. N bytes of data are copied into buffer Z
7602** from the open BLOB, starting at offset iOffset.)^
7603**
7604** ^If offset iOffset is less than N bytes from the end of the BLOB,
7605** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7606** less than zero, [SQLITE_ERROR] is returned and no data is read.
7607** ^The size of the blob (and hence the maximum value of N+iOffset)
7608** can be determined using the [sqlite3_blob_bytes()] interface.
7609**
7610** ^An attempt to read from an expired [BLOB handle] fails with an
7611** error code of [SQLITE_ABORT].
7612**
7613** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7614** Otherwise, an [error code] or an [extended error code] is returned.)^
7615**
7616** This routine only works on a [BLOB handle] which has been created
7617** by a prior successful call to [sqlite3_blob_open()] and which has not
7618** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7619** to this routine results in undefined and probably undesirable behavior.
7620**
7621** See also: [sqlite3_blob_write()].
7622*/
7623SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7624
7625/*
7626** CAPI3REF: Write Data Into A BLOB Incrementally
7627** METHOD: sqlite3_blob
7628**
7629** ^(This function is used to write data into an open [BLOB handle] from a
7630** caller-supplied buffer. N bytes of data are copied from the buffer Z
7631** into the open BLOB, starting at offset iOffset.)^
7632**
7633** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7634** Otherwise, an [error code] or an [extended error code] is returned.)^
7635** ^Unless SQLITE_MISUSE is returned, this function sets the
7636** [database connection] error code and message accessible via
7637** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7638**
7639** ^If the [BLOB handle] passed as the first argument was not opened for
7640** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7641** this function returns [SQLITE_READONLY].
7642**
7643** This function may only modify the contents of the BLOB; it is
7644** not possible to increase the size of a BLOB using this API.
7645** ^If offset iOffset is less than N bytes from the end of the BLOB,
7646** [SQLITE_ERROR] is returned and no data is written. The size of the
7647** BLOB (and hence the maximum value of N+iOffset) can be determined
7648** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7649** than zero [SQLITE_ERROR] is returned and no data is written.
7650**
7651** ^An attempt to write to an expired [BLOB handle] fails with an
7652** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7653** before the [BLOB handle] expired are not rolled back by the
7654** expiration of the handle, though of course those changes might
7655** have been overwritten by the statement that expired the BLOB handle
7656** or by other independent statements.
7657**
7658** This routine only works on a [BLOB handle] which has been created
7659** by a prior successful call to [sqlite3_blob_open()] and which has not
7660** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7661** to this routine results in undefined and probably undesirable behavior.
7662**
7663** See also: [sqlite3_blob_read()].
7664*/
7665SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7666
7667/*
7668** CAPI3REF: Virtual File System Objects
7669**
7670** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7671** that SQLite uses to interact
7672** with the underlying operating system. Most SQLite builds come with a
7673** single default VFS that is appropriate for the host computer.
7674** New VFSes can be registered and existing VFSes can be unregistered.
7675** The following interfaces are provided.
7676**
7677** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7678** ^Names are case sensitive.
7679** ^Names are zero-terminated UTF-8 strings.
7680** ^If there is no match, a NULL pointer is returned.
7681** ^If zVfsName is NULL then the default VFS is returned.
7682**
7683** ^New VFSes are registered with sqlite3_vfs_register().
7684** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7685** ^The same VFS can be registered multiple times without injury.
7686** ^To make an existing VFS into the default VFS, register it again
7687** with the makeDflt flag set. If two different VFSes with the
7688** same name are registered, the behavior is undefined. If a
7689** VFS is registered with a name that is NULL or an empty string,
7690** then the behavior is undefined.
7691**
7692** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7693** ^(If the default VFS is unregistered, another VFS is chosen as
7694** the default. The choice for the new VFS is arbitrary.)^
7695*/
7696SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7697SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7698SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7699
7700/*
7701** CAPI3REF: Mutexes
7702**
7703** The SQLite core uses these routines for thread
7704** synchronization. Though they are intended for internal
7705** use by SQLite, code that links against SQLite is
7706** permitted to use any of these routines.
7707**
7708** The SQLite source code contains multiple implementations
7709** of these mutex routines. An appropriate implementation
7710** is selected automatically at compile-time. The following
7711** implementations are available in the SQLite core:
7712**
7713** <ul>
7714** <li> SQLITE_MUTEX_PTHREADS
7715** <li> SQLITE_MUTEX_W32
7716** <li> SQLITE_MUTEX_NOOP
7717** </ul>
7718**
7719** The SQLITE_MUTEX_NOOP implementation is a set of routines
7720** that does no real locking and is appropriate for use in
7721** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7722** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7723** and Windows.
7724**
7725** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7726** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7727** implementation is included with the library. In this case the
7728** application must supply a custom mutex implementation using the
7729** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7730** before calling sqlite3_initialize() or any other public sqlite3_
7731** function that calls sqlite3_initialize().
7732**
7733** ^The sqlite3_mutex_alloc() routine allocates a new
7734** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7735** routine returns NULL if it is unable to allocate the requested
7736** mutex. The argument to sqlite3_mutex_alloc() must one of these
7737** integer constants:
7738**
7739** <ul>
7740** <li> SQLITE_MUTEX_FAST
7741** <li> SQLITE_MUTEX_RECURSIVE
7742** <li> SQLITE_MUTEX_STATIC_MAIN
7743** <li> SQLITE_MUTEX_STATIC_MEM
7744** <li> SQLITE_MUTEX_STATIC_OPEN
7745** <li> SQLITE_MUTEX_STATIC_PRNG
7746** <li> SQLITE_MUTEX_STATIC_LRU
7747** <li> SQLITE_MUTEX_STATIC_PMEM
7748** <li> SQLITE_MUTEX_STATIC_APP1
7749** <li> SQLITE_MUTEX_STATIC_APP2
7750** <li> SQLITE_MUTEX_STATIC_APP3
7751** <li> SQLITE_MUTEX_STATIC_VFS1
7752** <li> SQLITE_MUTEX_STATIC_VFS2
7753** <li> SQLITE_MUTEX_STATIC_VFS3
7754** </ul>
7755**
7756** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7757** cause sqlite3_mutex_alloc() to create
7758** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7759** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7760** The mutex implementation does not need to make a distinction
7761** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7762** not want to. SQLite will only request a recursive mutex in
7763** cases where it really needs one. If a faster non-recursive mutex
7764** implementation is available on the host platform, the mutex subsystem
7765** might return such a mutex in response to SQLITE_MUTEX_FAST.
7766**
7767** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7768** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7769** a pointer to a static preexisting mutex. ^Nine static mutexes are
7770** used by the current version of SQLite. Future versions of SQLite
7771** may add additional static mutexes. Static mutexes are for internal
7772** use by SQLite only. Applications that use SQLite mutexes should
7773** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7774** SQLITE_MUTEX_RECURSIVE.
7775**
7776** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7777** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7778** returns a different mutex on every call. ^For the static
7779** mutex types, the same mutex is returned on every call that has
7780** the same type number.
7781**
7782** ^The sqlite3_mutex_free() routine deallocates a previously
7783** allocated dynamic mutex. Attempting to deallocate a static
7784** mutex results in undefined behavior.
7785**
7786** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7787** to enter a mutex. ^If another thread is already within the mutex,
7788** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7789** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7790** upon successful entry. ^(Mutexes created using
7791** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7792** In such cases, the
7793** mutex must be exited an equal number of times before another thread
7794** can enter.)^ If the same thread tries to enter any mutex other
7795** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7796**
7797** ^(Some systems (for example, Windows 95) do not support the operation
7798** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7799** will always return SQLITE_BUSY. The SQLite core only ever uses
7800** sqlite3_mutex_try() as an optimization so this is acceptable
7801** behavior.)^
7802**
7803** ^The sqlite3_mutex_leave() routine exits a mutex that was
7804** previously entered by the same thread. The behavior
7805** is undefined if the mutex is not currently entered by the
7806** calling thread or is not currently allocated.
7807**
7808** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7809** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7810** behave as no-ops.
7811**
7812** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7813*/
7814SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7815SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7816SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7817SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7818SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7819
7820/*
7821** CAPI3REF: Mutex Methods Object
7822**
7823** An instance of this structure defines the low-level routines
7824** used to allocate and use mutexes.
7825**
7826** Usually, the default mutex implementations provided by SQLite are
7827** sufficient, however the application has the option of substituting a custom
7828** implementation for specialized deployments or systems for which SQLite
7829** does not provide a suitable implementation. In this case, the application
7830** creates and populates an instance of this structure to pass
7831** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7832** Additionally, an instance of this structure can be used as an
7833** output variable when querying the system for the current mutex
7834** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7835**
7836** ^The xMutexInit method defined by this structure is invoked as
7837** part of system initialization by the sqlite3_initialize() function.
7838** ^The xMutexInit routine is called by SQLite exactly once for each
7839** effective call to [sqlite3_initialize()].
7840**
7841** ^The xMutexEnd method defined by this structure is invoked as
7842** part of system shutdown by the sqlite3_shutdown() function. The
7843** implementation of this method is expected to release all outstanding
7844** resources obtained by the mutex methods implementation, especially
7845** those obtained by the xMutexInit method. ^The xMutexEnd()
7846** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7847**
7848** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7849** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7850** xMutexNotheld) implement the following interfaces (respectively):
7851**
7852** <ul>
7853** <li> [sqlite3_mutex_alloc()] </li>
7854** <li> [sqlite3_mutex_free()] </li>
7855** <li> [sqlite3_mutex_enter()] </li>
7856** <li> [sqlite3_mutex_try()] </li>
7857** <li> [sqlite3_mutex_leave()] </li>
7858** <li> [sqlite3_mutex_held()] </li>
7859** <li> [sqlite3_mutex_notheld()] </li>
7860** </ul>)^
7861**
7862** The only difference is that the public sqlite3_XXX functions enumerated
7863** above silently ignore any invocations that pass a NULL pointer instead
7864** of a valid mutex handle. The implementations of the methods defined
7865** by this structure are not required to handle this case. The results
7866** of passing a NULL pointer instead of a valid mutex handle are undefined
7867** (i.e. it is acceptable to provide an implementation that segfaults if
7868** it is passed a NULL pointer).
7869**
7870** The xMutexInit() method must be threadsafe. It must be harmless to
7871** invoke xMutexInit() multiple times within the same process and without
7872** intervening calls to xMutexEnd(). Second and subsequent calls to
7873** xMutexInit() must be no-ops.
7874**
7875** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7876** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7877** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7878** memory allocation for a fast or recursive mutex.
7879**
7880** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7881** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7882** If xMutexInit fails in any way, it is expected to clean up after itself
7883** prior to returning.
7884*/
7885typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7886struct sqlite3_mutex_methods {
7887 int (*xMutexInit)(void);
7888 int (*xMutexEnd)(void);
7889 sqlite3_mutex *(*xMutexAlloc)(int);
7890 void (*xMutexFree)(sqlite3_mutex *);
7891 void (*xMutexEnter)(sqlite3_mutex *);
7892 int (*xMutexTry)(sqlite3_mutex *);
7893 void (*xMutexLeave)(sqlite3_mutex *);
7894 int (*xMutexHeld)(sqlite3_mutex *);
7895 int (*xMutexNotheld)(sqlite3_mutex *);
7896};
7897
7898/*
7899** CAPI3REF: Mutex Verification Routines
7900**
7901** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7902** are intended for use inside assert() statements. The SQLite core
7903** never uses these routines except inside an assert() and applications
7904** are advised to follow the lead of the core. The SQLite core only
7905** provides implementations for these routines when it is compiled
7906** with the SQLITE_DEBUG flag. External mutex implementations
7907** are only required to provide these routines if SQLITE_DEBUG is
7908** defined and if NDEBUG is not defined.
7909**
7910** These routines should return true if the mutex in their argument
7911** is held or not held, respectively, by the calling thread.
7912**
7913** The implementation is not required to provide versions of these
7914** routines that actually work. If the implementation does not provide working
7915** versions of these routines, it should at least provide stubs that always
7916** return true so that one does not get spurious assertion failures.
7917**
7918** If the argument to sqlite3_mutex_held() is a NULL pointer then
7919** the routine should return 1. This seems counter-intuitive since
7920** clearly the mutex cannot be held if it does not exist. But
7921** the reason the mutex does not exist is because the build is not
7922** using mutexes. And we do not want the assert() containing the
7923** call to sqlite3_mutex_held() to fail, so a non-zero return is
7924** the appropriate thing to do. The sqlite3_mutex_notheld()
7925** interface should also return 1 when given a NULL pointer.
7926*/
7927#ifndef NDEBUG
7928SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7929SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7930#endif
7931
7932/*
7933** CAPI3REF: Mutex Types
7934**
7935** The [sqlite3_mutex_alloc()] interface takes a single argument
7936** which is one of these integer constants.
7937**
7938** The set of static mutexes may change from one SQLite release to the
7939** next. Applications that override the built-in mutex logic must be
7940** prepared to accommodate additional static mutexes.
7941*/
7942#define SQLITE_MUTEX_FAST 0
7943#define SQLITE_MUTEX_RECURSIVE 1
7944#define SQLITE_MUTEX_STATIC_MAIN 2
7945#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7946#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7947#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7948#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7949#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7950#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7951#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7952#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7953#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7954#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7955#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7956#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7957#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7958
7959/* Legacy compatibility: */
7960#define SQLITE_MUTEX_STATIC_MASTER 2
7961
7962
7963/*
7964** CAPI3REF: Retrieve the mutex for a database connection
7965** METHOD: sqlite3
7966**
7967** ^This interface returns a pointer the [sqlite3_mutex] object that
7968** serializes access to the [database connection] given in the argument
7969** when the [threading mode] is Serialized.
7970** ^If the [threading mode] is Single-thread or Multi-thread then this
7971** routine returns a NULL pointer.
7972*/
7973SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7974
7975/*
7976** CAPI3REF: Low-Level Control Of Database Files
7977** METHOD: sqlite3
7978** KEYWORDS: {file control}
7979**
7980** ^The [sqlite3_file_control()] interface makes a direct call to the
7981** xFileControl method for the [sqlite3_io_methods] object associated
7982** with a particular database identified by the second argument. ^The
7983** name of the database is "main" for the main database or "temp" for the
7984** TEMP database, or the name that appears after the AS keyword for
7985** databases that are added using the [ATTACH] SQL command.
7986** ^A NULL pointer can be used in place of "main" to refer to the
7987** main database file.
7988** ^The third and fourth parameters to this routine
7989** are passed directly through to the second and third parameters of
7990** the xFileControl method. ^The return value of the xFileControl
7991** method becomes the return value of this routine.
7992**
7993** A few opcodes for [sqlite3_file_control()] are handled directly
7994** by the SQLite core and never invoke the
7995** sqlite3_io_methods.xFileControl method.
7996** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7997** a pointer to the underlying [sqlite3_file] object to be written into
7998** the space pointed to by the 4th parameter. The
7999** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8000** the [sqlite3_file] object associated with the journal file instead of
8001** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8002** a pointer to the underlying [sqlite3_vfs] object for the file.
8003** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8004** from the pager.
8005**
8006** ^If the second parameter (zDbName) does not match the name of any
8007** open database file, then SQLITE_ERROR is returned. ^This error
8008** code is not remembered and will not be recalled by [sqlite3_errcode()]
8009** or [sqlite3_errmsg()]. The underlying xFileControl method might
8010** also return SQLITE_ERROR. There is no way to distinguish between
8011** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8012** xFileControl method.
8013**
8014** See also: [file control opcodes]
8015*/
8016SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8017
8018/*
8019** CAPI3REF: Testing Interface
8020**
8021** ^The sqlite3_test_control() interface is used to read out internal
8022** state of SQLite and to inject faults into SQLite for testing
8023** purposes. ^The first parameter is an operation code that determines
8024** the number, meaning, and operation of all subsequent parameters.
8025**
8026** This interface is not for use by applications. It exists solely
8027** for verifying the correct operation of the SQLite library. Depending
8028** on how the SQLite library is compiled, this interface might not exist.
8029**
8030** The details of the operation codes, their meanings, the parameters
8031** they take, and what they do are all subject to change without notice.
8032** Unlike most of the SQLite API, this function is not guaranteed to
8033** operate consistently from one release to the next.
8034*/
8035SQLITE_API int sqlite3_test_control(int op, ...);
8036
8037/*
8038** CAPI3REF: Testing Interface Operation Codes
8039**
8040** These constants are the valid operation code parameters used
8041** as the first argument to [sqlite3_test_control()].
8042**
8043** These parameters and their meanings are subject to change
8044** without notice. These values are for testing purposes only.
8045** Applications should not use any of these parameters or the
8046** [sqlite3_test_control()] interface.
8047*/
8048#define SQLITE_TESTCTRL_FIRST 5
8049#define SQLITE_TESTCTRL_PRNG_SAVE 5
8050#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8051#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8052#define SQLITE_TESTCTRL_BITVEC_TEST 8
8053#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8054#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8055#define SQLITE_TESTCTRL_PENDING_BYTE 11
8056#define SQLITE_TESTCTRL_ASSERT 12
8057#define SQLITE_TESTCTRL_ALWAYS 13
8058#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8059#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8060#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8061#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8062#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8063#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8064#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8065#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8066#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8067#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8068#define SQLITE_TESTCTRL_BYTEORDER 22
8069#define SQLITE_TESTCTRL_ISINIT 23
8070#define SQLITE_TESTCTRL_SORTER_MMAP 24
8071#define SQLITE_TESTCTRL_IMPOSTER 25
8072#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8073#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8074#define SQLITE_TESTCTRL_PRNG_SEED 28
8075#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8076#define SQLITE_TESTCTRL_SEEK_COUNT 30
8077#define SQLITE_TESTCTRL_TRACEFLAGS 31
8078#define SQLITE_TESTCTRL_TUNE 32
8079#define SQLITE_TESTCTRL_LOGEST 33
8080#define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */
8081
8082/*
8083** CAPI3REF: SQL Keyword Checking
8084**
8085** These routines provide access to the set of SQL language keywords
8086** recognized by SQLite. Applications can uses these routines to determine
8087** whether or not a specific identifier needs to be escaped (for example,
8088** by enclosing in double-quotes) so as not to confuse the parser.
8089**
8090** The sqlite3_keyword_count() interface returns the number of distinct
8091** keywords understood by SQLite.
8092**
8093** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
8094** makes *Z point to that keyword expressed as UTF8 and writes the number
8095** of bytes in the keyword into *L. The string that *Z points to is not
8096** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8097** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8098** or L are NULL or invalid pointers then calls to
8099** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8100**
8101** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8102** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8103** if it is and zero if not.
8104**
8105** The parser used by SQLite is forgiving. It is often possible to use
8106** a keyword as an identifier as long as such use does not result in a
8107** parsing ambiguity. For example, the statement
8108** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8109** creates a new table named "BEGIN" with three columns named
8110** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8111** using keywords as identifiers. Common techniques used to avoid keyword
8112** name collisions include:
8113** <ul>
8114** <li> Put all identifier names inside double-quotes. This is the official
8115** SQL way to escape identifier names.
8116** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8117** but it is what SQL Server does and so lots of programmers use this
8118** technique.
8119** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8120** with "Z".
8121** <li> Include a digit somewhere in every identifier name.
8122** </ul>
8123**
8124** Note that the number of keywords understood by SQLite can depend on
8125** compile-time options. For example, "VACUUM" is not a keyword if
8126** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8127** new keywords may be added to future releases of SQLite.
8128*/
8129SQLITE_API int sqlite3_keyword_count(void);
8130SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8131SQLITE_API int sqlite3_keyword_check(const char*,int);
8132
8133/*
8134** CAPI3REF: Dynamic String Object
8135** KEYWORDS: {dynamic string}
8136**
8137** An instance of the sqlite3_str object contains a dynamically-sized
8138** string under construction.
8139**
8140** The lifecycle of an sqlite3_str object is as follows:
8141** <ol>
8142** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8143** <li> ^Text is appended to the sqlite3_str object using various
8144** methods, such as [sqlite3_str_appendf()].
8145** <li> ^The sqlite3_str object is destroyed and the string it created
8146** is returned using the [sqlite3_str_finish()] interface.
8147** </ol>
8148*/
8149typedef struct sqlite3_str sqlite3_str;
8150
8151/*
8152** CAPI3REF: Create A New Dynamic String Object
8153** CONSTRUCTOR: sqlite3_str
8154**
8155** ^The [sqlite3_str_new(D)] interface allocates and initializes
8156** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8157** [sqlite3_str_new()] must be freed by a subsequent call to
8158** [sqlite3_str_finish(X)].
8159**
8160** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8161** valid [sqlite3_str] object, though in the event of an out-of-memory
8162** error the returned object might be a special singleton that will
8163** silently reject new text, always return SQLITE_NOMEM from
8164** [sqlite3_str_errcode()], always return 0 for
8165** [sqlite3_str_length()], and always return NULL from
8166** [sqlite3_str_finish(X)]. It is always safe to use the value
8167** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8168** to any of the other [sqlite3_str] methods.
8169**
8170** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8171** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8172** length of the string contained in the [sqlite3_str] object will be
8173** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8174** of [SQLITE_MAX_LENGTH].
8175*/
8176SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8177
8178/*
8179** CAPI3REF: Finalize A Dynamic String
8180** DESTRUCTOR: sqlite3_str
8181**
8182** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8183** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8184** that contains the constructed string. The calling application should
8185** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8186** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8187** errors were encountered during construction of the string. ^The
8188** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8189** string in [sqlite3_str] object X is zero bytes long.
8190*/
8191SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8192
8193/*
8194** CAPI3REF: Add Content To A Dynamic String
8195** METHOD: sqlite3_str
8196**
8197** These interfaces add content to an sqlite3_str object previously obtained
8198** from [sqlite3_str_new()].
8199**
8200** ^The [sqlite3_str_appendf(X,F,...)] and
8201** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8202** functionality of SQLite to append formatted text onto the end of
8203** [sqlite3_str] object X.
8204**
8205** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8206** onto the end of the [sqlite3_str] object X. N must be non-negative.
8207** S must contain at least N non-zero bytes of content. To append a
8208** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8209** method instead.
8210**
8211** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8212** zero-terminated string S onto the end of [sqlite3_str] object X.
8213**
8214** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8215** single-byte character C onto the end of [sqlite3_str] object X.
8216** ^This method can be used, for example, to add whitespace indentation.
8217**
8218** ^The [sqlite3_str_reset(X)] method resets the string under construction
8219** inside [sqlite3_str] object X back to zero bytes in length.
8220**
8221** These methods do not return a result code. ^If an error occurs, that fact
8222** is recorded in the [sqlite3_str] object and can be recovered by a
8223** subsequent call to [sqlite3_str_errcode(X)].
8224*/
8225SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8226SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8227SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8228SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8229SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8230SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8231
8232/*
8233** CAPI3REF: Status Of A Dynamic String
8234** METHOD: sqlite3_str
8235**
8236** These interfaces return the current status of an [sqlite3_str] object.
8237**
8238** ^If any prior errors have occurred while constructing the dynamic string
8239** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8240** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8241** [SQLITE_NOMEM] following any out-of-memory error, or
8242** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8243** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8244**
8245** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8246** of the dynamic string under construction in [sqlite3_str] object X.
8247** ^The length returned by [sqlite3_str_length(X)] does not include the
8248** zero-termination byte.
8249**
8250** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8251** content of the dynamic string under construction in X. The value
8252** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8253** and might be freed or altered by any subsequent method on the same
8254** [sqlite3_str] object. Applications must not used the pointer returned
8255** [sqlite3_str_value(X)] after any subsequent method call on the same
8256** object. ^Applications may change the content of the string returned
8257** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8258** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8259** write any byte after any subsequent sqlite3_str method call.
