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** Provide the ability to override linkage features of the interface.
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51#ifndef SQLITE_API
52# define SQLITE_API
53#endif
54#ifndef SQLITE_CDECL
55# define SQLITE_CDECL
56#endif
57#ifndef SQLITE_APICALL
58# define SQLITE_APICALL
59#endif
60#ifndef SQLITE_STDCALL
61# define SQLITE_STDCALL SQLITE_APICALL
62#endif
63#ifndef SQLITE_CALLBACK
64# define SQLITE_CALLBACK
65#endif
66#ifndef SQLITE_SYSAPI
67# define SQLITE_SYSAPI
68#endif
69
70/*
71** These no-op macros are used in front of interfaces to mark those
72** interfaces as either deprecated or experimental. New applications
73** should not use deprecated interfaces - they are supported for backwards
74** compatibility only. Application writers should be aware that
75** experimental interfaces are subject to change in point releases.
76**
77** These macros used to resolve to various kinds of compiler magic that
78** would generate warning messages when they were used. But that
79** compiler magic ended up generating such a flurry of bug reports
80** that we have taken it all out and gone back to using simple
81** noop macros.
82*/
83#define SQLITE_DEPRECATED
84#define SQLITE_EXPERIMENTAL
85
86/*
87** Ensure these symbols were not defined by some previous header file.
88*/
89#ifdef SQLITE_VERSION
90# undef SQLITE_VERSION
91#endif
92#ifdef SQLITE_VERSION_NUMBER
93# undef SQLITE_VERSION_NUMBER
94#endif
95
96/*
97** CAPI3REF: Compile-Time Library Version Numbers
98**
99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100** evaluates to a string literal that is the SQLite version in the
101** format "X.Y.Z" where X is the major version number (always 3 for
102** SQLite3) and Y is the minor version number and Z is the release number.)^
103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105** numbers used in [SQLITE_VERSION].)^
106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107** be larger than the release from which it is derived. Either Y will
108** be held constant and Z will be incremented or else Y will be incremented
109** and Z will be reset to zero.
110**
111** Since [version 3.6.18] ([dateof:3.6.18]),
112** SQLite source code has been stored in the
113** <a href="http://www.fossil-scm.org/">Fossil configuration management
114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115** a string which identifies a particular check-in of SQLite
116** within its configuration management system. ^The SQLITE_SOURCE_ID
117** string contains the date and time of the check-in (UTC) and a SHA1
118** or SHA3-256 hash of the entire source tree. If the source code has
119** been edited in any way since it was last checked in, then the last
120** four hexadecimal digits of the hash may be modified.
121**
122** See also: [sqlite3_libversion()],
123** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124** [sqlite_version()] and [sqlite_source_id()].
125*/
126#define SQLITE_VERSION "3.33.0"
127#define SQLITE_VERSION_NUMBER 3033000
128#define SQLITE_SOURCE_ID "2020-08-14 13:23:32 fca8dc8b578f215a969cd899336378966156154710873e68b3d9ac5881b0ff3f"
129
130/*
131** CAPI3REF: Run-Time Library Version Numbers
132** KEYWORDS: sqlite3_version sqlite3_sourceid
133**
134** These interfaces provide the same information as the [SQLITE_VERSION],
135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
136** but are associated with the library instead of the header file. ^(Cautious
137** programmers might include assert() statements in their application to
138** verify that values returned by these interfaces match the macros in
139** the header, and thus ensure that the application is
140** compiled with matching library and header files.
141**
142** <blockquote><pre>
143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
146** </pre></blockquote>)^
147**
148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
149** macro. ^The sqlite3_libversion() function returns a pointer to the
150** to the sqlite3_version[] string constant. The sqlite3_libversion()
151** function is provided for use in DLLs since DLL users usually do not have
152** direct access to string constants within the DLL. ^The
153** sqlite3_libversion_number() function returns an integer equal to
154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
155** a pointer to a string constant whose value is the same as the
156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
157** using an edited copy of [the amalgamation], then the last four characters
158** of the hash might be different from [SQLITE_SOURCE_ID].)^
159**
160** See also: [sqlite_version()] and [sqlite_source_id()].
161*/
162SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
163SQLITE_API const char *sqlite3_libversion(void);
164SQLITE_API const char *sqlite3_sourceid(void);
165SQLITE_API int sqlite3_libversion_number(void);
166
167/*
168** CAPI3REF: Run-Time Library Compilation Options Diagnostics
169**
170** ^The sqlite3_compileoption_used() function returns 0 or 1
171** indicating whether the specified option was defined at
172** compile time. ^The SQLITE_ prefix may be omitted from the
173** option name passed to sqlite3_compileoption_used().
174**
175** ^The sqlite3_compileoption_get() function allows iterating
176** over the list of options that were defined at compile time by
177** returning the N-th compile time option string. ^If N is out of range,
178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
179** prefix is omitted from any strings returned by
180** sqlite3_compileoption_get().
181**
182** ^Support for the diagnostic functions sqlite3_compileoption_used()
183** and sqlite3_compileoption_get() may be omitted by specifying the
184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
185**
186** See also: SQL functions [sqlite_compileoption_used()] and
187** [sqlite_compileoption_get()] and the [compile_options pragma].
188*/
189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
190SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
191SQLITE_API const char *sqlite3_compileoption_get(int N);
192#else
193# define sqlite3_compileoption_used(X) 0
194# define sqlite3_compileoption_get(X) ((void*)0)
195#endif
196
197/*
198** CAPI3REF: Test To See If The Library Is Threadsafe
199**
200** ^The sqlite3_threadsafe() function returns zero if and only if
201** SQLite was compiled with mutexing code omitted due to the
202** [SQLITE_THREADSAFE] compile-time option being set to 0.
203**
204** SQLite can be compiled with or without mutexes. When
205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
206** are enabled and SQLite is threadsafe. When the
207** [SQLITE_THREADSAFE] macro is 0,
208** the mutexes are omitted. Without the mutexes, it is not safe
209** to use SQLite concurrently from more than one thread.
210**
211** Enabling mutexes incurs a measurable performance penalty.
212** So if speed is of utmost importance, it makes sense to disable
213** the mutexes. But for maximum safety, mutexes should be enabled.
214** ^The default behavior is for mutexes to be enabled.
215**
216** This interface can be used by an application to make sure that the
217** version of SQLite that it is linking against was compiled with
218** the desired setting of the [SQLITE_THREADSAFE] macro.
219**
220** This interface only reports on the compile-time mutex setting
221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
223** can be fully or partially disabled using a call to [sqlite3_config()]
224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
226** sqlite3_threadsafe() function shows only the compile-time setting of
227** thread safety, not any run-time changes to that setting made by
228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
229** is unchanged by calls to sqlite3_config().)^
230**
231** See the [threading mode] documentation for additional information.
232*/
233SQLITE_API int sqlite3_threadsafe(void);
234
235/*
236** CAPI3REF: Database Connection Handle
237** KEYWORDS: {database connection} {database connections}
238**
239** Each open SQLite database is represented by a pointer to an instance of
240** the opaque structure named "sqlite3". It is useful to think of an sqlite3
241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
243** and [sqlite3_close_v2()] are its destructors. There are many other
244** interfaces (such as
245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
246** [sqlite3_busy_timeout()] to name but three) that are methods on an
247** sqlite3 object.
248*/
249typedef struct sqlite3 sqlite3;
250
251/*
252** CAPI3REF: 64-Bit Integer Types
253** KEYWORDS: sqlite_int64 sqlite_uint64
254**
255** Because there is no cross-platform way to specify 64-bit integer types
256** SQLite includes typedefs for 64-bit signed and unsigned integers.
257**
258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
259** The sqlite_int64 and sqlite_uint64 types are supported for backwards
260** compatibility only.
261**
262** ^The sqlite3_int64 and sqlite_int64 types can store integer values
263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
264** sqlite3_uint64 and sqlite_uint64 types can store integer values
265** between 0 and +18446744073709551615 inclusive.
266*/
267#ifdef SQLITE_INT64_TYPE
268 typedef SQLITE_INT64_TYPE sqlite_int64;
269# ifdef SQLITE_UINT64_TYPE
270 typedef SQLITE_UINT64_TYPE sqlite_uint64;
271# else
272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
273# endif
274#elif defined(_MSC_VER) || defined(__BORLANDC__)
275 typedef __int64 sqlite_int64;
276 typedef unsigned __int64 sqlite_uint64;
277#else
278 typedef long long int sqlite_int64;
279 typedef unsigned long long int sqlite_uint64;
280#endif
281typedef sqlite_int64 sqlite3_int64;
282typedef sqlite_uint64 sqlite3_uint64;
283
284/*
285** If compiling for a processor that lacks floating point support,
286** substitute integer for floating-point.
287*/
288#ifdef SQLITE_OMIT_FLOATING_POINT
289# define double sqlite3_int64
290#endif
291
292/*
293** CAPI3REF: Closing A Database Connection
294** DESTRUCTOR: sqlite3
295**
296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
297** for the [sqlite3] object.
298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
299** the [sqlite3] object is successfully destroyed and all associated
300** resources are deallocated.
301**
302** Ideally, applications should [sqlite3_finalize | finalize] all
303** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
304** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
305** with the [sqlite3] object prior to attempting to close the object.
306** ^If the database connection is associated with unfinalized prepared
307** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
308** sqlite3_close() will leave the database connection open and return
309** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
310** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
311** it returns [SQLITE_OK] regardless, but instead of deallocating the database
312** connection immediately, it marks the database connection as an unusable
313** "zombie" and makes arrangements to automatically deallocate the database
314** connection after all prepared statements are finalized, all BLOB handles
315** are closed, and all backups have finished. The sqlite3_close_v2() interface
316** is intended for use with host languages that are garbage collected, and
317** where the order in which destructors are called is arbitrary.
318**
319** ^If an [sqlite3] object is destroyed while a transaction is open,
320** the transaction is automatically rolled back.
321**
322** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
323** must be either a NULL
324** pointer or an [sqlite3] object pointer obtained
325** from [sqlite3_open()], [sqlite3_open16()], or
326** [sqlite3_open_v2()], and not previously closed.
327** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
328** argument is a harmless no-op.
329*/
330SQLITE_API int sqlite3_close(sqlite3*);
331SQLITE_API int sqlite3_close_v2(sqlite3*);
332
333/*
334** The type for a callback function.
335** This is legacy and deprecated. It is included for historical
336** compatibility and is not documented.
337*/
338typedef int (*sqlite3_callback)(void*,int,char**, char**);
339
340/*
341** CAPI3REF: One-Step Query Execution Interface
342** METHOD: sqlite3
343**
344** The sqlite3_exec() interface is a convenience wrapper around
345** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
346** that allows an application to run multiple statements of SQL
347** without having to use a lot of C code.
348**
349** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
350** semicolon-separate SQL statements passed into its 2nd argument,
351** in the context of the [database connection] passed in as its 1st
352** argument. ^If the callback function of the 3rd argument to
353** sqlite3_exec() is not NULL, then it is invoked for each result row
354** coming out of the evaluated SQL statements. ^The 4th argument to
355** sqlite3_exec() is relayed through to the 1st argument of each
356** callback invocation. ^If the callback pointer to sqlite3_exec()
357** is NULL, then no callback is ever invoked and result rows are
358** ignored.
359**
360** ^If an error occurs while evaluating the SQL statements passed into
361** sqlite3_exec(), then execution of the current statement stops and
362** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
363** is not NULL then any error message is written into memory obtained
364** from [sqlite3_malloc()] and passed back through the 5th parameter.
365** To avoid memory leaks, the application should invoke [sqlite3_free()]
366** on error message strings returned through the 5th parameter of
367** sqlite3_exec() after the error message string is no longer needed.
368** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
369** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
370** NULL before returning.
371**
372** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
373** routine returns SQLITE_ABORT without invoking the callback again and
374** without running any subsequent SQL statements.
375**
376** ^The 2nd argument to the sqlite3_exec() callback function is the
377** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
378** callback is an array of pointers to strings obtained as if from
379** [sqlite3_column_text()], one for each column. ^If an element of a
380** result row is NULL then the corresponding string pointer for the
381** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
382** sqlite3_exec() callback is an array of pointers to strings where each
383** entry represents the name of corresponding result column as obtained
384** from [sqlite3_column_name()].
385**
386** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
387** to an empty string, or a pointer that contains only whitespace and/or
388** SQL comments, then no SQL statements are evaluated and the database
389** is not changed.
390**
391** Restrictions:
392**
393** <ul>
394** <li> The application must ensure that the 1st parameter to sqlite3_exec()
395** is a valid and open [database connection].
396** <li> The application must not close the [database connection] specified by
397** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
398** <li> The application must not modify the SQL statement text passed into
399** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
400** </ul>
401*/
402SQLITE_API int sqlite3_exec(
403 sqlite3*, /* An open database */
404 const char *sql, /* SQL to be evaluated */
405 int (*callback)(void*,int,char**,char**), /* Callback function */
406 void *, /* 1st argument to callback */
407 char **errmsg /* Error msg written here */
408);
409
410/*
411** CAPI3REF: Result Codes
412** KEYWORDS: {result code definitions}
413**
414** Many SQLite functions return an integer result code from the set shown
415** here in order to indicate success or failure.
416**
417** New error codes may be added in future versions of SQLite.
418**
419** See also: [extended result code definitions]
420*/
421#define SQLITE_OK 0 /* Successful result */
422/* beginning-of-error-codes */
423#define SQLITE_ERROR 1 /* Generic error */
424#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
425#define SQLITE_PERM 3 /* Access permission denied */
426#define SQLITE_ABORT 4 /* Callback routine requested an abort */
427#define SQLITE_BUSY 5 /* The database file is locked */
428#define SQLITE_LOCKED 6 /* A table in the database is locked */
429#define SQLITE_NOMEM 7 /* A malloc() failed */
430#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
431#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
432#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
433#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
434#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
435#define SQLITE_FULL 13 /* Insertion failed because database is full */
436#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
437#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
438#define SQLITE_EMPTY 16 /* Internal use only */
439#define SQLITE_SCHEMA 17 /* The database schema changed */
440#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
441#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
442#define SQLITE_MISMATCH 20 /* Data type mismatch */
443#define SQLITE_MISUSE 21 /* Library used incorrectly */
444#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
445#define SQLITE_AUTH 23 /* Authorization denied */
446#define SQLITE_FORMAT 24 /* Not used */
447#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
448#define SQLITE_NOTADB 26 /* File opened that is not a database file */
449#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
450#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
451#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
452#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
453/* end-of-error-codes */
454
455/*
456** CAPI3REF: Extended Result Codes
457** KEYWORDS: {extended result code definitions}
458**
459** In its default configuration, SQLite API routines return one of 30 integer
460** [result codes]. However, experience has shown that many of
461** these result codes are too coarse-grained. They do not provide as
462** much information about problems as programmers might like. In an effort to
463** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
464** and later) include
465** support for additional result codes that provide more detailed information
466** about errors. These [extended result codes] are enabled or disabled
467** on a per database connection basis using the
468** [sqlite3_extended_result_codes()] API. Or, the extended code for
469** the most recent error can be obtained using
470** [sqlite3_extended_errcode()].
471*/
472#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
473#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
474#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
475#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
476#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
477#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
478#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
479#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
480#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
481#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
482#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
483#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
484#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
485#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
486#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
487#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
488#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
489#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
490#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
491#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
492#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
493#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
494#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
495#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
496#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
497#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
498#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
499#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
500#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
501#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
502#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
503#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
504#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
505#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
506#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
507#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
508#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
509#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
510#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
511#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
512#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
513#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
514#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
515#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
516#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
517#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
518#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
519#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
520#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
521#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
522#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
523#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
524#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
525#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
526#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
527#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
528#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
529#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
530#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
531#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
532#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
533#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
534#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
535#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
536#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
537#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
538#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
539#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
540#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
541#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
542#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
543#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
544#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8))
545
546/*
547** CAPI3REF: Flags For File Open Operations
548**
549** These bit values are intended for use in the
550** 3rd parameter to the [sqlite3_open_v2()] interface and
551** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
552*/
553#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
554#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
555#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
556#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
557#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
558#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
559#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
560#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
561#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
562#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
563#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
564#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
565#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
566#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
567#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
568#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
569#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
570#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
571#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
572#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
573#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
574
575/* Reserved: 0x00F00000 */
576/* Legacy compatibility: */
577#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
578
579
580/*
581** CAPI3REF: Device Characteristics
582**
583** The xDeviceCharacteristics method of the [sqlite3_io_methods]
584** object returns an integer which is a vector of these
585** bit values expressing I/O characteristics of the mass storage
586** device that holds the file that the [sqlite3_io_methods]
587** refers to.
588**
589** The SQLITE_IOCAP_ATOMIC property means that all writes of
590** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
591** mean that writes of blocks that are nnn bytes in size and
592** are aligned to an address which is an integer multiple of
593** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
594** that when data is appended to a file, the data is appended
595** first then the size of the file is extended, never the other
596** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
597** information is written to disk in the same order as calls
598** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
599** after reboot following a crash or power loss, the only bytes in a
600** file that were written at the application level might have changed
601** and that adjacent bytes, even bytes within the same sector are
602** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
603** flag indicates that a file cannot be deleted when open. The
604** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
605** read-only media and cannot be changed even by processes with
606** elevated privileges.
607**
608** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
609** filesystem supports doing multiple write operations atomically when those
610** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
611** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
612*/
613#define SQLITE_IOCAP_ATOMIC 0x00000001
614#define SQLITE_IOCAP_ATOMIC512 0x00000002
615#define SQLITE_IOCAP_ATOMIC1K 0x00000004
616#define SQLITE_IOCAP_ATOMIC2K 0x00000008
617#define SQLITE_IOCAP_ATOMIC4K 0x00000010
618#define SQLITE_IOCAP_ATOMIC8K 0x00000020
619#define SQLITE_IOCAP_ATOMIC16K 0x00000040
620#define SQLITE_IOCAP_ATOMIC32K 0x00000080
621#define SQLITE_IOCAP_ATOMIC64K 0x00000100
622#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
623#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
624#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
625#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
626#define SQLITE_IOCAP_IMMUTABLE 0x00002000
627#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
628
629/*
630** CAPI3REF: File Locking Levels
631**
632** SQLite uses one of these integer values as the second
633** argument to calls it makes to the xLock() and xUnlock() methods
634** of an [sqlite3_io_methods] object.
635*/
636#define SQLITE_LOCK_NONE 0
637#define SQLITE_LOCK_SHARED 1
638#define SQLITE_LOCK_RESERVED 2
639#define SQLITE_LOCK_PENDING 3
640#define SQLITE_LOCK_EXCLUSIVE 4
641
642/*
643** CAPI3REF: Synchronization Type Flags
644**
645** When SQLite invokes the xSync() method of an
646** [sqlite3_io_methods] object it uses a combination of
647** these integer values as the second argument.
648**
649** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
650** sync operation only needs to flush data to mass storage. Inode
651** information need not be flushed. If the lower four bits of the flag
652** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
653** If the lower four bits equal SQLITE_SYNC_FULL, that means
654** to use Mac OS X style fullsync instead of fsync().
655**
656** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
657** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
658** settings. The [synchronous pragma] determines when calls to the
659** xSync VFS method occur and applies uniformly across all platforms.
660** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
661** energetic or rigorous or forceful the sync operations are and
662** only make a difference on Mac OSX for the default SQLite code.
663** (Third-party VFS implementations might also make the distinction
664** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
665** operating systems natively supported by SQLite, only Mac OSX
666** cares about the difference.)
667*/
668#define SQLITE_SYNC_NORMAL 0x00002
669#define SQLITE_SYNC_FULL 0x00003
670#define SQLITE_SYNC_DATAONLY 0x00010
671
672/*
673** CAPI3REF: OS Interface Open File Handle
674**
675** An [sqlite3_file] object represents an open file in the
676** [sqlite3_vfs | OS interface layer]. Individual OS interface
677** implementations will
678** want to subclass this object by appending additional fields
679** for their own use. The pMethods entry is a pointer to an
680** [sqlite3_io_methods] object that defines methods for performing
681** I/O operations on the open file.
682*/
683typedef struct sqlite3_file sqlite3_file;
684struct sqlite3_file {
685 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
686};
687
688/*
689** CAPI3REF: OS Interface File Virtual Methods Object
690**
691** Every file opened by the [sqlite3_vfs.xOpen] method populates an
692** [sqlite3_file] object (or, more commonly, a subclass of the
693** [sqlite3_file] object) with a pointer to an instance of this object.