8260*/
8261SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8262SQLITE_API int sqlite3_str_length(sqlite3_str*);
8263SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8264
8265/*
8266** CAPI3REF: SQLite Runtime Status
8267**
8268** ^These interfaces are used to retrieve runtime status information
8269** about the performance of SQLite, and optionally to reset various
8270** highwater marks. ^The first argument is an integer code for
8271** the specific parameter to measure. ^(Recognized integer codes
8272** are of the form [status parameters | SQLITE_STATUS_...].)^
8273** ^The current value of the parameter is returned into *pCurrent.
8274** ^The highest recorded value is returned in *pHighwater. ^If the
8275** resetFlag is true, then the highest record value is reset after
8276** *pHighwater is written. ^(Some parameters do not record the highest
8277** value. For those parameters
8278** nothing is written into *pHighwater and the resetFlag is ignored.)^
8279** ^(Other parameters record only the highwater mark and not the current
8280** value. For these latter parameters nothing is written into *pCurrent.)^
8281**
8282** ^The sqlite3_status() and sqlite3_status64() routines return
8283** SQLITE_OK on success and a non-zero [error code] on failure.
8284**
8285** If either the current value or the highwater mark is too large to
8286** be represented by a 32-bit integer, then the values returned by
8287** sqlite3_status() are undefined.
8288**
8289** See also: [sqlite3_db_status()]
8290*/
8291SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8292SQLITE_API int sqlite3_status64(
8293 int op,
8294 sqlite3_int64 *pCurrent,
8295 sqlite3_int64 *pHighwater,
8296 int resetFlag
8297);
8298
8299
8300/*
8301** CAPI3REF: Status Parameters
8302** KEYWORDS: {status parameters}
8303**
8304** These integer constants designate various run-time status parameters
8305** that can be returned by [sqlite3_status()].
8306**
8307** <dl>
8308** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8309** <dd>This parameter is the current amount of memory checked out
8310** using [sqlite3_malloc()], either directly or indirectly. The
8311** figure includes calls made to [sqlite3_malloc()] by the application
8312** and internal memory usage by the SQLite library. Auxiliary page-cache
8313** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8314** this parameter. The amount returned is the sum of the allocation
8315** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8316**
8317** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8318** <dd>This parameter records the largest memory allocation request
8319** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8320** internal equivalents). Only the value returned in the
8321** *pHighwater parameter to [sqlite3_status()] is of interest.
8322** The value written into the *pCurrent parameter is undefined.</dd>)^
8323**
8324** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8325** <dd>This parameter records the number of separate memory allocations
8326** currently checked out.</dd>)^
8327**
8328** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8329** <dd>This parameter returns the number of pages used out of the
8330** [pagecache memory allocator] that was configured using
8331** [SQLITE_CONFIG_PAGECACHE]. The
8332** value returned is in pages, not in bytes.</dd>)^
8333**
8334** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8335** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8336** <dd>This parameter returns the number of bytes of page cache
8337** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8338** buffer and where forced to overflow to [sqlite3_malloc()]. The
8339** returned value includes allocations that overflowed because they
8340** where too large (they were larger than the "sz" parameter to
8341** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8342** no space was left in the page cache.</dd>)^
8343**
8344** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8345** <dd>This parameter records the largest memory allocation request
8346** handed to the [pagecache memory allocator]. Only the value returned in the
8347** *pHighwater parameter to [sqlite3_status()] is of interest.
8348** The value written into the *pCurrent parameter is undefined.</dd>)^
8349**
8350** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8351** <dd>No longer used.</dd>
8352**
8353** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8354** <dd>No longer used.</dd>
8355**
8356** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8357** <dd>No longer used.</dd>
8358**
8359** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8360** <dd>The *pHighwater parameter records the deepest parser stack.
8361** The *pCurrent value is undefined. The *pHighwater value is only
8362** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8363** </dl>
8364**
8365** New status parameters may be added from time to time.
8366*/
8367#define SQLITE_STATUS_MEMORY_USED 0
8368#define SQLITE_STATUS_PAGECACHE_USED 1
8369#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8370#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8371#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8372#define SQLITE_STATUS_MALLOC_SIZE 5
8373#define SQLITE_STATUS_PARSER_STACK 6
8374#define SQLITE_STATUS_PAGECACHE_SIZE 7
8375#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8376#define SQLITE_STATUS_MALLOC_COUNT 9
8377
8378/*
8379** CAPI3REF: Database Connection Status
8380** METHOD: sqlite3
8381**
8382** ^This interface is used to retrieve runtime status information
8383** about a single [database connection]. ^The first argument is the
8384** database connection object to be interrogated. ^The second argument
8385** is an integer constant, taken from the set of
8386** [SQLITE_DBSTATUS options], that
8387** determines the parameter to interrogate. The set of
8388** [SQLITE_DBSTATUS options] is likely
8389** to grow in future releases of SQLite.
8390**
8391** ^The current value of the requested parameter is written into *pCur
8392** and the highest instantaneous value is written into *pHiwtr. ^If
8393** the resetFlg is true, then the highest instantaneous value is
8394** reset back down to the current value.
8395**
8396** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8397** non-zero [error code] on failure.
8398**
8399** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8400*/
8401SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8402
8403/*
8404** CAPI3REF: Status Parameters for database connections
8405** KEYWORDS: {SQLITE_DBSTATUS options}
8406**
8407** These constants are the available integer "verbs" that can be passed as
8408** the second argument to the [sqlite3_db_status()] interface.
8409**
8410** New verbs may be added in future releases of SQLite. Existing verbs
8411** might be discontinued. Applications should check the return code from
8412** [sqlite3_db_status()] to make sure that the call worked.
8413** The [sqlite3_db_status()] interface will return a non-zero error code
8414** if a discontinued or unsupported verb is invoked.
8415**
8416** <dl>
8417** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8418** <dd>This parameter returns the number of lookaside memory slots currently
8419** checked out.</dd>)^
8420**
8421** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8422** <dd>This parameter returns the number of malloc attempts that were
8423** satisfied using lookaside memory. Only the high-water value is meaningful;
8424** the current value is always zero.)^
8425**
8426** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8427** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8428** <dd>This parameter returns the number malloc attempts that might have
8429** been satisfied using lookaside memory but failed due to the amount of
8430** memory requested being larger than the lookaside slot size.
8431** Only the high-water value is meaningful;
8432** the current value is always zero.)^
8433**
8434** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8435** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8436** <dd>This parameter returns the number malloc attempts that might have
8437** been satisfied using lookaside memory but failed due to all lookaside
8438** memory already being in use.
8439** Only the high-water value is meaningful;
8440** the current value is always zero.)^
8441**
8442** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8443** <dd>This parameter returns the approximate number of bytes of heap
8444** memory used by all pager caches associated with the database connection.)^
8445** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8446**
8447** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8448** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8449** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8450** pager cache is shared between two or more connections the bytes of heap
8451** memory used by that pager cache is divided evenly between the attached
8452** connections.)^ In other words, if none of the pager caches associated
8453** with the database connection are shared, this request returns the same
8454** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8455** shared, the value returned by this call will be smaller than that returned
8456** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8457** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8458**
8459** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8460** <dd>This parameter returns the approximate number of bytes of heap
8461** memory used to store the schema for all databases associated
8462** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8463** ^The full amount of memory used by the schemas is reported, even if the
8464** schema memory is shared with other database connections due to
8465** [shared cache mode] being enabled.
8466** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8467**
8468** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8469** <dd>This parameter returns the approximate number of bytes of heap
8470** and lookaside memory used by all prepared statements associated with
8471** the database connection.)^
8472** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8473** </dd>
8474**
8475** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8476** <dd>This parameter returns the number of pager cache hits that have
8477** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8478** is always 0.
8479** </dd>
8480**
8481** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8482** <dd>This parameter returns the number of pager cache misses that have
8483** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8484** is always 0.
8485** </dd>
8486**
8487** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8488** <dd>This parameter returns the number of dirty cache entries that have
8489** been written to disk. Specifically, the number of pages written to the
8490** wal file in wal mode databases, or the number of pages written to the
8491** database file in rollback mode databases. Any pages written as part of
8492** transaction rollback or database recovery operations are not included.
8493** If an IO or other error occurs while writing a page to disk, the effect
8494** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8495** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8496** </dd>
8497**
8498** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8499** <dd>This parameter returns the number of dirty cache entries that have
8500** been written to disk in the middle of a transaction due to the page
8501** cache overflowing. Transactions are more efficient if they are written
8502** to disk all at once. When pages spill mid-transaction, that introduces
8503** additional overhead. This parameter can be used help identify
8504** inefficiencies that can be resolved by increasing the cache size.
8505** </dd>
8506**
8507** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8508** <dd>This parameter returns zero for the current value if and only if
8509** all foreign key constraints (deferred or immediate) have been
8510** resolved.)^ ^The highwater mark is always 0.
8511** </dd>
8512** </dl>
8513*/
8514#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8515#define SQLITE_DBSTATUS_CACHE_USED 1
8516#define SQLITE_DBSTATUS_SCHEMA_USED 2
8517#define SQLITE_DBSTATUS_STMT_USED 3
8518#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8519#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8520#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8521#define SQLITE_DBSTATUS_CACHE_HIT 7
8522#define SQLITE_DBSTATUS_CACHE_MISS 8
8523#define SQLITE_DBSTATUS_CACHE_WRITE 9
8524#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8525#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8526#define SQLITE_DBSTATUS_CACHE_SPILL 12
8527#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8528
8529
8530/*
8531** CAPI3REF: Prepared Statement Status
8532** METHOD: sqlite3_stmt
8533**
8534** ^(Each prepared statement maintains various
8535** [SQLITE_STMTSTATUS counters] that measure the number
8536** of times it has performed specific operations.)^ These counters can
8537** be used to monitor the performance characteristics of the prepared
8538** statements. For example, if the number of table steps greatly exceeds
8539** the number of table searches or result rows, that would tend to indicate
8540** that the prepared statement is using a full table scan rather than
8541** an index.
8542**
8543** ^(This interface is used to retrieve and reset counter values from
8544** a [prepared statement]. The first argument is the prepared statement
8545** object to be interrogated. The second argument
8546** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8547** to be interrogated.)^
8548** ^The current value of the requested counter is returned.
8549** ^If the resetFlg is true, then the counter is reset to zero after this
8550** interface call returns.
8551**
8552** See also: [sqlite3_status()] and [sqlite3_db_status()].
8553*/
8554SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8555
8556/*
8557** CAPI3REF: Status Parameters for prepared statements
8558** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8559**
8560** These preprocessor macros define integer codes that name counter
8561** values associated with the [sqlite3_stmt_status()] interface.
8562** The meanings of the various counters are as follows:
8563**
8564** <dl>
8565** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8566** <dd>^This is the number of times that SQLite has stepped forward in
8567** a table as part of a full table scan. Large numbers for this counter
8568** may indicate opportunities for performance improvement through
8569** careful use of indices.</dd>
8570**
8571** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8572** <dd>^This is the number of sort operations that have occurred.
8573** A non-zero value in this counter may indicate an opportunity to
8574** improvement performance through careful use of indices.</dd>
8575**
8576** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8577** <dd>^This is the number of rows inserted into transient indices that
8578** were created automatically in order to help joins run faster.
8579** A non-zero value in this counter may indicate an opportunity to
8580** improvement performance by adding permanent indices that do not
8581** need to be reinitialized each time the statement is run.</dd>
8582**
8583** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8584** <dd>^This is the number of virtual machine operations executed
8585** by the prepared statement if that number is less than or equal
8586** to 2147483647. The number of virtual machine operations can be
8587** used as a proxy for the total work done by the prepared statement.
8588** If the number of virtual machine operations exceeds 2147483647
8589** then the value returned by this statement status code is undefined.
8590**
8591** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8592** <dd>^This is the number of times that the prepare statement has been
8593** automatically regenerated due to schema changes or changes to
8594** [bound parameters] that might affect the query plan.
8595**
8596** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8597** <dd>^This is the number of times that the prepared statement has
8598** been run. A single "run" for the purposes of this counter is one
8599** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8600** The counter is incremented on the first [sqlite3_step()] call of each
8601** cycle.
8602**
8603** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8604** [[SQLITE_STMTSTATUS_FILTER HIT]]
8605** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8606** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8607** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8608** step was bypassed because a Bloom filter returned not-found. The
8609** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8610** times that the Bloom filter returned a find, and thus the join step
8611** had to be processed as normal.
8612**
8613** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8614** <dd>^This is the approximate number of bytes of heap memory
8615** used to store the prepared statement. ^This value is not actually
8616** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8617** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8618** </dd>
8619** </dl>
8620*/
8621#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8622#define SQLITE_STMTSTATUS_SORT 2
8623#define SQLITE_STMTSTATUS_AUTOINDEX 3
8624#define SQLITE_STMTSTATUS_VM_STEP 4
8625#define SQLITE_STMTSTATUS_REPREPARE 5
8626#define SQLITE_STMTSTATUS_RUN 6
8627#define SQLITE_STMTSTATUS_FILTER_MISS 7
8628#define SQLITE_STMTSTATUS_FILTER_HIT 8
8629#define SQLITE_STMTSTATUS_MEMUSED 99
8630
8631/*
8632** CAPI3REF: Custom Page Cache Object
8633**
8634** The sqlite3_pcache type is opaque. It is implemented by
8635** the pluggable module. The SQLite core has no knowledge of
8636** its size or internal structure and never deals with the
8637** sqlite3_pcache object except by holding and passing pointers
8638** to the object.
8639**
8640** See [sqlite3_pcache_methods2] for additional information.
8641*/
8642typedef struct sqlite3_pcache sqlite3_pcache;
8643
8644/*
8645** CAPI3REF: Custom Page Cache Object
8646**
8647** The sqlite3_pcache_page object represents a single page in the
8648** page cache. The page cache will allocate instances of this
8649** object. Various methods of the page cache use pointers to instances
8650** of this object as parameters or as their return value.
8651**
8652** See [sqlite3_pcache_methods2] for additional information.
8653*/
8654typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8655struct sqlite3_pcache_page {
8656 void *pBuf; /* The content of the page */
8657 void *pExtra; /* Extra information associated with the page */
8658};
8659
8660/*
8661** CAPI3REF: Application Defined Page Cache.
8662** KEYWORDS: {page cache}
8663**
8664** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8665** register an alternative page cache implementation by passing in an
8666** instance of the sqlite3_pcache_methods2 structure.)^
8667** In many applications, most of the heap memory allocated by
8668** SQLite is used for the page cache.
8669** By implementing a
8670** custom page cache using this API, an application can better control
8671** the amount of memory consumed by SQLite, the way in which
8672** that memory is allocated and released, and the policies used to
8673** determine exactly which parts of a database file are cached and for
8674** how long.
8675**
8676** The alternative page cache mechanism is an
8677** extreme measure that is only needed by the most demanding applications.
8678** The built-in page cache is recommended for most uses.
8679**
8680** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8681** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8682** the application may discard the parameter after the call to
8683** [sqlite3_config()] returns.)^
8684**
8685** [[the xInit() page cache method]]
8686** ^(The xInit() method is called once for each effective
8687** call to [sqlite3_initialize()])^
8688** (usually only once during the lifetime of the process). ^(The xInit()
8689** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8690** The intent of the xInit() method is to set up global data structures
8691** required by the custom page cache implementation.
8692** ^(If the xInit() method is NULL, then the
8693** built-in default page cache is used instead of the application defined
8694** page cache.)^
8695**
8696** [[the xShutdown() page cache method]]
8697** ^The xShutdown() method is called by [sqlite3_shutdown()].
8698** It can be used to clean up
8699** any outstanding resources before process shutdown, if required.
8700** ^The xShutdown() method may be NULL.
8701**
8702** ^SQLite automatically serializes calls to the xInit method,
8703** so the xInit method need not be threadsafe. ^The
8704** xShutdown method is only called from [sqlite3_shutdown()] so it does
8705** not need to be threadsafe either. All other methods must be threadsafe
8706** in multithreaded applications.
8707**
8708** ^SQLite will never invoke xInit() more than once without an intervening
8709** call to xShutdown().
8710**
8711** [[the xCreate() page cache methods]]
8712** ^SQLite invokes the xCreate() method to construct a new cache instance.
8713** SQLite will typically create one cache instance for each open database file,
8714** though this is not guaranteed. ^The
8715** first parameter, szPage, is the size in bytes of the pages that must
8716** be allocated by the cache. ^szPage will always a power of two. ^The
8717** second parameter szExtra is a number of bytes of extra storage
8718** associated with each page cache entry. ^The szExtra parameter will
8719** a number less than 250. SQLite will use the
8720** extra szExtra bytes on each page to store metadata about the underlying
8721** database page on disk. The value passed into szExtra depends
8722** on the SQLite version, the target platform, and how SQLite was compiled.
8723** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8724** created will be used to cache database pages of a file stored on disk, or
8725** false if it is used for an in-memory database. The cache implementation
8726** does not have to do anything special based with the value of bPurgeable;
8727** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8728** never invoke xUnpin() except to deliberately delete a page.
8729** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8730** false will always have the "discard" flag set to true.
8731** ^Hence, a cache created with bPurgeable false will
8732** never contain any unpinned pages.
8733**
8734** [[the xCachesize() page cache method]]
8735** ^(The xCachesize() method may be called at any time by SQLite to set the
8736** suggested maximum cache-size (number of pages stored by) the cache
8737** instance passed as the first argument. This is the value configured using
8738** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8739** parameter, the implementation is not required to do anything with this
8740** value; it is advisory only.
8741**
8742** [[the xPagecount() page cache methods]]
8743** The xPagecount() method must return the number of pages currently
8744** stored in the cache, both pinned and unpinned.
8745**
8746** [[the xFetch() page cache methods]]
8747** The xFetch() method locates a page in the cache and returns a pointer to
8748** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8749** The pBuf element of the returned sqlite3_pcache_page object will be a
8750** pointer to a buffer of szPage bytes used to store the content of a
8751** single database page. The pExtra element of sqlite3_pcache_page will be
8752** a pointer to the szExtra bytes of extra storage that SQLite has requested
8753** for each entry in the page cache.
8754**
8755** The page to be fetched is determined by the key. ^The minimum key value
8756** is 1. After it has been retrieved using xFetch, the page is considered
8757** to be "pinned".
8758**
8759** If the requested page is already in the page cache, then the page cache
8760** implementation must return a pointer to the page buffer with its content
8761** intact. If the requested page is not already in the cache, then the
8762** cache implementation should use the value of the createFlag
8763** parameter to help it determined what action to take:
8764**
8765** <table border=1 width=85% align=center>
8766** <tr><th> createFlag <th> Behavior when page is not already in cache
8767** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8768** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8769** Otherwise return NULL.
8770** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8771** NULL if allocating a new page is effectively impossible.
8772** </table>
8773**
8774** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8775** will only use a createFlag of 2 after a prior call with a createFlag of 1
8776** failed.)^ In between the xFetch() calls, SQLite may
8777** attempt to unpin one or more cache pages by spilling the content of
8778** pinned pages to disk and synching the operating system disk cache.
8779**
8780** [[the xUnpin() page cache method]]
8781** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8782** as its second argument. If the third parameter, discard, is non-zero,
8783** then the page must be evicted from the cache.
8784** ^If the discard parameter is
8785** zero, then the page may be discarded or retained at the discretion of
8786** page cache implementation. ^The page cache implementation
8787** may choose to evict unpinned pages at any time.
8788**
8789** The cache must not perform any reference counting. A single
8790** call to xUnpin() unpins the page regardless of the number of prior calls
8791** to xFetch().
8792**
8793** [[the xRekey() page cache methods]]
8794** The xRekey() method is used to change the key value associated with the
8795** page passed as the second argument. If the cache
8796** previously contains an entry associated with newKey, it must be
8797** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8798** to be pinned.
8799**
8800** When SQLite calls the xTruncate() method, the cache must discard all
8801** existing cache entries with page numbers (keys) greater than or equal
8802** to the value of the iLimit parameter passed to xTruncate(). If any
8803** of these pages are pinned, they are implicitly unpinned, meaning that
8804** they can be safely discarded.
8805**
8806** [[the xDestroy() page cache method]]
8807** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8808** All resources associated with the specified cache should be freed. ^After
8809** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8810** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8811** functions.
8812**
8813** [[the xShrink() page cache method]]
8814** ^SQLite invokes the xShrink() method when it wants the page cache to
8815** free up as much of heap memory as possible. The page cache implementation
8816** is not obligated to free any memory, but well-behaved implementations should
8817** do their best.
8818*/
8819typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8820struct sqlite3_pcache_methods2 {
8821 int iVersion;
8822 void *pArg;
8823 int (*xInit)(void*);
8824 void (*xShutdown)(void*);
8825 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8826 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8827 int (*xPagecount)(sqlite3_pcache*);
8828 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8829 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8830 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8831 unsigned oldKey, unsigned newKey);
8832 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8833 void (*xDestroy)(sqlite3_pcache*);
8834 void (*xShrink)(sqlite3_pcache*);
8835};
8836
8837/*
8838** This is the obsolete pcache_methods object that has now been replaced
8839** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8840** retained in the header file for backwards compatibility only.
8841*/
8842typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8843struct sqlite3_pcache_methods {
8844 void *pArg;
8845 int (*xInit)(void*);
8846 void (*xShutdown)(void*);
8847 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8848 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8849 int (*xPagecount)(sqlite3_pcache*);
8850 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8851 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8852 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8853 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8854 void (*xDestroy)(sqlite3_pcache*);
8855};
8856
8857
8858/*
8859** CAPI3REF: Online Backup Object
8860**
8861** The sqlite3_backup object records state information about an ongoing
8862** online backup operation. ^The sqlite3_backup object is created by
8863** a call to [sqlite3_backup_init()] and is destroyed by a call to
8864** [sqlite3_backup_finish()].
8865**
8866** See Also: [Using the SQLite Online Backup API]
8867*/
8868typedef struct sqlite3_backup sqlite3_backup;
8869
8870/*
8871** CAPI3REF: Online Backup API.
8872**
8873** The backup API copies the content of one database into another.
8874** It is useful either for creating backups of databases or
8875** for copying in-memory databases to or from persistent files.
8876**
8877** See Also: [Using the SQLite Online Backup API]
8878**
8879** ^SQLite holds a write transaction open on the destination database file
8880** for the duration of the backup operation.
8881** ^The source database is read-locked only while it is being read;
8882** it is not locked continuously for the entire backup operation.
8883** ^Thus, the backup may be performed on a live source database without
8884** preventing other database connections from
8885** reading or writing to the source database while the backup is underway.
8886**
8887** ^(To perform a backup operation:
8888** <ol>
8889** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8890** backup,
8891** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8892** the data between the two databases, and finally
8893** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8894** associated with the backup operation.
8895** </ol>)^
8896** There should be exactly one call to sqlite3_backup_finish() for each
8897** successful call to sqlite3_backup_init().
8898**
8899** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8900**
8901** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8902** [database connection] associated with the destination database
8903** and the database name, respectively.
8904** ^The database name is "main" for the main database, "temp" for the
8905** temporary database, or the name specified after the AS keyword in
8906** an [ATTACH] statement for an attached database.
8907** ^The S and M arguments passed to
8908** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8909** and database name of the source database, respectively.
8910** ^The source and destination [database connections] (parameters S and D)
8911** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8912** an error.
8913**
8914** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8915** there is already a read or read-write transaction open on the
8916** destination database.
8917**
8918** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8919** returned and an error code and error message are stored in the
8920** destination [database connection] D.
8921** ^The error code and message for the failed call to sqlite3_backup_init()
8922** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8923** [sqlite3_errmsg16()] functions.
8924** ^A successful call to sqlite3_backup_init() returns a pointer to an
8925** [sqlite3_backup] object.
8926** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8927** sqlite3_backup_finish() functions to perform the specified backup
8928** operation.
8929**
8930** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8931**
8932** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8933** the source and destination databases specified by [sqlite3_backup] object B.
8934** ^If N is negative, all remaining source pages are copied.
8935** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8936** are still more pages to be copied, then the function returns [SQLITE_OK].
8937** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8938** from source to destination, then it returns [SQLITE_DONE].
8939** ^If an error occurs while running sqlite3_backup_step(B,N),
8940** then an [error code] is returned. ^As well as [SQLITE_OK] and
8941** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8942** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8943** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8944**
8945** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8946** <ol>
8947** <li> the destination database was opened read-only, or
8948** <li> the destination database is using write-ahead-log journaling
8949** and the destination and source page sizes differ, or
8950** <li> the destination database is an in-memory database and the
8951** destination and source page sizes differ.
8952** </ol>)^
8953**
8954** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8955** the [sqlite3_busy_handler | busy-handler function]
8956** is invoked (if one is specified). ^If the
8957** busy-handler returns non-zero before the lock is available, then
8958** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8959** sqlite3_backup_step() can be retried later. ^If the source
8960** [database connection]
8961** is being used to write to the source database when sqlite3_backup_step()
8962** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8963** case the call to sqlite3_backup_step() can be retried later on. ^(If
8964** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8965** [SQLITE_READONLY] is returned, then
8966** there is no point in retrying the call to sqlite3_backup_step(). These
8967** errors are considered fatal.)^ The application must accept
8968** that the backup operation has failed and pass the backup operation handle
8969** to the sqlite3_backup_finish() to release associated resources.
8970**
8971** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8972** on the destination file. ^The exclusive lock is not released until either
8973** sqlite3_backup_finish() is called or the backup operation is complete
8974** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8975** sqlite3_backup_step() obtains a [shared lock] on the source database that
8976** lasts for the duration of the sqlite3_backup_step() call.
8977** ^Because the source database is not locked between calls to
8978** sqlite3_backup_step(), the source database may be modified mid-way
8979** through the backup process. ^If the source database is modified by an
8980** external process or via a database connection other than the one being
8981** used by the backup operation, then the backup will be automatically
8982** restarted by the next call to sqlite3_backup_step(). ^If the source
8983** database is modified by the using the same database connection as is used
8984** by the backup operation, then the backup database is automatically
8985** updated at the same time.
8986**
8987** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8988**
8989** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8990** application wishes to abandon the backup operation, the application
8991** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8992** ^The sqlite3_backup_finish() interfaces releases all
8993** resources associated with the [sqlite3_backup] object.
8994** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8995** active write-transaction on the destination database is rolled back.
8996** The [sqlite3_backup] object is invalid
8997** and may not be used following a call to sqlite3_backup_finish().
8998**
8999** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9000** sqlite3_backup_step() errors occurred, regardless or whether or not
9001** sqlite3_backup_step() completed.
9002** ^If an out-of-memory condition or IO error occurred during any prior
9003** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9004** sqlite3_backup_finish() returns the corresponding [error code].
9005**
9006** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9007** is not a permanent error and does not affect the return value of
9008** sqlite3_backup_finish().
9009**
9010** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9011** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9012**
9013** ^The sqlite3_backup_remaining() routine returns the number of pages still
9014** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9015** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9016** in the source database at the conclusion of the most recent
9017** sqlite3_backup_step().
9018** ^(The values returned by these functions are only updated by
9019** sqlite3_backup_step(). If the source database is modified in a way that
9020** changes the size of the source database or the number of pages remaining,
9021** those changes are not reflected in the output of sqlite3_backup_pagecount()
9022** and sqlite3_backup_remaining() until after the next
9023** sqlite3_backup_step().)^
9024**
9025** <b>Concurrent Usage of Database Handles</b>
9026**
9027** ^The source [database connection] may be used by the application for other
9028** purposes while a backup operation is underway or being initialized.
9029** ^If SQLite is compiled and configured to support threadsafe database
9030** connections, then the source database connection may be used concurrently
9031** from within other threads.
9032**
9033** However, the application must guarantee that the destination
9034** [database connection] is not passed to any other API (by any thread) after
9035** sqlite3_backup_init() is called and before the corresponding call to
9036** sqlite3_backup_finish(). SQLite does not currently check to see
9037** if the application incorrectly accesses the destination [database connection]
9038** and so no error code is reported, but the operations may malfunction
9039** nevertheless. Use of the destination database connection while a
9040** backup is in progress might also cause a mutex deadlock.
9041**
9042** If running in [shared cache mode], the application must
9043** guarantee that the shared cache used by the destination database
9044** is not accessed while the backup is running. In practice this means
9045** that the application must guarantee that the disk file being
9046** backed up to is not accessed by any connection within the process,
9047** not just the specific connection that was passed to sqlite3_backup_init().
9048**
9049** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9050** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9051** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9052** APIs are not strictly speaking threadsafe. If they are invoked at the
9053** same time as another thread is invoking sqlite3_backup_step() it is
9054** possible that they return invalid values.
9055*/
9056SQLITE_API sqlite3_backup *sqlite3_backup_init(
9057 sqlite3 *pDest, /* Destination database handle */
9058 const char *zDestName, /* Destination database name */
9059 sqlite3 *pSource, /* Source database handle */
9060 const char *zSourceName /* Source database name */
9061);
9062SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9063SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9064SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9065SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9066
9067/*
9068** CAPI3REF: Unlock Notification
9069** METHOD: sqlite3
9070**
9071** ^When running in shared-cache mode, a database operation may fail with
9072** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9073** individual tables within the shared-cache cannot be obtained. See
9074** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9075** ^This API may be used to register a callback that SQLite will invoke
9076** when the connection currently holding the required lock relinquishes it.
9077** ^This API is only available if the library was compiled with the
9078** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9079**
9080** See Also: [Using the SQLite Unlock Notification Feature].
9081**
9082** ^Shared-cache locks are released when a database connection concludes
9083** its current transaction, either by committing it or rolling it back.
9084**
9085** ^When a connection (known as the blocked connection) fails to obtain a
9086** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9087** identity of the database connection (the blocking connection) that
9088** has locked the required resource is stored internally. ^After an
9089** application receives an SQLITE_LOCKED error, it may call the
9090** sqlite3_unlock_notify() method with the blocked connection handle as
9091** the first argument to register for a callback that will be invoked
9092** when the blocking connections current transaction is concluded. ^The
9093** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9094** call that concludes the blocking connection's transaction.
9095**
9096** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9097** there is a chance that the blocking connection will have already
9098** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9099** If this happens, then the specified callback is invoked immediately,
9100** from within the call to sqlite3_unlock_notify().)^
9101**
9102** ^If the blocked connection is attempting to obtain a write-lock on a
9103** shared-cache table, and more than one other connection currently holds
9104** a read-lock on the same table, then SQLite arbitrarily selects one of
9105** the other connections to use as the blocking connection.
9106**
9107** ^(There may be at most one unlock-notify callback registered by a
9108** blocked connection. If sqlite3_unlock_notify() is called when the
9109** blocked connection already has a registered unlock-notify callback,
9110** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9111** called with a NULL pointer as its second argument, then any existing
9112** unlock-notify callback is canceled. ^The blocked connections
9113** unlock-notify callback may also be canceled by closing the blocked
9114** connection using [sqlite3_close()].
9115**
9116** The unlock-notify callback is not reentrant. If an application invokes
9117** any sqlite3_xxx API functions from within an unlock-notify callback, a
9118** crash or deadlock may be the result.
9119**
9120** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9121** returns SQLITE_OK.
9122**
9123** <b>Callback Invocation Details</b>
9124**
9125** When an unlock-notify callback is registered, the application provides a
9126** single void* pointer that is passed to the callback when it is invoked.
9127** However, the signature of the callback function allows SQLite to pass
9128** it an array of void* context pointers. The first argument passed to
9129** an unlock-notify callback is a pointer to an array of void* pointers,
9130** and the second is the number of entries in the array.
9131**
9132** When a blocking connection's transaction is concluded, there may be
9133** more than one blocked connection that has registered for an unlock-notify
9134** callback. ^If two or more such blocked connections have specified the
9135** same callback function, then instead of invoking the callback function
9136** multiple times, it is invoked once with the set of void* context pointers
9137** specified by the blocked connections bundled together into an array.
9138** This gives the application an opportunity to prioritize any actions
9139** related to the set of unblocked database connections.
9140**
9141** <b>Deadlock Detection</b>
9142**
9143** Assuming that after registering for an unlock-notify callback a
9144** database waits for the callback to be issued before taking any further
9145** action (a reasonable assumption), then using this API may cause the
9146** application to deadlock. For example, if connection X is waiting for
9147** connection Y's transaction to be concluded, and similarly connection
9148** Y is waiting on connection X's transaction, then neither connection
9149** will proceed and the system may remain deadlocked indefinitely.
9150**
9151** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9152** detection. ^If a given call to sqlite3_unlock_notify() would put the
9153** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9154** unlock-notify callback is registered. The system is said to be in
9155** a deadlocked state if connection A has registered for an unlock-notify
9156** callback on the conclusion of connection B's transaction, and connection
9157** B has itself registered for an unlock-notify callback when connection
9158** A's transaction is concluded. ^Indirect deadlock is also detected, so
9159** the system is also considered to be deadlocked if connection B has
9160** registered for an unlock-notify callback on the conclusion of connection
9161** C's transaction, where connection C is waiting on connection A. ^Any
9162** number of levels of indirection are allowed.
9163**
9164** <b>The "DROP TABLE" Exception</b>
9165**
9166** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9167** always appropriate to call sqlite3_unlock_notify(). There is however,
9168** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9169** SQLite checks if there are any currently executing SELECT statements
9170** that belong to the same connection. If there are, SQLITE_LOCKED is
9171** returned. In this case there is no "blocking connection", so invoking
9172** sqlite3_unlock_notify() results in the unlock-notify callback being
9173** invoked immediately. If the application then re-attempts the "DROP TABLE"
9174** or "DROP INDEX" query, an infinite loop might be the result.
9175**
9176** One way around this problem is to check the extended error code returned
9177** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9178** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9179** the special "DROP TABLE/INDEX" case, the extended error code is just
9180** SQLITE_LOCKED.)^
9181*/
9182SQLITE_API int sqlite3_unlock_notify(
9183 sqlite3 *pBlocked, /* Waiting connection */
9184 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9185 void *pNotifyArg /* Argument to pass to xNotify */
9186);
9187
9188
9189/*
9190** CAPI3REF: String Comparison
9191**
9192** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9193** and extensions to compare the contents of two buffers containing UTF-8
9194** strings in a case-independent fashion, using the same definition of "case
9195** independence" that SQLite uses internally when comparing identifiers.
9196*/
9197SQLITE_API int sqlite3_stricmp(const char *, const char *);
9198SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9199
9200/*
9201** CAPI3REF: String Globbing
9202*
9203** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9204** string X matches the [GLOB] pattern P.
9205** ^The definition of [GLOB] pattern matching used in
9206** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9207** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9208** is case sensitive.
9209**
9210** Note that this routine returns zero on a match and non-zero if the strings
9211** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9212**
9213** See also: [sqlite3_strlike()].
9214*/
9215SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9216
9217/*
9218** CAPI3REF: String LIKE Matching
9219*
9220** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9221** string X matches the [LIKE] pattern P with escape character E.
9222** ^The definition of [LIKE] pattern matching used in
9223** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9224** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9225** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9226** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9227** insensitive - equivalent upper and lower case ASCII characters match
9228** one another.
9229**
9230** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9231** only ASCII characters are case folded.
9232**
9233** Note that this routine returns zero on a match and non-zero if the strings
9234** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9235**
9236** See also: [sqlite3_strglob()].
9237*/
9238SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9239
9240/*
9241** CAPI3REF: Error Logging Interface
9242**
9243** ^The [sqlite3_log()] interface writes a message into the [error log]
9244** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9245** ^If logging is enabled, the zFormat string and subsequent arguments are
9246** used with [sqlite3_snprintf()] to generate the final output string.
9247**
9248** The sqlite3_log() interface is intended for use by extensions such as
9249** virtual tables, collating functions, and SQL functions. While there is
9250** nothing to prevent an application from calling sqlite3_log(), doing so
9251** is considered bad form.
9252**
9253** The zFormat string must not be NULL.
9254**
9255** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9256** will not use dynamically allocated memory. The log message is stored in
9257** a fixed-length buffer on the stack. If the log message is longer than
9258** a few hundred characters, it will be truncated to the length of the
9259** buffer.
9260*/
9261SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9262
9263/*
9264** CAPI3REF: Write-Ahead Log Commit Hook
9265** METHOD: sqlite3
9266**
9267** ^The [sqlite3_wal_hook()] function is used to register a callback that
9268** is invoked each time data is committed to a database in wal mode.
9269**
9270** ^(The callback is invoked by SQLite after the commit has taken place and
9271** the associated write-lock on the database released)^, so the implementation
9272** may read, write or [checkpoint] the database as required.
9273**
9274** ^The first parameter passed to the callback function when it is invoked
9275** is a copy of the third parameter passed to sqlite3_wal_hook() when
9276** registering the callback. ^The second is a copy of the database handle.
9277** ^The third parameter is the name of the database that was written to -
9278** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9279** is the number of pages currently in the write-ahead log file,
9280** including those that were just committed.
9281**
9282** The callback function should normally return [SQLITE_OK]. ^If an error
9283** code is returned, that error will propagate back up through the
9284** SQLite code base to cause the statement that provoked the callback
9285** to report an error, though the commit will have still occurred. If the
9286** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9287** that does not correspond to any valid SQLite error code, the results
9288** are undefined.
9289**
9290** A single database handle may have at most a single write-ahead log callback
9291** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9292** previously registered write-ahead log callback. ^The return value is
9293** a copy of the third parameter from the previous call, if any, or 0.
9294** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9295** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9296** overwrite any prior [sqlite3_wal_hook()] settings.
9297*/
9298SQLITE_API void *sqlite3_wal_hook(
9299 sqlite3*,
9300 int(*)(void *,sqlite3*,const char*,int),
9301 void*
9302);
9303
9304/*
9305** CAPI3REF: Configure an auto-checkpoint
9306** METHOD: sqlite3
9307**
9308** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9309** [sqlite3_wal_hook()] that causes any database on [database connection] D
9310** to automatically [checkpoint]
9311** after committing a transaction if there are N or
9312** more frames in the [write-ahead log] file. ^Passing zero or
9313** a negative value as the nFrame parameter disables automatic
9314** checkpoints entirely.
9315**
9316** ^The callback registered by this function replaces any existing callback
9317** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9318** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9319** configured by this function.
9320**
9321** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9322** from SQL.
9323**
9324** ^Checkpoints initiated by this mechanism are
9325** [sqlite3_wal_checkpoint_v2|PASSIVE].
9326**
9327** ^Every new [database connection] defaults to having the auto-checkpoint
9328** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9329** pages. The use of this interface
9330** is only necessary if the default setting is found to be suboptimal
9331** for a particular application.
9332*/
9333SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9334
9335/*
9336** CAPI3REF: Checkpoint a database
9337** METHOD: sqlite3
9338**
9339** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9340** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9341**
9342** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9343** [write-ahead log] for database X on [database connection] D to be
9344** transferred into the database file and for the write-ahead log to
9345** be reset. See the [checkpointing] documentation for addition
9346** information.
9347**
9348** This interface used to be the only way to cause a checkpoint to
9349** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9350** interface was added. This interface is retained for backwards
9351** compatibility and as a convenience for applications that need to manually
9352** start a callback but which do not need the full power (and corresponding
9353** complication) of [sqlite3_wal_checkpoint_v2()].
9354*/
9355SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9356
9357/*
9358** CAPI3REF: Checkpoint a database
9359** METHOD: sqlite3
9360**
9361** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9362** operation on database X of [database connection] D in mode M. Status
9363** information is written back into integers pointed to by L and C.)^
9364** ^(The M parameter must be a valid [checkpoint mode]:)^
9365**
9366** <dl>
9367** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9368** ^Checkpoint as many frames as possible without waiting for any database
9369** readers or writers to finish, then sync the database file if all frames
9370** in the log were checkpointed. ^The [busy-handler callback]
9371** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9372** ^On the other hand, passive mode might leave the checkpoint unfinished
9373** if there are concurrent readers or writers.
9374**
9375** <dt>SQLITE_CHECKPOINT_FULL<dd>
9376** ^This mode blocks (it invokes the
9377** [sqlite3_busy_handler|busy-handler callback]) until there is no
9378** database writer and all readers are reading from the most recent database
9379** snapshot. ^It then checkpoints all frames in the log file and syncs the
9380** database file. ^This mode blocks new database writers while it is pending,
9381** but new database readers are allowed to continue unimpeded.
9382**
9383** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9384** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9385** that after checkpointing the log file it blocks (calls the
9386** [busy-handler callback])
9387** until all readers are reading from the database file only. ^This ensures
9388** that the next writer will restart the log file from the beginning.
9389** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9390** database writer attempts while it is pending, but does not impede readers.
9391**
9392** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9393** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9394** addition that it also truncates the log file to zero bytes just prior
9395** to a successful return.
9396** </dl>
9397**
9398** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9399** the log file or to -1 if the checkpoint could not run because
9400** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9401** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9402** log file (including any that were already checkpointed before the function
9403** was called) or to -1 if the checkpoint could not run due to an error or
9404** because the database is not in WAL mode. ^Note that upon successful
9405** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9406** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9407**
9408** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9409** any other process is running a checkpoint operation at the same time, the
9410** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9411** busy-handler configured, it will not be invoked in this case.
9412**
9413** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9414** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9415** obtained immediately, and a busy-handler is configured, it is invoked and
9416** the writer lock retried until either the busy-handler returns 0 or the lock
9417** is successfully obtained. ^The busy-handler is also invoked while waiting for
9418** database readers as described above. ^If the busy-handler returns 0 before
9419** the writer lock is obtained or while waiting for database readers, the
9420** checkpoint operation proceeds from that point in the same way as
9421** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9422** without blocking any further. ^SQLITE_BUSY is returned in this case.
9423**
9424** ^If parameter zDb is NULL or points to a zero length string, then the
9425** specified operation is attempted on all WAL databases [attached] to
9426** [database connection] db. In this case the
9427** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9428** an SQLITE_BUSY error is encountered when processing one or more of the
9429** attached WAL databases, the operation is still attempted on any remaining
9430** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9431** error occurs while processing an attached database, processing is abandoned
9432** and the error code is returned to the caller immediately. ^If no error
9433** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9434** databases, SQLITE_OK is returned.
9435**
9436** ^If database zDb is the name of an attached database that is not in WAL
9437** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9438** zDb is not NULL (or a zero length string) and is not the name of any
9439** attached database, SQLITE_ERROR is returned to the caller.
9440**
9441** ^Unless it returns SQLITE_MISUSE,
9442** the sqlite3_wal_checkpoint_v2() interface
9443** sets the error information that is queried by
9444** [sqlite3_errcode()] and [sqlite3_errmsg()].
9445**
9446** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9447** from SQL.
9448*/
9449SQLITE_API int sqlite3_wal_checkpoint_v2(
9450 sqlite3 *db, /* Database handle */
9451 const char *zDb, /* Name of attached database (or NULL) */
9452 int eMode, /* SQLITE_CHECKPOINT_* value */
9453 int *pnLog, /* OUT: Size of WAL log in frames */
9454 int *pnCkpt /* OUT: Total number of frames checkpointed */
9455);
9456
9457/*
9458** CAPI3REF: Checkpoint Mode Values
9459** KEYWORDS: {checkpoint mode}
9460**
9461** These constants define all valid values for the "checkpoint mode" passed
9462** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9463** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9464** meaning of each of these checkpoint modes.
9465*/
9466#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9467#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9468#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9469#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9470
9471/*
9472** CAPI3REF: Virtual Table Interface Configuration
9473**
9474** This function may be called by either the [xConnect] or [xCreate] method
9475** of a [virtual table] implementation to configure
9476** various facets of the virtual table interface.
9477**
9478** If this interface is invoked outside the context of an xConnect or
9479** xCreate virtual table method then the behavior is undefined.
9480**
9481** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9482** [database connection] in which the virtual table is being created and
9483** which is passed in as the first argument to the [xConnect] or [xCreate]
9484** method that is invoking sqlite3_vtab_config(). The C parameter is one
9485** of the [virtual table configuration options]. The presence and meaning
9486** of parameters after C depend on which [virtual table configuration option]
9487** is used.
9488*/
9489SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9490
9491/*
9492** CAPI3REF: Virtual Table Configuration Options
9493** KEYWORDS: {virtual table configuration options}
9494** KEYWORDS: {virtual table configuration option}
9495**
9496** These macros define the various options to the
9497** [sqlite3_vtab_config()] interface that [virtual table] implementations
9498** can use to customize and optimize their behavior.
9499**
9500** <dl>
9501** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9502** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9503** <dd>Calls of the form
9504** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9505** where X is an integer. If X is zero, then the [virtual table] whose
9506** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9507** support constraints. In this configuration (which is the default) if
9508** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9509** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9510** specified as part of the users SQL statement, regardless of the actual
9511** ON CONFLICT mode specified.
9512**
9513** If X is non-zero, then the virtual table implementation guarantees
9514** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9515** any modifications to internal or persistent data structures have been made.
9516** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9517** is able to roll back a statement or database transaction, and abandon
9518** or continue processing the current SQL statement as appropriate.
9519** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9520** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9521** had been ABORT.
9522**
9523** Virtual table implementations that are required to handle OR REPLACE
9524** must do so within the [xUpdate] method. If a call to the
9525** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9526** CONFLICT policy is REPLACE, the virtual table implementation should
9527** silently replace the appropriate rows within the xUpdate callback and
9528** return SQLITE_OK. Or, if this is not possible, it may return
9529** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9530** constraint handling.
9531** </dd>
9532**
9533** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9534** <dd>Calls of the form
9535** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9536** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9537** prohibits that virtual table from being used from within triggers and
9538** views.
9539** </dd>
9540**
9541** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9542** <dd>Calls of the form
9543** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9544** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9545** identify that virtual table as being safe to use from within triggers
9546** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9547** virtual table can do no serious harm even if it is controlled by a
9548** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9549** flag unless absolutely necessary.
9550** </dd>
9551** </dl>
9552*/
9553#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9554#define SQLITE_VTAB_INNOCUOUS 2
9555#define SQLITE_VTAB_DIRECTONLY 3
9556
9557/*
9558** CAPI3REF: Determine The Virtual Table Conflict Policy
9559**
9560** This function may only be called from within a call to the [xUpdate] method
9561** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9562** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9563** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9564** of the SQL statement that triggered the call to the [xUpdate] method of the
9565** [virtual table].
9566*/
9567SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9568
9569/*
9570** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9571**
9572** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9573** method of a [virtual table], then it might return true if the
9574** column is being fetched as part of an UPDATE operation during which the
9575** column value will not change. The virtual table implementation can use
9576** this hint as permission to substitute a return value that is less
9577** expensive to compute and that the corresponding
9578** [xUpdate] method understands as a "no-change" value.
9579**
9580** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9581** the column is not changed by the UPDATE statement, then the xColumn
9582** method can optionally return without setting a result, without calling
9583** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9584** In that case, [sqlite3_value_nochange(X)] will return true for the
9585** same column in the [xUpdate] method.
9586**
9587** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9588** implementations should continue to give a correct answer even if the
9589** sqlite3_vtab_nochange() interface were to always return false. In the
9590** current implementation, the sqlite3_vtab_nochange() interface does always
9591** returns false for the enhanced [UPDATE FROM] statement.
9592*/
9593SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9594
9595/*
9596** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9597** METHOD: sqlite3_index_info
9598**
9599** This function may only be called from within a call to the [xBestIndex]
9600** method of a [virtual table]. This function returns a pointer to a string
9601** that is the name of the appropriate collation sequence to use for text
9602** comparisons on the constraint identified by its arguments.
9603**
9604** The first argument must be the pointer to the [sqlite3_index_info] object
9605** that is the first parameter to the xBestIndex() method. The second argument
9606** must be an index into the aConstraint[] array belonging to the
9607** sqlite3_index_info structure passed to xBestIndex.