694** This object defines the methods used to perform various operations
695** against the open file represented by the [sqlite3_file] object.
696**
697** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
698** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
699** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
700** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
701** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
702** to NULL.
703**
704** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
705** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
706** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
707** flag may be ORed in to indicate that only the data of the file
708** and not its inode needs to be synced.
709**
710** The integer values to xLock() and xUnlock() are one of
711** <ul>
712** <li> [SQLITE_LOCK_NONE],
713** <li> [SQLITE_LOCK_SHARED],
714** <li> [SQLITE_LOCK_RESERVED],
715** <li> [SQLITE_LOCK_PENDING], or
716** <li> [SQLITE_LOCK_EXCLUSIVE].
717** </ul>
718** xLock() increases the lock. xUnlock() decreases the lock.
719** The xCheckReservedLock() method checks whether any database connection,
720** either in this process or in some other process, is holding a RESERVED,
721** PENDING, or EXCLUSIVE lock on the file. It returns true
722** if such a lock exists and false otherwise.
723**
724** The xFileControl() method is a generic interface that allows custom
725** VFS implementations to directly control an open file using the
726** [sqlite3_file_control()] interface. The second "op" argument is an
727** integer opcode. The third argument is a generic pointer intended to
728** point to a structure that may contain arguments or space in which to
729** write return values. Potential uses for xFileControl() might be
730** functions to enable blocking locks with timeouts, to change the
731** locking strategy (for example to use dot-file locks), to inquire
732** about the status of a lock, or to break stale locks. The SQLite
733** core reserves all opcodes less than 100 for its own use.
734** A [file control opcodes | list of opcodes] less than 100 is available.
735** Applications that define a custom xFileControl method should use opcodes
736** greater than 100 to avoid conflicts. VFS implementations should
737** return [SQLITE_NOTFOUND] for file control opcodes that they do not
738** recognize.
739**
740** The xSectorSize() method returns the sector size of the
741** device that underlies the file. The sector size is the
742** minimum write that can be performed without disturbing
743** other bytes in the file. The xDeviceCharacteristics()
744** method returns a bit vector describing behaviors of the
745** underlying device:
746**
747** <ul>
748** <li> [SQLITE_IOCAP_ATOMIC]
749** <li> [SQLITE_IOCAP_ATOMIC512]
750** <li> [SQLITE_IOCAP_ATOMIC1K]
751** <li> [SQLITE_IOCAP_ATOMIC2K]
752** <li> [SQLITE_IOCAP_ATOMIC4K]
753** <li> [SQLITE_IOCAP_ATOMIC8K]
754** <li> [SQLITE_IOCAP_ATOMIC16K]
755** <li> [SQLITE_IOCAP_ATOMIC32K]
756** <li> [SQLITE_IOCAP_ATOMIC64K]
757** <li> [SQLITE_IOCAP_SAFE_APPEND]
758** <li> [SQLITE_IOCAP_SEQUENTIAL]
759** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
760** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
761** <li> [SQLITE_IOCAP_IMMUTABLE]
762** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
763** </ul>
764**
765** The SQLITE_IOCAP_ATOMIC property means that all writes of
766** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
767** mean that writes of blocks that are nnn bytes in size and
768** are aligned to an address which is an integer multiple of
769** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
770** that when data is appended to a file, the data is appended
771** first then the size of the file is extended, never the other
772** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
773** information is written to disk in the same order as calls
774** to xWrite().
775**
776** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
777** in the unread portions of the buffer with zeros. A VFS that
778** fails to zero-fill short reads might seem to work. However,
779** failure to zero-fill short reads will eventually lead to
780** database corruption.
781*/
782typedef struct sqlite3_io_methods sqlite3_io_methods;
783struct sqlite3_io_methods {
784 int iVersion;
785 int (*xClose)(sqlite3_file*);
786 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
787 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
788 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
789 int (*xSync)(sqlite3_file*, int flags);
790 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
791 int (*xLock)(sqlite3_file*, int);
792 int (*xUnlock)(sqlite3_file*, int);
793 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
794 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
795 int (*xSectorSize)(sqlite3_file*);
796 int (*xDeviceCharacteristics)(sqlite3_file*);
797 /* Methods above are valid for version 1 */
798 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
799 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
800 void (*xShmBarrier)(sqlite3_file*);
801 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
802 /* Methods above are valid for version 2 */
803 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
804 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
805 /* Methods above are valid for version 3 */
806 /* Additional methods may be added in future releases */
807};
808
809/*
810** CAPI3REF: Standard File Control Opcodes
811** KEYWORDS: {file control opcodes} {file control opcode}
812**
813** These integer constants are opcodes for the xFileControl method
814** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
815** interface.
816**
817** <ul>
818** <li>[[SQLITE_FCNTL_LOCKSTATE]]
819** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
820** opcode causes the xFileControl method to write the current state of
821** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
822** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
823** into an integer that the pArg argument points to. This capability
824** is used during testing and is only available when the SQLITE_TEST
825** compile-time option is used.
826**
827** <li>[[SQLITE_FCNTL_SIZE_HINT]]
828** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
829** layer a hint of how large the database file will grow to be during the
830** current transaction. This hint is not guaranteed to be accurate but it
831** is often close. The underlying VFS might choose to preallocate database
832** file space based on this hint in order to help writes to the database
833** file run faster.
834**
835** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
836** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
837** implements [sqlite3_deserialize()] to set an upper bound on the size
838** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
839** If the integer pointed to is negative, then it is filled in with the
840** current limit. Otherwise the limit is set to the larger of the value
841** of the integer pointed to and the current database size. The integer
842** pointed to is set to the new limit.
843**
844** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
845** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
846** extends and truncates the database file in chunks of a size specified
847** by the user. The fourth argument to [sqlite3_file_control()] should
848** point to an integer (type int) containing the new chunk-size to use
849** for the nominated database. Allocating database file space in large
850** chunks (say 1MB at a time), may reduce file-system fragmentation and
851** improve performance on some systems.
852**
853** <li>[[SQLITE_FCNTL_FILE_POINTER]]
854** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
855** to the [sqlite3_file] object associated with a particular database
856** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
857**
858** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
859** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
860** to the [sqlite3_file] object associated with the journal file (either
861** the [rollback journal] or the [write-ahead log]) for a particular database
862** connection. See also [SQLITE_FCNTL_FILE_POINTER].
863**
864** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
865** No longer in use.
866**
867** <li>[[SQLITE_FCNTL_SYNC]]
868** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
869** sent to the VFS immediately before the xSync method is invoked on a
870** database file descriptor. Or, if the xSync method is not invoked
871** because the user has configured SQLite with
872** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
873** of the xSync method. In most cases, the pointer argument passed with
874** this file-control is NULL. However, if the database file is being synced
875** as part of a multi-database commit, the argument points to a nul-terminated
876** string containing the transactions super-journal file name. VFSes that
877** do not need this signal should silently ignore this opcode. Applications
878** should not call [sqlite3_file_control()] with this opcode as doing so may
879** disrupt the operation of the specialized VFSes that do require it.
880**
881** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
882** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
883** and sent to the VFS after a transaction has been committed immediately
884** but before the database is unlocked. VFSes that do not need this signal
885** should silently ignore this opcode. Applications should not call
886** [sqlite3_file_control()] with this opcode as doing so may disrupt the
887** operation of the specialized VFSes that do require it.
888**
889** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
890** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
891** retry counts and intervals for certain disk I/O operations for the
892** windows [VFS] in order to provide robustness in the presence of
893** anti-virus programs. By default, the windows VFS will retry file read,
894** file write, and file delete operations up to 10 times, with a delay
895** of 25 milliseconds before the first retry and with the delay increasing
896** by an additional 25 milliseconds with each subsequent retry. This
897** opcode allows these two values (10 retries and 25 milliseconds of delay)
898** to be adjusted. The values are changed for all database connections
899** within the same process. The argument is a pointer to an array of two
900** integers where the first integer is the new retry count and the second
901** integer is the delay. If either integer is negative, then the setting
902** is not changed but instead the prior value of that setting is written
903** into the array entry, allowing the current retry settings to be
904** interrogated. The zDbName parameter is ignored.
905**
906** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
907** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
908** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
909** write ahead log ([WAL file]) and shared memory
910** files used for transaction control
911** are automatically deleted when the latest connection to the database
912** closes. Setting persistent WAL mode causes those files to persist after
913** close. Persisting the files is useful when other processes that do not
914** have write permission on the directory containing the database file want
915** to read the database file, as the WAL and shared memory files must exist
916** in order for the database to be readable. The fourth parameter to
917** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
918** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
919** WAL mode. If the integer is -1, then it is overwritten with the current
920** WAL persistence setting.
921**
922** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
923** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
924** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
925** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
926** xDeviceCharacteristics methods. The fourth parameter to
927** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
928** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
929** mode. If the integer is -1, then it is overwritten with the current
930** zero-damage mode setting.
931**
932** <li>[[SQLITE_FCNTL_OVERWRITE]]
933** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
934** a write transaction to indicate that, unless it is rolled back for some
935** reason, the entire database file will be overwritten by the current
936** transaction. This is used by VACUUM operations.
937**
938** <li>[[SQLITE_FCNTL_VFSNAME]]
939** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
940** all [VFSes] in the VFS stack. The names are of all VFS shims and the
941** final bottom-level VFS are written into memory obtained from
942** [sqlite3_malloc()] and the result is stored in the char* variable
943** that the fourth parameter of [sqlite3_file_control()] points to.
944** The caller is responsible for freeing the memory when done. As with
945** all file-control actions, there is no guarantee that this will actually
946** do anything. Callers should initialize the char* variable to a NULL
947** pointer in case this file-control is not implemented. This file-control
948** is intended for diagnostic use only.
949**
950** <li>[[SQLITE_FCNTL_VFS_POINTER]]
951** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
952** [VFSes] currently in use. ^(The argument X in
953** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
954** of type "[sqlite3_vfs] **". This opcodes will set *X
955** to a pointer to the top-level VFS.)^
956** ^When there are multiple VFS shims in the stack, this opcode finds the
957** upper-most shim only.
958**
959** <li>[[SQLITE_FCNTL_PRAGMA]]
960** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
961** file control is sent to the open [sqlite3_file] object corresponding
962** to the database file to which the pragma statement refers. ^The argument
963** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
964** pointers to strings (char**) in which the second element of the array
965** is the name of the pragma and the third element is the argument to the
966** pragma or NULL if the pragma has no argument. ^The handler for an
967** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
968** of the char** argument point to a string obtained from [sqlite3_mprintf()]
969** or the equivalent and that string will become the result of the pragma or
970** the error message if the pragma fails. ^If the
971** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
972** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
973** file control returns [SQLITE_OK], then the parser assumes that the
974** VFS has handled the PRAGMA itself and the parser generates a no-op
975** prepared statement if result string is NULL, or that returns a copy
976** of the result string if the string is non-NULL.
977** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
978** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
979** that the VFS encountered an error while handling the [PRAGMA] and the
980** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
981** file control occurs at the beginning of pragma statement analysis and so
982** it is able to override built-in [PRAGMA] statements.
983**
984** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
985** ^The [SQLITE_FCNTL_BUSYHANDLER]
986** file-control may be invoked by SQLite on the database file handle
987** shortly after it is opened in order to provide a custom VFS with access
988** to the connection's busy-handler callback. The argument is of type (void**)
989** - an array of two (void *) values. The first (void *) actually points
990** to a function of type (int (*)(void *)). In order to invoke the connection's
991** busy-handler, this function should be invoked with the second (void *) in
992** the array as the only argument. If it returns non-zero, then the operation
993** should be retried. If it returns zero, the custom VFS should abandon the
994** current operation.
995**
996** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
997** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
998** to have SQLite generate a
999** temporary filename using the same algorithm that is followed to generate
1000** temporary filenames for TEMP tables and other internal uses. The
1001** argument should be a char** which will be filled with the filename
1002** written into memory obtained from [sqlite3_malloc()]. The caller should
1003** invoke [sqlite3_free()] on the result to avoid a memory leak.
1004**
1005** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1006** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1007** maximum number of bytes that will be used for memory-mapped I/O.
1008** The argument is a pointer to a value of type sqlite3_int64 that
1009** is an advisory maximum number of bytes in the file to memory map. The
1010** pointer is overwritten with the old value. The limit is not changed if
1011** the value originally pointed to is negative, and so the current limit
1012** can be queried by passing in a pointer to a negative number. This
1013** file-control is used internally to implement [PRAGMA mmap_size].
1014**
1015** <li>[[SQLITE_FCNTL_TRACE]]
1016** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1017** to the VFS about what the higher layers of the SQLite stack are doing.
1018** This file control is used by some VFS activity tracing [shims].
1019** The argument is a zero-terminated string. Higher layers in the
1020** SQLite stack may generate instances of this file control if
1021** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1022**
1023** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1024** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1025** pointer to an integer and it writes a boolean into that integer depending
1026** on whether or not the file has been renamed, moved, or deleted since it
1027** was first opened.
1028**
1029** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1030** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1031** underlying native file handle associated with a file handle. This file
1032** control interprets its argument as a pointer to a native file handle and
1033** writes the resulting value there.
1034**
1035** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1036** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1037** opcode causes the xFileControl method to swap the file handle with the one
1038** pointed to by the pArg argument. This capability is used during testing
1039** and only needs to be supported when SQLITE_TEST is defined.
1040**
1041** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1042** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1043** be advantageous to block on the next WAL lock if the lock is not immediately
1044** available. The WAL subsystem issues this signal during rare
1045** circumstances in order to fix a problem with priority inversion.
1046** Applications should <em>not</em> use this file-control.
1047**
1048** <li>[[SQLITE_FCNTL_ZIPVFS]]
1049** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1050** VFS should return SQLITE_NOTFOUND for this opcode.
1051**
1052** <li>[[SQLITE_FCNTL_RBU]]
1053** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1054** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1055** this opcode.
1056**
1057** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1058** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1059** the file descriptor is placed in "batch write mode", which
1060** means all subsequent write operations will be deferred and done
1061** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1062** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1063** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1064** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1065** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1066** no VFS interface calls on the same [sqlite3_file] file descriptor
1067** except for calls to the xWrite method and the xFileControl method
1068** with [SQLITE_FCNTL_SIZE_HINT].
1069**
1070** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1071** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1072** operations since the previous successful call to
1073** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1074** This file control returns [SQLITE_OK] if and only if the writes were
1075** all performed successfully and have been committed to persistent storage.
1076** ^Regardless of whether or not it is successful, this file control takes
1077** the file descriptor out of batch write mode so that all subsequent
1078** write operations are independent.
1079** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1080** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1081**
1082** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1083** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1084** operations since the previous successful call to
1085** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1086** ^This file control takes the file descriptor out of batch write mode
1087** so that all subsequent write operations are independent.
1088** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1089** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1090**
1091** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1092** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1093** to block for up to M milliseconds before failing when attempting to
1094** obtain a file lock using the xLock or xShmLock methods of the VFS.
1095** The parameter is a pointer to a 32-bit signed integer that contains
1096** the value that M is to be set to. Before returning, the 32-bit signed
1097** integer is overwritten with the previous value of M.
1098**
1099** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1100** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1101** a database file. The argument is a pointer to a 32-bit unsigned integer.
1102** The "data version" for the pager is written into the pointer. The
1103** "data version" changes whenever any change occurs to the corresponding
1104** database file, either through SQL statements on the same database
1105** connection or through transactions committed by separate database
1106** connections possibly in other processes. The [sqlite3_total_changes()]
1107** interface can be used to find if any database on the connection has changed,
1108** but that interface responds to changes on TEMP as well as MAIN and does
1109** not provide a mechanism to detect changes to MAIN only. Also, the
1110** [sqlite3_total_changes()] interface responds to internal changes only and
1111** omits changes made by other database connections. The
1112** [PRAGMA data_version] command provides a mechanism to detect changes to
1113** a single attached database that occur due to other database connections,
1114** but omits changes implemented by the database connection on which it is
1115** called. This file control is the only mechanism to detect changes that
1116** happen either internally or externally and that are associated with
1117** a particular attached database.
1118**
1119** <li>[[SQLITE_FCNTL_CKPT_START]]
1120** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1121** in wal mode before the client starts to copy pages from the wal
1122** file to the database file.
1123**
1124** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1125** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1126** in wal mode after the client has finished copying pages from the wal
1127** file to the database file, but before the *-shm file is updated to
1128** record the fact that the pages have been checkpointed.
1129** </ul>
1130*/
1131#define SQLITE_FCNTL_LOCKSTATE 1
1132#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1133#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1134#define SQLITE_FCNTL_LAST_ERRNO 4
1135#define SQLITE_FCNTL_SIZE_HINT 5
1136#define SQLITE_FCNTL_CHUNK_SIZE 6
1137#define SQLITE_FCNTL_FILE_POINTER 7
1138#define SQLITE_FCNTL_SYNC_OMITTED 8
1139#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1140#define SQLITE_FCNTL_PERSIST_WAL 10
1141#define SQLITE_FCNTL_OVERWRITE 11
1142#define SQLITE_FCNTL_VFSNAME 12
1143#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1144#define SQLITE_FCNTL_PRAGMA 14
1145#define SQLITE_FCNTL_BUSYHANDLER 15
1146#define SQLITE_FCNTL_TEMPFILENAME 16
1147#define SQLITE_FCNTL_MMAP_SIZE 18
1148#define SQLITE_FCNTL_TRACE 19
1149#define SQLITE_FCNTL_HAS_MOVED 20
1150#define SQLITE_FCNTL_SYNC 21
1151#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1152#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1153#define SQLITE_FCNTL_WAL_BLOCK 24
1154#define SQLITE_FCNTL_ZIPVFS 25
1155#define SQLITE_FCNTL_RBU 26
1156#define SQLITE_FCNTL_VFS_POINTER 27
1157#define SQLITE_FCNTL_JOURNAL_POINTER 28
1158#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1159#define SQLITE_FCNTL_PDB 30
1160#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1161#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1162#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1163#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1164#define SQLITE_FCNTL_DATA_VERSION 35
1165#define SQLITE_FCNTL_SIZE_LIMIT 36
1166#define SQLITE_FCNTL_CKPT_DONE 37
1167#define SQLITE_FCNTL_RESERVE_BYTES 38
1168#define SQLITE_FCNTL_CKPT_START 39
1169
1170/* deprecated names */
1171#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1172#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1173#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1174
1175
1176/*
1177** CAPI3REF: Mutex Handle
1178**
1179** The mutex module within SQLite defines [sqlite3_mutex] to be an
1180** abstract type for a mutex object. The SQLite core never looks
1181** at the internal representation of an [sqlite3_mutex]. It only
1182** deals with pointers to the [sqlite3_mutex] object.
1183**
1184** Mutexes are created using [sqlite3_mutex_alloc()].
1185*/
1186typedef struct sqlite3_mutex sqlite3_mutex;
1187
1188/*
1189** CAPI3REF: Loadable Extension Thunk
1190**
1191** A pointer to the opaque sqlite3_api_routines structure is passed as
1192** the third parameter to entry points of [loadable extensions]. This
1193** structure must be typedefed in order to work around compiler warnings
1194** on some platforms.
1195*/
1196typedef struct sqlite3_api_routines sqlite3_api_routines;
1197
1198/*
1199** CAPI3REF: OS Interface Object
1200**
1201** An instance of the sqlite3_vfs object defines the interface between
1202** the SQLite core and the underlying operating system. The "vfs"
1203** in the name of the object stands for "virtual file system". See
1204** the [VFS | VFS documentation] for further information.
1205**
1206** The VFS interface is sometimes extended by adding new methods onto
1207** the end. Each time such an extension occurs, the iVersion field
1208** is incremented. The iVersion value started out as 1 in
1209** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1210** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1211** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1212** may be appended to the sqlite3_vfs object and the iVersion value
1213** may increase again in future versions of SQLite.
1214** Note that due to an oversight, the structure
1215** of the sqlite3_vfs object changed in the transition from
1216** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1217** and yet the iVersion field was not increased.
1218**
1219** The szOsFile field is the size of the subclassed [sqlite3_file]
1220** structure used by this VFS. mxPathname is the maximum length of
1221** a pathname in this VFS.