9608**
9609** Important:
9610** The first parameter must be the same pointer that is passed into the
9611** xBestMethod() method. The first parameter may not be a pointer to a
9612** different [sqlite3_index_info] object, even an exact copy.
9613**
9614** The return value is computed as follows:
9615**
9616** <ol>
9617** <li><p> If the constraint comes from a WHERE clause expression that contains
9618** a [COLLATE operator], then the name of the collation specified by
9619** that COLLATE operator is returned.
9620** <li><p> If there is no COLLATE operator, but the column that is the subject
9621** of the constraint specifies an alternative collating sequence via
9622** a [COLLATE clause] on the column definition within the CREATE TABLE
9623** statement that was passed into [sqlite3_declare_vtab()], then the
9624** name of that alternative collating sequence is returned.
9625** <li><p> Otherwise, "BINARY" is returned.
9626** </ol>
9627*/
9628SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9629
9630/*
9631** CAPI3REF: Determine if a virtual table query is DISTINCT
9632** METHOD: sqlite3_index_info
9633**
9634** This API may only be used from within an [xBestIndex|xBestIndex method]
9635** of a [virtual table] implementation. The result of calling this
9636** interface from outside of xBestIndex() is undefined and probably harmful.
9637**
9638** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9639** 3. The integer returned by sqlite3_vtab_distinct()
9640** gives the virtual table additional information about how the query
9641** planner wants the output to be ordered. As long as the virtual table
9642** can meet the ordering requirements of the query planner, it may set
9643** the "orderByConsumed" flag.
9644**
9645** <ol><li value="0"><p>
9646** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9647** that the query planner needs the virtual table to return all rows in the
9648** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9649** [sqlite3_index_info] object. This is the default expectation. If the
9650** virtual table outputs all rows in sorted order, then it is always safe for
9651** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9652** the return value from sqlite3_vtab_distinct().
9653** <li value="1"><p>
9654** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9655** that the query planner does not need the rows to be returned in sorted order
9656** as long as all rows with the same values in all columns identified by the
9657** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9658** is doing a GROUP BY.
9659** <li value="2"><p>
9660** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9661** that the query planner does not need the rows returned in any particular
9662** order, as long as rows with the same values in all "aOrderBy" columns
9663** are adjacent.)^ ^(Furthermore, only a single row for each particular
9664** combination of values in the columns identified by the "aOrderBy" field
9665** needs to be returned.)^ ^It is always ok for two or more rows with the same
9666** values in all "aOrderBy" columns to be returned, as long as all such rows
9667** are adjacent. ^The virtual table may, if it chooses, omit extra rows
9668** that have the same value for all columns identified by "aOrderBy".
9669** ^However omitting the extra rows is optional.
9670** This mode is used for a DISTINCT query.
9671** <li value="3"><p>
9672** ^(If the sqlite3_vtab_distinct() interface returns 3, that means
9673** that the query planner needs only distinct rows but it does need the
9674** rows to be sorted.)^ ^The virtual table implementation is free to omit
9675** rows that are identical in all aOrderBy columns, if it wants to, but
9676** it is not required to omit any rows. This mode is used for queries
9677** that have both DISTINCT and ORDER BY clauses.
9678** </ol>
9679**
9680** ^For the purposes of comparing virtual table output values to see if the
9681** values are same value for sorting purposes, two NULL values are considered
9682** to be the same. In other words, the comparison operator is "IS"
9683** (or "IS NOT DISTINCT FROM") and not "==".
9684**
9685** If a virtual table implementation is unable to meet the requirements
9686** specified above, then it must not set the "orderByConsumed" flag in the
9687** [sqlite3_index_info] object or an incorrect answer may result.
9688**
9689** ^A virtual table implementation is always free to return rows in any order
9690** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9691** the "orderByConsumed" flag is unset, the query planner will add extra
9692** [bytecode] to ensure that the final results returned by the SQL query are
9693** ordered correctly. The use of the "orderByConsumed" flag and the
9694** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9695** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
9696** flag might help queries against a virtual table to run faster. Being
9697** overly aggressive and setting the "orderByConsumed" flag when it is not
9698** valid to do so, on the other hand, might cause SQLite to return incorrect
9699** results.
9700*/
9701SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
9702
9703/*
9704** CAPI3REF: Identify and handle IN constraints in xBestIndex
9705**
9706** This interface may only be used from within an
9707** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
9708** The result of invoking this interface from any other context is
9709** undefined and probably harmful.
9710**
9711** ^(A constraint on a virtual table of the form
9712** "[IN operator|column IN (...)]" is
9713** communicated to the xBestIndex method as a
9714** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
9715** this constraint, it must set the corresponding
9716** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under
9717** the usual mode of handling IN operators, SQLite generates [bytecode]
9718** that invokes the [xFilter|xFilter() method] once for each value
9719** on the right-hand side of the IN operator.)^ Thus the virtual table
9720** only sees a single value from the right-hand side of the IN operator
9721** at a time.
9722**
9723** In some cases, however, it would be advantageous for the virtual
9724** table to see all values on the right-hand of the IN operator all at
9725** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
9726**
9727** <ol>
9728** <li><p>
9729** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
9730** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
9731** is an [IN operator] that can be processed all at once. ^In other words,
9732** sqlite3_vtab_in() with -1 in the third argument is a mechanism
9733** by which the virtual table can ask SQLite if all-at-once processing
9734** of the IN operator is even possible.
9735**
9736** <li><p>
9737** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
9738** to SQLite that the virtual table does or does not want to process
9739** the IN operator all-at-once, respectively. ^Thus when the third
9740** parameter (F) is non-negative, this interface is the mechanism by
9741** which the virtual table tells SQLite how it wants to process the
9742** IN operator.
9743** </ol>
9744**
9745** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
9746** within the same xBestIndex method call. ^For any given P,N pair,
9747** the return value from sqlite3_vtab_in(P,N,F) will always be the same
9748** within the same xBestIndex call. ^If the interface returns true
9749** (non-zero), that means that the constraint is an IN operator
9750** that can be processed all-at-once. ^If the constraint is not an IN
9751** operator or cannot be processed all-at-once, then the interface returns
9752** false.
9753**
9754** ^(All-at-once processing of the IN operator is selected if both of the
9755** following conditions are met:
9756**
9757** <ol>
9758** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
9759** integer. This is how the virtual table tells SQLite that it wants to
9760** use the N-th constraint.
9761**
9762** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
9763** non-negative had F>=1.
9764** </ol>)^
9765**
9766** ^If either or both of the conditions above are false, then SQLite uses
9767** the traditional one-at-a-time processing strategy for the IN constraint.
9768** ^If both conditions are true, then the argvIndex-th parameter to the
9769** xFilter method will be an [sqlite3_value] that appears to be NULL,
9770** but which can be passed to [sqlite3_vtab_in_first()] and
9771** [sqlite3_vtab_in_next()] to find all values on the right-hand side
9772** of the IN constraint.
9773*/
9774SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
9775
9776/*
9777** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
9778**
9779** These interfaces are only useful from within the
9780** [xFilter|xFilter() method] of a [virtual table] implementation.
9781** The result of invoking these interfaces from any other context
9782** is undefined and probably harmful.
9783**
9784** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
9785** sqlite3_vtab_in_next(X,P) must be one of the parameters to the
9786** xFilter method which invokes these routines, and specifically
9787** a parameter that was previously selected for all-at-once IN constraint
9788** processing use the [sqlite3_vtab_in()] interface in the
9789** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
9790** an xFilter argument that was selected for all-at-once IN constraint
9791** processing, then these routines return [SQLITE_MISUSE])^ or perhaps
9792** exhibit some other undefined or harmful behavior.
9793**
9794** ^(Use these routines to access all values on the right-hand side
9795** of the IN constraint using code like the following:
9796**
9797** <blockquote><pre>
9798** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
9799** &nbsp; rc==SQLITE_OK && pVal
9800** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
9801** &nbsp; ){
9802** &nbsp; // do something with pVal
9803** &nbsp; }
9804** &nbsp; if( rc!=SQLITE_OK ){
9805** &nbsp; // an error has occurred
9806** &nbsp; }
9807** </pre></blockquote>)^
9808**
9809** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
9810** routines return SQLITE_OK and set *P to point to the first or next value
9811** on the RHS of the IN constraint. ^If there are no more values on the
9812** right hand side of the IN constraint, then *P is set to NULL and these
9813** routines return [SQLITE_DONE]. ^The return value might be
9814** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
9815**
9816** The *ppOut values returned by these routines are only valid until the
9817** next call to either of these routines or until the end of the xFilter
9818** method from which these routines were called. If the virtual table
9819** implementation needs to retain the *ppOut values for longer, it must make
9820** copies. The *ppOut values are [protected sqlite3_value|protected].
9821*/
9822SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
9823SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
9824
9825/*
9826** CAPI3REF: Constraint values in xBestIndex()
9827** METHOD: sqlite3_index_info
9828**
9829** This API may only be used from within the [xBestIndex|xBestIndex method]
9830** of a [virtual table] implementation. The result of calling this interface
9831** from outside of an xBestIndex method are undefined and probably harmful.
9832**
9833** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
9834** the [xBestIndex] method of a [virtual table] implementation, with P being
9835** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
9836** J being a 0-based index into P->aConstraint[], then this routine
9837** attempts to set *V to the value of the right-hand operand of
9838** that constraint if the right-hand operand is known. ^If the
9839** right-hand operand is not known, then *V is set to a NULL pointer.
9840** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
9841** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
9842** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
9843** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
9844** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
9845** something goes wrong.
9846**
9847** The sqlite3_vtab_rhs_value() interface is usually only successful if
9848** the right-hand operand of a constraint is a literal value in the original
9849** SQL statement. If the right-hand operand is an expression or a reference
9850** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
9851** will probably return [SQLITE_NOTFOUND].
9852**
9853** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
9854** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
9855** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
9856**
9857** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
9858** and remains valid for the duration of the xBestIndex method call.
9859** ^When xBestIndex returns, the sqlite3_value object returned by
9860** sqlite3_vtab_rhs_value() is automatically deallocated.
9861**
9862** The "_rhs_" in the name of this routine is an abbreviation for
9863** "Right-Hand Side".
9864*/
9865SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
9866
9867/*
9868** CAPI3REF: Conflict resolution modes
9869** KEYWORDS: {conflict resolution mode}
9870**
9871** These constants are returned by [sqlite3_vtab_on_conflict()] to
9872** inform a [virtual table] implementation what the [ON CONFLICT] mode
9873** is for the SQL statement being evaluated.
9874**
9875** Note that the [SQLITE_IGNORE] constant is also used as a potential
9876** return value from the [sqlite3_set_authorizer()] callback and that
9877** [SQLITE_ABORT] is also a [result code].
9878*/
9879#define SQLITE_ROLLBACK 1
9880/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9881#define SQLITE_FAIL 3
9882/* #define SQLITE_ABORT 4 // Also an error code */
9883#define SQLITE_REPLACE 5
9884
9885/*
9886** CAPI3REF: Prepared Statement Scan Status Opcodes
9887** KEYWORDS: {scanstatus options}
9888**
9889** The following constants can be used for the T parameter to the
9890** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9891** different metric for sqlite3_stmt_scanstatus() to return.
9892**
9893** When the value returned to V is a string, space to hold that string is
9894** managed by the prepared statement S and will be automatically freed when
9895** S is finalized.
9896**
9897** <dl>
9898** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
9899** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
9900** set to the total number of times that the X-th loop has run.</dd>
9901**
9902** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
9903** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
9904** to the total number of rows examined by all iterations of the X-th loop.</dd>
9905**
9906** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
9907** <dd>^The "double" variable pointed to by the V parameter will be set to the
9908** query planner's estimate for the average number of rows output from each
9909** iteration of the X-th loop. If the query planner's estimates was accurate,
9910** then this value will approximate the quotient NVISIT/NLOOP and the
9911** product of this value for all prior loops with the same SELECTID will
9912** be the NLOOP value for the current loop.
9913**
9914** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
9915** <dd>^The "const char *" variable pointed to by the V parameter will be set
9916** to a zero-terminated UTF-8 string containing the name of the index or table
9917** used for the X-th loop.
9918**
9919** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
9920** <dd>^The "const char *" variable pointed to by the V parameter will be set
9921** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9922** description for the X-th loop.
9923**
9924** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
9925** <dd>^The "int" variable pointed to by the V parameter will be set to the
9926** "select-id" for the X-th loop. The select-id identifies which query or
9927** subquery the loop is part of. The main query has a select-id of zero.
9928** The select-id is the same value as is output in the first column
9929** of an [EXPLAIN QUERY PLAN] query.
9930** </dl>
9931*/
9932#define SQLITE_SCANSTAT_NLOOP 0
9933#define SQLITE_SCANSTAT_NVISIT 1
9934#define SQLITE_SCANSTAT_EST 2
9935#define SQLITE_SCANSTAT_NAME 3
9936#define SQLITE_SCANSTAT_EXPLAIN 4
9937#define SQLITE_SCANSTAT_SELECTID 5
9938
9939/*
9940** CAPI3REF: Prepared Statement Scan Status
9941** METHOD: sqlite3_stmt
9942**
9943** This interface returns information about the predicted and measured
9944** performance for pStmt. Advanced applications can use this
9945** interface to compare the predicted and the measured performance and
9946** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9947**
9948** Since this interface is expected to be rarely used, it is only
9949** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9950** compile-time option.
9951**
9952** The "iScanStatusOp" parameter determines which status information to return.
9953** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9954** of this interface is undefined.
9955** ^The requested measurement is written into a variable pointed to by
9956** the "pOut" parameter.
9957** Parameter "idx" identifies the specific loop to retrieve statistics for.
9958** Loops are numbered starting from zero. ^If idx is out of range - less than
9959** zero or greater than or equal to the total number of loops used to implement
9960** the statement - a non-zero value is returned and the variable that pOut
9961** points to is unchanged.
9962**
9963** ^Statistics might not be available for all loops in all statements. ^In cases
9964** where there exist loops with no available statistics, this function behaves
9965** as if the loop did not exist - it returns non-zero and leave the variable
9966** that pOut points to unchanged.
9967**
9968** See also: [sqlite3_stmt_scanstatus_reset()]
9969*/
9970SQLITE_API int sqlite3_stmt_scanstatus(
9971 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9972 int idx, /* Index of loop to report on */
9973 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9974 void *pOut /* Result written here */
9975);
9976
9977/*
9978** CAPI3REF: Zero Scan-Status Counters
9979** METHOD: sqlite3_stmt
9980**
9981** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9982**
9983** This API is only available if the library is built with pre-processor
9984** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9985*/
9986SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9987
9988/*
9989** CAPI3REF: Flush caches to disk mid-transaction
9990** METHOD: sqlite3
9991**
9992** ^If a write-transaction is open on [database connection] D when the
9993** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
9994** pages in the pager-cache that are not currently in use are written out
9995** to disk. A dirty page may be in use if a database cursor created by an
9996** active SQL statement is reading from it, or if it is page 1 of a database
9997** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9998** interface flushes caches for all schemas - "main", "temp", and
9999** any [attached] databases.
10000**
10001** ^If this function needs to obtain extra database locks before dirty pages
10002** can be flushed to disk, it does so. ^If those locks cannot be obtained
10003** immediately and there is a busy-handler callback configured, it is invoked
10004** in the usual manner. ^If the required lock still cannot be obtained, then
10005** the database is skipped and an attempt made to flush any dirty pages
10006** belonging to the next (if any) database. ^If any databases are skipped
10007** because locks cannot be obtained, but no other error occurs, this
10008** function returns SQLITE_BUSY.
10009**
10010** ^If any other error occurs while flushing dirty pages to disk (for
10011** example an IO error or out-of-memory condition), then processing is
10012** abandoned and an SQLite [error code] is returned to the caller immediately.
10013**
10014** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10015**
10016** ^This function does not set the database handle error code or message
10017** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10018*/
10019SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10020
10021/*
10022** CAPI3REF: The pre-update hook.
10023** METHOD: sqlite3
10024**
10025** ^These interfaces are only available if SQLite is compiled using the
10026** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10027**
10028** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10029** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10030** on a database table.
10031** ^At most one preupdate hook may be registered at a time on a single
10032** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10033** the previous setting.
10034** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10035** with a NULL pointer as the second parameter.
10036** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10037** the first parameter to callbacks.
10038**
10039** ^The preupdate hook only fires for changes to real database tables; the
10040** preupdate hook is not invoked for changes to [virtual tables] or to
10041** system tables like sqlite_sequence or sqlite_stat1.
10042**
10043** ^The second parameter to the preupdate callback is a pointer to
10044** the [database connection] that registered the preupdate hook.
10045** ^The third parameter to the preupdate callback is one of the constants
10046** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10047** kind of update operation that is about to occur.
10048** ^(The fourth parameter to the preupdate callback is the name of the
10049** database within the database connection that is being modified. This
10050** will be "main" for the main database or "temp" for TEMP tables or
10051** the name given after the AS keyword in the [ATTACH] statement for attached
10052** databases.)^
10053** ^The fifth parameter to the preupdate callback is the name of the
10054** table that is being modified.
10055**
10056** For an UPDATE or DELETE operation on a [rowid table], the sixth
10057** parameter passed to the preupdate callback is the initial [rowid] of the
10058** row being modified or deleted. For an INSERT operation on a rowid table,
10059** or any operation on a WITHOUT ROWID table, the value of the sixth
10060** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10061** seventh parameter is the final rowid value of the row being inserted
10062** or updated. The value of the seventh parameter passed to the callback
10063** function is not defined for operations on WITHOUT ROWID tables, or for
10064** DELETE operations on rowid tables.
10065**
10066** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10067** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10068** provide additional information about a preupdate event. These routines
10069** may only be called from within a preupdate callback. Invoking any of
10070** these routines from outside of a preupdate callback or with a
10071** [database connection] pointer that is different from the one supplied
10072** to the preupdate callback results in undefined and probably undesirable
10073** behavior.
10074**
10075** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10076** in the row that is being inserted, updated, or deleted.
10077**
10078** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10079** a [protected sqlite3_value] that contains the value of the Nth column of
10080** the table row before it is updated. The N parameter must be between 0
10081** and one less than the number of columns or the behavior will be
10082** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10083** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10084** behavior is undefined. The [sqlite3_value] that P points to
10085** will be destroyed when the preupdate callback returns.
10086**
10087** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10088** a [protected sqlite3_value] that contains the value of the Nth column of
10089** the table row after it is updated. The N parameter must be between 0
10090** and one less than the number of columns or the behavior will be
10091** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10092** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10093** behavior is undefined. The [sqlite3_value] that P points to
10094** will be destroyed when the preupdate callback returns.
10095**
10096** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10097** callback was invoked as a result of a direct insert, update, or delete
10098** operation; or 1 for inserts, updates, or deletes invoked by top-level
10099** triggers; or 2 for changes resulting from triggers called by top-level
10100** triggers; and so forth.
10101**
10102** When the [sqlite3_blob_write()] API is used to update a blob column,
10103** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10104** in this case the new values are not available. In this case, when a
10105** callback made with op==SQLITE_DELETE is actuall a write using the
10106** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10107** the index of the column being written. In other cases, where the
10108** pre-update hook is being invoked for some other reason, including a
10109** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10110**
10111** See also: [sqlite3_update_hook()]
10112*/
10113#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10114SQLITE_API void *sqlite3_preupdate_hook(
10115 sqlite3 *db,
10116 void(*xPreUpdate)(
10117 void *pCtx, /* Copy of third arg to preupdate_hook() */
10118 sqlite3 *db, /* Database handle */
10119 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10120 char const *zDb, /* Database name */
10121 char const *zName, /* Table name */
10122 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10123 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10124 ),
10125 void*
10126);
10127SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10128SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10129SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10130SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10131SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10132#endif
10133
10134/*
10135** CAPI3REF: Low-level system error code
10136** METHOD: sqlite3
10137**
10138** ^Attempt to return the underlying operating system error code or error
10139** number that caused the most recent I/O error or failure to open a file.
10140** The return value is OS-dependent. For example, on unix systems, after
10141** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10142** called to get back the underlying "errno" that caused the problem, such
10143** as ENOSPC, EAUTH, EISDIR, and so forth.
10144*/
10145SQLITE_API int sqlite3_system_errno(sqlite3*);
10146
10147/*
10148** CAPI3REF: Database Snapshot
10149** KEYWORDS: {snapshot} {sqlite3_snapshot}
10150**
10151** An instance of the snapshot object records the state of a [WAL mode]
10152** database for some specific point in history.
10153**
10154** In [WAL mode], multiple [database connections] that are open on the
10155** same database file can each be reading a different historical version
10156** of the database file. When a [database connection] begins a read
10157** transaction, that connection sees an unchanging copy of the database
10158** as it existed for the point in time when the transaction first started.
10159** Subsequent changes to the database from other connections are not seen
10160** by the reader until a new read transaction is started.
10161**
10162** The sqlite3_snapshot object records state information about an historical
10163** version of the database file so that it is possible to later open a new read
10164** transaction that sees that historical version of the database rather than
10165** the most recent version.
10166*/
10167typedef struct sqlite3_snapshot {
10168 unsigned char hidden[48];
10169} sqlite3_snapshot;
10170
10171/*
10172** CAPI3REF: Record A Database Snapshot
10173** CONSTRUCTOR: sqlite3_snapshot
10174**
10175** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10176** new [sqlite3_snapshot] object that records the current state of
10177** schema S in database connection D. ^On success, the
10178** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10179** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10180** If there is not already a read-transaction open on schema S when
10181** this function is called, one is opened automatically.
10182**
10183** The following must be true for this function to succeed. If any of
10184** the following statements are false when sqlite3_snapshot_get() is
10185** called, SQLITE_ERROR is returned. The final value of *P is undefined
10186** in this case.
10187**
10188** <ul>
10189** <li> The database handle must not be in [autocommit mode].
10190**
10191** <li> Schema S of [database connection] D must be a [WAL mode] database.
10192**
10193** <li> There must not be a write transaction open on schema S of database
10194** connection D.
10195**
10196** <li> One or more transactions must have been written to the current wal
10197** file since it was created on disk (by any connection). This means
10198** that a snapshot cannot be taken on a wal mode database with no wal
10199** file immediately after it is first opened. At least one transaction
10200** must be written to it first.
10201** </ul>
10202**
10203** This function may also return SQLITE_NOMEM. If it is called with the
10204** database handle in autocommit mode but fails for some other reason,
10205** whether or not a read transaction is opened on schema S is undefined.
10206**
10207** The [sqlite3_snapshot] object returned from a successful call to
10208** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10209** to avoid a memory leak.
10210**
10211** The [sqlite3_snapshot_get()] interface is only available when the
10212** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10213*/
10214SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10215 sqlite3 *db,
10216 const char *zSchema,
10217 sqlite3_snapshot **ppSnapshot
10218);
10219
10220/*
10221** CAPI3REF: Start a read transaction on an historical snapshot
10222** METHOD: sqlite3_snapshot
10223**
10224** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10225** transaction or upgrades an existing one for schema S of
10226** [database connection] D such that the read transaction refers to
10227** historical [snapshot] P, rather than the most recent change to the
10228** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10229** on success or an appropriate [error code] if it fails.
10230**
10231** ^In order to succeed, the database connection must not be in
10232** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10233** is already a read transaction open on schema S, then the database handle
10234** must have no active statements (SELECT statements that have been passed
10235** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10236** SQLITE_ERROR is returned if either of these conditions is violated, or
10237** if schema S does not exist, or if the snapshot object is invalid.
10238**
10239** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10240** snapshot has been overwritten by a [checkpoint]. In this case
10241** SQLITE_ERROR_SNAPSHOT is returned.
10242**
10243** If there is already a read transaction open when this function is
10244** invoked, then the same read transaction remains open (on the same
10245** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10246** is returned. If another error code - for example SQLITE_PROTOCOL or an
10247** SQLITE_IOERR error code - is returned, then the final state of the
10248** read transaction is undefined. If SQLITE_OK is returned, then the
10249** read transaction is now open on database snapshot P.