1222**
1223** Registered sqlite3_vfs objects are kept on a linked list formed by
1224** the pNext pointer. The [sqlite3_vfs_register()]
1225** and [sqlite3_vfs_unregister()] interfaces manage this list
1226** in a thread-safe way. The [sqlite3_vfs_find()] interface
1227** searches the list. Neither the application code nor the VFS
1228** implementation should use the pNext pointer.
1229**
1230** The pNext field is the only field in the sqlite3_vfs
1231** structure that SQLite will ever modify. SQLite will only access
1232** or modify this field while holding a particular static mutex.
1233** The application should never modify anything within the sqlite3_vfs
1234** object once the object has been registered.
1235**
1236** The zName field holds the name of the VFS module. The name must
1237** be unique across all VFS modules.
1238**
1239** [[sqlite3_vfs.xOpen]]
1240** ^SQLite guarantees that the zFilename parameter to xOpen
1241** is either a NULL pointer or string obtained
1242** from xFullPathname() with an optional suffix added.
1243** ^If a suffix is added to the zFilename parameter, it will
1244** consist of a single "-" character followed by no more than
1245** 11 alphanumeric and/or "-" characters.
1246** ^SQLite further guarantees that
1247** the string will be valid and unchanged until xClose() is
1248** called. Because of the previous sentence,
1249** the [sqlite3_file] can safely store a pointer to the
1250** filename if it needs to remember the filename for some reason.
1251** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1252** must invent its own temporary name for the file. ^Whenever the
1253** xFilename parameter is NULL it will also be the case that the
1254** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1255**
1256** The flags argument to xOpen() includes all bits set in
1257** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1258** or [sqlite3_open16()] is used, then flags includes at least
1259** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1260** If xOpen() opens a file read-only then it sets *pOutFlags to
1261** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1262**
1263** ^(SQLite will also add one of the following flags to the xOpen()
1264** call, depending on the object being opened:
1265**
1266** <ul>
1267** <li> [SQLITE_OPEN_MAIN_DB]
1268** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1269** <li> [SQLITE_OPEN_TEMP_DB]
1270** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1271** <li> [SQLITE_OPEN_TRANSIENT_DB]
1272** <li> [SQLITE_OPEN_SUBJOURNAL]
1273** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1274** <li> [SQLITE_OPEN_WAL]
1275** </ul>)^
1276**
1277** The file I/O implementation can use the object type flags to
1278** change the way it deals with files. For example, an application
1279** that does not care about crash recovery or rollback might make
1280** the open of a journal file a no-op. Writes to this journal would
1281** also be no-ops, and any attempt to read the journal would return
1282** SQLITE_IOERR. Or the implementation might recognize that a database
1283** file will be doing page-aligned sector reads and writes in a random
1284** order and set up its I/O subsystem accordingly.
1285**
1286** SQLite might also add one of the following flags to the xOpen method:
1287**
1288** <ul>
1289** <li> [SQLITE_OPEN_DELETEONCLOSE]
1290** <li> [SQLITE_OPEN_EXCLUSIVE]
1291** </ul>
1292**
1293** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1294** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1295** will be set for TEMP databases and their journals, transient
1296** databases, and subjournals.
1297**
1298** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1299** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1300** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1301** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1302** SQLITE_OPEN_CREATE, is used to indicate that file should always
1303** be created, and that it is an error if it already exists.
1304** It is <i>not</i> used to indicate the file should be opened
1305** for exclusive access.
1306**
1307** ^At least szOsFile bytes of memory are allocated by SQLite
1308** to hold the [sqlite3_file] structure passed as the third
1309** argument to xOpen. The xOpen method does not have to
1310** allocate the structure; it should just fill it in. Note that
1311** the xOpen method must set the sqlite3_file.pMethods to either
1312** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1313** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1314** element will be valid after xOpen returns regardless of the success
1315** or failure of the xOpen call.
1316**
1317** [[sqlite3_vfs.xAccess]]
1318** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1319** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1320** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1321** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1322** flag is never actually used and is not implemented in the built-in
1323** VFSes of SQLite. The file is named by the second argument and can be a
1324** directory. The xAccess method returns [SQLITE_OK] on success or some
1325** non-zero error code if there is an I/O error or if the name of
1326** the file given in the second argument is illegal. If SQLITE_OK
1327** is returned, then non-zero or zero is written into *pResOut to indicate
1328** whether or not the file is accessible.
1329**
1330** ^SQLite will always allocate at least mxPathname+1 bytes for the
1331** output buffer xFullPathname. The exact size of the output buffer
1332** is also passed as a parameter to both methods. If the output buffer
1333** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1334** handled as a fatal error by SQLite, vfs implementations should endeavor
1335** to prevent this by setting mxPathname to a sufficiently large value.
1336**
1337** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1338** interfaces are not strictly a part of the filesystem, but they are
1339** included in the VFS structure for completeness.
1340** The xRandomness() function attempts to return nBytes bytes
1341** of good-quality randomness into zOut. The return value is
1342** the actual number of bytes of randomness obtained.
1343** The xSleep() method causes the calling thread to sleep for at
1344** least the number of microseconds given. ^The xCurrentTime()
1345** method returns a Julian Day Number for the current date and time as
1346** a floating point value.
1347** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1348** Day Number multiplied by 86400000 (the number of milliseconds in
1349** a 24-hour day).
1350** ^SQLite will use the xCurrentTimeInt64() method to get the current
1351** date and time if that method is available (if iVersion is 2 or
1352** greater and the function pointer is not NULL) and will fall back
1353** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1354**
1355** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1356** are not used by the SQLite core. These optional interfaces are provided
1357** by some VFSes to facilitate testing of the VFS code. By overriding
1358** system calls with functions under its control, a test program can
1359** simulate faults and error conditions that would otherwise be difficult
1360** or impossible to induce. The set of system calls that can be overridden
1361** varies from one VFS to another, and from one version of the same VFS to the
1362** next. Applications that use these interfaces must be prepared for any
1363** or all of these interfaces to be NULL or for their behavior to change
1364** from one release to the next. Applications must not attempt to access
1365** any of these methods if the iVersion of the VFS is less than 3.
1366*/
1367typedef struct sqlite3_vfs sqlite3_vfs;
1368typedef void (*sqlite3_syscall_ptr)(void);
1369struct sqlite3_vfs {
1370 int iVersion; /* Structure version number (currently 3) */
1371 int szOsFile; /* Size of subclassed sqlite3_file */
1372 int mxPathname; /* Maximum file pathname length */
1373 sqlite3_vfs *pNext; /* Next registered VFS */
1374 const char *zName; /* Name of this virtual file system */
1375 void *pAppData; /* Pointer to application-specific data */
1376 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1377 int flags, int *pOutFlags);
1378 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1379 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1380 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1381 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1382 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1383 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1384 void (*xDlClose)(sqlite3_vfs*, void*);
1385 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1386 int (*xSleep)(sqlite3_vfs*, int microseconds);
1387 int (*xCurrentTime)(sqlite3_vfs*, double*);
1388 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1389 /*
1390 ** The methods above are in version 1 of the sqlite_vfs object
1391 ** definition. Those that follow are added in version 2 or later
1392 */
1393 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1394 /*
1395 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1396 ** Those below are for version 3 and greater.
1397 */
1398 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1399 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1400 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1401 /*
1402 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1403 ** New fields may be appended in future versions. The iVersion
1404 ** value will increment whenever this happens.
1405 */
1406};
1407
1408/*
1409** CAPI3REF: Flags for the xAccess VFS method
1410**
1411** These integer constants can be used as the third parameter to
1412** the xAccess method of an [sqlite3_vfs] object. They determine
1413** what kind of permissions the xAccess method is looking for.
1414** With SQLITE_ACCESS_EXISTS, the xAccess method
1415** simply checks whether the file exists.
1416** With SQLITE_ACCESS_READWRITE, the xAccess method
1417** checks whether the named directory is both readable and writable
1418** (in other words, if files can be added, removed, and renamed within
1419** the directory).
1420** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1421** [temp_store_directory pragma], though this could change in a future
1422** release of SQLite.
1423** With SQLITE_ACCESS_READ, the xAccess method
1424** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1425** currently unused, though it might be used in a future release of
1426** SQLite.
1427*/
1428#define SQLITE_ACCESS_EXISTS 0
1429#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1430#define SQLITE_ACCESS_READ 2 /* Unused */
1431
1432/*
1433** CAPI3REF: Flags for the xShmLock VFS method
1434**
1435** These integer constants define the various locking operations
1436** allowed by the xShmLock method of [sqlite3_io_methods]. The
1437** following are the only legal combinations of flags to the
1438** xShmLock method:
1439**
1440** <ul>
1441** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1442** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1443** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1444** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1445** </ul>
1446**
1447** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1448** was given on the corresponding lock.
1449**
1450** The xShmLock method can transition between unlocked and SHARED or
1451** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1452** and EXCLUSIVE.
1453*/
1454#define SQLITE_SHM_UNLOCK 1
1455#define SQLITE_SHM_LOCK 2
1456#define SQLITE_SHM_SHARED 4
1457#define SQLITE_SHM_EXCLUSIVE 8
1458
1459/*
1460** CAPI3REF: Maximum xShmLock index
1461**
1462** The xShmLock method on [sqlite3_io_methods] may use values
1463** between 0 and this upper bound as its "offset" argument.
1464** The SQLite core will never attempt to acquire or release a
1465** lock outside of this range
1466*/
1467#define SQLITE_SHM_NLOCK 8
1468
1469
1470/*
1471** CAPI3REF: Initialize The SQLite Library
1472**
1473** ^The sqlite3_initialize() routine initializes the
1474** SQLite library. ^The sqlite3_shutdown() routine
1475** deallocates any resources that were allocated by sqlite3_initialize().
1476** These routines are designed to aid in process initialization and
1477** shutdown on embedded systems. Workstation applications using
1478** SQLite normally do not need to invoke either of these routines.
1479**
1480** A call to sqlite3_initialize() is an "effective" call if it is
1481** the first time sqlite3_initialize() is invoked during the lifetime of
1482** the process, or if it is the first time sqlite3_initialize() is invoked
1483** following a call to sqlite3_shutdown(). ^(Only an effective call
1484** of sqlite3_initialize() does any initialization. All other calls
1485** are harmless no-ops.)^
1486**
1487** A call to sqlite3_shutdown() is an "effective" call if it is the first
1488** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1489** an effective call to sqlite3_shutdown() does any deinitialization.
1490** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1491**
1492** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1493** is not. The sqlite3_shutdown() interface must only be called from a
1494** single thread. All open [database connections] must be closed and all
1495** other SQLite resources must be deallocated prior to invoking
1496** sqlite3_shutdown().
1497**
1498** Among other things, ^sqlite3_initialize() will invoke
1499** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1500** will invoke sqlite3_os_end().
1501**
1502** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1503** ^If for some reason, sqlite3_initialize() is unable to initialize
1504** the library (perhaps it is unable to allocate a needed resource such
1505** as a mutex) it returns an [error code] other than [SQLITE_OK].
1506**
1507** ^The sqlite3_initialize() routine is called internally by many other
1508** SQLite interfaces so that an application usually does not need to
1509** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1510** calls sqlite3_initialize() so the SQLite library will be automatically
1511** initialized when [sqlite3_open()] is called if it has not be initialized
1512** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1513** compile-time option, then the automatic calls to sqlite3_initialize()
1514** are omitted and the application must call sqlite3_initialize() directly
1515** prior to using any other SQLite interface. For maximum portability,
1516** it is recommended that applications always invoke sqlite3_initialize()
1517** directly prior to using any other SQLite interface. Future releases
1518** of SQLite may require this. In other words, the behavior exhibited
1519** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1520** default behavior in some future release of SQLite.
1521**
1522** The sqlite3_os_init() routine does operating-system specific
1523** initialization of the SQLite library. The sqlite3_os_end()
1524** routine undoes the effect of sqlite3_os_init(). Typical tasks
1525** performed by these routines include allocation or deallocation
1526** of static resources, initialization of global variables,
1527** setting up a default [sqlite3_vfs] module, or setting up
1528** a default configuration using [sqlite3_config()].
1529**
1530** The application should never invoke either sqlite3_os_init()
1531** or sqlite3_os_end() directly. The application should only invoke
1532** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1533** interface is called automatically by sqlite3_initialize() and
1534** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1535** implementations for sqlite3_os_init() and sqlite3_os_end()
1536** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1537** When [custom builds | built for other platforms]
1538** (using the [SQLITE_OS_OTHER=1] compile-time
1539** option) the application must supply a suitable implementation for
1540** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1541** implementation of sqlite3_os_init() or sqlite3_os_end()
1542** must return [SQLITE_OK] on success and some other [error code] upon
1543** failure.
1544*/
1545SQLITE_API int sqlite3_initialize(void);
1546SQLITE_API int sqlite3_shutdown(void);
1547SQLITE_API int sqlite3_os_init(void);
1548SQLITE_API int sqlite3_os_end(void);
1549
1550/*
1551** CAPI3REF: Configuring The SQLite Library
1552**
1553** The sqlite3_config() interface is used to make global configuration
1554** changes to SQLite in order to tune SQLite to the specific needs of
1555** the application. The default configuration is recommended for most
1556** applications and so this routine is usually not necessary. It is
1557** provided to support rare applications with unusual needs.
1558**
1559** <b>The sqlite3_config() interface is not threadsafe. The application
1560** must ensure that no other SQLite interfaces are invoked by other
1561** threads while sqlite3_config() is running.</b>
1562**
1563** The sqlite3_config() interface
1564** may only be invoked prior to library initialization using
1565** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1566** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1567** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1568** Note, however, that ^sqlite3_config() can be called as part of the
1569** implementation of an application-defined [sqlite3_os_init()].
1570**
1571** The first argument to sqlite3_config() is an integer
1572** [configuration option] that determines
1573** what property of SQLite is to be configured. Subsequent arguments
1574** vary depending on the [configuration option]
1575** in the first argument.
1576**
1577** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1578** ^If the option is unknown or SQLite is unable to set the option
1579** then this routine returns a non-zero [error code].
1580*/
1581SQLITE_API int sqlite3_config(int, ...);
1582
1583/*
1584** CAPI3REF: Configure database connections
1585** METHOD: sqlite3
1586**
1587** The sqlite3_db_config() interface is used to make configuration
1588** changes to a [database connection]. The interface is similar to
1589** [sqlite3_config()] except that the changes apply to a single
1590** [database connection] (specified in the first argument).
1591**
1592** The second argument to sqlite3_db_config(D,V,...) is the
1593** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1594** that indicates what aspect of the [database connection] is being configured.
1595** Subsequent arguments vary depending on the configuration verb.
1596**
1597** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1598** the call is considered successful.
1599*/
1600SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1601
1602/*
1603** CAPI3REF: Memory Allocation Routines
1604**
1605** An instance of this object defines the interface between SQLite
1606** and low-level memory allocation routines.
1607**
1608** This object is used in only one place in the SQLite interface.
1609** A pointer to an instance of this object is the argument to
1610** [sqlite3_config()] when the configuration option is
1611** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1612** By creating an instance of this object
1613** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1614** during configuration, an application can specify an alternative
1615** memory allocation subsystem for SQLite to use for all of its
1616** dynamic memory needs.
1617**
1618** Note that SQLite comes with several [built-in memory allocators]
1619** that are perfectly adequate for the overwhelming majority of applications
1620** and that this object is only useful to a tiny minority of applications
1621** with specialized memory allocation requirements. This object is
1622** also used during testing of SQLite in order to specify an alternative
1623** memory allocator that simulates memory out-of-memory conditions in
1624** order to verify that SQLite recovers gracefully from such
1625** conditions.
1626**
1627** The xMalloc, xRealloc, and xFree methods must work like the
1628** malloc(), realloc() and free() functions from the standard C library.
1629** ^SQLite guarantees that the second argument to
1630** xRealloc is always a value returned by a prior call to xRoundup.
1631**
1632** xSize should return the allocated size of a memory allocation
1633** previously obtained from xMalloc or xRealloc. The allocated size
1634** is always at least as big as the requested size but may be larger.
1635**
1636** The xRoundup method returns what would be the allocated size of
1637** a memory allocation given a particular requested size. Most memory
1638** allocators round up memory allocations at least to the next multiple
1639** of 8. Some allocators round up to a larger multiple or to a power of 2.
1640** Every memory allocation request coming in through [sqlite3_malloc()]
1641** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1642** that causes the corresponding memory allocation to fail.
1643**
1644** The xInit method initializes the memory allocator. For example,
1645** it might allocate any required mutexes or initialize internal data
1646** structures. The xShutdown method is invoked (indirectly) by
1647** [sqlite3_shutdown()] and should deallocate any resources acquired
1648** by xInit. The pAppData pointer is used as the only parameter to
1649** xInit and xShutdown.
1650**
1651** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1652** the xInit method, so the xInit method need not be threadsafe. The
1653** xShutdown method is only called from [sqlite3_shutdown()] so it does
1654** not need to be threadsafe either. For all other methods, SQLite
1655** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1656** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1657** it is by default) and so the methods are automatically serialized.
1658** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1659** methods must be threadsafe or else make their own arrangements for
1660** serialization.
1661**
1662** SQLite will never invoke xInit() more than once without an intervening
1663** call to xShutdown().
1664*/
1665typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1666struct sqlite3_mem_methods {
1667 void *(*xMalloc)(int); /* Memory allocation function */
1668 void (*xFree)(void*); /* Free a prior allocation */
1669 void *(*xRealloc)(void*,int); /* Resize an allocation */
1670 int (*xSize)(void*); /* Return the size of an allocation */
1671 int (*xRoundup)(int); /* Round up request size to allocation size */
1672 int (*xInit)(void*); /* Initialize the memory allocator */
1673 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1674 void *pAppData; /* Argument to xInit() and xShutdown() */
1675};
1676
1677/*
1678** CAPI3REF: Configuration Options
1679** KEYWORDS: {configuration option}
1680**
1681** These constants are the available integer configuration options that
1682** can be passed as the first argument to the [sqlite3_config()] interface.
1683**
1684** New configuration options may be added in future releases of SQLite.
1685** Existing configuration options might be discontinued. Applications
1686** should check the return code from [sqlite3_config()] to make sure that
1687** the call worked. The [sqlite3_config()] interface will return a
1688** non-zero [error code] if a discontinued or unsupported configuration option
1689** is invoked.
1690**
1691** <dl>
1692** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1693** <dd>There are no arguments to this option. ^This option sets the
1694** [threading mode] to Single-thread. In other words, it disables
1695** all mutexing and puts SQLite into a mode where it can only be used
1696** by a single thread. ^If SQLite is compiled with
1697** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1698** it is not possible to change the [threading mode] from its default
1699** value of Single-thread and so [sqlite3_config()] will return
1700** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1701** configuration option.</dd>
1702**
1703** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1704** <dd>There are no arguments to this option. ^This option sets the
1705** [threading mode] to Multi-thread. In other words, it disables
1706** mutexing on [database connection] and [prepared statement] objects.
1707** The application is responsible for serializing access to
1708** [database connections] and [prepared statements]. But other mutexes
1709** are enabled so that SQLite will be safe to use in a multi-threaded
1710** environment as long as no two threads attempt to use the same
1711** [database connection] at the same time. ^If SQLite is compiled with
1712** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1713** it is not possible to set the Multi-thread [threading mode] and
1714** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1715** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1716**
1717** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1718** <dd>There are no arguments to this option. ^This option sets the
1719** [threading mode] to Serialized. In other words, this option enables
1720** all mutexes including the recursive
1721** mutexes on [database connection] and [prepared statement] objects.
1722** In this mode (which is the default when SQLite is compiled with
1723** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1724** to [database connections] and [prepared statements] so that the
1725** application is free to use the same [database connection] or the
1726** same [prepared statement] in different threads at the same time.
1727** ^If SQLite is compiled with
1728** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1729** it is not possible to set the Serialized [threading mode] and
1730** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1731** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1732**
1733** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1734** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1735** a pointer to an instance of the [sqlite3_mem_methods] structure.
1736** The argument specifies
1737** alternative low-level memory allocation routines to be used in place of
1738** the memory allocation routines built into SQLite.)^ ^SQLite makes
1739** its own private copy of the content of the [sqlite3_mem_methods] structure
1740** before the [sqlite3_config()] call returns.</dd>
1741**
1742** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1743** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1744** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1745** The [sqlite3_mem_methods]
1746** structure is filled with the currently defined memory allocation routines.)^
1747** This option can be used to overload the default memory allocation
1748** routines with a wrapper that simulations memory allocation failure or
1749** tracks memory usage, for example. </dd>
1750**
1751** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1752** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1753** type int, interpreted as a boolean, which if true provides a hint to
1754** SQLite that it should avoid large memory allocations if possible.
1755** SQLite will run faster if it is free to make large memory allocations,
1756** but some application might prefer to run slower in exchange for
1757** guarantees about memory fragmentation that are possible if large
1758** allocations are avoided. This hint is normally off.
1759** </dd>
1760**
1761** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1762** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1763** interpreted as a boolean, which enables or disables the collection of
1764** memory allocation statistics. ^(When memory allocation statistics are
1765** disabled, the following SQLite interfaces become non-operational:
1766** <ul>
1767** <li> [sqlite3_hard_heap_limit64()]
1768** <li> [sqlite3_memory_used()]
1769** <li> [sqlite3_memory_highwater()]
1770** <li> [sqlite3_soft_heap_limit64()]
1771** <li> [sqlite3_status64()]
1772** </ul>)^
1773** ^Memory allocation statistics are enabled by default unless SQLite is
1774** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1775** allocation statistics are disabled by default.
1776** </dd>
1777**
1778** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1779** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1780** </dd>
1781**
1782** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1783** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1784** that SQLite can use for the database page cache with the default page
1785** cache implementation.
1786** This configuration option is a no-op if an application-defined page
1787** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1788** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1789** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1790** and the number of cache lines (N).
1791** The sz argument should be the size of the largest database page
1792** (a power of two between 512 and 65536) plus some extra bytes for each
1793** page header. ^The number of extra bytes needed by the page header
1794** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1795** ^It is harmless, apart from the wasted memory,
1796** for the sz parameter to be larger than necessary. The pMem
1797** argument must be either a NULL pointer or a pointer to an 8-byte
1798** aligned block of memory of at least sz*N bytes, otherwise
1799** subsequent behavior is undefined.
1800** ^When pMem is not NULL, SQLite will strive to use the memory provided
1801** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1802** a page cache line is larger than sz bytes or if all of the pMem buffer
1803** is exhausted.
1804** ^If pMem is NULL and N is non-zero, then each database connection
1805** does an initial bulk allocation for page cache memory
1806** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1807** of -1024*N bytes if N is negative, . ^If additional
1808** page cache memory is needed beyond what is provided by the initial
1809** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1810** additional cache line. </dd>
1811**
1812** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1813** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1814** that SQLite will use for all of its dynamic memory allocation needs
1815** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1816** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1817** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1818** [SQLITE_ERROR] if invoked otherwise.
1819** ^There are three arguments to SQLITE_CONFIG_HEAP:
1820** An 8-byte aligned pointer to the memory,
1821** the number of bytes in the memory buffer, and the minimum allocation size.
1822** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1823** to using its default memory allocator (the system malloc() implementation),
1824** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1825** memory pointer is not NULL then the alternative memory
1826** allocator is engaged to handle all of SQLites memory allocation needs.
1827** The first pointer (the memory pointer) must be aligned to an 8-byte
1828** boundary or subsequent behavior of SQLite will be undefined.
1829** The minimum allocation size is capped at 2**12. Reasonable values
1830** for the minimum allocation size are 2**5 through 2**8.</dd>
1831**
1832** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1833** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1834** pointer to an instance of the [sqlite3_mutex_methods] structure.
1835** The argument specifies alternative low-level mutex routines to be used
1836** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1837** the content of the [sqlite3_mutex_methods] structure before the call to
1838** [sqlite3_config()] returns. ^If SQLite is compiled with
1839** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1840** the entire mutexing subsystem is omitted from the build and hence calls to
1841** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1842** return [SQLITE_ERROR].</dd>
1843**
1844** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1845** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1846** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1847** [sqlite3_mutex_methods]
1848** structure is filled with the currently defined mutex routines.)^
1849** This option can be used to overload the default mutex allocation
1850** routines with a wrapper used to track mutex usage for performance
1851** profiling or testing, for example. ^If SQLite is compiled with
1852** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1853** the entire mutexing subsystem is omitted from the build and hence calls to
1854** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1855** return [SQLITE_ERROR].</dd>
1856**
1857** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1858** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1859** the default size of lookaside memory on each [database connection].
1860** The first argument is the
1861** size of each lookaside buffer slot and the second is the number of
1862** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1863** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1864** option to [sqlite3_db_config()] can be used to change the lookaside
1865** configuration on individual connections.)^ </dd>
1866**
1867** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1868** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1869** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1870** the interface to a custom page cache implementation.)^
1871** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1872**
1873** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1874** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1875** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1876** the current page cache implementation into that object.)^ </dd>
1877**
1878** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1879** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1880** global [error log].
1881** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1882** function with a call signature of void(*)(void*,int,const char*),
1883** and a pointer to void. ^If the function pointer is not NULL, it is
1884** invoked by [sqlite3_log()] to process each logging event. ^If the
1885** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1886** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1887** passed through as the first parameter to the application-defined logger
1888** function whenever that function is invoked. ^The second parameter to
1889** the logger function is a copy of the first parameter to the corresponding
1890** [sqlite3_log()] call and is intended to be a [result code] or an
1891** [extended result code]. ^The third parameter passed to the logger is
1892** log message after formatting via [sqlite3_snprintf()].
1893** The SQLite logging interface is not reentrant; the logger function
1894** supplied by the application must not invoke any SQLite interface.
1895** In a multi-threaded application, the application-defined logger
1896** function must be threadsafe. </dd>
1897**
1898** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1899** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1900** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1901** then URI handling is globally disabled.)^ ^If URI handling is globally
1902** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1903** [sqlite3_open16()] or
1904** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1905** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1906** connection is opened. ^If it is globally disabled, filenames are
1907** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1908** database connection is opened. ^(By default, URI handling is globally
1909** disabled. The default value may be changed by compiling with the
1910** [SQLITE_USE_URI] symbol defined.)^
1911**
1912** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1913** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1914** argument which is interpreted as a boolean in order to enable or disable
1915** the use of covering indices for full table scans in the query optimizer.
1916** ^The default setting is determined
1917** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1918** if that compile-time option is omitted.
1919** The ability to disable the use of covering indices for full table scans
1920** is because some incorrectly coded legacy applications might malfunction
1921** when the optimization is enabled. Providing the ability to
1922** disable the optimization allows the older, buggy application code to work
1923** without change even with newer versions of SQLite.
1924**
1925** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1926** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1927** <dd> These options are obsolete and should not be used by new code.
1928** They are retained for backwards compatibility but are now no-ops.
1929** </dd>
1930**
1931** [[SQLITE_CONFIG_SQLLOG]]
1932** <dt>SQLITE_CONFIG_SQLLOG
1933** <dd>This option is only available if sqlite is compiled with the
1934** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1935** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1936** The second should be of type (void*). The callback is invoked by the library
1937** in three separate circumstances, identified by the value passed as the
1938** fourth parameter. If the fourth parameter is 0, then the database connection
1939** passed as the second argument has just been opened. The third argument
1940** points to a buffer containing the name of the main database file. If the
1941** fourth parameter is 1, then the SQL statement that the third parameter
1942** points to has just been executed. Or, if the fourth parameter is 2, then
1943** the connection being passed as the second parameter is being closed. The
1944** third parameter is passed NULL In this case. An example of using this
1945** configuration option can be seen in the "test_sqllog.c" source file in
1946** the canonical SQLite source tree.</dd>
1947**
1948** [[SQLITE_CONFIG_MMAP_SIZE]]
1949** <dt>SQLITE_CONFIG_MMAP_SIZE
1950** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1951** that are the default mmap size limit (the default setting for
1952** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1953** ^The default setting can be overridden by each database connection using
1954** either the [PRAGMA mmap_size] command, or by using the
1955** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1956** will be silently truncated if necessary so that it does not exceed the
1957** compile-time maximum mmap size set by the
1958** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1959** ^If either argument to this option is negative, then that argument is
1960** changed to its compile-time default.
1961**
1962** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1963** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1964** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1965** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1966** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1967** that specifies the maximum size of the created heap.
1968**
1969** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1970** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1971** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1972** is a pointer to an integer and writes into that integer the number of extra
1973** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1974** The amount of extra space required can change depending on the compiler,
1975** target platform, and SQLite version.
1976**
1977** [[SQLITE_CONFIG_PMASZ]]
1978** <dt>SQLITE_CONFIG_PMASZ
1979** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1980** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1981** sorter to that integer. The default minimum PMA Size is set by the
1982** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1983** to help with sort operations when multithreaded sorting
1984** is enabled (using the [PRAGMA threads] command) and the amount of content
1985** to be sorted exceeds the page size times the minimum of the
1986** [PRAGMA cache_size] setting and this value.
1987**
1988** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1989** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1990** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1991** becomes the [statement journal] spill-to-disk threshold.
1992** [Statement journals] are held in memory until their size (in bytes)
1993** exceeds this threshold, at which point they are written to disk.
1994** Or if the threshold is -1, statement journals are always held
1995** exclusively in memory.
1996** Since many statement journals never become large, setting the spill
1997** threshold to a value such as 64KiB can greatly reduce the amount of
1998** I/O required to support statement rollback.
1999** The default value for this setting is controlled by the
2000** [SQLITE_STMTJRNL_SPILL] compile-time option.
2001**
2002** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2003** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2004** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2005** of type (int) - the new value of the sorter-reference size threshold.
2006** Usually, when SQLite uses an external sort to order records according
2007** to an ORDER BY clause, all fields required by the caller are present in the
2008** sorted records. However, if SQLite determines based on the declared type
2009** of a table column that its values are likely to be very large - larger
2010** than the configured sorter-reference size threshold - then a reference
2011** is stored in each sorted record and the required column values loaded
2012** from the database as records are returned in sorted order. The default
2013** value for this option is to never use this optimization. Specifying a
2014** negative value for this option restores the default behaviour.
2015** This option is only available if SQLite is compiled with the
2016** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2017**
2018** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2019** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2020** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2021** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2022** database created using [sqlite3_deserialize()]. This default maximum
2023** size can be adjusted up or down for individual databases using the
2024** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2025** configuration setting is never used, then the default maximum is determined
2026** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2027** compile-time option is not set, then the default maximum is 1073741824.
2028** </dl>
2029*/
2030#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2031#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2032#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2033#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2034#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2035#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2036#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2037#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2038#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2039#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2040#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2041/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2042#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2043#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2044#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2045#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2046#define SQLITE_CONFIG_URI 17 /* int */
2047#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2048#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2049#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2050#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2051#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2052#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2053#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2054#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2055#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2056#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2057#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2058#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2059
2060/*
2061** CAPI3REF: Database Connection Configuration Options
2062**
2063** These constants are the available integer configuration options that
2064** can be passed as the second argument to the [sqlite3_db_config()] interface.
2065**
2066** New configuration options may be added in future releases of SQLite.
2067** Existing configuration options might be discontinued. Applications
2068** should check the return code from [sqlite3_db_config()] to make sure that
2069** the call worked. ^The [sqlite3_db_config()] interface will return a
2070** non-zero [error code] if a discontinued or unsupported configuration option
2071** is invoked.
2072**
2073** <dl>
2074** [[SQLITE_DBCONFIG_LOOKASIDE]]
2075** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2076** <dd> ^This option takes three additional arguments that determine the
2077** [lookaside memory allocator] configuration for the [database connection].
2078** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2079** pointer to a memory buffer to use for lookaside memory.
2080** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2081** may be NULL in which case SQLite will allocate the
2082** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2083** size of each lookaside buffer slot. ^The third argument is the number of
2084** slots. The size of the buffer in the first argument must be greater than
2085** or equal to the product of the second and third arguments. The buffer
2086** must be aligned to an 8-byte boundary. ^If the second argument to
2087** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2088** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2089** configuration for a database connection can only be changed when that
2090** connection is not currently using lookaside memory, or in other words
2091** when the "current value" returned by
2092** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2093** Any attempt to change the lookaside memory configuration when lookaside
2094** memory is in use leaves the configuration unchanged and returns
2095** [SQLITE_BUSY].)^</dd>
2096**
2097** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2098** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2099** <dd> ^This option is used to enable or disable the enforcement of
2100** [foreign key constraints]. There should be two additional arguments.
2101** The first argument is an integer which is 0 to disable FK enforcement,
2102** positive to enable FK enforcement or negative to leave FK enforcement
2103** unchanged. The second parameter is a pointer to an integer into which
2104** is written 0 or 1 to indicate whether FK enforcement is off or on
2105** following this call. The second parameter may be a NULL pointer, in
2106** which case the FK enforcement setting is not reported back. </dd>
2107**
2108** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2109** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2110** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2111** There should be two additional arguments.
2112** The first argument is an integer which is 0 to disable triggers,
2113** positive to enable triggers or negative to leave the setting unchanged.
2114** The second parameter is a pointer to an integer into which
2115** is written 0 or 1 to indicate whether triggers are disabled or enabled
2116** following this call. The second parameter may be a NULL pointer, in
2117** which case the trigger setting is not reported back. </dd>
2118**
2119** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2120** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2121** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2122** There should be two additional arguments.
2123** The first argument is an integer which is 0 to disable views,
2124** positive to enable views or negative to leave the setting unchanged.
2125** The second parameter is a pointer to an integer into which
2126** is written 0 or 1 to indicate whether views are disabled or enabled
2127** following this call. The second parameter may be a NULL pointer, in
2128** which case the view setting is not reported back. </dd>
2129**
2130** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2131** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2132** <dd> ^This option is used to enable or disable the
2133** [fts3_tokenizer()] function which is part of the
2134** [FTS3] full-text search engine extension.
2135** There should be two additional arguments.
2136** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2137** positive to enable fts3_tokenizer() or negative to leave the setting
2138** unchanged.
2139** The second parameter is a pointer to an integer into which
2140** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2141** following this call. The second parameter may be a NULL pointer, in
2142** which case the new setting is not reported back. </dd>
2143**
2144** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2145** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2146** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2147** interface independently of the [load_extension()] SQL function.
2148** The [sqlite3_enable_load_extension()] API enables or disables both the
2149** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2150** There should be two additional arguments.
2151** When the first argument to this interface is 1, then only the C-API is
2152** enabled and the SQL function remains disabled. If the first argument to
2153** this interface is 0, then both the C-API and the SQL function are disabled.
2154** If the first argument is -1, then no changes are made to state of either the
2155** C-API or the SQL function.
2156** The second parameter is a pointer to an integer into which
2157** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2158** is disabled or enabled following this call. The second parameter may
2159** be a NULL pointer, in which case the new setting is not reported back.
2160** </dd>
2161**
2162** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2163** <dd> ^This option is used to change the name of the "main" database
2164** schema. ^The sole argument is a pointer to a constant UTF8 string
2165** which will become the new schema name in place of "main". ^SQLite
2166** does not make a copy of the new main schema name string, so the application
2167** must ensure that the argument passed into this DBCONFIG option is unchanged
2168** until after the database connection closes.
2169** </dd>
2170**
2171** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2172** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2173** <dd> Usually, when a database in wal mode is closed or detached from a
2174** database handle, SQLite checks if this will mean that there are now no
2175** connections at all to the database. If so, it performs a checkpoint
2176** operation before closing the connection. This option may be used to
2177** override this behaviour. The first parameter passed to this operation
2178** is an integer - positive to disable checkpoints-on-close, or zero (the
2179** default) to enable them, and negative to leave the setting unchanged.
2180** The second parameter is a pointer to an integer
2181** into which is written 0 or 1 to indicate whether checkpoints-on-close
2182** have been disabled - 0 if they are not disabled, 1 if they are.
2183** </dd>
2184**
2185** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2186** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2187** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2188** a single SQL query statement will always use the same algorithm regardless
2189** of values of [bound parameters].)^ The QPSG disables some query optimizations
2190** that look at the values of bound parameters, which can make some queries
2191** slower. But the QPSG has the advantage of more predictable behavior. With
2192** the QPSG active, SQLite will always use the same query plan in the field as
2193** was used during testing in the lab.
2194** The first argument to this setting is an integer which is 0 to disable
2195** the QPSG, positive to enable QPSG, or negative to leave the setting
2196** unchanged. The second parameter is a pointer to an integer into which
2197** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2198** following this call.
2199** </dd>
2200**
2201** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2202** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2203** include output for any operations performed by trigger programs. This
2204** option is used to set or clear (the default) a flag that governs this
2205** behavior. The first parameter passed to this operation is an integer -
2206** positive to enable output for trigger programs, or zero to disable it,
2207** or negative to leave the setting unchanged.
2208** The second parameter is a pointer to an integer into which is written
2209** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2210** it is not disabled, 1 if it is.
2211** </dd>
2212**
2213** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2214** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2215** [VACUUM] in order to reset a database back to an empty database
2216** with no schema and no content. The following process works even for
2217** a badly corrupted database file:
2218** <ol>
2219** <li> If the database connection is newly opened, make sure it has read the
2220** database schema by preparing then discarding some query against the
2221** database, or calling sqlite3_table_column_metadata(), ignoring any
2222** errors. This step is only necessary if the application desires to keep
2223** the database in WAL mode after the reset if it was in WAL mode before
2224** the reset.
2225** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2226** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2227** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2228** </ol>
2229** Because resetting a database is destructive and irreversible, the
2230** process requires the use of this obscure API and multiple steps to help
2231** ensure that it does not happen by accident.
2232**
2233** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2234** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2235** "defensive" flag for a database connection. When the defensive
2236** flag is enabled, language features that allow ordinary SQL to
2237** deliberately corrupt the database file are disabled. The disabled
2238** features include but are not limited to the following:
2239** <ul>
2240** <li> The [PRAGMA writable_schema=ON] statement.
2241** <li> The [PRAGMA journal_mode=OFF] statement.
2242** <li> Writes to the [sqlite_dbpage] virtual table.
2243** <li> Direct writes to [shadow tables].
2244** </ul>
2245** </dd>
2246**
2247** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2248** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2249** "writable_schema" flag. This has the same effect and is logically equivalent
2250** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2251** The first argument to this setting is an integer which is 0 to disable
2252** the writable_schema, positive to enable writable_schema, or negative to
2253** leave the setting unchanged. The second parameter is a pointer to an
2254** integer into which is written 0 or 1 to indicate whether the writable_schema
2255** is enabled or disabled following this call.
2256** </dd>
2257**
2258** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2259** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2260** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2261** the legacy behavior of the [ALTER TABLE RENAME] command such it
2262** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2263** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2264** additional information. This feature can also be turned on and off
2265** using the [PRAGMA legacy_alter_table] statement.
2266** </dd>
2267**
2268** [[SQLITE_DBCONFIG_DQS_DML]]
2269** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2270** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2271** the legacy [double-quoted string literal] misfeature for DML statements
2272** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2273** default value of this setting is determined by the [-DSQLITE_DQS]
2274** compile-time option.
2275** </dd>
2276**
2277** [[SQLITE_DBCONFIG_DQS_DDL]]
2278** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2279** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2280** the legacy [double-quoted string literal] misfeature for DDL statements,
2281** such as CREATE TABLE and CREATE INDEX. The
2282** default value of this setting is determined by the [-DSQLITE_DQS]
2283** compile-time option.
2284** </dd>
2285**
2286** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2287** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2288** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2289** assume that database schemas are untainted by malicious content.
2290** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2291** takes additional defensive steps to protect the application from harm
2292** including:
2293** <ul>
2294** <li> Prohibit the use of SQL functions inside triggers, views,
2295** CHECK constraints, DEFAULT clauses, expression indexes,
2296** partial indexes, or generated columns
2297** unless those functions are tagged with [SQLITE_INNOCUOUS].
2298** <li> Prohibit the use of virtual tables inside of triggers or views
2299** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2300** </ul>
2301** This setting defaults to "on" for legacy compatibility, however
2302** all applications are advised to turn it off if possible. This setting
2303** can also be controlled using the [PRAGMA trusted_schema] statement.
2304** </dd>
2305**
2306** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2307** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2308** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2309** the legacy file format flag. When activated, this flag causes all newly
2310** created database file to have a schema format version number (the 4-byte
2311** integer found at offset 44 into the database header) of 1. This in turn
2312** means that the resulting database file will be readable and writable by
2313** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2314** newly created databases are generally not understandable by SQLite versions
2315** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2316** is now scarcely any need to generated database files that are compatible
2317** all the way back to version 3.0.0, and so this setting is of little
2318** practical use, but is provided so that SQLite can continue to claim the
2319** ability to generate new database files that are compatible with version
2320** 3.0.0.