10250**
10251** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10252** database connection D does not know that the database file for
10253** schema S is in [WAL mode]. A database connection might not know
10254** that the database file is in [WAL mode] if there has been no prior
10255** I/O on that database connection, or if the database entered [WAL mode]
10256** after the most recent I/O on the database connection.)^
10257** (Hint: Run "[PRAGMA application_id]" against a newly opened
10258** database connection in order to make it ready to use snapshots.)
10259**
10260** The [sqlite3_snapshot_open()] interface is only available when the
10261** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10262*/
10263SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10264 sqlite3 *db,
10265 const char *zSchema,
10266 sqlite3_snapshot *pSnapshot
10267);
10268
10269/*
10270** CAPI3REF: Destroy a snapshot
10271** DESTRUCTOR: sqlite3_snapshot
10272**
10273** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10274** The application must eventually free every [sqlite3_snapshot] object
10275** using this routine to avoid a memory leak.
10276**
10277** The [sqlite3_snapshot_free()] interface is only available when the
10278** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10279*/
10280SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10281
10282/*
10283** CAPI3REF: Compare the ages of two snapshot handles.
10284** METHOD: sqlite3_snapshot
10285**
10286** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10287** of two valid snapshot handles.
10288**
10289** If the two snapshot handles are not associated with the same database
10290** file, the result of the comparison is undefined.
10291**
10292** Additionally, the result of the comparison is only valid if both of the
10293** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10294** last time the wal file was deleted. The wal file is deleted when the
10295** database is changed back to rollback mode or when the number of database
10296** clients drops to zero. If either snapshot handle was obtained before the
10297** wal file was last deleted, the value returned by this function
10298** is undefined.
10299**
10300** Otherwise, this API returns a negative value if P1 refers to an older
10301** snapshot than P2, zero if the two handles refer to the same database
10302** snapshot, and a positive value if P1 is a newer snapshot than P2.
10303**
10304** This interface is only available if SQLite is compiled with the
10305** [SQLITE_ENABLE_SNAPSHOT] option.
10306*/
10307SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10308 sqlite3_snapshot *p1,
10309 sqlite3_snapshot *p2
10310);
10311
10312/*
10313** CAPI3REF: Recover snapshots from a wal file
10314** METHOD: sqlite3_snapshot
10315**
10316** If a [WAL file] remains on disk after all database connections close
10317** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10318** or because the last process to have the database opened exited without
10319** calling [sqlite3_close()]) and a new connection is subsequently opened
10320** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10321** will only be able to open the last transaction added to the WAL file
10322** even though the WAL file contains other valid transactions.
10323**
10324** This function attempts to scan the WAL file associated with database zDb
10325** of database handle db and make all valid snapshots available to
10326** sqlite3_snapshot_open(). It is an error if there is already a read
10327** transaction open on the database, or if the database is not a WAL mode
10328** database.
10329**
10330** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10331**
10332** This interface is only available if SQLite is compiled with the
10333** [SQLITE_ENABLE_SNAPSHOT] option.
10334*/
10335SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10336
10337/*
10338** CAPI3REF: Serialize a database
10339**
10340** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10341** that is a serialization of the S database on [database connection] D.
10342** If P is not a NULL pointer, then the size of the database in bytes
10343** is written into *P.
10344**
10345** For an ordinary on-disk database file, the serialization is just a
10346** copy of the disk file. For an in-memory database or a "TEMP" database,
10347** the serialization is the same sequence of bytes which would be written
10348** to disk if that database where backed up to disk.
10349**
10350** The usual case is that sqlite3_serialize() copies the serialization of
10351** the database into memory obtained from [sqlite3_malloc64()] and returns
10352** a pointer to that memory. The caller is responsible for freeing the
10353** returned value to avoid a memory leak. However, if the F argument
10354** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10355** are made, and the sqlite3_serialize() function will return a pointer
10356** to the contiguous memory representation of the database that SQLite
10357** is currently using for that database, or NULL if the no such contiguous
10358** memory representation of the database exists. A contiguous memory
10359** representation of the database will usually only exist if there has
10360** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10361** values of D and S.
10362** The size of the database is written into *P even if the
10363** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10364** of the database exists.
10365**
10366** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10367** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10368** allocation error occurs.
10369**
10370** This interface is omitted if SQLite is compiled with the
10371** [SQLITE_OMIT_DESERIALIZE] option.
10372*/
10373SQLITE_API unsigned char *sqlite3_serialize(
10374 sqlite3 *db, /* The database connection */
10375 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10376 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10377 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10378);
10379
10380/*
10381** CAPI3REF: Flags for sqlite3_serialize
10382**
10383** Zero or more of the following constants can be OR-ed together for
10384** the F argument to [sqlite3_serialize(D,S,P,F)].
10385**
10386** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10387** a pointer to contiguous in-memory database that it is currently using,
10388** without making a copy of the database. If SQLite is not currently using
10389** a contiguous in-memory database, then this option causes
10390** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10391** using a contiguous in-memory database if it has been initialized by a
10392** prior call to [sqlite3_deserialize()].
10393*/
10394#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10395
10396/*
10397** CAPI3REF: Deserialize a database
10398**
10399** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10400** [database connection] D to disconnect from database S and then
10401** reopen S as an in-memory database based on the serialization contained
10402** in P. The serialized database P is N bytes in size. M is the size of
10403** the buffer P, which might be larger than N. If M is larger than N, and
10404** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10405** permitted to add content to the in-memory database as long as the total
10406** size does not exceed M bytes.
10407**
10408** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10409** invoke sqlite3_free() on the serialization buffer when the database
10410** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10411** SQLite will try to increase the buffer size using sqlite3_realloc64()
10412** if writes on the database cause it to grow larger than M bytes.
10413**
10414** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10415** database is currently in a read transaction or is involved in a backup
10416** operation.
10417**
10418** It is not possible to deserialized into the TEMP database. If the
10419** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10420** function returns SQLITE_ERROR.
10421**
10422** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10423** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10424** [sqlite3_free()] is invoked on argument P prior to returning.
10425**
10426** This interface is omitted if SQLite is compiled with the
10427** [SQLITE_OMIT_DESERIALIZE] option.
10428*/
10429SQLITE_API int sqlite3_deserialize(
10430 sqlite3 *db, /* The database connection */
10431 const char *zSchema, /* Which DB to reopen with the deserialization */
10432 unsigned char *pData, /* The serialized database content */
10433 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10434 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10435 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10436);
10437
10438/*
10439** CAPI3REF: Flags for sqlite3_deserialize()
10440**
10441** The following are allowed values for 6th argument (the F argument) to
10442** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10443**
10444** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10445** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10446** and that SQLite should take ownership of this memory and automatically
10447** free it when it has finished using it. Without this flag, the caller
10448** is responsible for freeing any dynamically allocated memory.
10449**
10450** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10451** grow the size of the database using calls to [sqlite3_realloc64()]. This
10452** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10453** Without this flag, the deserialized database cannot increase in size beyond
10454** the number of bytes specified by the M parameter.
10455**
10456** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10457** should be treated as read-only.
10458*/
10459#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10460#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10461#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10462
10463/*
10464** Undo the hack that converts floating point types to integer for
10465** builds on processors without floating point support.
10466*/
10467#ifdef SQLITE_OMIT_FLOATING_POINT
10468# undef double
10469#endif
10470
10471#ifdef __cplusplus
10472} /* End of the 'extern "C"' block */
10473#endif
10474#endif /* SQLITE3_H */
10475
10476/******** Begin file sqlite3rtree.h *********/
10477/*
10478** 2010 August 30
10479**
10480** The author disclaims copyright to this source code. In place of
10481** a legal notice, here is a blessing:
10482**
10483** May you do good and not evil.
10484** May you find forgiveness for yourself and forgive others.
10485** May you share freely, never taking more than you give.
10486**
10487*************************************************************************
10488*/
10489
10490#ifndef _SQLITE3RTREE_H_
10491#define _SQLITE3RTREE_H_
10492
10493
10494#ifdef __cplusplus
10495extern "C" {
10496#endif
10497
10498typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10499typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10500
10501/* The double-precision datatype used by RTree depends on the
10502** SQLITE_RTREE_INT_ONLY compile-time option.
10503*/
10504#ifdef SQLITE_RTREE_INT_ONLY
10505 typedef sqlite3_int64 sqlite3_rtree_dbl;
10506#else
10507 typedef double sqlite3_rtree_dbl;
10508#endif
10509
10510/*
10511** Register a geometry callback named zGeom that can be used as part of an
10512** R-Tree geometry query as follows:
10513**
10514** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10515*/
10516SQLITE_API int sqlite3_rtree_geometry_callback(
10517 sqlite3 *db,
10518 const char *zGeom,
10519 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10520 void *pContext
10521);
10522
10523
10524/*
10525** A pointer to a structure of the following type is passed as the first
10526** argument to callbacks registered using rtree_geometry_callback().
10527*/
10528struct sqlite3_rtree_geometry {
10529 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10530 int nParam; /* Size of array aParam[] */
10531 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10532 void *pUser; /* Callback implementation user data */
10533 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10534};
10535
10536/*
10537** Register a 2nd-generation geometry callback named zScore that can be
10538** used as part of an R-Tree geometry query as follows:
10539**
10540** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10541*/
10542SQLITE_API int sqlite3_rtree_query_callback(
10543 sqlite3 *db,
10544 const char *zQueryFunc,
10545 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10546 void *pContext,
10547 void (*xDestructor)(void*)
10548);
10549
10550
10551/*
10552** A pointer to a structure of the following type is passed as the
10553** argument to scored geometry callback registered using
10554** sqlite3_rtree_query_callback().
10555**
10556** Note that the first 5 fields of this structure are identical to
10557** sqlite3_rtree_geometry. This structure is a subclass of
10558** sqlite3_rtree_geometry.
10559*/
10560struct sqlite3_rtree_query_info {
10561 void *pContext; /* pContext from when function registered */
10562 int nParam; /* Number of function parameters */
10563 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10564 void *pUser; /* callback can use this, if desired */
10565 void (*xDelUser)(void*); /* function to free pUser */
10566 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10567 unsigned int *anQueue; /* Number of pending entries in the queue */
10568 int nCoord; /* Number of coordinates */
10569 int iLevel; /* Level of current node or entry */
10570 int mxLevel; /* The largest iLevel value in the tree */
10571 sqlite3_int64 iRowid; /* Rowid for current entry */
10572 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10573 int eParentWithin; /* Visibility of parent node */
10574 int eWithin; /* OUT: Visibility */
10575 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10576 /* The following fields are only available in 3.8.11 and later */
10577 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10578};
10579
10580/*
10581** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10582*/
10583#define NOT_WITHIN 0 /* Object completely outside of query region */
10584#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10585#define FULLY_WITHIN 2 /* Object fully contained within query region */
10586
10587
10588#ifdef __cplusplus
10589} /* end of the 'extern "C"' block */
10590#endif
10591
10592#endif /* ifndef _SQLITE3RTREE_H_ */
10593
10594/******** End of sqlite3rtree.h *********/
10595/******** Begin file sqlite3session.h *********/
10596
10597#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10598#define __SQLITESESSION_H_ 1
10599
10600/*
10601** Make sure we can call this stuff from C++.
10602*/
10603#ifdef __cplusplus
10604extern "C" {
10605#endif
10606
10607
10608/*
10609** CAPI3REF: Session Object Handle
10610**
10611** An instance of this object is a [session] that can be used to
10612** record changes to a database.
10613*/
10614typedef struct sqlite3_session sqlite3_session;
10615
10616/*
10617** CAPI3REF: Changeset Iterator Handle
10618**
10619** An instance of this object acts as a cursor for iterating
10620** over the elements of a [changeset] or [patchset].
10621*/
10622typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10623
10624/*
10625** CAPI3REF: Create A New Session Object
10626** CONSTRUCTOR: sqlite3_session
10627**
10628** Create a new session object attached to database handle db. If successful,
10629** a pointer to the new object is written to *ppSession and SQLITE_OK is
10630** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10631** error code (e.g. SQLITE_NOMEM) is returned.
10632**
10633** It is possible to create multiple session objects attached to a single
10634** database handle.
10635**
10636** Session objects created using this function should be deleted using the
10637** [sqlite3session_delete()] function before the database handle that they
10638** are attached to is itself closed. If the database handle is closed before
10639** the session object is deleted, then the results of calling any session
10640** module function, including [sqlite3session_delete()] on the session object
10641** are undefined.
10642**
10643** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10644** is not possible for an application to register a pre-update hook on a
10645** database handle that has one or more session objects attached. Nor is
10646** it possible to create a session object attached to a database handle for
10647** which a pre-update hook is already defined. The results of attempting
10648** either of these things are undefined.
10649**
10650** The session object will be used to create changesets for tables in
10651** database zDb, where zDb is either "main", or "temp", or the name of an
10652** attached database. It is not an error if database zDb is not attached
10653** to the database when the session object is created.
10654*/
10655SQLITE_API int sqlite3session_create(
10656 sqlite3 *db, /* Database handle */
10657 const char *zDb, /* Name of db (e.g. "main") */
10658 sqlite3_session **ppSession /* OUT: New session object */
10659);
10660
10661/*
10662** CAPI3REF: Delete A Session Object
10663** DESTRUCTOR: sqlite3_session
10664**
10665** Delete a session object previously allocated using
10666** [sqlite3session_create()]. Once a session object has been deleted, the
10667** results of attempting to use pSession with any other session module
10668** function are undefined.
10669**
10670** Session objects must be deleted before the database handle to which they
10671** are attached is closed. Refer to the documentation for
10672** [sqlite3session_create()] for details.
10673*/
10674SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10675
10676/*
10677** CAPIREF: Conigure a Session Object
10678** METHOD: sqlite3_session
10679**
10680** This method is used to configure a session object after it has been
10681** created. At present the only valid value for the second parameter is
10682** [SQLITE_SESSION_OBJCONFIG_SIZE].
10683**
10684** Arguments for sqlite3session_object_config()
10685**
10686** The following values may passed as the the 4th parameter to
10687** sqlite3session_object_config().
10688**
10689** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
10690** This option is used to set, clear or query the flag that enables
10691** the [sqlite3session_changeset_size()] API. Because it imposes some
10692** computational overhead, this API is disabled by default. Argument
10693** pArg must point to a value of type (int). If the value is initially
10694** 0, then the sqlite3session_changeset_size() API is disabled. If it
10695** is greater than 0, then the same API is enabled. Or, if the initial
10696** value is less than zero, no change is made. In all cases the (int)
10697** variable is set to 1 if the sqlite3session_changeset_size() API is
10698** enabled following the current call, or 0 otherwise.
10699**
10700** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10701** the first table has been attached to the session object.
10702*/
10703SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
10704
10705/*
10706*/
10707#define SQLITE_SESSION_OBJCONFIG_SIZE 1
10708
10709/*
10710** CAPI3REF: Enable Or Disable A Session Object
10711** METHOD: sqlite3_session
10712**
10713** Enable or disable the recording of changes by a session object. When
10714** enabled, a session object records changes made to the database. When
10715** disabled - it does not. A newly created session object is enabled.
10716** Refer to the documentation for [sqlite3session_changeset()] for further
10717** details regarding how enabling and disabling a session object affects
10718** the eventual changesets.
10719**
10720** Passing zero to this function disables the session. Passing a value
10721** greater than zero enables it. Passing a value less than zero is a
10722** no-op, and may be used to query the current state of the session.
10723**
10724** The return value indicates the final state of the session object: 0 if
10725** the session is disabled, or 1 if it is enabled.
10726*/
10727SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10728
10729/*
10730** CAPI3REF: Set Or Clear the Indirect Change Flag
10731** METHOD: sqlite3_session
10732**
10733** Each change recorded by a session object is marked as either direct or
10734** indirect. A change is marked as indirect if either:
10735**
10736** <ul>
10737** <li> The session object "indirect" flag is set when the change is
10738** made, or
10739** <li> The change is made by an SQL trigger or foreign key action
10740** instead of directly as a result of a users SQL statement.
10741** </ul>
10742**
10743** If a single row is affected by more than one operation within a session,
10744** then the change is considered indirect if all operations meet the criteria
10745** for an indirect change above, or direct otherwise.
10746**
10747** This function is used to set, clear or query the session object indirect
10748** flag. If the second argument passed to this function is zero, then the
10749** indirect flag is cleared. If it is greater than zero, the indirect flag
10750** is set. Passing a value less than zero does not modify the current value
10751** of the indirect flag, and may be used to query the current state of the
10752** indirect flag for the specified session object.
10753**
10754** The return value indicates the final state of the indirect flag: 0 if
10755** it is clear, or 1 if it is set.
10756*/
10757SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10758
10759/*
10760** CAPI3REF: Attach A Table To A Session Object
10761** METHOD: sqlite3_session
10762**
10763** If argument zTab is not NULL, then it is the name of a table to attach
10764** to the session object passed as the first argument. All subsequent changes
10765** made to the table while the session object is enabled will be recorded. See
10766** documentation for [sqlite3session_changeset()] for further details.
10767**
10768** Or, if argument zTab is NULL, then changes are recorded for all tables
10769** in the database. If additional tables are added to the database (by
10770** executing "CREATE TABLE" statements) after this call is made, changes for
10771** the new tables are also recorded.
10772**
10773** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10774** defined as part of their CREATE TABLE statement. It does not matter if the
10775** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10776** KEY may consist of a single column, or may be a composite key.
10777**
10778** It is not an error if the named table does not exist in the database. Nor
10779** is it an error if the named table does not have a PRIMARY KEY. However,
10780** no changes will be recorded in either of these scenarios.
10781**
10782** Changes are not recorded for individual rows that have NULL values stored
10783** in one or more of their PRIMARY KEY columns.
10784**
10785** SQLITE_OK is returned if the call completes without error. Or, if an error
10786** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10787**
10788** <h3>Special sqlite_stat1 Handling</h3>
10789**
10790** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10791** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10792** <pre>
10793** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
10794** </pre>
10795**
10796** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10797** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10798** are recorded for rows for which (idx IS NULL) is true. However, for such
10799** rows a zero-length blob (SQL value X'') is stored in the changeset or
10800** patchset instead of a NULL value. This allows such changesets to be
10801** manipulated by legacy implementations of sqlite3changeset_invert(),
10802** concat() and similar.
10803**
10804** The sqlite3changeset_apply() function automatically converts the
10805** zero-length blob back to a NULL value when updating the sqlite_stat1
10806** table. However, if the application calls sqlite3changeset_new(),
10807** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10808** iterator directly (including on a changeset iterator passed to a
10809** conflict-handler callback) then the X'' value is returned. The application
10810** must translate X'' to NULL itself if required.
10811**
10812** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10813** changes made to the sqlite_stat1 table. Legacy versions of the
10814** sqlite3changeset_apply() function silently ignore any modifications to the
10815** sqlite_stat1 table that are part of a changeset or patchset.
10816*/
10817SQLITE_API int sqlite3session_attach(
10818 sqlite3_session *pSession, /* Session object */
10819 const char *zTab /* Table name */
10820);
10821
10822/*
10823** CAPI3REF: Set a table filter on a Session Object.
10824** METHOD: sqlite3_session
10825**
10826** The second argument (xFilter) is the "filter callback". For changes to rows
10827** in tables that are not attached to the Session object, the filter is called
10828** to determine whether changes to the table's rows should be tracked or not.
10829** If xFilter returns 0, changes are not tracked. Note that once a table is
10830** attached, xFilter will not be called again.
10831*/
10832SQLITE_API void sqlite3session_table_filter(
10833 sqlite3_session *pSession, /* Session object */
10834 int(*xFilter)(
10835 void *pCtx, /* Copy of third arg to _filter_table() */
10836 const char *zTab /* Table name */
10837 ),
10838 void *pCtx /* First argument passed to xFilter */
10839);
10840
10841/*
10842** CAPI3REF: Generate A Changeset From A Session Object
10843** METHOD: sqlite3_session
10844**
10845** Obtain a changeset containing changes to the tables attached to the
10846** session object passed as the first argument. If successful,
10847** set *ppChangeset to point to a buffer containing the changeset
10848** and *pnChangeset to the size of the changeset in bytes before returning
10849** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10850** zero and return an SQLite error code.
10851**
10852** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10853** each representing a change to a single row of an attached table. An INSERT
10854** change contains the values of each field of a new database row. A DELETE
10855** contains the original values of each field of a deleted database row. An
10856** UPDATE change contains the original values of each field of an updated
10857** database row along with the updated values for each updated non-primary-key
10858** column. It is not possible for an UPDATE change to represent a change that
10859** modifies the values of primary key columns. If such a change is made, it
10860** is represented in a changeset as a DELETE followed by an INSERT.
10861**
10862** Changes are not recorded for rows that have NULL values stored in one or
10863** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10864** no corresponding change is present in the changesets returned by this
10865** function. If an existing row with one or more NULL values stored in
10866** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10867** only an INSERT is appears in the changeset. Similarly, if an existing row
10868** with non-NULL PRIMARY KEY values is updated so that one or more of its
10869** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10870** DELETE change only.
10871**
10872** The contents of a changeset may be traversed using an iterator created
10873** using the [sqlite3changeset_start()] API. A changeset may be applied to
10874** a database with a compatible schema using the [sqlite3changeset_apply()]
10875** API.
10876**
10877** Within a changeset generated by this function, all changes related to a
10878** single table are grouped together. In other words, when iterating through
10879** a changeset or when applying a changeset to a database, all changes related
10880** to a single table are processed before moving on to the next table. Tables
10881** are sorted in the same order in which they were attached (or auto-attached)
10882** to the sqlite3_session object. The order in which the changes related to
10883** a single table are stored is undefined.
10884**
10885** Following a successful call to this function, it is the responsibility of
10886** the caller to eventually free the buffer that *ppChangeset points to using
10887** [sqlite3_free()].
10888**
10889** <h3>Changeset Generation</h3>
10890**
10891** Once a table has been attached to a session object, the session object
10892** records the primary key values of all new rows inserted into the table.
10893** It also records the original primary key and other column values of any
10894** deleted or updated rows. For each unique primary key value, data is only
10895** recorded once - the first time a row with said primary key is inserted,
10896** updated or deleted in the lifetime of the session.
10897**
10898** There is one exception to the previous paragraph: when a row is inserted,
10899** updated or deleted, if one or more of its primary key columns contain a
10900** NULL value, no record of the change is made.
10901**
10902** The session object therefore accumulates two types of records - those
10903** that consist of primary key values only (created when the user inserts
10904** a new record) and those that consist of the primary key values and the
10905** original values of other table columns (created when the users deletes
10906** or updates a record).
10907**
10908** When this function is called, the requested changeset is created using
10909** both the accumulated records and the current contents of the database
10910** file. Specifically:
10911**
10912** <ul>
10913** <li> For each record generated by an insert, the database is queried
10914** for a row with a matching primary key. If one is found, an INSERT
10915** change is added to the changeset. If no such row is found, no change
10916** is added to the changeset.
10917**
10918** <li> For each record generated by an update or delete, the database is
10919** queried for a row with a matching primary key. If such a row is
10920** found and one or more of the non-primary key fields have been
10921** modified from their original values, an UPDATE change is added to
10922** the changeset. Or, if no such row is found in the table, a DELETE
10923** change is added to the changeset. If there is a row with a matching
10924** primary key in the database, but all fields contain their original
10925** values, no change is added to the changeset.
10926** </ul>
10927**
10928** This means, amongst other things, that if a row is inserted and then later
10929** deleted while a session object is active, neither the insert nor the delete
10930** will be present in the changeset. Or if a row is deleted and then later a
10931** row with the same primary key values inserted while a session object is
10932** active, the resulting changeset will contain an UPDATE change instead of
10933** a DELETE and an INSERT.
10934**
10935** When a session object is disabled (see the [sqlite3session_enable()] API),
10936** it does not accumulate records when rows are inserted, updated or deleted.