2321** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2322** the [VACUUM] command will fail with an obscure error when attempting to
2323** process a table with generated columns and a descending index. This is
2324** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2325** either generated columns or decending indexes.
2326** </dd>
2327** </dl>
2328*/
2329#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2330#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2331#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2332#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2333#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2334#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2335#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2336#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2337#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2338#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2339#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2340#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2341#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2342#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2343#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2344#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2345#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2346#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2347#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
2348
2349/*
2350** CAPI3REF: Enable Or Disable Extended Result Codes
2351** METHOD: sqlite3
2352**
2353** ^The sqlite3_extended_result_codes() routine enables or disables the
2354** [extended result codes] feature of SQLite. ^The extended result
2355** codes are disabled by default for historical compatibility.
2356*/
2357SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2358
2359/*
2360** CAPI3REF: Last Insert Rowid
2361** METHOD: sqlite3
2362**
2363** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2364** has a unique 64-bit signed
2365** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2366** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2367** names are not also used by explicitly declared columns. ^If
2368** the table has a column of type [INTEGER PRIMARY KEY] then that column
2369** is another alias for the rowid.
2370**
2371** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2372** the most recent successful [INSERT] into a rowid table or [virtual table]
2373** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2374** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2375** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2376** zero.
2377**
2378** As well as being set automatically as rows are inserted into database
2379** tables, the value returned by this function may be set explicitly by
2380** [sqlite3_set_last_insert_rowid()]
2381**
2382** Some virtual table implementations may INSERT rows into rowid tables as
2383** part of committing a transaction (e.g. to flush data accumulated in memory
2384** to disk). In this case subsequent calls to this function return the rowid
2385** associated with these internal INSERT operations, which leads to
2386** unintuitive results. Virtual table implementations that do write to rowid
2387** tables in this way can avoid this problem by restoring the original
2388** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2389** control to the user.
2390**
2391** ^(If an [INSERT] occurs within a trigger then this routine will
2392** return the [rowid] of the inserted row as long as the trigger is
2393** running. Once the trigger program ends, the value returned
2394** by this routine reverts to what it was before the trigger was fired.)^
2395**
2396** ^An [INSERT] that fails due to a constraint violation is not a
2397** successful [INSERT] and does not change the value returned by this
2398** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2399** and INSERT OR ABORT make no changes to the return value of this
2400** routine when their insertion fails. ^(When INSERT OR REPLACE
2401** encounters a constraint violation, it does not fail. The
2402** INSERT continues to completion after deleting rows that caused
2403** the constraint problem so INSERT OR REPLACE will always change
2404** the return value of this interface.)^
2405**
2406** ^For the purposes of this routine, an [INSERT] is considered to
2407** be successful even if it is subsequently rolled back.
2408**
2409** This function is accessible to SQL statements via the
2410** [last_insert_rowid() SQL function].
2411**
2412** If a separate thread performs a new [INSERT] on the same
2413** database connection while the [sqlite3_last_insert_rowid()]
2414** function is running and thus changes the last insert [rowid],
2415** then the value returned by [sqlite3_last_insert_rowid()] is
2416** unpredictable and might not equal either the old or the new
2417** last insert [rowid].
2418*/
2419SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2420
2421/*
2422** CAPI3REF: Set the Last Insert Rowid value.
2423** METHOD: sqlite3
2424**
2425** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2426** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2427** without inserting a row into the database.
2428*/
2429SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2430
2431/*
2432** CAPI3REF: Count The Number Of Rows Modified
2433** METHOD: sqlite3
2434**
2435** ^This function returns the number of rows modified, inserted or
2436** deleted by the most recently completed INSERT, UPDATE or DELETE
2437** statement on the database connection specified by the only parameter.
2438** ^Executing any other type of SQL statement does not modify the value
2439** returned by this function.
2440**
2441** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2442** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2443** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2444**
2445** Changes to a view that are intercepted by
2446** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2447** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2448** DELETE statement run on a view is always zero. Only changes made to real
2449** tables are counted.
2450**
2451** Things are more complicated if the sqlite3_changes() function is
2452** executed while a trigger program is running. This may happen if the
2453** program uses the [changes() SQL function], or if some other callback
2454** function invokes sqlite3_changes() directly. Essentially:
2455**
2456** <ul>
2457** <li> ^(Before entering a trigger program the value returned by
2458** sqlite3_changes() function is saved. After the trigger program
2459** has finished, the original value is restored.)^
2460**
2461** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2462** statement sets the value returned by sqlite3_changes()
2463** upon completion as normal. Of course, this value will not include
2464** any changes performed by sub-triggers, as the sqlite3_changes()
2465** value will be saved and restored after each sub-trigger has run.)^
2466** </ul>
2467**
2468** ^This means that if the changes() SQL function (or similar) is used
2469** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2470** returns the value as set when the calling statement began executing.
2471** ^If it is used by the second or subsequent such statement within a trigger
2472** program, the value returned reflects the number of rows modified by the
2473** previous INSERT, UPDATE or DELETE statement within the same trigger.
2474**
2475** If a separate thread makes changes on the same database connection
2476** while [sqlite3_changes()] is running then the value returned
2477** is unpredictable and not meaningful.
2478**
2479** See also:
2480** <ul>
2481** <li> the [sqlite3_total_changes()] interface
2482** <li> the [count_changes pragma]
2483** <li> the [changes() SQL function]
2484** <li> the [data_version pragma]
2485** </ul>
2486*/
2487SQLITE_API int sqlite3_changes(sqlite3*);
2488
2489/*
2490** CAPI3REF: Total Number Of Rows Modified
2491** METHOD: sqlite3
2492**
2493** ^This function returns the total number of rows inserted, modified or
2494** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2495** since the database connection was opened, including those executed as
2496** part of trigger programs. ^Executing any other type of SQL statement
2497** does not affect the value returned by sqlite3_total_changes().
2498**
2499** ^Changes made as part of [foreign key actions] are included in the
2500** count, but those made as part of REPLACE constraint resolution are
2501** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2502** are not counted.
2503**
2504** The [sqlite3_total_changes(D)] interface only reports the number
2505** of rows that changed due to SQL statement run against database
2506** connection D. Any changes by other database connections are ignored.
2507** To detect changes against a database file from other database
2508** connections use the [PRAGMA data_version] command or the
2509** [SQLITE_FCNTL_DATA_VERSION] [file control].
2510**
2511** If a separate thread makes changes on the same database connection
2512** while [sqlite3_total_changes()] is running then the value
2513** returned is unpredictable and not meaningful.
2514**
2515** See also:
2516** <ul>
2517** <li> the [sqlite3_changes()] interface
2518** <li> the [count_changes pragma]
2519** <li> the [changes() SQL function]
2520** <li> the [data_version pragma]
2521** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2522** </ul>
2523*/
2524SQLITE_API int sqlite3_total_changes(sqlite3*);
2525
2526/*
2527** CAPI3REF: Interrupt A Long-Running Query
2528** METHOD: sqlite3
2529**
2530** ^This function causes any pending database operation to abort and
2531** return at its earliest opportunity. This routine is typically
2532** called in response to a user action such as pressing "Cancel"
2533** or Ctrl-C where the user wants a long query operation to halt
2534** immediately.
2535**
2536** ^It is safe to call this routine from a thread different from the
2537** thread that is currently running the database operation. But it
2538** is not safe to call this routine with a [database connection] that
2539** is closed or might close before sqlite3_interrupt() returns.
2540**
2541** ^If an SQL operation is very nearly finished at the time when
2542** sqlite3_interrupt() is called, then it might not have an opportunity
2543** to be interrupted and might continue to completion.
2544**
2545** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2546** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2547** that is inside an explicit transaction, then the entire transaction
2548** will be rolled back automatically.
2549**
2550** ^The sqlite3_interrupt(D) call is in effect until all currently running
2551** SQL statements on [database connection] D complete. ^Any new SQL statements
2552** that are started after the sqlite3_interrupt() call and before the
2553** running statement count reaches zero are interrupted as if they had been
2554** running prior to the sqlite3_interrupt() call. ^New SQL statements
2555** that are started after the running statement count reaches zero are
2556** not effected by the sqlite3_interrupt().
2557** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2558** SQL statements is a no-op and has no effect on SQL statements
2559** that are started after the sqlite3_interrupt() call returns.
2560*/
2561SQLITE_API void sqlite3_interrupt(sqlite3*);
2562
2563/*
2564** CAPI3REF: Determine If An SQL Statement Is Complete
2565**
2566** These routines are useful during command-line input to determine if the
2567** currently entered text seems to form a complete SQL statement or
2568** if additional input is needed before sending the text into
2569** SQLite for parsing. ^These routines return 1 if the input string
2570** appears to be a complete SQL statement. ^A statement is judged to be
2571** complete if it ends with a semicolon token and is not a prefix of a
2572** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2573** string literals or quoted identifier names or comments are not
2574** independent tokens (they are part of the token in which they are
2575** embedded) and thus do not count as a statement terminator. ^Whitespace
2576** and comments that follow the final semicolon are ignored.
2577**
2578** ^These routines return 0 if the statement is incomplete. ^If a
2579** memory allocation fails, then SQLITE_NOMEM is returned.
2580**
2581** ^These routines do not parse the SQL statements thus
2582** will not detect syntactically incorrect SQL.
2583**
2584** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2585** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2586** automatically by sqlite3_complete16(). If that initialization fails,
2587** then the return value from sqlite3_complete16() will be non-zero
2588** regardless of whether or not the input SQL is complete.)^
2589**
2590** The input to [sqlite3_complete()] must be a zero-terminated
2591** UTF-8 string.
2592**
2593** The input to [sqlite3_complete16()] must be a zero-terminated
2594** UTF-16 string in native byte order.
2595*/
2596SQLITE_API int sqlite3_complete(const char *sql);
2597SQLITE_API int sqlite3_complete16(const void *sql);
2598
2599/*
2600** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2601** KEYWORDS: {busy-handler callback} {busy handler}
2602** METHOD: sqlite3
2603**
2604** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2605** that might be invoked with argument P whenever
2606** an attempt is made to access a database table associated with
2607** [database connection] D when another thread
2608** or process has the table locked.
2609** The sqlite3_busy_handler() interface is used to implement
2610** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2611**
2612** ^If the busy callback is NULL, then [SQLITE_BUSY]
2613** is returned immediately upon encountering the lock. ^If the busy callback
2614** is not NULL, then the callback might be invoked with two arguments.
2615**
2616** ^The first argument to the busy handler is a copy of the void* pointer which
2617** is the third argument to sqlite3_busy_handler(). ^The second argument to
2618** the busy handler callback is the number of times that the busy handler has
2619** been invoked previously for the same locking event. ^If the
2620** busy callback returns 0, then no additional attempts are made to
2621** access the database and [SQLITE_BUSY] is returned
2622** to the application.
2623** ^If the callback returns non-zero, then another attempt
2624** is made to access the database and the cycle repeats.
2625**
2626** The presence of a busy handler does not guarantee that it will be invoked
2627** when there is lock contention. ^If SQLite determines that invoking the busy
2628** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2629** to the application instead of invoking the
2630** busy handler.
2631** Consider a scenario where one process is holding a read lock that
2632** it is trying to promote to a reserved lock and
2633** a second process is holding a reserved lock that it is trying
2634** to promote to an exclusive lock. The first process cannot proceed
2635** because it is blocked by the second and the second process cannot
2636** proceed because it is blocked by the first. If both processes
2637** invoke the busy handlers, neither will make any progress. Therefore,
2638** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2639** will induce the first process to release its read lock and allow
2640** the second process to proceed.
2641**
2642** ^The default busy callback is NULL.
2643**
2644** ^(There can only be a single busy handler defined for each
2645** [database connection]. Setting a new busy handler clears any
2646** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2647** or evaluating [PRAGMA busy_timeout=N] will change the
2648** busy handler and thus clear any previously set busy handler.
2649**
2650** The busy callback should not take any actions which modify the
2651** database connection that invoked the busy handler. In other words,
2652** the busy handler is not reentrant. Any such actions
2653** result in undefined behavior.
2654**
2655** A busy handler must not close the database connection
2656** or [prepared statement] that invoked the busy handler.
2657*/
2658SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2659
2660/*
2661** CAPI3REF: Set A Busy Timeout
2662** METHOD: sqlite3
2663**
2664** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2665** for a specified amount of time when a table is locked. ^The handler
2666** will sleep multiple times until at least "ms" milliseconds of sleeping
2667** have accumulated. ^After at least "ms" milliseconds of sleeping,
2668** the handler returns 0 which causes [sqlite3_step()] to return
2669** [SQLITE_BUSY].
2670**
2671** ^Calling this routine with an argument less than or equal to zero
2672** turns off all busy handlers.
2673**
2674** ^(There can only be a single busy handler for a particular
2675** [database connection] at any given moment. If another busy handler
2676** was defined (using [sqlite3_busy_handler()]) prior to calling
2677** this routine, that other busy handler is cleared.)^
2678**
2679** See also: [PRAGMA busy_timeout]
2680*/
2681SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2682
2683/*
2684** CAPI3REF: Convenience Routines For Running Queries
2685** METHOD: sqlite3
2686**
2687** This is a legacy interface that is preserved for backwards compatibility.
2688** Use of this interface is not recommended.
2689**
2690** Definition: A <b>result table</b> is memory data structure created by the
2691** [sqlite3_get_table()] interface. A result table records the
2692** complete query results from one or more queries.
2693**
2694** The table conceptually has a number of rows and columns. But
2695** these numbers are not part of the result table itself. These
2696** numbers are obtained separately. Let N be the number of rows
2697** and M be the number of columns.
2698**
2699** A result table is an array of pointers to zero-terminated UTF-8 strings.
2700** There are (N+1)*M elements in the array. The first M pointers point
2701** to zero-terminated strings that contain the names of the columns.
2702** The remaining entries all point to query results. NULL values result
2703** in NULL pointers. All other values are in their UTF-8 zero-terminated
2704** string representation as returned by [sqlite3_column_text()].
2705**
2706** A result table might consist of one or more memory allocations.
2707** It is not safe to pass a result table directly to [sqlite3_free()].
2708** A result table should be deallocated using [sqlite3_free_table()].
2709**
2710** ^(As an example of the result table format, suppose a query result
2711** is as follows:
2712**
2713** <blockquote><pre>
2714** Name | Age
2715** -----------------------
2716** Alice | 43
2717** Bob | 28
2718** Cindy | 21
2719** </pre></blockquote>
2720**
2721** There are two columns (M==2) and three rows (N==3). Thus the
2722** result table has 8 entries. Suppose the result table is stored
2723** in an array named azResult. Then azResult holds this content:
2724**
2725** <blockquote><pre>
2726** azResult&#91;0] = "Name";
2727** azResult&#91;1] = "Age";
2728** azResult&#91;2] = "Alice";
2729** azResult&#91;3] = "43";
2730** azResult&#91;4] = "Bob";
2731** azResult&#91;5] = "28";
2732** azResult&#91;6] = "Cindy";
2733** azResult&#91;7] = "21";
2734** </pre></blockquote>)^
2735**
2736** ^The sqlite3_get_table() function evaluates one or more
2737** semicolon-separated SQL statements in the zero-terminated UTF-8
2738** string of its 2nd parameter and returns a result table to the
2739** pointer given in its 3rd parameter.
2740**
2741** After the application has finished with the result from sqlite3_get_table(),
2742** it must pass the result table pointer to sqlite3_free_table() in order to
2743** release the memory that was malloced. Because of the way the
2744** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2745** function must not try to call [sqlite3_free()] directly. Only
2746** [sqlite3_free_table()] is able to release the memory properly and safely.
2747**
2748** The sqlite3_get_table() interface is implemented as a wrapper around
2749** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2750** to any internal data structures of SQLite. It uses only the public
2751** interface defined here. As a consequence, errors that occur in the
2752** wrapper layer outside of the internal [sqlite3_exec()] call are not
2753** reflected in subsequent calls to [sqlite3_errcode()] or
2754** [sqlite3_errmsg()].
2755*/
2756SQLITE_API int sqlite3_get_table(
2757 sqlite3 *db, /* An open database */
2758 const char *zSql, /* SQL to be evaluated */
2759 char ***pazResult, /* Results of the query */
2760 int *pnRow, /* Number of result rows written here */
2761 int *pnColumn, /* Number of result columns written here */
2762 char **pzErrmsg /* Error msg written here */
2763);
2764SQLITE_API void sqlite3_free_table(char **result);
2765
2766/*
2767** CAPI3REF: Formatted String Printing Functions
2768**
2769** These routines are work-alikes of the "printf()" family of functions
2770** from the standard C library.
2771** These routines understand most of the common formatting options from
2772** the standard library printf()
2773** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2774** See the [built-in printf()] documentation for details.
2775**
2776** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2777** results into memory obtained from [sqlite3_malloc64()].
2778** The strings returned by these two routines should be
2779** released by [sqlite3_free()]. ^Both routines return a
2780** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2781** memory to hold the resulting string.
2782**
2783** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2784** the standard C library. The result is written into the
2785** buffer supplied as the second parameter whose size is given by
2786** the first parameter. Note that the order of the
2787** first two parameters is reversed from snprintf().)^ This is an
2788** historical accident that cannot be fixed without breaking
2789** backwards compatibility. ^(Note also that sqlite3_snprintf()
2790** returns a pointer to its buffer instead of the number of
2791** characters actually written into the buffer.)^ We admit that
2792** the number of characters written would be a more useful return
2793** value but we cannot change the implementation of sqlite3_snprintf()
2794** now without breaking compatibility.
2795**
2796** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2797** guarantees that the buffer is always zero-terminated. ^The first
2798** parameter "n" is the total size of the buffer, including space for
2799** the zero terminator. So the longest string that can be completely
2800** written will be n-1 characters.
2801**
2802** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2803**
2804** See also: [built-in printf()], [printf() SQL function]
2805*/
2806SQLITE_API char *sqlite3_mprintf(const char*,...);
2807SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2808SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2809SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2810
2811/*
2812** CAPI3REF: Memory Allocation Subsystem
2813**
2814** The SQLite core uses these three routines for all of its own
2815** internal memory allocation needs. "Core" in the previous sentence
2816** does not include operating-system specific [VFS] implementation. The
2817** Windows VFS uses native malloc() and free() for some operations.
2818**
2819** ^The sqlite3_malloc() routine returns a pointer to a block
2820** of memory at least N bytes in length, where N is the parameter.
2821** ^If sqlite3_malloc() is unable to obtain sufficient free
2822** memory, it returns a NULL pointer. ^If the parameter N to
2823** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2824** a NULL pointer.
2825**
2826** ^The sqlite3_malloc64(N) routine works just like
2827** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2828** of a signed 32-bit integer.
2829**
2830** ^Calling sqlite3_free() with a pointer previously returned
2831** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2832** that it might be reused. ^The sqlite3_free() routine is
2833** a no-op if is called with a NULL pointer. Passing a NULL pointer
2834** to sqlite3_free() is harmless. After being freed, memory
2835** should neither be read nor written. Even reading previously freed
2836** memory might result in a segmentation fault or other severe error.
2837** Memory corruption, a segmentation fault, or other severe error
2838** might result if sqlite3_free() is called with a non-NULL pointer that
2839** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2840**
2841** ^The sqlite3_realloc(X,N) interface attempts to resize a
2842** prior memory allocation X to be at least N bytes.
2843** ^If the X parameter to sqlite3_realloc(X,N)
2844** is a NULL pointer then its behavior is identical to calling
2845** sqlite3_malloc(N).
2846** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2847** negative then the behavior is exactly the same as calling
2848** sqlite3_free(X).
2849** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2850** of at least N bytes in size or NULL if insufficient memory is available.
2851** ^If M is the size of the prior allocation, then min(N,M) bytes
2852** of the prior allocation are copied into the beginning of buffer returned
2853** by sqlite3_realloc(X,N) and the prior allocation is freed.
2854** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2855** prior allocation is not freed.
2856**
2857** ^The sqlite3_realloc64(X,N) interfaces works the same as
2858** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2859** of a 32-bit signed integer.
2860**
2861** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2862** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2863** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2864** ^The value returned by sqlite3_msize(X) might be larger than the number
2865** of bytes requested when X was allocated. ^If X is a NULL pointer then
2866** sqlite3_msize(X) returns zero. If X points to something that is not
2867** the beginning of memory allocation, or if it points to a formerly
2868** valid memory allocation that has now been freed, then the behavior
2869** of sqlite3_msize(X) is undefined and possibly harmful.
2870**
2871** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2872** sqlite3_malloc64(), and sqlite3_realloc64()
2873** is always aligned to at least an 8 byte boundary, or to a
2874** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2875** option is used.
2876**
2877** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2878** must be either NULL or else pointers obtained from a prior
2879** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2880** not yet been released.
2881**
2882** The application must not read or write any part of
2883** a block of memory after it has been released using
2884** [sqlite3_free()] or [sqlite3_realloc()].
2885*/
2886SQLITE_API void *sqlite3_malloc(int);
2887SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2888SQLITE_API void *sqlite3_realloc(void*, int);
2889SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2890SQLITE_API void sqlite3_free(void*);
2891SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2892
2893/*
2894** CAPI3REF: Memory Allocator Statistics
2895**
2896** SQLite provides these two interfaces for reporting on the status
2897** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2898** routines, which form the built-in memory allocation subsystem.
2899**
2900** ^The [sqlite3_memory_used()] routine returns the number of bytes
2901** of memory currently outstanding (malloced but not freed).
2902** ^The [sqlite3_memory_highwater()] routine returns the maximum
2903** value of [sqlite3_memory_used()] since the high-water mark
2904** was last reset. ^The values returned by [sqlite3_memory_used()] and
2905** [sqlite3_memory_highwater()] include any overhead
2906** added by SQLite in its implementation of [sqlite3_malloc()],
2907** but not overhead added by the any underlying system library
2908** routines that [sqlite3_malloc()] may call.
2909**
2910** ^The memory high-water mark is reset to the current value of
2911** [sqlite3_memory_used()] if and only if the parameter to
2912** [sqlite3_memory_highwater()] is true. ^The value returned
2913** by [sqlite3_memory_highwater(1)] is the high-water mark
2914** prior to the reset.
2915*/
2916SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2917SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2918
2919/*
2920** CAPI3REF: Pseudo-Random Number Generator
2921**
2922** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2923** select random [ROWID | ROWIDs] when inserting new records into a table that
2924** already uses the largest possible [ROWID]. The PRNG is also used for
2925** the built-in random() and randomblob() SQL functions. This interface allows
2926** applications to access the same PRNG for other purposes.
2927**
2928** ^A call to this routine stores N bytes of randomness into buffer P.
2929** ^The P parameter can be a NULL pointer.
2930**
2931** ^If this routine has not been previously called or if the previous
2932** call had N less than one or a NULL pointer for P, then the PRNG is
2933** seeded using randomness obtained from the xRandomness method of
2934** the default [sqlite3_vfs] object.
2935** ^If the previous call to this routine had an N of 1 or more and a
2936** non-NULL P then the pseudo-randomness is generated
2937** internally and without recourse to the [sqlite3_vfs] xRandomness
2938** method.
2939*/
2940SQLITE_API void sqlite3_randomness(int N, void *P);
2941
2942/*
2943** CAPI3REF: Compile-Time Authorization Callbacks
2944** METHOD: sqlite3
2945** KEYWORDS: {authorizer callback}
2946**
2947** ^This routine registers an authorizer callback with a particular
2948** [database connection], supplied in the first argument.
2949** ^The authorizer callback is invoked as SQL statements are being compiled
2950** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2951** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2952** and [sqlite3_prepare16_v3()]. ^At various
2953** points during the compilation process, as logic is being created
2954** to perform various actions, the authorizer callback is invoked to
2955** see if those actions are allowed. ^The authorizer callback should
2956** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2957** specific action but allow the SQL statement to continue to be
2958** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2959** rejected with an error. ^If the authorizer callback returns
2960** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2961** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2962** the authorizer will fail with an error message.
2963**
2964** When the callback returns [SQLITE_OK], that means the operation
2965** requested is ok. ^When the callback returns [SQLITE_DENY], the
2966** [sqlite3_prepare_v2()] or equivalent call that triggered the
2967** authorizer will fail with an error message explaining that
2968** access is denied.
2969**
2970** ^The first parameter to the authorizer callback is a copy of the third
2971** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2972** to the callback is an integer [SQLITE_COPY | action code] that specifies
2973** the particular action to be authorized. ^The third through sixth parameters
2974** to the callback are either NULL pointers or zero-terminated strings
2975** that contain additional details about the action to be authorized.
2976** Applications must always be prepared to encounter a NULL pointer in any
2977** of the third through the sixth parameters of the authorization callback.
2978**
2979** ^If the action code is [SQLITE_READ]
2980** and the callback returns [SQLITE_IGNORE] then the
2981** [prepared statement] statement is constructed to substitute
2982** a NULL value in place of the table column that would have
2983** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2984** return can be used to deny an untrusted user access to individual
2985** columns of a table.
2986** ^When a table is referenced by a [SELECT] but no column values are
2987** extracted from that table (for example in a query like
2988** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2989** is invoked once for that table with a column name that is an empty string.
2990** ^If the action code is [SQLITE_DELETE] and the callback returns
2991** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2992** [truncate optimization] is disabled and all rows are deleted individually.
2993**
2994** An authorizer is used when [sqlite3_prepare | preparing]
2995** SQL statements from an untrusted source, to ensure that the SQL statements
2996** do not try to access data they are not allowed to see, or that they do not
2997** try to execute malicious statements that damage the database. For
2998** example, an application may allow a user to enter arbitrary
2999** SQL queries for evaluation by a database. But the application does
3000** not want the user to be able to make arbitrary changes to the
3001** database. An authorizer could then be put in place while the
3002** user-entered SQL is being [sqlite3_prepare | prepared] that
3003** disallows everything except [SELECT] statements.
3004**
3005** Applications that need to process SQL from untrusted sources
3006** might also consider lowering resource limits using [sqlite3_limit()]
3007** and limiting database size using the [max_page_count] [PRAGMA]
3008** in addition to using an authorizer.
3009**
3010** ^(Only a single authorizer can be in place on a database connection
3011** at a time. Each call to sqlite3_set_authorizer overrides the
3012** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3013** The authorizer is disabled by default.
3014**
3015** The authorizer callback must not do anything that will modify
3016** the database connection that invoked the authorizer callback.
3017** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3018** database connections for the meaning of "modify" in this paragraph.
3019**
3020** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3021** statement might be re-prepared during [sqlite3_step()] due to a
3022** schema change. Hence, the application should ensure that the
3023** correct authorizer callback remains in place during the [sqlite3_step()].
3024**
3025** ^Note that the authorizer callback is invoked only during
3026** [sqlite3_prepare()] or its variants. Authorization is not
3027** performed during statement evaluation in [sqlite3_step()], unless
3028** as stated in the previous paragraph, sqlite3_step() invokes
3029** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3030*/
3031SQLITE_API int sqlite3_set_authorizer(
3032 sqlite3*,
3033 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3034 void *pUserData
3035);
3036
3037/*
3038** CAPI3REF: Authorizer Return Codes
3039**
3040** The [sqlite3_set_authorizer | authorizer callback function] must
3041** return either [SQLITE_OK] or one of these two constants in order
3042** to signal SQLite whether or not the action is permitted. See the
3043** [sqlite3_set_authorizer | authorizer documentation] for additional
3044** information.
3045**
3046** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3047** returned from the [sqlite3_vtab_on_conflict()] interface.
3048*/
3049#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3050#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3051
3052/*
3053** CAPI3REF: Authorizer Action Codes
3054**
3055** The [sqlite3_set_authorizer()] interface registers a callback function
3056** that is invoked to authorize certain SQL statement actions. The
3057** second parameter to the callback is an integer code that specifies
3058** what action is being authorized. These are the integer action codes that
3059** the authorizer callback may be passed.
3060**
3061** These action code values signify what kind of operation is to be
3062** authorized. The 3rd and 4th parameters to the authorization
3063** callback function will be parameters or NULL depending on which of these
3064** codes is used as the second parameter. ^(The 5th parameter to the
3065** authorizer callback is the name of the database ("main", "temp",
3066** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3067** is the name of the inner-most trigger or view that is responsible for
3068** the access attempt or NULL if this access attempt is directly from
3069** top-level SQL code.
3070*/
3071/******************************************* 3rd ************ 4th ***********/
3072#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3073#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3074#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3075#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3076#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3077#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3078#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3079#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3080#define SQLITE_DELETE 9 /* Table Name NULL */
3081#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3082#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3083#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3084#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3085#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3086#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3087#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3088#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3089#define SQLITE_INSERT 18 /* Table Name NULL */
3090#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3091#define SQLITE_READ 20 /* Table Name Column Name */
3092#define SQLITE_SELECT 21 /* NULL NULL */
3093#define SQLITE_TRANSACTION 22 /* Operation NULL */
3094#define SQLITE_UPDATE 23 /* Table Name Column Name */
3095#define SQLITE_ATTACH 24 /* Filename NULL */
3096#define SQLITE_DETACH 25 /* Database Name NULL */
3097#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3098#define SQLITE_REINDEX 27 /* Index Name NULL */
3099#define SQLITE_ANALYZE 28 /* Table Name NULL */
3100#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3101#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3102#define SQLITE_FUNCTION 31 /* NULL Function Name */
3103#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3104#define SQLITE_COPY 0 /* No longer used */
3105#define SQLITE_RECURSIVE 33 /* NULL NULL */
3106
3107/*
3108** CAPI3REF: Tracing And Profiling Functions
3109** METHOD: sqlite3
3110**
3111** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3112** instead of the routines described here.
3113**
3114** These routines register callback functions that can be used for
3115** tracing and profiling the execution of SQL statements.
3116**
3117** ^The callback function registered by sqlite3_trace() is invoked at
3118** various times when an SQL statement is being run by [sqlite3_step()].
3119** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3120** SQL statement text as the statement first begins executing.
3121** ^(Additional sqlite3_trace() callbacks might occur
3122** as each triggered subprogram is entered. The callbacks for triggers
3123** contain a UTF-8 SQL comment that identifies the trigger.)^
3124**
3125** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3126** the length of [bound parameter] expansion in the output of sqlite3_trace().
3127**
3128** ^The callback function registered by sqlite3_profile() is invoked
3129** as each SQL statement finishes. ^The profile callback contains
3130** the original statement text and an estimate of wall-clock time
3131** of how long that statement took to run. ^The profile callback
3132** time is in units of nanoseconds, however the current implementation
3133** is only capable of millisecond resolution so the six least significant
3134** digits in the time are meaningless. Future versions of SQLite
3135** might provide greater resolution on the profiler callback. Invoking
3136** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3137** profile callback.
3138*/
3139SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3140 void(*xTrace)(void*,const char*), void*);
3141SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3142 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3143
3144/*
3145** CAPI3REF: SQL Trace Event Codes
3146** KEYWORDS: SQLITE_TRACE
3147**
3148** These constants identify classes of events that can be monitored
3149** using the [sqlite3_trace_v2()] tracing logic. The M argument
3150** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3151** the following constants. ^The first argument to the trace callback
3152** is one of the following constants.
3153**
3154** New tracing constants may be added in future releases.
3155**
3156** ^A trace callback has four arguments: xCallback(T,C,P,X).
3157** ^The T argument is one of the integer type codes above.
3158** ^The C argument is a copy of the context pointer passed in as the
3159** fourth argument to [sqlite3_trace_v2()].
3160** The P and X arguments are pointers whose meanings depend on T.
3161**
3162** <dl>
3163** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3164** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3165** first begins running and possibly at other times during the
3166** execution of the prepared statement, such as at the start of each
3167** trigger subprogram. ^The P argument is a pointer to the
3168** [prepared statement]. ^The X argument is a pointer to a string which
3169** is the unexpanded SQL text of the prepared statement or an SQL comment
3170** that indicates the invocation of a trigger. ^The callback can compute
3171** the same text that would have been returned by the legacy [sqlite3_trace()]
3172** interface by using the X argument when X begins with "--" and invoking
3173** [sqlite3_expanded_sql(P)] otherwise.
3174**
3175** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3176** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3177** information as is provided by the [sqlite3_profile()] callback.
3178** ^The P argument is a pointer to the [prepared statement] and the
3179** X argument points to a 64-bit integer which is the estimated of
3180** the number of nanosecond that the prepared statement took to run.
3181** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3182**
3183** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3184** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3185** statement generates a single row of result.
3186** ^The P argument is a pointer to the [prepared statement] and the
3187** X argument is unused.
3188**
3189** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3190** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3191** connection closes.
3192** ^The P argument is a pointer to the [database connection] object
3193** and the X argument is unused.
3194** </dl>
3195*/
3196#define SQLITE_TRACE_STMT 0x01
3197#define SQLITE_TRACE_PROFILE 0x02
3198#define SQLITE_TRACE_ROW 0x04
3199#define SQLITE_TRACE_CLOSE 0x08
3200
3201/*
3202** CAPI3REF: SQL Trace Hook
3203** METHOD: sqlite3
3204**
3205** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3206** function X against [database connection] D, using property mask M
3207** and context pointer P. ^If the X callback is
3208** NULL or if the M mask is zero, then tracing is disabled. The
3209** M argument should be the bitwise OR-ed combination of
3210** zero or more [SQLITE_TRACE] constants.
3211**
3212** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3213** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3214**
3215** ^The X callback is invoked whenever any of the events identified by
3216** mask M occur. ^The integer return value from the callback is currently
3217** ignored, though this may change in future releases. Callback
3218** implementations should return zero to ensure future compatibility.
3219**
3220** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3221** ^The T argument is one of the [SQLITE_TRACE]
3222** constants to indicate why the callback was invoked.
3223** ^The C argument is a copy of the context pointer.
3224** The P and X arguments are pointers whose meanings depend on T.
3225**
3226** The sqlite3_trace_v2() interface is intended to replace the legacy
3227** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3228** are deprecated.
3229*/
3230SQLITE_API int sqlite3_trace_v2(
3231 sqlite3*,
3232 unsigned uMask,
3233 int(*xCallback)(unsigned,void*,void*,void*),
3234 void *pCtx
3235);
3236
3237/*
3238** CAPI3REF: Query Progress Callbacks
3239** METHOD: sqlite3
3240**
3241** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3242** function X to be invoked periodically during long running calls to
3243** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3244** database connection D. An example use for this
3245** interface is to keep a GUI updated during a large query.
3246**
3247** ^The parameter P is passed through as the only parameter to the
3248** callback function X. ^The parameter N is the approximate number of
3249** [virtual machine instructions] that are evaluated between successive
3250** invocations of the callback X. ^If N is less than one then the progress
3251** handler is disabled.
3252**
3253** ^Only a single progress handler may be defined at one time per
3254** [database connection]; setting a new progress handler cancels the
3255** old one. ^Setting parameter X to NULL disables the progress handler.
3256** ^The progress handler is also disabled by setting N to a value less
3257** than 1.
3258**
3259** ^If the progress callback returns non-zero, the operation is
3260** interrupted. This feature can be used to implement a
3261** "Cancel" button on a GUI progress dialog box.
3262**
3263** The progress handler callback must not do anything that will modify
3264** the database connection that invoked the progress handler.
3265** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3266** database connections for the meaning of "modify" in this paragraph.
3267**
3268*/
3269SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3270
3271/*
3272** CAPI3REF: Opening A New Database Connection
3273** CONSTRUCTOR: sqlite3
3274**
3275** ^These routines open an SQLite database file as specified by the
3276** filename argument. ^The filename argument is interpreted as UTF-8 for
3277** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3278** order for sqlite3_open16(). ^(A [database connection] handle is usually
3279** returned in *ppDb, even if an error occurs. The only exception is that
3280** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3281** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3282** object.)^ ^(If the database is opened (and/or created) successfully, then
3283** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3284** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3285** an English language description of the error following a failure of any
3286** of the sqlite3_open() routines.
3287**
3288** ^The default encoding will be UTF-8 for databases created using
3289** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3290** created using sqlite3_open16() will be UTF-16 in the native byte order.
3291**
3292** Whether or not an error occurs when it is opened, resources
3293** associated with the [database connection] handle should be released by
3294** passing it to [sqlite3_close()] when it is no longer required.
3295**
3296** The sqlite3_open_v2() interface works like sqlite3_open()
3297** except that it accepts two additional parameters for additional control
3298** over the new database connection. ^(The flags parameter to
3299** sqlite3_open_v2() must include, at a minimum, one of the following
3300** three flag combinations:)^
3301**
3302** <dl>
3303** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3304** <dd>The database is opened in read-only mode. If the database does not
3305** already exist, an error is returned.</dd>)^
3306**
3307** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3308** <dd>The database is opened for reading and writing if possible, or reading
3309** only if the file is write protected by the operating system. In either
3310** case the database must already exist, otherwise an error is returned.</dd>)^
3311**
3312** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3313** <dd>The database is opened for reading and writing, and is created if
3314** it does not already exist. This is the behavior that is always used for
3315** sqlite3_open() and sqlite3_open16().</dd>)^
3316** </dl>
3317**
3318** In addition to the required flags, the following optional flags are
3319** also supported:
3320**
3321** <dl>
3322** ^(<dt>[SQLITE_OPEN_URI]</dt>
3323** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3324**
3325** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3326** <dd>The database will be opened as an in-memory database. The database
3327** is named by the "filename" argument for the purposes of cache-sharing,
3328** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3329** </dd>)^
3330**
3331** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3332** <dd>The new database connection will use the "multi-thread"
3333** [threading mode].)^ This means that separate threads are allowed
3334** to use SQLite at the same time, as long as each thread is using
3335** a different [database connection].
3336**
3337** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3338** <dd>The new database connection will use the "serialized"
3339** [threading mode].)^ This means the multiple threads can safely
3340** attempt to use the same database connection at the same time.
3341** (Mutexes will block any actual concurrency, but in this mode
3342** there is no harm in trying.)
3343**
3344** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3345** <dd>The database is opened [shared cache] enabled, overriding
3346** the default shared cache setting provided by
3347** [sqlite3_enable_shared_cache()].)^
3348**
3349** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3350** <dd>The database is opened [shared cache] disabled, overriding
3351** the default shared cache setting provided by
3352** [sqlite3_enable_shared_cache()].)^
3353**
3354** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3355** <dd>The database filename is not allowed to be a symbolic link</dd>
3356** </dl>)^
3357**
3358** If the 3rd parameter to sqlite3_open_v2() is not one of the
3359** required combinations shown above optionally combined with other
3360** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3361** then the behavior is undefined.
3362**
3363** ^The fourth parameter to sqlite3_open_v2() is the name of the
3364** [sqlite3_vfs] object that defines the operating system interface that
3365** the new database connection should use. ^If the fourth parameter is
3366** a NULL pointer then the default [sqlite3_vfs] object is used.
3367**
3368** ^If the filename is ":memory:", then a private, temporary in-memory database
3369** is created for the connection. ^This in-memory database will vanish when
3370** the database connection is closed. Future versions of SQLite might
3371** make use of additional special filenames that begin with the ":" character.
3372** It is recommended that when a database filename actually does begin with
3373** a ":" character you should prefix the filename with a pathname such as
3374** "./" to avoid ambiguity.
3375**
3376** ^If the filename is an empty string, then a private, temporary
3377** on-disk database will be created. ^This private database will be
3378** automatically deleted as soon as the database connection is closed.
3379**
3380** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3381**
3382** ^If [URI filename] interpretation is enabled, and the filename argument
3383** begins with "file:", then the filename is interpreted as a URI. ^URI
3384** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3385** set in the third argument to sqlite3_open_v2(), or if it has
3386** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3387** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3388** URI filename interpretation is turned off
3389** by default, but future releases of SQLite might enable URI filename
3390** interpretation by default. See "[URI filenames]" for additional
3391** information.
3392**
3393** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3394** authority, then it must be either an empty string or the string
3395** "localhost". ^If the authority is not an empty string or "localhost", an
3396** error is returned to the caller. ^The fragment component of a URI, if
3397** present, is ignored.
3398**
3399** ^SQLite uses the path component of the URI as the name of the disk file
3400** which contains the database. ^If the path begins with a '/' character,
3401** then it is interpreted as an absolute path. ^If the path does not begin
3402** with a '/' (meaning that the authority section is omitted from the URI)
3403** then the path is interpreted as a relative path.
3404** ^(On windows, the first component of an absolute path
3405** is a drive specification (e.g. "C:").)^
3406**
3407** [[core URI query parameters]]
3408** The query component of a URI may contain parameters that are interpreted
3409** either by SQLite itself, or by a [VFS | custom VFS implementation].