10937** This may appear to have some counter-intuitive effects if a single row
10938** is written to more than once during a session. For example, if a row
10939** is inserted while a session object is enabled, then later deleted while
10940** the same session object is disabled, no INSERT record will appear in the
10941** changeset, even though the delete took place while the session was disabled.
10942** Or, if one field of a row is updated while a session is disabled, and
10943** another field of the same row is updated while the session is enabled, the
10944** resulting changeset will contain an UPDATE change that updates both fields.
10945*/
10946SQLITE_API int sqlite3session_changeset(
10947 sqlite3_session *pSession, /* Session object */
10948 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10949 void **ppChangeset /* OUT: Buffer containing changeset */
10950);
10951
10952/*
10953** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
10954** METHOD: sqlite3_session
10955**
10956** By default, this function always returns 0. For it to return
10957** a useful result, the sqlite3_session object must have been configured
10958** to enable this API using sqlite3session_object_config() with the
10959** SQLITE_SESSION_OBJCONFIG_SIZE verb.
10960**
10961** When enabled, this function returns an upper limit, in bytes, for the size
10962** of the changeset that might be produced if sqlite3session_changeset() were
10963** called. The final changeset size might be equal to or smaller than the
10964** size in bytes returned by this function.
10965*/
10966SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
10967
10968/*
10969** CAPI3REF: Load The Difference Between Tables Into A Session
10970** METHOD: sqlite3_session
10971**
10972** If it is not already attached to the session object passed as the first
10973** argument, this function attaches table zTbl in the same manner as the
10974** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10975** does not have a primary key, this function is a no-op (but does not return
10976** an error).
10977**
10978** Argument zFromDb must be the name of a database ("main", "temp" etc.)
10979** attached to the same database handle as the session object that contains
10980** a table compatible with the table attached to the session by this function.
10981** A table is considered compatible if it:
10982**
10983** <ul>
10984** <li> Has the same name,
10985** <li> Has the same set of columns declared in the same order, and
10986** <li> Has the same PRIMARY KEY definition.
10987** </ul>
10988**
10989** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10990** are compatible but do not have any PRIMARY KEY columns, it is not an error
10991** but no changes are added to the session object. As with other session
10992** APIs, tables without PRIMARY KEYs are simply ignored.
10993**
10994** This function adds a set of changes to the session object that could be
10995** used to update the table in database zFrom (call this the "from-table")
10996** so that its content is the same as the table attached to the session
10997** object (call this the "to-table"). Specifically:
10998**
10999** <ul>
11000** <li> For each row (primary key) that exists in the to-table but not in
11001** the from-table, an INSERT record is added to the session object.
11002**
11003** <li> For each row (primary key) that exists in the to-table but not in
11004** the from-table, a DELETE record is added to the session object.
11005**
11006** <li> For each row (primary key) that exists in both tables, but features
11007** different non-PK values in each, an UPDATE record is added to the
11008** session.
11009** </ul>
11010**
11011** To clarify, if this function is called and then a changeset constructed
11012** using [sqlite3session_changeset()], then after applying that changeset to
11013** database zFrom the contents of the two compatible tables would be
11014** identical.
11015**
11016** It an error if database zFrom does not exist or does not contain the
11017** required compatible table.
11018**
11019** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11020** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11021** may be set to point to a buffer containing an English language error
11022** message. It is the responsibility of the caller to free this buffer using
11023** sqlite3_free().
11024*/
11025SQLITE_API int sqlite3session_diff(
11026 sqlite3_session *pSession,
11027 const char *zFromDb,
11028 const char *zTbl,
11029 char **pzErrMsg
11030);
11031
11032
11033/*
11034** CAPI3REF: Generate A Patchset From A Session Object
11035** METHOD: sqlite3_session
11036**
11037** The differences between a patchset and a changeset are that:
11038**
11039** <ul>
11040** <li> DELETE records consist of the primary key fields only. The
11041** original values of other fields are omitted.
11042** <li> The original values of any modified fields are omitted from
11043** UPDATE records.
11044** </ul>
11045**
11046** A patchset blob may be used with up to date versions of all
11047** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11048** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11049** attempting to use a patchset blob with old versions of the
11050** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11051**
11052** Because the non-primary key "old.*" fields are omitted, no
11053** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11054** is passed to the sqlite3changeset_apply() API. Other conflict types work
11055** in the same way as for changesets.
11056**
11057** Changes within a patchset are ordered in the same way as for changesets
11058** generated by the sqlite3session_changeset() function (i.e. all changes for
11059** a single table are grouped together, tables appear in the order in which
11060** they were attached to the session object).
11061*/
11062SQLITE_API int sqlite3session_patchset(
11063 sqlite3_session *pSession, /* Session object */
11064 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11065 void **ppPatchset /* OUT: Buffer containing patchset */
11066);
11067
11068/*
11069** CAPI3REF: Test if a changeset has recorded any changes.
11070**
11071** Return non-zero if no changes to attached tables have been recorded by
11072** the session object passed as the first argument. Otherwise, if one or
11073** more changes have been recorded, return zero.
11074**
11075** Even if this function returns zero, it is possible that calling
11076** [sqlite3session_changeset()] on the session handle may still return a
11077** changeset that contains no changes. This can happen when a row in
11078** an attached table is modified and then later on the original values
11079** are restored. However, if this function returns non-zero, then it is
11080** guaranteed that a call to sqlite3session_changeset() will return a
11081** changeset containing zero changes.
11082*/
11083SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11084
11085/*
11086** CAPI3REF: Query for the amount of heap memory used by a session object.
11087**
11088** This API returns the total amount of heap memory in bytes currently
11089** used by the session object passed as the only argument.
11090*/
11091SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11092
11093/*
11094** CAPI3REF: Create An Iterator To Traverse A Changeset
11095** CONSTRUCTOR: sqlite3_changeset_iter
11096**
11097** Create an iterator used to iterate through the contents of a changeset.
11098** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11099** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11100** SQLite error code is returned.
11101**
11102** The following functions can be used to advance and query a changeset
11103** iterator created by this function:
11104**
11105** <ul>
11106** <li> [sqlite3changeset_next()]
11107** <li> [sqlite3changeset_op()]
11108** <li> [sqlite3changeset_new()]
11109** <li> [sqlite3changeset_old()]
11110** </ul>
11111**
11112** It is the responsibility of the caller to eventually destroy the iterator
11113** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11114** changeset (pChangeset) must remain valid until after the iterator is
11115** destroyed.
11116**
11117** Assuming the changeset blob was created by one of the
11118** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11119** [sqlite3changeset_invert()] functions, all changes within the changeset
11120** that apply to a single table are grouped together. This means that when
11121** an application iterates through a changeset using an iterator created by
11122** this function, all changes that relate to a single table are visited
11123** consecutively. There is no chance that the iterator will visit a change
11124** the applies to table X, then one for table Y, and then later on visit
11125** another change for table X.
11126**
11127** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11128** may be modified by passing a combination of
11129** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11130**
11131** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11132** and therefore subject to change.
11133*/
11134SQLITE_API int sqlite3changeset_start(
11135 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11136 int nChangeset, /* Size of changeset blob in bytes */
11137 void *pChangeset /* Pointer to blob containing changeset */
11138);
11139SQLITE_API int sqlite3changeset_start_v2(
11140 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11141 int nChangeset, /* Size of changeset blob in bytes */
11142 void *pChangeset, /* Pointer to blob containing changeset */
11143 int flags /* SESSION_CHANGESETSTART_* flags */
11144);
11145
11146/*
11147** CAPI3REF: Flags for sqlite3changeset_start_v2
11148**
11149** The following flags may passed via the 4th parameter to
11150** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11151**
11152** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11153** Invert the changeset while iterating through it. This is equivalent to
11154** inverting a changeset using sqlite3changeset_invert() before applying it.
11155** It is an error to specify this flag with a patchset.
11156*/
11157#define SQLITE_CHANGESETSTART_INVERT 0x0002
11158
11159
11160/*
11161** CAPI3REF: Advance A Changeset Iterator
11162** METHOD: sqlite3_changeset_iter
11163**
11164** This function may only be used with iterators created by the function
11165** [sqlite3changeset_start()]. If it is called on an iterator passed to
11166** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11167** is returned and the call has no effect.
11168**
11169** Immediately after an iterator is created by sqlite3changeset_start(), it
11170** does not point to any change in the changeset. Assuming the changeset
11171** is not empty, the first call to this function advances the iterator to
11172** point to the first change in the changeset. Each subsequent call advances
11173** the iterator to point to the next change in the changeset (if any). If
11174** no error occurs and the iterator points to a valid change after a call
11175** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11176** Otherwise, if all changes in the changeset have already been visited,
11177** SQLITE_DONE is returned.
11178**
11179** If an error occurs, an SQLite error code is returned. Possible error
11180** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11181** SQLITE_NOMEM.
11182*/
11183SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11184
11185/*
11186** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11187** METHOD: sqlite3_changeset_iter
11188**
11189** The pIter argument passed to this function may either be an iterator
11190** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11191** created by [sqlite3changeset_start()]. In the latter case, the most recent
11192** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11193** is not the case, this function returns [SQLITE_MISUSE].
11194**
11195** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11196** outputs are set through these pointers:
11197**
11198** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11199** depending on the type of change that the iterator currently points to;
11200**
11201** *pnCol is set to the number of columns in the table affected by the change; and
11202**
11203** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11204** the name of the table affected by the current change. The buffer remains
11205** valid until either sqlite3changeset_next() is called on the iterator
11206** or until the conflict-handler function returns.
11207**
11208** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11209** is an indirect change, or false (0) otherwise. See the documentation for
11210** [sqlite3session_indirect()] for a description of direct and indirect
11211** changes.
11212**
11213** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11214** SQLite error code is returned. The values of the output variables may not
11215** be trusted in this case.
11216*/
11217SQLITE_API int sqlite3changeset_op(
11218 sqlite3_changeset_iter *pIter, /* Iterator object */
11219 const char **pzTab, /* OUT: Pointer to table name */
11220 int *pnCol, /* OUT: Number of columns in table */
11221 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11222 int *pbIndirect /* OUT: True for an 'indirect' change */
11223);
11224
11225/*
11226** CAPI3REF: Obtain The Primary Key Definition Of A Table
11227** METHOD: sqlite3_changeset_iter
11228**
11229** For each modified table, a changeset includes the following:
11230**
11231** <ul>
11232** <li> The number of columns in the table, and
11233** <li> Which of those columns make up the tables PRIMARY KEY.
11234** </ul>
11235**
11236** This function is used to find which columns comprise the PRIMARY KEY of
11237** the table modified by the change that iterator pIter currently points to.
11238** If successful, *pabPK is set to point to an array of nCol entries, where
11239** nCol is the number of columns in the table. Elements of *pabPK are set to
11240** 0x01 if the corresponding column is part of the tables primary key, or
11241** 0x00 if it is not.
11242**
11243** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11244** in the table.
11245**
11246** If this function is called when the iterator does not point to a valid
11247** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11248** SQLITE_OK is returned and the output variables populated as described
11249** above.
11250*/
11251SQLITE_API int sqlite3changeset_pk(
11252 sqlite3_changeset_iter *pIter, /* Iterator object */
11253 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11254 int *pnCol /* OUT: Number of entries in output array */
11255);
11256
11257/*
11258** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11259** METHOD: sqlite3_changeset_iter
11260**
11261** The pIter argument passed to this function may either be an iterator
11262** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11263** created by [sqlite3changeset_start()]. In the latter case, the most recent
11264** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11265** Furthermore, it may only be called if the type of change that the iterator
11266** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11267** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11268**
11269** Argument iVal must be greater than or equal to 0, and less than the number
11270** of columns in the table affected by the current change. Otherwise,
11271** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11272**
11273** If successful, this function sets *ppValue to point to a protected
11274** sqlite3_value object containing the iVal'th value from the vector of
11275** original row values stored as part of the UPDATE or DELETE change and
11276** returns SQLITE_OK. The name of the function comes from the fact that this
11277** is similar to the "old.*" columns available to update or delete triggers.
11278**
11279** If some other error occurs (e.g. an OOM condition), an SQLite error code
11280** is returned and *ppValue is set to NULL.
11281*/
11282SQLITE_API int sqlite3changeset_old(
11283 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11284 int iVal, /* Column number */
11285 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11286);
11287
11288/*
11289** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11290** METHOD: sqlite3_changeset_iter
11291**
11292** The pIter argument passed to this function may either be an iterator
11293** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11294** created by [sqlite3changeset_start()]. In the latter case, the most recent
11295** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11296** Furthermore, it may only be called if the type of change that the iterator
11297** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11298** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11299**
11300** Argument iVal must be greater than or equal to 0, and less than the number
11301** of columns in the table affected by the current change. Otherwise,
11302** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11303**
11304** If successful, this function sets *ppValue to point to a protected
11305** sqlite3_value object containing the iVal'th value from the vector of
11306** new row values stored as part of the UPDATE or INSERT change and
11307** returns SQLITE_OK. If the change is an UPDATE and does not include
11308** a new value for the requested column, *ppValue is set to NULL and
11309** SQLITE_OK returned. The name of the function comes from the fact that
11310** this is similar to the "new.*" columns available to update or delete
11311** triggers.
11312**
11313** If some other error occurs (e.g. an OOM condition), an SQLite error code
11314** is returned and *ppValue is set to NULL.
11315*/
11316SQLITE_API int sqlite3changeset_new(
11317 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11318 int iVal, /* Column number */
11319 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11320);
11321
11322/*
11323** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11324** METHOD: sqlite3_changeset_iter
11325**
11326** This function should only be used with iterator objects passed to a
11327** conflict-handler callback by [sqlite3changeset_apply()] with either
11328** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11329** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11330** is set to NULL.
11331**
11332** Argument iVal must be greater than or equal to 0, and less than the number
11333** of columns in the table affected by the current change. Otherwise,
11334** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11335**
11336** If successful, this function sets *ppValue to point to a protected
11337** sqlite3_value object containing the iVal'th value from the
11338** "conflicting row" associated with the current conflict-handler callback
11339** and returns SQLITE_OK.
11340**
11341** If some other error occurs (e.g. an OOM condition), an SQLite error code
11342** is returned and *ppValue is set to NULL.
11343*/
11344SQLITE_API int sqlite3changeset_conflict(
11345 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11346 int iVal, /* Column number */
11347 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11348);
11349
11350/*
11351** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11352** METHOD: sqlite3_changeset_iter
11353**
11354** This function may only be called with an iterator passed to an
11355** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11356** it sets the output variable to the total number of known foreign key
11357** violations in the destination database and returns SQLITE_OK.
11358**
11359** In all other cases this function returns SQLITE_MISUSE.
11360*/
11361SQLITE_API int sqlite3changeset_fk_conflicts(
11362 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11363 int *pnOut /* OUT: Number of FK violations */
11364);
11365
11366
11367/*
11368** CAPI3REF: Finalize A Changeset Iterator
11369** METHOD: sqlite3_changeset_iter
11370**
11371** This function is used to finalize an iterator allocated with
11372** [sqlite3changeset_start()].
11373**
11374** This function should only be called on iterators created using the
11375** [sqlite3changeset_start()] function. If an application calls this
11376** function with an iterator passed to a conflict-handler by
11377** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11378** call has no effect.
11379**
11380** If an error was encountered within a call to an sqlite3changeset_xxx()
11381** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11382** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11383** to that error is returned by this function. Otherwise, SQLITE_OK is
11384** returned. This is to allow the following pattern (pseudo-code):
11385**
11386** <pre>
11387** sqlite3changeset_start();
11388** while( SQLITE_ROW==sqlite3changeset_next() ){
11389** // Do something with change.
11390** }
11391** rc = sqlite3changeset_finalize();
11392** if( rc!=SQLITE_OK ){
11393** // An error has occurred
11394** }
11395** </pre>
11396*/
11397SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11398
11399/*
11400** CAPI3REF: Invert A Changeset
11401**
11402** This function is used to "invert" a changeset object. Applying an inverted
11403** changeset to a database reverses the effects of applying the uninverted
11404** changeset. Specifically:
11405**
11406** <ul>
11407** <li> Each DELETE change is changed to an INSERT, and
11408** <li> Each INSERT change is changed to a DELETE, and
11409** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11410** </ul>
11411**
11412** This function does not change the order in which changes appear within
11413** the changeset. It merely reverses the sense of each individual change.
11414**
11415** If successful, a pointer to a buffer containing the inverted changeset
11416** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11417** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11418** zeroed and an SQLite error code returned.
11419**
11420** It is the responsibility of the caller to eventually call sqlite3_free()
11421** on the *ppOut pointer to free the buffer allocation following a successful
11422** call to this function.
11423**
11424** WARNING/TODO: This function currently assumes that the input is a valid
11425** changeset. If it is not, the results are undefined.
11426*/
11427SQLITE_API int sqlite3changeset_invert(
11428 int nIn, const void *pIn, /* Input changeset */
11429 int *pnOut, void **ppOut /* OUT: Inverse of input */
11430);
11431
11432/*
11433** CAPI3REF: Concatenate Two Changeset Objects
11434**
11435** This function is used to concatenate two changesets, A and B, into a
11436** single changeset. The result is a changeset equivalent to applying
11437** changeset A followed by changeset B.
11438**
11439** This function combines the two input changesets using an
11440** sqlite3_changegroup object. Calling it produces similar results as the
11441** following code fragment:
11442**
11443** <pre>
11444** sqlite3_changegroup *pGrp;
11445** rc = sqlite3_changegroup_new(&pGrp);
11446** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11447** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11448** if( rc==SQLITE_OK ){
11449** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11450** }else{
11451** *ppOut = 0;
11452** *pnOut = 0;
11453** }
11454** </pre>
11455**
11456** Refer to the sqlite3_changegroup documentation below for details.
11457*/
11458SQLITE_API int sqlite3changeset_concat(
11459 int nA, /* Number of bytes in buffer pA */
11460 void *pA, /* Pointer to buffer containing changeset A */
11461 int nB, /* Number of bytes in buffer pB */
11462 void *pB, /* Pointer to buffer containing changeset B */
11463 int *pnOut, /* OUT: Number of bytes in output changeset */
11464 void **ppOut /* OUT: Buffer containing output changeset */
11465);
11466
11467
11468/*
11469** CAPI3REF: Changegroup Handle
11470**
11471** A changegroup is an object used to combine two or more
11472** [changesets] or [patchsets]
11473*/
11474typedef struct sqlite3_changegroup sqlite3_changegroup;
11475
11476/*
11477** CAPI3REF: Create A New Changegroup Object
11478** CONSTRUCTOR: sqlite3_changegroup
11479**
11480** An sqlite3_changegroup object is used to combine two or more changesets
11481** (or patchsets) into a single changeset (or patchset). A single changegroup
11482** object may combine changesets or patchsets, but not both. The output is
11483** always in the same format as the input.
11484**
11485** If successful, this function returns SQLITE_OK and populates (*pp) with
11486** a pointer to a new sqlite3_changegroup object before returning. The caller
11487** should eventually free the returned object using a call to
11488** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11489** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11490**
11491** The usual usage pattern for an sqlite3_changegroup object is as follows:
11492**
11493** <ul>
11494** <li> It is created using a call to sqlite3changegroup_new().
11495**
11496** <li> Zero or more changesets (or patchsets) are added to the object
11497** by calling sqlite3changegroup_add().
11498**
11499** <li> The result of combining all input changesets together is obtained
11500** by the application via a call to sqlite3changegroup_output().
11501**
11502** <li> The object is deleted using a call to sqlite3changegroup_delete().
11503** </ul>
11504**
11505** Any number of calls to add() and output() may be made between the calls to
11506** new() and delete(), and in any order.
11507**
11508** As well as the regular sqlite3changegroup_add() and
11509** sqlite3changegroup_output() functions, also available are the streaming
11510** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11511*/
11512SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11513
11514/*
11515** CAPI3REF: Add A Changeset To A Changegroup
11516** METHOD: sqlite3_changegroup
11517**
11518** Add all changes within the changeset (or patchset) in buffer pData (size
11519** nData bytes) to the changegroup.
11520**
11521** If the buffer contains a patchset, then all prior calls to this function
11522** on the same changegroup object must also have specified patchsets. Or, if
11523** the buffer contains a changeset, so must have the earlier calls to this
11524** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11525** to the changegroup.
11526**
11527** Rows within the changeset and changegroup are identified by the values in
11528** their PRIMARY KEY columns. A change in the changeset is considered to
11529** apply to the same row as a change already present in the changegroup if
11530** the two rows have the same primary key.
11531**
11532** Changes to rows that do not already appear in the changegroup are
11533** simply copied into it. Or, if both the new changeset and the changegroup
11534** contain changes that apply to a single row, the final contents of the
11535** changegroup depends on the type of each change, as follows:
11536**
11537** <table border=1 style="margin-left:8ex;margin-right:8ex">
11538** <tr><th style="white-space:pre">Existing Change </th>
11539** <th style="white-space:pre">New Change </th>
11540** <th>Output Change
11541** <tr><td>INSERT <td>INSERT <td>
11542** The new change is ignored. This case does not occur if the new
11543** changeset was recorded immediately after the changesets already
11544** added to the changegroup.
11545** <tr><td>INSERT <td>UPDATE <td>
11546** The INSERT change remains in the changegroup. The values in the
11547** INSERT change are modified as if the row was inserted by the
11548** existing change and then updated according to the new change.
11549** <tr><td>INSERT <td>DELETE <td>
11550** The existing INSERT is removed from the changegroup. The DELETE is
11551** not added.
11552** <tr><td>UPDATE <td>INSERT <td>
11553** The new change is ignored. This case does not occur if the new
11554** changeset was recorded immediately after the changesets already
11555** added to the changegroup.
11556** <tr><td>UPDATE <td>UPDATE <td>
11557** The existing UPDATE remains within the changegroup. It is amended
11558** so that the accompanying values are as if the row was updated once
11559** by the existing change and then again by the new change.
11560** <tr><td>UPDATE <td>DELETE <td>
11561** The existing UPDATE is replaced by the new DELETE within the
11562** changegroup.
11563** <tr><td>DELETE <td>INSERT <td>
11564** If one or more of the column values in the row inserted by the
11565** new change differ from those in the row deleted by the existing
11566** change, the existing DELETE is replaced by an UPDATE within the
11567** changegroup. Otherwise, if the inserted row is exactly the same
11568** as the deleted row, the existing DELETE is simply discarded.
11569** <tr><td>DELETE <td>UPDATE <td>
11570** The new change is ignored. This case does not occur if the new
11571** changeset was recorded immediately after the changesets already
11572** added to the changegroup.
11573** <tr><td>DELETE <td>DELETE <td>
11574** The new change is ignored. This case does not occur if the new
11575** changeset was recorded immediately after the changesets already
11576** added to the changegroup.
11577** </table>
11578**
11579** If the new changeset contains changes to a table that is already present
11580** in the changegroup, then the number of columns and the position of the
11581** primary key columns for the table must be consistent. If this is not the
11582** case, this function fails with SQLITE_SCHEMA. If the input changeset
11583** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
11584** returned. Or, if an out-of-memory condition occurs during processing, this
11585** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
11586** of the final contents of the changegroup is undefined.
11587**
11588** If no error occurs, SQLITE_OK is returned.
11589*/
11590SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11591
11592/*
11593** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11594** METHOD: sqlite3_changegroup
11595**
11596** Obtain a buffer containing a changeset (or patchset) representing the
11597** current contents of the changegroup. If the inputs to the changegroup
11598** were themselves changesets, the output is a changeset. Or, if the
11599** inputs were patchsets, the output is also a patchset.
11600**
11601** As with the output of the sqlite3session_changeset() and
11602** sqlite3session_patchset() functions, all changes related to a single
11603** table are grouped together in the output of this function. Tables appear
11604** in the same order as for the very first changeset added to the changegroup.
11605** If the second or subsequent changesets added to the changegroup contain
11606** changes for tables that do not appear in the first changeset, they are
11607** appended onto the end of the output changeset, again in the order in
11608** which they are first encountered.