3410** SQLite and its built-in [VFSes] interpret the
3411** following query parameters:
3412**
3413** <ul>
3414** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3415** a VFS object that provides the operating system interface that should
3416** be used to access the database file on disk. ^If this option is set to
3417** an empty string the default VFS object is used. ^Specifying an unknown
3418** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3419** present, then the VFS specified by the option takes precedence over
3420** the value passed as the fourth parameter to sqlite3_open_v2().
3421**
3422** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3423** "rwc", or "memory". Attempting to set it to any other value is
3424** an error)^.
3425** ^If "ro" is specified, then the database is opened for read-only
3426** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3427** third argument to sqlite3_open_v2(). ^If the mode option is set to
3428** "rw", then the database is opened for read-write (but not create)
3429** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3430** been set. ^Value "rwc" is equivalent to setting both
3431** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3432** set to "memory" then a pure [in-memory database] that never reads
3433** or writes from disk is used. ^It is an error to specify a value for
3434** the mode parameter that is less restrictive than that specified by
3435** the flags passed in the third parameter to sqlite3_open_v2().
3436**
3437** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3438** "private". ^Setting it to "shared" is equivalent to setting the
3439** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3440** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3441** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3442** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3443** a URI filename, its value overrides any behavior requested by setting
3444** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3445**
3446** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3447** [powersafe overwrite] property does or does not apply to the
3448** storage media on which the database file resides.
3449**
3450** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3451** which if set disables file locking in rollback journal modes. This
3452** is useful for accessing a database on a filesystem that does not
3453** support locking. Caution: Database corruption might result if two
3454** or more processes write to the same database and any one of those
3455** processes uses nolock=1.
3456**
3457** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3458** parameter that indicates that the database file is stored on
3459** read-only media. ^When immutable is set, SQLite assumes that the
3460** database file cannot be changed, even by a process with higher
3461** privilege, and so the database is opened read-only and all locking
3462** and change detection is disabled. Caution: Setting the immutable
3463** property on a database file that does in fact change can result
3464** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3465** See also: [SQLITE_IOCAP_IMMUTABLE].
3466**
3467** </ul>
3468**
3469** ^Specifying an unknown parameter in the query component of a URI is not an
3470** error. Future versions of SQLite might understand additional query
3471** parameters. See "[query parameters with special meaning to SQLite]" for
3472** additional information.
3473**
3474** [[URI filename examples]] <h3>URI filename examples</h3>
3475**
3476** <table border="1" align=center cellpadding=5>
3477** <tr><th> URI filenames <th> Results
3478** <tr><td> file:data.db <td>
3479** Open the file "data.db" in the current directory.
3480** <tr><td> file:/home/fred/data.db<br>
3481** file:///home/fred/data.db <br>
3482** file://localhost/home/fred/data.db <br> <td>
3483** Open the database file "/home/fred/data.db".
3484** <tr><td> file://darkstar/home/fred/data.db <td>
3485** An error. "darkstar" is not a recognized authority.
3486** <tr><td style="white-space:nowrap">
3487** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3488** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3489** C:. Note that the %20 escaping in this example is not strictly
3490** necessary - space characters can be used literally
3491** in URI filenames.
3492** <tr><td> file:data.db?mode=ro&cache=private <td>
3493** Open file "data.db" in the current directory for read-only access.
3494** Regardless of whether or not shared-cache mode is enabled by
3495** default, use a private cache.
3496** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3497** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3498** that uses dot-files in place of posix advisory locking.
3499** <tr><td> file:data.db?mode=readonly <td>
3500** An error. "readonly" is not a valid option for the "mode" parameter.
3501** </table>
3502**
3503** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3504** query components of a URI. A hexadecimal escape sequence consists of a
3505** percent sign - "%" - followed by exactly two hexadecimal digits
3506** specifying an octet value. ^Before the path or query components of a
3507** URI filename are interpreted, they are encoded using UTF-8 and all
3508** hexadecimal escape sequences replaced by a single byte containing the
3509** corresponding octet. If this process generates an invalid UTF-8 encoding,
3510** the results are undefined.
3511**
3512** <b>Note to Windows users:</b> The encoding used for the filename argument
3513** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3514** codepage is currently defined. Filenames containing international
3515** characters must be converted to UTF-8 prior to passing them into
3516** sqlite3_open() or sqlite3_open_v2().
3517**
3518** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3519** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3520** features that require the use of temporary files may fail.
3521**
3522** See also: [sqlite3_temp_directory]
3523*/
3524SQLITE_API int sqlite3_open(
3525 const char *filename, /* Database filename (UTF-8) */
3526 sqlite3 **ppDb /* OUT: SQLite db handle */
3527);
3528SQLITE_API int sqlite3_open16(
3529 const void *filename, /* Database filename (UTF-16) */
3530 sqlite3 **ppDb /* OUT: SQLite db handle */
3531);
3532SQLITE_API int sqlite3_open_v2(
3533 const char *filename, /* Database filename (UTF-8) */
3534 sqlite3 **ppDb, /* OUT: SQLite db handle */
3535 int flags, /* Flags */
3536 const char *zVfs /* Name of VFS module to use */
3537);
3538
3539/*
3540** CAPI3REF: Obtain Values For URI Parameters
3541**
3542** These are utility routines, useful to [VFS|custom VFS implementations],
3543** that check if a database file was a URI that contained a specific query
3544** parameter, and if so obtains the value of that query parameter.
3545**
3546** The first parameter to these interfaces (hereafter referred to
3547** as F) must be one of:
3548** <ul>
3549** <li> A database filename pointer created by the SQLite core and
3550** passed into the xOpen() method of a VFS implemention, or
3551** <li> A filename obtained from [sqlite3_db_filename()], or
3552** <li> A new filename constructed using [sqlite3_create_filename()].
3553** </ul>
3554** If the F parameter is not one of the above, then the behavior is
3555** undefined and probably undesirable. Older versions of SQLite were
3556** more tolerant of invalid F parameters than newer versions.
3557**
3558** If F is a suitable filename (as described in the previous paragraph)
3559** and if P is the name of the query parameter, then
3560** sqlite3_uri_parameter(F,P) returns the value of the P
3561** parameter if it exists or a NULL pointer if P does not appear as a
3562** query parameter on F. If P is a query parameter of F and it
3563** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3564** a pointer to an empty string.
3565**
3566** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3567** parameter and returns true (1) or false (0) according to the value
3568** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3569** value of query parameter P is one of "yes", "true", or "on" in any
3570** case or if the value begins with a non-zero number. The
3571** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3572** query parameter P is one of "no", "false", or "off" in any case or
3573** if the value begins with a numeric zero. If P is not a query
3574** parameter on F or if the value of P does not match any of the
3575** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3576**
3577** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3578** 64-bit signed integer and returns that integer, or D if P does not
3579** exist. If the value of P is something other than an integer, then
3580** zero is returned.
3581**
3582** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3583** the value) of the N-th query parameter for filename F, or a NULL
3584** pointer if N is less than zero or greater than the number of query
3585** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3586** the name of the first query parameter, 1 for the second parameter, and
3587** so forth.
3588**
3589** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3590** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3591** is not a database file pathname pointer that the SQLite core passed
3592** into the xOpen VFS method, then the behavior of this routine is undefined
3593** and probably undesirable.
3594**
3595** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3596** parameter can also be the name of a rollback journal file or WAL file
3597** in addition to the main database file. Prior to version 3.31.0, these
3598** routines would only work if F was the name of the main database file.
3599** When the F parameter is the name of the rollback journal or WAL file,
3600** it has access to all the same query parameters as were found on the
3601** main database file.
3602**
3603** See the [URI filename] documentation for additional information.
3604*/
3605SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3606SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3607SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3608SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N);
3609
3610/*
3611** CAPI3REF: Translate filenames
3612**
3613** These routines are available to [VFS|custom VFS implementations] for
3614** translating filenames between the main database file, the journal file,
3615** and the WAL file.
3616**
3617** If F is the name of an sqlite database file, journal file, or WAL file
3618** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3619** returns the name of the corresponding database file.
3620**
3621** If F is the name of an sqlite database file, journal file, or WAL file
3622** passed by the SQLite core into the VFS, or if F is a database filename
3623** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3624** returns the name of the corresponding rollback journal file.
3625**
3626** If F is the name of an sqlite database file, journal file, or WAL file
3627** that was passed by the SQLite core into the VFS, or if F is a database
3628** filename obtained from [sqlite3_db_filename()], then
3629** sqlite3_filename_wal(F) returns the name of the corresponding
3630** WAL file.
3631**
3632** In all of the above, if F is not the name of a database, journal or WAL
3633** filename passed into the VFS from the SQLite core and F is not the
3634** return value from [sqlite3_db_filename()], then the result is
3635** undefined and is likely a memory access violation.
3636*/
3637SQLITE_API const char *sqlite3_filename_database(const char*);
3638SQLITE_API const char *sqlite3_filename_journal(const char*);
3639SQLITE_API const char *sqlite3_filename_wal(const char*);
3640
3641/*
3642** CAPI3REF: Database File Corresponding To A Journal
3643**
3644** ^If X is the name of a rollback or WAL-mode journal file that is
3645** passed into the xOpen method of [sqlite3_vfs], then
3646** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3647** object that represents the main database file.
3648**
3649** This routine is intended for use in custom [VFS] implementations
3650** only. It is not a general-purpose interface.
3651** The argument sqlite3_file_object(X) must be a filename pointer that
3652** has been passed into [sqlite3_vfs].xOpen method where the
3653** flags parameter to xOpen contains one of the bits
3654** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3655** of this routine results in undefined and probably undesirable
3656** behavior.
3657*/
3658SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3659
3660/*
3661** CAPI3REF: Create and Destroy VFS Filenames
3662**
3663** These interfces are provided for use by [VFS shim] implementations and
3664** are not useful outside of that context.
3665**
3666** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3667** database filename D with corresponding journal file J and WAL file W and
3668** with N URI parameters key/values pairs in the array P. The result from
3669** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3670** is safe to pass to routines like:
3671** <ul>
3672** <li> [sqlite3_uri_parameter()],
3673** <li> [sqlite3_uri_boolean()],
3674** <li> [sqlite3_uri_int64()],
3675** <li> [sqlite3_uri_key()],
3676** <li> [sqlite3_filename_database()],
3677** <li> [sqlite3_filename_journal()], or
3678** <li> [sqlite3_filename_wal()].
3679** </ul>
3680** If a memory allocation error occurs, sqlite3_create_filename() might
3681** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3682** must be released by a corresponding call to sqlite3_free_filename(Y).
3683**
3684** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3685** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3686** to a key and value for a query parameter. The P parameter may be a NULL
3687** pointer if N is zero. None of the 2*N pointers in the P array may be
3688** NULL pointers and key pointers should not be empty strings.
3689** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3690** be NULL pointers, though they can be empty strings.
3691**
3692** The sqlite3_free_filename(Y) routine releases a memory allocation
3693** previously obtained from sqlite3_create_filename(). Invoking
3694** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3695**
3696** If the Y parameter to sqlite3_free_filename(Y) is anything other
3697** than a NULL pointer or a pointer previously acquired from
3698** sqlite3_create_filename(), then bad things such as heap
3699** corruption or segfaults may occur. The value Y should be
3700** used again after sqlite3_free_filename(Y) has been called. This means
3701** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3702** then the corresponding [sqlite3_module.xClose() method should also be
3703** invoked prior to calling sqlite3_free_filename(Y).
3704*/
3705SQLITE_API char *sqlite3_create_filename(
3706 const char *zDatabase,
3707 const char *zJournal,
3708 const char *zWal,
3709 int nParam,
3710 const char **azParam
3711);
3712SQLITE_API void sqlite3_free_filename(char*);
3713
3714/*
3715** CAPI3REF: Error Codes And Messages
3716** METHOD: sqlite3
3717**
3718** ^If the most recent sqlite3_* API call associated with
3719** [database connection] D failed, then the sqlite3_errcode(D) interface
3720** returns the numeric [result code] or [extended result code] for that
3721** API call.
3722** ^The sqlite3_extended_errcode()
3723** interface is the same except that it always returns the
3724** [extended result code] even when extended result codes are
3725** disabled.
3726**
3727** The values returned by sqlite3_errcode() and/or
3728** sqlite3_extended_errcode() might change with each API call.
3729** Except, there are some interfaces that are guaranteed to never
3730** change the value of the error code. The error-code preserving
3731** interfaces are:
3732**
3733** <ul>
3734** <li> sqlite3_errcode()
3735** <li> sqlite3_extended_errcode()
3736** <li> sqlite3_errmsg()
3737** <li> sqlite3_errmsg16()
3738** </ul>
3739**
3740** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3741** text that describes the error, as either UTF-8 or UTF-16 respectively.
3742** ^(Memory to hold the error message string is managed internally.
3743** The application does not need to worry about freeing the result.
3744** However, the error string might be overwritten or deallocated by
3745** subsequent calls to other SQLite interface functions.)^
3746**
3747** ^The sqlite3_errstr() interface returns the English-language text
3748** that describes the [result code], as UTF-8.
3749** ^(Memory to hold the error message string is managed internally
3750** and must not be freed by the application)^.
3751**
3752** When the serialized [threading mode] is in use, it might be the
3753** case that a second error occurs on a separate thread in between
3754** the time of the first error and the call to these interfaces.
3755** When that happens, the second error will be reported since these
3756** interfaces always report the most recent result. To avoid
3757** this, each thread can obtain exclusive use of the [database connection] D
3758** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3759** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3760** all calls to the interfaces listed here are completed.
3761**
3762** If an interface fails with SQLITE_MISUSE, that means the interface
3763** was invoked incorrectly by the application. In that case, the
3764** error code and message may or may not be set.
3765*/
3766SQLITE_API int sqlite3_errcode(sqlite3 *db);
3767SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3768SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3769SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3770SQLITE_API const char *sqlite3_errstr(int);
3771
3772/*
3773** CAPI3REF: Prepared Statement Object
3774** KEYWORDS: {prepared statement} {prepared statements}
3775**
3776** An instance of this object represents a single SQL statement that
3777** has been compiled into binary form and is ready to be evaluated.
3778**
3779** Think of each SQL statement as a separate computer program. The
3780** original SQL text is source code. A prepared statement object
3781** is the compiled object code. All SQL must be converted into a
3782** prepared statement before it can be run.
3783**
3784** The life-cycle of a prepared statement object usually goes like this:
3785**
3786** <ol>
3787** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3788** <li> Bind values to [parameters] using the sqlite3_bind_*()
3789** interfaces.
3790** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3791** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3792** to step 2. Do this zero or more times.
3793** <li> Destroy the object using [sqlite3_finalize()].
3794** </ol>
3795*/
3796typedef struct sqlite3_stmt sqlite3_stmt;
3797
3798/*
3799** CAPI3REF: Run-time Limits
3800** METHOD: sqlite3
3801**
3802** ^(This interface allows the size of various constructs to be limited
3803** on a connection by connection basis. The first parameter is the
3804** [database connection] whose limit is to be set or queried. The
3805** second parameter is one of the [limit categories] that define a
3806** class of constructs to be size limited. The third parameter is the
3807** new limit for that construct.)^
3808**
3809** ^If the new limit is a negative number, the limit is unchanged.
3810** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3811** [limits | hard upper bound]
3812** set at compile-time by a C preprocessor macro called
3813** [limits | SQLITE_MAX_<i>NAME</i>].
3814** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3815** ^Attempts to increase a limit above its hard upper bound are
3816** silently truncated to the hard upper bound.
3817**
3818** ^Regardless of whether or not the limit was changed, the
3819** [sqlite3_limit()] interface returns the prior value of the limit.
3820** ^Hence, to find the current value of a limit without changing it,
3821** simply invoke this interface with the third parameter set to -1.
3822**
3823** Run-time limits are intended for use in applications that manage
3824** both their own internal database and also databases that are controlled
3825** by untrusted external sources. An example application might be a
3826** web browser that has its own databases for storing history and
3827** separate databases controlled by JavaScript applications downloaded
3828** off the Internet. The internal databases can be given the
3829** large, default limits. Databases managed by external sources can
3830** be given much smaller limits designed to prevent a denial of service
3831** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3832** interface to further control untrusted SQL. The size of the database
3833** created by an untrusted script can be contained using the
3834** [max_page_count] [PRAGMA].
3835**
3836** New run-time limit categories may be added in future releases.
3837*/
3838SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3839
3840/*
3841** CAPI3REF: Run-Time Limit Categories
3842** KEYWORDS: {limit category} {*limit categories}
3843**
3844** These constants define various performance limits
3845** that can be lowered at run-time using [sqlite3_limit()].
3846** The synopsis of the meanings of the various limits is shown below.
3847** Additional information is available at [limits | Limits in SQLite].
3848**
3849** <dl>
3850** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3851** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3852**
3853** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3854** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3855**
3856** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3857** <dd>The maximum number of columns in a table definition or in the
3858** result set of a [SELECT] or the maximum number of columns in an index
3859** or in an ORDER BY or GROUP BY clause.</dd>)^
3860**
3861** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3862** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3863**
3864** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3865** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3866**
3867** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3868** <dd>The maximum number of instructions in a virtual machine program
3869** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3870** the equivalent tries to allocate space for more than this many opcodes
3871** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3872**
3873** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3874** <dd>The maximum number of arguments on a function.</dd>)^
3875**
3876** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3877** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3878**
3879** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3880** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3881** <dd>The maximum length of the pattern argument to the [LIKE] or
3882** [GLOB] operators.</dd>)^
3883**
3884** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3885** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3886** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3887**
3888** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3889** <dd>The maximum depth of recursion for triggers.</dd>)^
3890**
3891** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3892** <dd>The maximum number of auxiliary worker threads that a single
3893** [prepared statement] may start.</dd>)^
3894** </dl>
3895*/
3896#define SQLITE_LIMIT_LENGTH 0
3897#define SQLITE_LIMIT_SQL_LENGTH 1
3898#define SQLITE_LIMIT_COLUMN 2
3899#define SQLITE_LIMIT_EXPR_DEPTH 3
3900#define SQLITE_LIMIT_COMPOUND_SELECT 4
3901#define SQLITE_LIMIT_VDBE_OP 5
3902#define SQLITE_LIMIT_FUNCTION_ARG 6
3903#define SQLITE_LIMIT_ATTACHED 7
3904#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3905#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3906#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3907#define SQLITE_LIMIT_WORKER_THREADS 11
3908
3909/*
3910** CAPI3REF: Prepare Flags
3911**
3912** These constants define various flags that can be passed into
3913** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3914** [sqlite3_prepare16_v3()] interfaces.
3915**
3916** New flags may be added in future releases of SQLite.
3917**
3918** <dl>
3919** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3920** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3921** that the prepared statement will be retained for a long time and
3922** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3923** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3924** be used just once or at most a few times and then destroyed using
3925** [sqlite3_finalize()] relatively soon. The current implementation acts
3926** on this hint by avoiding the use of [lookaside memory] so as not to
3927** deplete the limited store of lookaside memory. Future versions of
3928** SQLite may act on this hint differently.
3929**
3930** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
3931** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
3932** to be required for any prepared statement that wanted to use the
3933** [sqlite3_normalized_sql()] interface. However, the
3934** [sqlite3_normalized_sql()] interface is now available to all
3935** prepared statements, regardless of whether or not they use this
3936** flag.
3937**
3938** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
3939** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
3940** to return an error (error code SQLITE_ERROR) if the statement uses
3941** any virtual tables.
3942** </dl>
3943*/
3944#define SQLITE_PREPARE_PERSISTENT 0x01
3945#define SQLITE_PREPARE_NORMALIZE 0x02
3946#define SQLITE_PREPARE_NO_VTAB 0x04
3947
3948/*
3949** CAPI3REF: Compiling An SQL Statement
3950** KEYWORDS: {SQL statement compiler}
3951** METHOD: sqlite3
3952** CONSTRUCTOR: sqlite3_stmt
3953**
3954** To execute an SQL statement, it must first be compiled into a byte-code
3955** program using one of these routines. Or, in other words, these routines
3956** are constructors for the [prepared statement] object.
3957**
3958** The preferred routine to use is [sqlite3_prepare_v2()]. The
3959** [sqlite3_prepare()] interface is legacy and should be avoided.
3960** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3961** for special purposes.