11609**
11610** If an error occurs, an SQLite error code is returned and the output
11611** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
11612** is returned and the output variables are set to the size of and a
11613** pointer to the output buffer, respectively. In this case it is the
11614** responsibility of the caller to eventually free the buffer using a
11615** call to sqlite3_free().
11616*/
11617SQLITE_API int sqlite3changegroup_output(
11618 sqlite3_changegroup*,
11619 int *pnData, /* OUT: Size of output buffer in bytes */
11620 void **ppData /* OUT: Pointer to output buffer */
11621);
11622
11623/*
11624** CAPI3REF: Delete A Changegroup Object
11625** DESTRUCTOR: sqlite3_changegroup
11626*/
11627SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
11628
11629/*
11630** CAPI3REF: Apply A Changeset To A Database
11631**
11632** Apply a changeset or patchset to a database. These functions attempt to
11633** update the "main" database attached to handle db with the changes found in
11634** the changeset passed via the second and third arguments.
11635**
11636** The fourth argument (xFilter) passed to these functions is the "filter
11637** callback". If it is not NULL, then for each table affected by at least one
11638** change in the changeset, the filter callback is invoked with
11639** the table name as the second argument, and a copy of the context pointer
11640** passed as the sixth argument as the first. If the "filter callback"
11641** returns zero, then no attempt is made to apply any changes to the table.
11642** Otherwise, if the return value is non-zero or the xFilter argument to
11643** is NULL, all changes related to the table are attempted.
11644**
11645** For each table that is not excluded by the filter callback, this function
11646** tests that the target database contains a compatible table. A table is
11647** considered compatible if all of the following are true:
11648**
11649** <ul>
11650** <li> The table has the same name as the name recorded in the
11651** changeset, and
11652** <li> The table has at least as many columns as recorded in the
11653** changeset, and
11654** <li> The table has primary key columns in the same position as
11655** recorded in the changeset.
11656** </ul>
11657**
11658** If there is no compatible table, it is not an error, but none of the
11659** changes associated with the table are applied. A warning message is issued
11660** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11661** one such warning is issued for each table in the changeset.
11662**
11663** For each change for which there is a compatible table, an attempt is made
11664** to modify the table contents according to the UPDATE, INSERT or DELETE
11665** change. If a change cannot be applied cleanly, the conflict handler
11666** function passed as the fifth argument to sqlite3changeset_apply() may be
11667** invoked. A description of exactly when the conflict handler is invoked for
11668** each type of change is below.
11669**
11670** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11671** of passing anything other than a valid function pointer as the xConflict
11672** argument are undefined.
11673**
11674** Each time the conflict handler function is invoked, it must return one
11675** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11676** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11677** if the second argument passed to the conflict handler is either
11678** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11679** returns an illegal value, any changes already made are rolled back and
11680** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11681** actions are taken by sqlite3changeset_apply() depending on the value
11682** returned by each invocation of the conflict-handler function. Refer to
11683** the documentation for the three
11684** [SQLITE_CHANGESET_OMIT|available return values] for details.
11685**
11686** <dl>
11687** <dt>DELETE Changes<dd>
11688** For each DELETE change, the function checks if the target database
11689** contains a row with the same primary key value (or values) as the
11690** original row values stored in the changeset. If it does, and the values
11691** stored in all non-primary key columns also match the values stored in
11692** the changeset the row is deleted from the target database.
11693**
11694** If a row with matching primary key values is found, but one or more of
11695** the non-primary key fields contains a value different from the original
11696** row value stored in the changeset, the conflict-handler function is
11697** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11698** database table has more columns than are recorded in the changeset,
11699** only the values of those non-primary key fields are compared against
11700** the current database contents - any trailing database table columns
11701** are ignored.
11702**
11703** If no row with matching primary key values is found in the database,
11704** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11705** passed as the second argument.
11706**
11707** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11708** (which can only happen if a foreign key constraint is violated), the
11709** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11710** passed as the second argument. This includes the case where the DELETE
11711** operation is attempted because an earlier call to the conflict handler
11712** function returned [SQLITE_CHANGESET_REPLACE].
11713**
11714** <dt>INSERT Changes<dd>
11715** For each INSERT change, an attempt is made to insert the new row into
11716** the database. If the changeset row contains fewer fields than the
11717** database table, the trailing fields are populated with their default
11718** values.
11719**
11720** If the attempt to insert the row fails because the database already
11721** contains a row with the same primary key values, the conflict handler
11722** function is invoked with the second argument set to
11723** [SQLITE_CHANGESET_CONFLICT].
11724**
11725** If the attempt to insert the row fails because of some other constraint
11726** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11727** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11728** This includes the case where the INSERT operation is re-attempted because
11729** an earlier call to the conflict handler function returned
11730** [SQLITE_CHANGESET_REPLACE].
11731**
11732** <dt>UPDATE Changes<dd>
11733** For each UPDATE change, the function checks if the target database
11734** contains a row with the same primary key value (or values) as the
11735** original row values stored in the changeset. If it does, and the values
11736** stored in all modified non-primary key columns also match the values
11737** stored in the changeset the row is updated within the target database.
11738**
11739** If a row with matching primary key values is found, but one or more of
11740** the modified non-primary key fields contains a value different from an
11741** original row value stored in the changeset, the conflict-handler function
11742** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11743** UPDATE changes only contain values for non-primary key fields that are
11744** to be modified, only those fields need to match the original values to
11745** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11746**
11747** If no row with matching primary key values is found in the database,
11748** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11749** passed as the second argument.
11750**
11751** If the UPDATE operation is attempted, but SQLite returns
11752** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11753** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11754** This includes the case where the UPDATE operation is attempted after
11755** an earlier call to the conflict handler function returned
11756** [SQLITE_CHANGESET_REPLACE].
11757** </dl>
11758**
11759** It is safe to execute SQL statements, including those that write to the
11760** table that the callback related to, from within the xConflict callback.
11761** This can be used to further customize the application's conflict
11762** resolution strategy.
11763**
11764** All changes made by these functions are enclosed in a savepoint transaction.
11765** If any other error (aside from a constraint failure when attempting to
11766** write to the target database) occurs, then the savepoint transaction is
11767** rolled back, restoring the target database to its original state, and an
11768** SQLite error code returned.
11769**
11770** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11771** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11772** may set (*ppRebase) to point to a "rebase" that may be used with the
11773** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11774** is set to the size of the buffer in bytes. It is the responsibility of the
11775** caller to eventually free any such buffer using sqlite3_free(). The buffer
11776** is only allocated and populated if one or more conflicts were encountered
11777** while applying the patchset. See comments surrounding the sqlite3_rebaser
11778** APIs for further details.
11779**
11780** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11781** may be modified by passing a combination of
11782** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11783**
11784** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11785** and therefore subject to change.
11786*/
11787SQLITE_API int sqlite3changeset_apply(
11788 sqlite3 *db, /* Apply change to "main" db of this handle */
11789 int nChangeset, /* Size of changeset in bytes */
11790 void *pChangeset, /* Changeset blob */
11791 int(*xFilter)(
11792 void *pCtx, /* Copy of sixth arg to _apply() */
11793 const char *zTab /* Table name */
11794 ),
11795 int(*xConflict)(
11796 void *pCtx, /* Copy of sixth arg to _apply() */
11797 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11798 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11799 ),
11800 void *pCtx /* First argument passed to xConflict */
11801);
11802SQLITE_API int sqlite3changeset_apply_v2(
11803 sqlite3 *db, /* Apply change to "main" db of this handle */
11804 int nChangeset, /* Size of changeset in bytes */
11805 void *pChangeset, /* Changeset blob */
11806 int(*xFilter)(
11807 void *pCtx, /* Copy of sixth arg to _apply() */
11808 const char *zTab /* Table name */
11809 ),
11810 int(*xConflict)(
11811 void *pCtx, /* Copy of sixth arg to _apply() */
11812 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11813 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11814 ),
11815 void *pCtx, /* First argument passed to xConflict */
11816 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11817 int flags /* SESSION_CHANGESETAPPLY_* flags */
11818);
11819
11820/*
11821** CAPI3REF: Flags for sqlite3changeset_apply_v2
11822**
11823** The following flags may passed via the 9th parameter to
11824** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11825**
11826** <dl>
11827** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11828** Usually, the sessions module encloses all operations performed by
11829** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11830** SAVEPOINT is committed if the changeset or patchset is successfully
11831** applied, or rolled back if an error occurs. Specifying this flag
11832** causes the sessions module to omit this savepoint. In this case, if the
11833** caller has an open transaction or savepoint when apply_v2() is called,
11834** it may revert the partially applied changeset by rolling it back.
11835**
11836** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11837** Invert the changeset before applying it. This is equivalent to inverting
11838** a changeset using sqlite3changeset_invert() before applying it. It is
11839** an error to specify this flag with a patchset.
11840*/
11841#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11842#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11843
11844/*
11845** CAPI3REF: Constants Passed To The Conflict Handler
11846**
11847** Values that may be passed as the second argument to a conflict-handler.
11848**
11849** <dl>
11850** <dt>SQLITE_CHANGESET_DATA<dd>
11851** The conflict handler is invoked with CHANGESET_DATA as the second argument
11852** when processing a DELETE or UPDATE change if a row with the required
11853** PRIMARY KEY fields is present in the database, but one or more other
11854** (non primary-key) fields modified by the update do not contain the
11855** expected "before" values.
11856**
11857** The conflicting row, in this case, is the database row with the matching
11858** primary key.
11859**
11860** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11861** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11862** argument when processing a DELETE or UPDATE change if a row with the
11863** required PRIMARY KEY fields is not present in the database.
11864**
11865** There is no conflicting row in this case. The results of invoking the
11866** sqlite3changeset_conflict() API are undefined.
11867**
11868** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11869** CHANGESET_CONFLICT is passed as the second argument to the conflict
11870** handler while processing an INSERT change if the operation would result
11871** in duplicate primary key values.
11872**
11873** The conflicting row in this case is the database row with the matching
11874** primary key.
11875**
11876** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11877** If foreign key handling is enabled, and applying a changeset leaves the
11878** database in a state containing foreign key violations, the conflict
11879** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11880** exactly once before the changeset is committed. If the conflict handler
11881** returns CHANGESET_OMIT, the changes, including those that caused the
11882** foreign key constraint violation, are committed. Or, if it returns
11883** CHANGESET_ABORT, the changeset is rolled back.
11884**
11885** No current or conflicting row information is provided. The only function
11886** it is possible to call on the supplied sqlite3_changeset_iter handle
11887** is sqlite3changeset_fk_conflicts().
11888**
11889** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
11890** If any other constraint violation occurs while applying a change (i.e.
11891** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
11892** invoked with CHANGESET_CONSTRAINT as the second argument.
11893**
11894** There is no conflicting row in this case. The results of invoking the
11895** sqlite3changeset_conflict() API are undefined.
11896**
11897** </dl>
11898*/
11899#define SQLITE_CHANGESET_DATA 1
11900#define SQLITE_CHANGESET_NOTFOUND 2
11901#define SQLITE_CHANGESET_CONFLICT 3
11902#define SQLITE_CHANGESET_CONSTRAINT 4
11903#define SQLITE_CHANGESET_FOREIGN_KEY 5
11904
11905/*
11906** CAPI3REF: Constants Returned By The Conflict Handler
11907**
11908** A conflict handler callback must return one of the following three values.
11909**
11910** <dl>
11911** <dt>SQLITE_CHANGESET_OMIT<dd>
11912** If a conflict handler returns this value no special action is taken. The
11913** change that caused the conflict is not applied. The session module
11914** continues to the next change in the changeset.
11915**
11916** <dt>SQLITE_CHANGESET_REPLACE<dd>
11917** This value may only be returned if the second argument to the conflict
11918** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
11919** is not the case, any changes applied so far are rolled back and the
11920** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11921**
11922** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11923** handler, then the conflicting row is either updated or deleted, depending
11924** on the type of change.
11925**
11926** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11927** handler, then the conflicting row is removed from the database and a
11928** second attempt to apply the change is made. If this second attempt fails,
11929** the original row is restored to the database before continuing.
11930**
11931** <dt>SQLITE_CHANGESET_ABORT<dd>
11932** If this value is returned, any changes applied so far are rolled back
11933** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11934** </dl>
11935*/
11936#define SQLITE_CHANGESET_OMIT 0
11937#define SQLITE_CHANGESET_REPLACE 1
11938#define SQLITE_CHANGESET_ABORT 2
11939
11940/*
11941** CAPI3REF: Rebasing changesets
11942** EXPERIMENTAL
11943**
11944** Suppose there is a site hosting a database in state S0. And that
11945** modifications are made that move that database to state S1 and a
11946** changeset recorded (the "local" changeset). Then, a changeset based
11947** on S0 is received from another site (the "remote" changeset) and
11948** applied to the database. The database is then in state
11949** (S1+"remote"), where the exact state depends on any conflict
11950** resolution decisions (OMIT or REPLACE) made while applying "remote".
11951** Rebasing a changeset is to update it to take those conflict
11952** resolution decisions into account, so that the same conflicts
11953** do not have to be resolved elsewhere in the network.
11954**
11955** For example, if both the local and remote changesets contain an
11956** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11957**
11958** local: INSERT INTO t1 VALUES(1, 'v1');
11959** remote: INSERT INTO t1 VALUES(1, 'v2');
11960**
11961** and the conflict resolution is REPLACE, then the INSERT change is
11962** removed from the local changeset (it was overridden). Or, if the
11963** conflict resolution was "OMIT", then the local changeset is modified
11964** to instead contain:
11965**
11966** UPDATE t1 SET b = 'v2' WHERE a=1;
11967**
11968** Changes within the local changeset are rebased as follows:
11969**
11970** <dl>
11971** <dt>Local INSERT<dd>
11972** This may only conflict with a remote INSERT. If the conflict
11973** resolution was OMIT, then add an UPDATE change to the rebased
11974** changeset. Or, if the conflict resolution was REPLACE, add
11975** nothing to the rebased changeset.
11976**
11977** <dt>Local DELETE<dd>
11978** This may conflict with a remote UPDATE or DELETE. In both cases the
11979** only possible resolution is OMIT. If the remote operation was a
11980** DELETE, then add no change to the rebased changeset. If the remote
11981** operation was an UPDATE, then the old.* fields of change are updated
11982** to reflect the new.* values in the UPDATE.
11983**
11984** <dt>Local UPDATE<dd>
11985** This may conflict with a remote UPDATE or DELETE. If it conflicts
11986** with a DELETE, and the conflict resolution was OMIT, then the update
11987** is changed into an INSERT. Any undefined values in the new.* record
11988** from the update change are filled in using the old.* values from
11989** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11990** the UPDATE change is simply omitted from the rebased changeset.
11991**
11992** If conflict is with a remote UPDATE and the resolution is OMIT, then
11993** the old.* values are rebased using the new.* values in the remote
11994** change. Or, if the resolution is REPLACE, then the change is copied
11995** into the rebased changeset with updates to columns also updated by
11996** the conflicting remote UPDATE removed. If this means no columns would
11997** be updated, the change is omitted.
11998** </dl>
11999**
12000** A local change may be rebased against multiple remote changes
12001** simultaneously. If a single key is modified by multiple remote
12002** changesets, they are combined as follows before the local changeset
12003** is rebased:
12004**
12005** <ul>
12006** <li> If there has been one or more REPLACE resolutions on a
12007** key, it is rebased according to a REPLACE.
12008**
12009** <li> If there have been no REPLACE resolutions on a key, then
12010** the local changeset is rebased according to the most recent
12011** of the OMIT resolutions.
12012** </ul>
12013**
12014** Note that conflict resolutions from multiple remote changesets are
12015** combined on a per-field basis, not per-row. This means that in the
12016** case of multiple remote UPDATE operations, some fields of a single
12017** local change may be rebased for REPLACE while others are rebased for
12018** OMIT.
12019**
12020** In order to rebase a local changeset, the remote changeset must first
12021** be applied to the local database using sqlite3changeset_apply_v2() and
12022** the buffer of rebase information captured. Then:
12023**
12024** <ol>
12025** <li> An sqlite3_rebaser object is created by calling
12026** sqlite3rebaser_create().
12027** <li> The new object is configured with the rebase buffer obtained from
12028** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12029** If the local changeset is to be rebased against multiple remote
12030** changesets, then sqlite3rebaser_configure() should be called
12031** multiple times, in the same order that the multiple
12032** sqlite3changeset_apply_v2() calls were made.
12033** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12034** <li> The sqlite3_rebaser object is deleted by calling
12035** sqlite3rebaser_delete().
12036** </ol>
12037*/
12038typedef struct sqlite3_rebaser sqlite3_rebaser;
12039
12040/*
12041** CAPI3REF: Create a changeset rebaser object.
12042** EXPERIMENTAL
12043**
12044** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12045** point to the new object and return SQLITE_OK. Otherwise, if an error
12046** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12047** to NULL.
12048*/
12049SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12050
12051/*
12052** CAPI3REF: Configure a changeset rebaser object.
12053** EXPERIMENTAL
12054**
12055** Configure the changeset rebaser object to rebase changesets according
12056** to the conflict resolutions described by buffer pRebase (size nRebase
12057** bytes), which must have been obtained from a previous call to
12058** sqlite3changeset_apply_v2().
12059*/
12060SQLITE_API int sqlite3rebaser_configure(
12061 sqlite3_rebaser*,
12062 int nRebase, const void *pRebase
12063);
12064
12065/*
12066** CAPI3REF: Rebase a changeset
12067** EXPERIMENTAL
12068**
12069** Argument pIn must point to a buffer containing a changeset nIn bytes
12070** in size. This function allocates and populates a buffer with a copy
12071** of the changeset rebased according to the configuration of the
12072** rebaser object passed as the first argument. If successful, (*ppOut)
12073** is set to point to the new buffer containing the rebased changeset and
12074** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12075** responsibility of the caller to eventually free the new buffer using
12076** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12077** are set to zero and an SQLite error code returned.
12078*/
12079SQLITE_API int sqlite3rebaser_rebase(
12080 sqlite3_rebaser*,
12081 int nIn, const void *pIn,
12082 int *pnOut, void **ppOut
12083);
12084
12085/*
12086** CAPI3REF: Delete a changeset rebaser object.
12087** EXPERIMENTAL
12088**
12089** Delete the changeset rebaser object and all associated resources. There
12090** should be one call to this function for each successful invocation
12091** of sqlite3rebaser_create().
12092*/
12093SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12094
12095/*
12096** CAPI3REF: Streaming Versions of API functions.
12097**
12098** The six streaming API xxx_strm() functions serve similar purposes to the
12099** corresponding non-streaming API functions:
12100**
12101** <table border=1 style="margin-left:8ex;margin-right:8ex">
12102** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12103** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12104** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12105** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12106** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12107** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12108** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12109** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12110** </table>
12111**
12112** Non-streaming functions that accept changesets (or patchsets) as input
12113** require that the entire changeset be stored in a single buffer in memory.
12114** Similarly, those that return a changeset or patchset do so by returning
12115** a pointer to a single large buffer allocated using sqlite3_malloc().
12116** Normally this is convenient. However, if an application running in a
12117** low-memory environment is required to handle very large changesets, the
12118** large contiguous memory allocations required can become onerous.
12119**
12120** In order to avoid this problem, instead of a single large buffer, input
12121** is passed to a streaming API functions by way of a callback function that
12122** the sessions module invokes to incrementally request input data as it is
12123** required. In all cases, a pair of API function parameters such as
12124**
12125** <pre>
12126** &nbsp; int nChangeset,
12127** &nbsp; void *pChangeset,
12128** </pre>
12129**
12130** Is replaced by:
12131**
12132** <pre>
12133** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
12134** &nbsp; void *pIn,
12135** </pre>
12136**
12137** Each time the xInput callback is invoked by the sessions module, the first
12138** argument passed is a copy of the supplied pIn context pointer. The second
12139** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12140** error occurs the xInput method should copy up to (*pnData) bytes of data
12141** into the buffer and set (*pnData) to the actual number of bytes copied
12142** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12143** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12144** error code should be returned. In all cases, if an xInput callback returns
12145** an error, all processing is abandoned and the streaming API function
12146** returns a copy of the error code to the caller.
12147**
12148** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12149** invoked by the sessions module at any point during the lifetime of the
12150** iterator. If such an xInput callback returns an error, the iterator enters
12151** an error state, whereby all subsequent calls to iterator functions
12152** immediately fail with the same error code as returned by xInput.
12153**
12154** Similarly, streaming API functions that return changesets (or patchsets)
12155** return them in chunks by way of a callback function instead of via a
12156** pointer to a single large buffer. In this case, a pair of parameters such
12157** as:
12158**
12159** <pre>
12160** &nbsp; int *pnChangeset,
12161** &nbsp; void **ppChangeset,
12162** </pre>
12163**
12164** Is replaced by:
12165**
12166** <pre>
12167** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
12168** &nbsp; void *pOut
12169** </pre>
12170**
12171** The xOutput callback is invoked zero or more times to return data to
12172** the application. The first parameter passed to each call is a copy of the
12173** pOut pointer supplied by the application. The second parameter, pData,
12174** points to a buffer nData bytes in size containing the chunk of output
12175** data being returned. If the xOutput callback successfully processes the
12176** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12177** it should return some other SQLite error code. In this case processing
12178** is immediately abandoned and the streaming API function returns a copy
12179** of the xOutput error code to the application.
12180**
12181** The sessions module never invokes an xOutput callback with the third
12182** parameter set to a value less than or equal to zero. Other than this,
12183** no guarantees are made as to the size of the chunks of data returned.
12184*/
12185SQLITE_API int sqlite3changeset_apply_strm(
12186 sqlite3 *db, /* Apply change to "main" db of this handle */
12187 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12188 void *pIn, /* First arg for xInput */
12189 int(*xFilter)(
12190 void *pCtx, /* Copy of sixth arg to _apply() */
12191 const char *zTab /* Table name */
12192 ),
12193 int(*xConflict)(
12194 void *pCtx, /* Copy of sixth arg to _apply() */
12195 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12196 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12197 ),
12198 void *pCtx /* First argument passed to xConflict */
12199);
12200SQLITE_API int sqlite3changeset_apply_v2_strm(
12201 sqlite3 *db, /* Apply change to "main" db of this handle */
12202 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12203 void *pIn, /* First arg for xInput */
12204 int(*xFilter)(
12205 void *pCtx, /* Copy of sixth arg to _apply() */
12206 const char *zTab /* Table name */
12207 ),
12208 int(*xConflict)(
12209 void *pCtx, /* Copy of sixth arg to _apply() */
12210 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12211 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12212 ),
12213 void *pCtx, /* First argument passed to xConflict */
12214 void **ppRebase, int *pnRebase,
12215 int flags
12216);
12217SQLITE_API int sqlite3changeset_concat_strm(
12218 int (*xInputA)(void *pIn, void *pData, int *pnData),
12219 void *pInA,
12220 int (*xInputB)(void *pIn, void *pData, int *pnData),
12221 void *pInB,
12222 int (*xOutput)(void *pOut, const void *pData, int nData),
12223 void *pOut
12224);
12225SQLITE_API int sqlite3changeset_invert_strm(
12226 int (*xInput)(void *pIn, void *pData, int *pnData),
12227 void *pIn,
12228 int (*xOutput)(void *pOut, const void *pData, int nData),
12229 void *pOut
12230);
12231SQLITE_API int sqlite3changeset_start_strm(
12232 sqlite3_changeset_iter **pp,
12233 int (*xInput)(void *pIn, void *pData, int *pnData),
12234 void *pIn
12235);
12236SQLITE_API int sqlite3changeset_start_v2_strm(
12237 sqlite3_changeset_iter **pp,
12238 int (*xInput)(void *pIn, void *pData, int *pnData),
12239 void *pIn,
12240 int flags
12241);
12242SQLITE_API int sqlite3session_changeset_strm(
12243 sqlite3_session *pSession,
12244 int (*xOutput)(void *pOut, const void *pData, int nData),
12245 void *pOut
12246);
12247SQLITE_API int sqlite3session_patchset_strm(
12248 sqlite3_session *pSession,
12249 int (*xOutput)(void *pOut, const void *pData, int nData),
12250 void *pOut
12251);
12252SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12253 int (*xInput)(void *pIn, void *pData, int *pnData),
12254 void *pIn
12255);
12256SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12257 int (*xOutput)(void *pOut, const void *pData, int nData),
12258 void *pOut
12259);
12260SQLITE_API int sqlite3rebaser_rebase_strm(
12261 sqlite3_rebaser *pRebaser,
12262 int (*xInput)(void *pIn, void *pData, int *pnData),
12263 void *pIn,
12264 int (*xOutput)(void *pOut, const void *pData, int nData),
12265 void *pOut
12266);
12267
12268/*
12269** CAPI3REF: Configure global parameters
12270**
12271** The sqlite3session_config() interface is used to make global configuration
12272** changes to the sessions module in order to tune it to the specific needs
12273** of the application.
12274**
12275** The sqlite3session_config() interface is not threadsafe. If it is invoked
12276** while any other thread is inside any other sessions method then the
12277** results are undefined. Furthermore, if it is invoked after any sessions
12278** related objects have been created, the results are also undefined.
12279**
12280** The first argument to the sqlite3session_config() function must be one
12281** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12282** interpretation of the (void*) value passed as the second parameter and
12283** the effect of calling this function depends on the value of the first
12284** parameter.
12285**
12286** <dl>
12287** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12288** By default, the sessions module streaming interfaces attempt to input
12289** and output data in approximately 1 KiB chunks. This operand may be used
12290** to set and query the value of this configuration setting. The pointer
12291** passed as the second argument must point to a value of type (int).
12292** If this value is greater than 0, it is used as the new streaming data
12293** chunk size for both input and output. Before returning, the (int) value
12294** pointed to by pArg is set to the final value of the streaming interface
12295** chunk size.
12296** </dl>
12297**
12298** This function returns SQLITE_OK if successful, or an SQLite error code
12299** otherwise.
12300*/
12301SQLITE_API int sqlite3session_config(int op, void *pArg);
12302
12303/*
12304** CAPI3REF: Values for sqlite3session_config().
12305*/
12306#define SQLITE_SESSION_CONFIG_STRMSIZE 1
12307
12308/*
12309** Make sure we can call this stuff from C++.
12310*/
12311#ifdef __cplusplus
12312}
12313#endif
12314
12315#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12316
12317/******** End of sqlite3session.h *********/
12318/******** Begin file fts5.h *********/
12319/*
12320** 2014 May 31
12321**
12322** The author disclaims copyright to this source code. In place of
12323** a legal notice, here is a blessing:
12324**
12325** May you do good and not evil.
12326** May you find forgiveness for yourself and forgive others.
12327** May you share freely, never taking more than you give.
12328**
12329******************************************************************************
12330**
12331** Interfaces to extend FTS5. Using the interfaces defined in this file,
12332** FTS5 may be extended with:
12333**
12334** * custom tokenizers, and
12335** * custom auxiliary functions.
12336*/
12337
12338
12339#ifndef _FTS5_H
12340#define _FTS5_H
12341
12342
12343#ifdef __cplusplus
12344extern "C" {
12345#endif
12346
12347/*************************************************************************
12348** CUSTOM AUXILIARY FUNCTIONS
12349**
12350** Virtual table implementations may overload SQL functions by implementing
12351** the sqlite3_module.xFindFunction() method.
12352*/
12353
12354typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12355typedef struct Fts5Context Fts5Context;
12356typedef struct Fts5PhraseIter Fts5PhraseIter;
12357
12358typedef void (*fts5_extension_function)(
12359 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12360 Fts5Context *pFts, /* First arg to pass to pApi functions */
12361 sqlite3_context *pCtx, /* Context for returning result/error */
12362 int nVal, /* Number of values in apVal[] array */
12363 sqlite3_value **apVal /* Array of trailing arguments */
12364);
12365
12366struct Fts5PhraseIter {
12367 const unsigned char *a;
12368 const unsigned char *b;
12369};
12370
12371/*
12372** EXTENSION API FUNCTIONS
12373**
12374** xUserData(pFts):
12375** Return a copy of the context pointer the extension function was
12376** registered with.
12377**
12378** xColumnTotalSize(pFts, iCol, pnToken):
12379** If parameter iCol is less than zero, set output variable *pnToken
12380** to the total number of tokens in the FTS5 table. Or, if iCol is
12381** non-negative but less than the number of columns in the table, return
12382** the total number of tokens in column iCol, considering all rows in
12383** the FTS5 table.
12384**
12385** If parameter iCol is greater than or equal to the number of columns
12386** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12387** an OOM condition or IO error), an appropriate SQLite error code is
12388** returned.
12389**
12390** xColumnCount(pFts):
12391** Return the number of columns in the table.
12392**
12393** xColumnSize(pFts, iCol, pnToken):
12394** If parameter iCol is less than zero, set output variable *pnToken
12395** to the total number of tokens in the current row. Or, if iCol is
12396** non-negative but less than the number of columns in the table, set
12397** *pnToken to the number of tokens in column iCol of the current row.
12398**
12399** If parameter iCol is greater than or equal to the number of columns
12400** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12401** an OOM condition or IO error), an appropriate SQLite error code is
12402** returned.
12403**
12404** This function may be quite inefficient if used with an FTS5 table
12405** created with the "columnsize=0" option.
12406**
12407** xColumnText:
12408** This function attempts to retrieve the text of column iCol of the
12409** current document. If successful, (*pz) is set to point to a buffer
12410** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12411** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12412** if an error occurs, an SQLite error code is returned and the final values
12413** of (*pz) and (*pn) are undefined.
12414**
12415** xPhraseCount:
12416** Returns the number of phrases in the current query expression.
12417**
12418** xPhraseSize:
12419** Returns the number of tokens in phrase iPhrase of the query. Phrases
12420** are numbered starting from zero.
12421**
12422** xInstCount:
12423** Set *pnInst to the total number of occurrences of all phrases within
12424** the query within the current row. Return SQLITE_OK if successful, or
12425** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12426**
12427** This API can be quite slow if used with an FTS5 table created with the
12428** "detail=none" or "detail=column" option. If the FTS5 table is created
12429** with either "detail=none" or "detail=column" and "content=" option
12430** (i.e. if it is a contentless table), then this API always returns 0.
12431**
12432** xInst:
12433** Query for the details of phrase match iIdx within the current row.
12434** Phrase matches are numbered starting from zero, so the iIdx argument
12435** should be greater than or equal to zero and smaller than the value
12436** output by xInstCount().
12437**
12438** Usually, output parameter *piPhrase is set to the phrase number, *piCol
12439** to the column in which it occurs and *piOff the token offset of the
12440** first token of the phrase. Returns SQLITE_OK if successful, or an error
12441** code (i.e. SQLITE_NOMEM) if an error occurs.
12442**
12443** This API can be quite slow if used with an FTS5 table created with the
12444** "detail=none" or "detail=column" option.
12445**
12446** xRowid:
12447** Returns the rowid of the current row.
12448**
12449** xTokenize:
12450** Tokenize text using the tokenizer belonging to the FTS5 table.
12451**
12452** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12453** This API function is used to query the FTS table for phrase iPhrase
12454** of the current query. Specifically, a query equivalent to:
12455**
12456** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12457**
12458** with $p set to a phrase equivalent to the phrase iPhrase of the
12459** current query is executed. Any column filter that applies to
12460** phrase iPhrase of the current query is included in $p. For each
12461** row visited, the callback function passed as the fourth argument
12462** is invoked. The context and API objects passed to the callback
12463** function may be used to access the properties of each matched row.
12464** Invoking Api.xUserData() returns a copy of the pointer passed as
12465** the third argument to pUserData.
12466**
12467** If the callback function returns any value other than SQLITE_OK, the
12468** query is abandoned and the xQueryPhrase function returns immediately.
12469** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12470** Otherwise, the error code is propagated upwards.
12471**
12472** If the query runs to completion without incident, SQLITE_OK is returned.
12473** Or, if some error occurs before the query completes or is aborted by
12474** the callback, an SQLite error code is returned.
12475**
12476**
12477** xSetAuxdata(pFts5, pAux, xDelete)
12478**
12479** Save the pointer passed as the second argument as the extension function's
12480** "auxiliary data". The pointer may then be retrieved by the current or any
12481** future invocation of the same fts5 extension function made as part of
12482** the same MATCH query using the xGetAuxdata() API.
12483**
12484** Each extension function is allocated a single auxiliary data slot for
12485** each FTS query (MATCH expression). If the extension function is invoked
12486** more than once for a single FTS query, then all invocations share a
12487** single auxiliary data context.
12488**
12489** If there is already an auxiliary data pointer when this function is
12490** invoked, then it is replaced by the new pointer. If an xDelete callback
12491** was specified along with the original pointer, it is invoked at this
12492** point.
12493**
12494** The xDelete callback, if one is specified, is also invoked on the
12495** auxiliary data pointer after the FTS5 query has finished.
12496**
12497** If an error (e.g. an OOM condition) occurs within this function,
12498** the auxiliary data is set to NULL and an error code returned. If the
12499** xDelete parameter was not NULL, it is invoked on the auxiliary data
12500** pointer before returning.
12501**
12502**
12503** xGetAuxdata(pFts5, bClear)
12504**
12505** Returns the current auxiliary data pointer for the fts5 extension
12506** function. See the xSetAuxdata() method for details.
12507**
12508** If the bClear argument is non-zero, then the auxiliary data is cleared
12509** (set to NULL) before this function returns. In this case the xDelete,
12510** if any, is not invoked.
12511**
12512**
12513** xRowCount(pFts5, pnRow)
12514**
12515** This function is used to retrieve the total number of rows in the table.
12516** In other words, the same value that would be returned by:
12517**
12518** SELECT count(*) FROM ftstable;
12519**
12520** xPhraseFirst()
12521** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12522** method, to iterate through all instances of a single query phrase within
12523** the current row. This is the same information as is accessible via the
12524** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12525** to use, this API may be faster under some circumstances. To iterate
12526** through instances of phrase iPhrase, use the following code:
12527**
12528** Fts5PhraseIter iter;
12529** int iCol, iOff;
12530** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12531** iCol>=0;
12532** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12533** ){
12534** // An instance of phrase iPhrase at offset iOff of column iCol
12535** }
12536**
12537** The Fts5PhraseIter structure is defined above. Applications should not
12538** modify this structure directly - it should only be used as shown above
12539** with the xPhraseFirst() and xPhraseNext() API methods (and by
12540** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12541**
12542** This API can be quite slow if used with an FTS5 table created with the
12543** "detail=none" or "detail=column" option. If the FTS5 table is created
12544** with either "detail=none" or "detail=column" and "content=" option
12545** (i.e. if it is a contentless table), then this API always iterates
12546** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12547**
12548** xPhraseNext()
12549** See xPhraseFirst above.
12550**
12551** xPhraseFirstColumn()
12552** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12553** and xPhraseNext() APIs described above. The difference is that instead
12554** of iterating through all instances of a phrase in the current row, these
12555** APIs are used to iterate through the set of columns in the current row
12556** that contain one or more instances of a specified phrase. For example:
12557**
12558** Fts5PhraseIter iter;
12559** int iCol;
12560** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12561** iCol>=0;
12562** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12563** ){
12564** // Column iCol contains at least one instance of phrase iPhrase
12565** }
12566**
12567** This API can be quite slow if used with an FTS5 table created with the
12568** "detail=none" option. If the FTS5 table is created with either
12569** "detail=none" "content=" option (i.e. if it is a contentless table),
12570** then this API always iterates through an empty set (all calls to
12571** xPhraseFirstColumn() set iCol to -1).
12572**
12573** The information accessed using this API and its companion
12574** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12575** (or xInst/xInstCount). The chief advantage of this API is that it is
12576** significantly more efficient than those alternatives when used with
12577** "detail=column" tables.
12578**
12579** xPhraseNextColumn()
12580** See xPhraseFirstColumn above.
12581*/
12582struct Fts5ExtensionApi {
12583 int iVersion; /* Currently always set to 3 */
12584
12585 void *(*xUserData)(Fts5Context*);
12586
12587 int (*xColumnCount)(Fts5Context*);
12588 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
12589 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
12590
12591 int (*xTokenize)(Fts5Context*,
12592 const char *pText, int nText, /* Text to tokenize */
12593 void *pCtx, /* Context passed to xToken() */
12594 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
12595 );
12596
12597 int (*xPhraseCount)(Fts5Context*);
12598 int (*xPhraseSize)(Fts5Context*, int iPhrase);
12599
12600 int (*xInstCount)(Fts5Context*, int *pnInst);
12601 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
12602
12603 sqlite3_int64 (*xRowid)(Fts5Context*);
12604 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
12605 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
12606
12607 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
12608 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
12609 );
12610 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
12611 void *(*xGetAuxdata)(Fts5Context*, int bClear);
12612
12613 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
12614 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
12615
12616 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
12617 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
12618};
12619
12620/*
12621** CUSTOM AUXILIARY FUNCTIONS
12622*************************************************************************/
12623
12624/*************************************************************************
12625** CUSTOM TOKENIZERS
12626**
12627** Applications may also register custom tokenizer types. A tokenizer
12628** is registered by providing fts5 with a populated instance of the
12629** following structure. All structure methods must be defined, setting
12630** any member of the fts5_tokenizer struct to NULL leads to undefined
12631** behaviour. The structure methods are expected to function as follows:
12632**
12633** xCreate:
12634** This function is used to allocate and initialize a tokenizer instance.
12635** A tokenizer instance is required to actually tokenize text.
12636**
12637** The first argument passed to this function is a copy of the (void*)
12638** pointer provided by the application when the fts5_tokenizer object
12639** was registered with FTS5 (the third argument to xCreateTokenizer()).
12640** The second and third arguments are an array of nul-terminated strings
12641** containing the tokenizer arguments, if any, specified following the
12642** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12643** to create the FTS5 table.
12644**
12645** The final argument is an output variable. If successful, (*ppOut)
12646** should be set to point to the new tokenizer handle and SQLITE_OK
12647** returned. If an error occurs, some value other than SQLITE_OK should
12648** be returned. In this case, fts5 assumes that the final value of *ppOut
12649** is undefined.
12650**
12651** xDelete:
12652** This function is invoked to delete a tokenizer handle previously
12653** allocated using xCreate(). Fts5 guarantees that this function will
12654** be invoked exactly once for each successful call to xCreate().
12655**
12656** xTokenize:
12657** This function is expected to tokenize the nText byte string indicated
12658** by argument pText. pText may or may not be nul-terminated. The first
12659** argument passed to this function is a pointer to an Fts5Tokenizer object
12660** returned by an earlier call to xCreate().
12661**
12662** The second argument indicates the reason that FTS5 is requesting
12663** tokenization of the supplied text. This is always one of the following
12664** four values:
12665**
12666** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12667** or removed from the FTS table. The tokenizer is being invoked to
12668** determine the set of tokens to add to (or delete from) the
12669** FTS index.
12670**
12671** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12672** against the FTS index. The tokenizer is being called to tokenize
12673** a bareword or quoted string specified as part of the query.
12674**
12675** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12676** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12677** followed by a "*" character, indicating that the last token
12678** returned by the tokenizer will be treated as a token prefix.
12679**
12680** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12681** satisfy an fts5_api.xTokenize() request made by an auxiliary
12682** function. Or an fts5_api.xColumnSize() request made by the same
12683** on a columnsize=0 database.
12684** </ul>
12685**
12686** For each token in the input string, the supplied callback xToken() must
12687** be invoked. The first argument to it should be a copy of the pointer
12688** passed as the second argument to xTokenize(). The third and fourth
12689** arguments are a pointer to a buffer containing the token text, and the
12690** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12691** of the first byte of and first byte immediately following the text from
12692** which the token is derived within the input.
12693**
12694** The second argument passed to the xToken() callback ("tflags") should
12695** normally be set to 0. The exception is if the tokenizer supports
12696** synonyms. In this case see the discussion below for details.
12697**
12698** FTS5 assumes the xToken() callback is invoked for each token in the
12699** order that they occur within the input text.
12700**
12701** If an xToken() callback returns any value other than SQLITE_OK, then
12702** the tokenization should be abandoned and the xTokenize() method should
12703** immediately return a copy of the xToken() return value. Or, if the
12704** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12705** if an error occurs with the xTokenize() implementation itself, it
12706** may abandon the tokenization and return any error code other than
12707** SQLITE_OK or SQLITE_DONE.
12708**
12709** SYNONYM SUPPORT
12710**
12711** Custom tokenizers may also support synonyms. Consider a case in which a
12712** user wishes to query for a phrase such as "first place". Using the
12713** built-in tokenizers, the FTS5 query 'first + place' will match instances
12714** of "first place" within the document set, but not alternative forms
12715** such as "1st place". In some applications, it would be better to match
12716** all instances of "first place" or "1st place" regardless of which form
12717** the user specified in the MATCH query text.
12718**
12719** There are several ways to approach this in FTS5:
12720**
12721** <ol><li> By mapping all synonyms to a single token. In this case, using
12722** the above example, this means that the tokenizer returns the
12723** same token for inputs "first" and "1st". Say that token is in
12724** fact "first", so that when the user inserts the document "I won
12725** 1st place" entries are added to the index for tokens "i", "won",
12726** "first" and "place". If the user then queries for '1st + place',
12727** the tokenizer substitutes "first" for "1st" and the query works
12728** as expected.
12729**
12730** <li> By querying the index for all synonyms of each query term
12731** separately. In this case, when tokenizing query text, the
12732** tokenizer may provide multiple synonyms for a single term
12733** within the document. FTS5 then queries the index for each
12734** synonym individually. For example, faced with the query:
12735**
12736** <codeblock>
12737** ... MATCH 'first place'</codeblock>
12738**
12739** the tokenizer offers both "1st" and "first" as synonyms for the
12740** first token in the MATCH query and FTS5 effectively runs a query
12741** similar to:
12742**
12743** <codeblock>
12744** ... MATCH '(first OR 1st) place'</codeblock>
12745**
12746** except that, for the purposes of auxiliary functions, the query
12747** still appears to contain just two phrases - "(first OR 1st)"
12748** being treated as a single phrase.
12749**
12750** <li> By adding multiple synonyms for a single term to the FTS index.
12751** Using this method, when tokenizing document text, the tokenizer
12752** provides multiple synonyms for each token. So that when a
12753** document such as "I won first place" is tokenized, entries are
12754** added to the FTS index for "i", "won", "first", "1st" and
12755** "place".
12756**
12757** This way, even if the tokenizer does not provide synonyms
12758** when tokenizing query text (it should not - to do so would be
12759** inefficient), it doesn't matter if the user queries for
12760** 'first + place' or '1st + place', as there are entries in the
12761** FTS index corresponding to both forms of the first token.
12762** </ol>
12763**
12764** Whether it is parsing document or query text, any call to xToken that
12765** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12766** is considered to supply a synonym for the previous token. For example,
12767** when parsing the document "I won first place", a tokenizer that supports
12768** synonyms would call xToken() 5 times, as follows:
12769**
12770** <codeblock>
12771** xToken(pCtx, 0, "i", 1, 0, 1);
12772** xToken(pCtx, 0, "won", 3, 2, 5);
12773** xToken(pCtx, 0, "first", 5, 6, 11);
12774** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12775** xToken(pCtx, 0, "place", 5, 12, 17);
12776**</codeblock>
12777**
12778** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12779** xToken() is called. Multiple synonyms may be specified for a single token
12780** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
12781** There is no limit to the number of synonyms that may be provided for a
12782** single token.
12783**
12784** In many cases, method (1) above is the best approach. It does not add
12785** extra data to the FTS index or require FTS5 to query for multiple terms,
12786** so it is efficient in terms of disk space and query speed. However, it
12787** does not support prefix queries very well. If, as suggested above, the
12788** token "first" is substituted for "1st" by the tokenizer, then the query:
12789**
12790** <codeblock>
12791** ... MATCH '1s*'</codeblock>
12792**
12793** will not match documents that contain the token "1st" (as the tokenizer
12794** will probably not map "1s" to any prefix of "first").
12795**
12796** For full prefix support, method (3) may be preferred. In this case,
12797** because the index contains entries for both "first" and "1st", prefix
12798** queries such as 'fi*' or '1s*' will match correctly. However, because
12799** extra entries are added to the FTS index, this method uses more space
12800** within the database.
12801**
12802** Method (2) offers a midpoint between (1) and (3). Using this method,
12803** a query such as '1s*' will match documents that contain the literal
12804** token "1st", but not "first" (assuming the tokenizer is not able to
12805** provide synonyms for prefixes). However, a non-prefix query like '1st'
12806** will match against "1st" and "first". This method does not require
12807** extra disk space, as no extra entries are added to the FTS index.
12808** On the other hand, it may require more CPU cycles to run MATCH queries,
12809** as separate queries of the FTS index are required for each synonym.
12810**
12811** When using methods (2) or (3), it is important that the tokenizer only
12812** provide synonyms when tokenizing document text (method (2)) or query
12813** text (method (3)), not both. Doing so will not cause any errors, but is
12814** inefficient.
12815*/
12816typedef struct Fts5Tokenizer Fts5Tokenizer;
12817typedef struct fts5_tokenizer fts5_tokenizer;
12818struct fts5_tokenizer {
12819 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12820 void (*xDelete)(Fts5Tokenizer*);
12821 int (*xTokenize)(Fts5Tokenizer*,
12822 void *pCtx,
12823 int flags, /* Mask of FTS5_TOKENIZE_* flags */
12824 const char *pText, int nText,
12825 int (*xToken)(
12826 void *pCtx, /* Copy of 2nd argument to xTokenize() */
12827 int tflags, /* Mask of FTS5_TOKEN_* flags */
12828 const char *pToken, /* Pointer to buffer containing token */
12829 int nToken, /* Size of token in bytes */
12830 int iStart, /* Byte offset of token within input text */
12831 int iEnd /* Byte offset of end of token within input text */
12832 )
12833 );
12834};
12835
12836/* Flags that may be passed as the third argument to xTokenize() */
12837#define FTS5_TOKENIZE_QUERY 0x0001
12838#define FTS5_TOKENIZE_PREFIX 0x0002
12839#define FTS5_TOKENIZE_DOCUMENT 0x0004
12840#define FTS5_TOKENIZE_AUX 0x0008
12841
12842/* Flags that may be passed by the tokenizer implementation back to FTS5
12843** as the third argument to the supplied xToken callback. */
12844#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12845
12846/*
12847** END OF CUSTOM TOKENIZERS
12848*************************************************************************/
12849
12850/*************************************************************************
12851** FTS5 EXTENSION REGISTRATION API
12852*/
12853typedef struct fts5_api fts5_api;
12854struct fts5_api {
12855 int iVersion; /* Currently always set to 2 */
12856
12857 /* Create a new tokenizer */
12858 int (*xCreateTokenizer)(
12859 fts5_api *pApi,
12860 const char *zName,
12861 void *pContext,
12862 fts5_tokenizer *pTokenizer,
12863 void (*xDestroy)(void*)
12864 );
12865
12866 /* Find an existing tokenizer */
12867 int (*xFindTokenizer)(
12868 fts5_api *pApi,
12869 const char *zName,
12870 void **ppContext,
12871 fts5_tokenizer *pTokenizer
12872 );
12873
12874 /* Create a new auxiliary function */
12875 int (*xCreateFunction)(
12876 fts5_api *pApi,
12877 const char *zName,
12878 void *pContext,
12879 fts5_extension_function xFunction,
12880 void (*xDestroy)(void*)
12881 );
12882};
12883
12884/*
12885** END OF REGISTRATION API
12886*************************************************************************/
12887
12888#ifdef __cplusplus
12889} /* end of the 'extern "C"' block */
12890#endif
12891
12892#endif /* _FTS5_H */
12893
12894/******** End of fts5.h *********/
12895