3962**
3963** The use of the UTF-8 interfaces is preferred, as SQLite currently
3964** does all parsing using UTF-8. The UTF-16 interfaces are provided
3965** as a convenience. The UTF-16 interfaces work by converting the
3966** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3967**
3968** The first argument, "db", is a [database connection] obtained from a
3969** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3970** [sqlite3_open16()]. The database connection must not have been closed.
3971**
3972** The second argument, "zSql", is the statement to be compiled, encoded
3973** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3974** and sqlite3_prepare_v3()
3975** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3976** and sqlite3_prepare16_v3() use UTF-16.
3977**
3978** ^If the nByte argument is negative, then zSql is read up to the
3979** first zero terminator. ^If nByte is positive, then it is the
3980** number of bytes read from zSql. ^If nByte is zero, then no prepared
3981** statement is generated.
3982** If the caller knows that the supplied string is nul-terminated, then
3983** there is a small performance advantage to passing an nByte parameter that
3984** is the number of bytes in the input string <i>including</i>
3985** the nul-terminator.
3986**
3987** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3988** past the end of the first SQL statement in zSql. These routines only
3989** compile the first statement in zSql, so *pzTail is left pointing to
3990** what remains uncompiled.
3991**
3992** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3993** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3994** to NULL. ^If the input text contains no SQL (if the input is an empty
3995** string or a comment) then *ppStmt is set to NULL.
3996** The calling procedure is responsible for deleting the compiled
3997** SQL statement using [sqlite3_finalize()] after it has finished with it.
3998** ppStmt may not be NULL.
3999**
4000** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4001** otherwise an [error code] is returned.
4002**
4003** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4004** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4005** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4006** are retained for backwards compatibility, but their use is discouraged.
4007** ^In the "vX" interfaces, the prepared statement
4008** that is returned (the [sqlite3_stmt] object) contains a copy of the
4009** original SQL text. This causes the [sqlite3_step()] interface to
4010** behave differently in three ways:
4011**
4012** <ol>
4013** <li>
4014** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4015** always used to do, [sqlite3_step()] will automatically recompile the SQL
4016** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4017** retries will occur before sqlite3_step() gives up and returns an error.
4018** </li>
4019**
4020** <li>
4021** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4022** [error codes] or [extended error codes]. ^The legacy behavior was that
4023** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4024** and the application would have to make a second call to [sqlite3_reset()]
4025** in order to find the underlying cause of the problem. With the "v2" prepare
4026** interfaces, the underlying reason for the error is returned immediately.
4027** </li>
4028**
4029** <li>
4030** ^If the specific value bound to a [parameter | host parameter] in the
4031** WHERE clause might influence the choice of query plan for a statement,
4032** then the statement will be automatically recompiled, as if there had been
4033** a schema change, on the first [sqlite3_step()] call following any change
4034** to the [sqlite3_bind_text | bindings] of that [parameter].
4035** ^The specific value of a WHERE-clause [parameter] might influence the
4036** choice of query plan if the parameter is the left-hand side of a [LIKE]
4037** or [GLOB] operator or if the parameter is compared to an indexed column
4038** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4039** </li>
4040** </ol>
4041**
4042** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4043** the extra prepFlags parameter, which is a bit array consisting of zero or
4044** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4045** sqlite3_prepare_v2() interface works exactly the same as
4046** sqlite3_prepare_v3() with a zero prepFlags parameter.
4047*/
4048SQLITE_API int sqlite3_prepare(
4049 sqlite3 *db, /* Database handle */
4050 const char *zSql, /* SQL statement, UTF-8 encoded */
4051 int nByte, /* Maximum length of zSql in bytes. */
4052 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4053 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4054);
4055SQLITE_API int sqlite3_prepare_v2(
4056 sqlite3 *db, /* Database handle */
4057 const char *zSql, /* SQL statement, UTF-8 encoded */
4058 int nByte, /* Maximum length of zSql in bytes. */
4059 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4060 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4061);
4062SQLITE_API int sqlite3_prepare_v3(
4063 sqlite3 *db, /* Database handle */
4064 const char *zSql, /* SQL statement, UTF-8 encoded */
4065 int nByte, /* Maximum length of zSql in bytes. */
4066 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4067 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4068 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4069);
4070SQLITE_API int sqlite3_prepare16(
4071 sqlite3 *db, /* Database handle */
4072 const void *zSql, /* SQL statement, UTF-16 encoded */
4073 int nByte, /* Maximum length of zSql in bytes. */
4074 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4075 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4076);
4077SQLITE_API int sqlite3_prepare16_v2(
4078 sqlite3 *db, /* Database handle */
4079 const void *zSql, /* SQL statement, UTF-16 encoded */
4080 int nByte, /* Maximum length of zSql in bytes. */
4081 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4082 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4083);
4084SQLITE_API int sqlite3_prepare16_v3(
4085 sqlite3 *db, /* Database handle */
4086 const void *zSql, /* SQL statement, UTF-16 encoded */
4087 int nByte, /* Maximum length of zSql in bytes. */
4088 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4089 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4090 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4091);
4092
4093/*
4094** CAPI3REF: Retrieving Statement SQL
4095** METHOD: sqlite3_stmt
4096**
4097** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4098** SQL text used to create [prepared statement] P if P was
4099** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4100** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4101** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4102** string containing the SQL text of prepared statement P with
4103** [bound parameters] expanded.
4104** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4105** string containing the normalized SQL text of prepared statement P. The
4106** semantics used to normalize a SQL statement are unspecified and subject
4107** to change. At a minimum, literal values will be replaced with suitable
4108** placeholders.
4109**
4110** ^(For example, if a prepared statement is created using the SQL
4111** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4112** and parameter :xyz is unbound, then sqlite3_sql() will return
4113** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4114** will return "SELECT 2345,NULL".)^
4115**
4116** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4117** is available to hold the result, or if the result would exceed the
4118** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4119**
4120** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4121** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4122** option causes sqlite3_expanded_sql() to always return NULL.
4123**
4124** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4125** are managed by SQLite and are automatically freed when the prepared
4126** statement is finalized.
4127** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4128** is obtained from [sqlite3_malloc()] and must be free by the application
4129** by passing it to [sqlite3_free()].
4130*/
4131SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4132SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4133SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4134
4135/*
4136** CAPI3REF: Determine If An SQL Statement Writes The Database
4137** METHOD: sqlite3_stmt
4138**
4139** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4140** and only if the [prepared statement] X makes no direct changes to
4141** the content of the database file.
4142**
4143** Note that [application-defined SQL functions] or
4144** [virtual tables] might change the database indirectly as a side effect.
4145** ^(For example, if an application defines a function "eval()" that
4146** calls [sqlite3_exec()], then the following SQL statement would
4147** change the database file through side-effects:
4148**
4149** <blockquote><pre>
4150** SELECT eval('DELETE FROM t1') FROM t2;
4151** </pre></blockquote>
4152**
4153** But because the [SELECT] statement does not change the database file
4154** directly, sqlite3_stmt_readonly() would still return true.)^
4155**
4156** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4157** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4158** since the statements themselves do not actually modify the database but
4159** rather they control the timing of when other statements modify the
4160** database. ^The [ATTACH] and [DETACH] statements also cause
4161** sqlite3_stmt_readonly() to return true since, while those statements
4162** change the configuration of a database connection, they do not make
4163** changes to the content of the database files on disk.
4164** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4165** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4166** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4167** sqlite3_stmt_readonly() returns false for those commands.
4168*/
4169SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4170
4171/*
4172** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4173** METHOD: sqlite3_stmt
4174**
4175** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4176** prepared statement S is an EXPLAIN statement, or 2 if the
4177** statement S is an EXPLAIN QUERY PLAN.
4178** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4179** an ordinary statement or a NULL pointer.
4180*/
4181SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4182
4183/*
4184** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4185** METHOD: sqlite3_stmt
4186**
4187** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4188** [prepared statement] S has been stepped at least once using
4189** [sqlite3_step(S)] but has neither run to completion (returned
4190** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4191** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4192** interface returns false if S is a NULL pointer. If S is not a
4193** NULL pointer and is not a pointer to a valid [prepared statement]
4194** object, then the behavior is undefined and probably undesirable.
4195**
4196** This interface can be used in combination [sqlite3_next_stmt()]
4197** to locate all prepared statements associated with a database
4198** connection that are in need of being reset. This can be used,
4199** for example, in diagnostic routines to search for prepared
4200** statements that are holding a transaction open.
4201*/
4202SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4203
4204/*
4205** CAPI3REF: Dynamically Typed Value Object
4206** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4207**
4208** SQLite uses the sqlite3_value object to represent all values
4209** that can be stored in a database table. SQLite uses dynamic typing
4210** for the values it stores. ^Values stored in sqlite3_value objects
4211** can be integers, floating point values, strings, BLOBs, or NULL.
4212**
4213** An sqlite3_value object may be either "protected" or "unprotected".
4214** Some interfaces require a protected sqlite3_value. Other interfaces
4215** will accept either a protected or an unprotected sqlite3_value.
4216** Every interface that accepts sqlite3_value arguments specifies
4217** whether or not it requires a protected sqlite3_value. The
4218** [sqlite3_value_dup()] interface can be used to construct a new
4219** protected sqlite3_value from an unprotected sqlite3_value.
4220**
4221** The terms "protected" and "unprotected" refer to whether or not
4222** a mutex is held. An internal mutex is held for a protected
4223** sqlite3_value object but no mutex is held for an unprotected
4224** sqlite3_value object. If SQLite is compiled to be single-threaded
4225** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4226** or if SQLite is run in one of reduced mutex modes
4227** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4228** then there is no distinction between protected and unprotected
4229** sqlite3_value objects and they can be used interchangeably. However,
4230** for maximum code portability it is recommended that applications
4231** still make the distinction between protected and unprotected
4232** sqlite3_value objects even when not strictly required.
4233**
4234** ^The sqlite3_value objects that are passed as parameters into the
4235** implementation of [application-defined SQL functions] are protected.
4236** ^The sqlite3_value object returned by
4237** [sqlite3_column_value()] is unprotected.
4238** Unprotected sqlite3_value objects may only be used as arguments
4239** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4240** [sqlite3_value_dup()].
4241** The [sqlite3_value_blob | sqlite3_value_type()] family of
4242** interfaces require protected sqlite3_value objects.
4243*/
4244typedef struct sqlite3_value sqlite3_value;
4245
4246/*
4247** CAPI3REF: SQL Function Context Object
4248**
4249** The context in which an SQL function executes is stored in an
4250** sqlite3_context object. ^A pointer to an sqlite3_context object
4251** is always first parameter to [application-defined SQL functions].
4252** The application-defined SQL function implementation will pass this
4253** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4254** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4255** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4256** and/or [sqlite3_set_auxdata()].
4257*/
4258typedef struct sqlite3_context sqlite3_context;
4259
4260/*
4261** CAPI3REF: Binding Values To Prepared Statements
4262** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4263** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4264** METHOD: sqlite3_stmt
4265**
4266** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4267** literals may be replaced by a [parameter] that matches one of following
4268** templates:
4269**
4270** <ul>
4271** <li> ?
4272** <li> ?NNN
4273** <li> :VVV
4274** <li> @VVV
4275** <li> $VVV
4276** </ul>
4277**
4278** In the templates above, NNN represents an integer literal,
4279** and VVV represents an alphanumeric identifier.)^ ^The values of these
4280** parameters (also called "host parameter names" or "SQL parameters")
4281** can be set using the sqlite3_bind_*() routines defined here.
4282**
4283** ^The first argument to the sqlite3_bind_*() routines is always
4284** a pointer to the [sqlite3_stmt] object returned from
4285** [sqlite3_prepare_v2()] or its variants.
4286**
4287** ^The second argument is the index of the SQL parameter to be set.
4288** ^The leftmost SQL parameter has an index of 1. ^When the same named
4289** SQL parameter is used more than once, second and subsequent
4290** occurrences have the same index as the first occurrence.
4291** ^The index for named parameters can be looked up using the
4292** [sqlite3_bind_parameter_index()] API if desired. ^The index
4293** for "?NNN" parameters is the value of NNN.
4294** ^The NNN value must be between 1 and the [sqlite3_limit()]
4295** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4296**
4297** ^The third argument is the value to bind to the parameter.
4298** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4299** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4300** is ignored and the end result is the same as sqlite3_bind_null().
4301** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4302** it should be a pointer to well-formed UTF8 text.
4303** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4304** it should be a pointer to well-formed UTF16 text.
4305** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4306** it should be a pointer to a well-formed unicode string that is
4307** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4308** otherwise.
4309**
4310** [[byte-order determination rules]] ^The byte-order of
4311** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4312** found in first character, which is removed, or in the absence of a BOM
4313** the byte order is the native byte order of the host
4314** machine for sqlite3_bind_text16() or the byte order specified in
4315** the 6th parameter for sqlite3_bind_text64().)^
4316** ^If UTF16 input text contains invalid unicode
4317** characters, then SQLite might change those invalid characters
4318** into the unicode replacement character: U+FFFD.
4319**
4320** ^(In those routines that have a fourth argument, its value is the
4321** number of bytes in the parameter. To be clear: the value is the
4322** number of <u>bytes</u> in the value, not the number of characters.)^
4323** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4324** is negative, then the length of the string is
4325** the number of bytes up to the first zero terminator.
4326** If the fourth parameter to sqlite3_bind_blob() is negative, then
4327** the behavior is undefined.
4328** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4329** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4330** that parameter must be the byte offset
4331** where the NUL terminator would occur assuming the string were NUL
4332** terminated. If any NUL characters occurs at byte offsets less than
4333** the value of the fourth parameter then the resulting string value will
4334** contain embedded NULs. The result of expressions involving strings
4335** with embedded NULs is undefined.
4336**
4337** ^The fifth argument to the BLOB and string binding interfaces
4338** is a destructor used to dispose of the BLOB or
4339** string after SQLite has finished with it. ^The destructor is called
4340** to dispose of the BLOB or string even if the call to the bind API fails,
4341** except the destructor is not called if the third parameter is a NULL
4342** pointer or the fourth parameter is negative.
4343** ^If the fifth argument is
4344** the special value [SQLITE_STATIC], then SQLite assumes that the
4345** information is in static, unmanaged space and does not need to be freed.
4346** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
4347** SQLite makes its own private copy of the data immediately, before
4348** the sqlite3_bind_*() routine returns.
4349**
4350** ^The sixth argument to sqlite3_bind_text64() must be one of
4351** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4352** to specify the encoding of the text in the third parameter. If
4353** the sixth argument to sqlite3_bind_text64() is not one of the
4354** allowed values shown above, or if the text encoding is different
4355** from the encoding specified by the sixth parameter, then the behavior
4356** is undefined.
4357**
4358** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4359** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4360** (just an integer to hold its size) while it is being processed.
4361** Zeroblobs are intended to serve as placeholders for BLOBs whose
4362** content is later written using
4363** [sqlite3_blob_open | incremental BLOB I/O] routines.
4364** ^A negative value for the zeroblob results in a zero-length BLOB.
4365**
4366** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4367** [prepared statement] S to have an SQL value of NULL, but to also be
4368** associated with the pointer P of type T. ^D is either a NULL pointer or
4369** a pointer to a destructor function for P. ^SQLite will invoke the
4370** destructor D with a single argument of P when it is finished using
4371** P. The T parameter should be a static string, preferably a string
4372** literal. The sqlite3_bind_pointer() routine is part of the
4373** [pointer passing interface] added for SQLite 3.20.0.
4374**
4375** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4376** for the [prepared statement] or with a prepared statement for which
4377** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4378** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4379** routine is passed a [prepared statement] that has been finalized, the
4380** result is undefined and probably harmful.
4381**
4382** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4383** ^Unbound parameters are interpreted as NULL.
4384**
4385** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4386** [error code] if anything goes wrong.
4387** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4388** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4389** [SQLITE_MAX_LENGTH].
4390** ^[SQLITE_RANGE] is returned if the parameter
4391** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4392**
4393** See also: [sqlite3_bind_parameter_count()],
4394** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4395*/
4396SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4397SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4398 void(*)(void*));
4399SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4400SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4401SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4402SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4403SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4404SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4405SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4406 void(*)(void*), unsigned char encoding);
4407SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4408SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4409SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4410SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4411
4412/*
4413** CAPI3REF: Number Of SQL Parameters
4414** METHOD: sqlite3_stmt
4415**
4416** ^This routine can be used to find the number of [SQL parameters]
4417** in a [prepared statement]. SQL parameters are tokens of the
4418** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4419** placeholders for values that are [sqlite3_bind_blob | bound]
4420** to the parameters at a later time.
4421**
4422** ^(This routine actually returns the index of the largest (rightmost)
4423** parameter. For all forms except ?NNN, this will correspond to the
4424** number of unique parameters. If parameters of the ?NNN form are used,
4425** there may be gaps in the list.)^
4426**
4427** See also: [sqlite3_bind_blob|sqlite3_bind()],
4428** [sqlite3_bind_parameter_name()], and
4429** [sqlite3_bind_parameter_index()].
4430*/
4431SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4432
4433/*
4434** CAPI3REF: Name Of A Host Parameter
4435** METHOD: sqlite3_stmt
4436**
4437** ^The sqlite3_bind_parameter_name(P,N) interface returns
4438** the name of the N-th [SQL parameter] in the [prepared statement] P.
4439** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4440** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4441** respectively.
4442** In other words, the initial ":" or "$" or "@" or "?"
4443** is included as part of the name.)^
4444** ^Parameters of the form "?" without a following integer have no name
4445** and are referred to as "nameless" or "anonymous parameters".
4446**
4447** ^The first host parameter has an index of 1, not 0.
4448**
4449** ^If the value N is out of range or if the N-th parameter is
4450** nameless, then NULL is returned. ^The returned string is
4451** always in UTF-8 encoding even if the named parameter was
4452** originally specified as UTF-16 in [sqlite3_prepare16()],
4453** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4454**
4455** See also: [sqlite3_bind_blob|sqlite3_bind()],
4456** [sqlite3_bind_parameter_count()], and
4457** [sqlite3_bind_parameter_index()].
4458*/
4459SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4460
4461/*
4462** CAPI3REF: Index Of A Parameter With A Given Name
4463** METHOD: sqlite3_stmt
4464**
4465** ^Return the index of an SQL parameter given its name. ^The
4466** index value returned is suitable for use as the second
4467** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4468** is returned if no matching parameter is found. ^The parameter
4469** name must be given in UTF-8 even if the original statement
4470** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4471** [sqlite3_prepare16_v3()].
4472**
4473** See also: [sqlite3_bind_blob|sqlite3_bind()],
4474** [sqlite3_bind_parameter_count()], and
4475** [sqlite3_bind_parameter_name()].
4476*/
4477SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4478
4479/*
4480** CAPI3REF: Reset All Bindings On A Prepared Statement
4481** METHOD: sqlite3_stmt
4482**
4483** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4484** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4485** ^Use this routine to reset all host parameters to NULL.
4486*/
4487SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4488
4489/*
4490** CAPI3REF: Number Of Columns In A Result Set
4491** METHOD: sqlite3_stmt
4492**
4493** ^Return the number of columns in the result set returned by the
4494** [prepared statement]. ^If this routine returns 0, that means the
4495** [prepared statement] returns no data (for example an [UPDATE]).
4496** ^However, just because this routine returns a positive number does not
4497** mean that one or more rows of data will be returned. ^A SELECT statement
4498** will always have a positive sqlite3_column_count() but depending on the
4499** WHERE clause constraints and the table content, it might return no rows.
4500**
4501** See also: [sqlite3_data_count()]
4502*/
4503SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4504
4505/*
4506** CAPI3REF: Column Names In A Result Set
4507** METHOD: sqlite3_stmt
4508**
4509** ^These routines return the name assigned to a particular column
4510** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4511** interface returns a pointer to a zero-terminated UTF-8 string
4512** and sqlite3_column_name16() returns a pointer to a zero-terminated
4513** UTF-16 string. ^The first parameter is the [prepared statement]
4514** that implements the [SELECT] statement. ^The second parameter is the
4515** column number. ^The leftmost column is number 0.
4516**
4517** ^The returned string pointer is valid until either the [prepared statement]
4518** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4519** reprepared by the first call to [sqlite3_step()] for a particular run
4520** or until the next call to
4521** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4522**
4523** ^If sqlite3_malloc() fails during the processing of either routine
4524** (for example during a conversion from UTF-8 to UTF-16) then a
4525** NULL pointer is returned.
4526**
4527** ^The name of a result column is the value of the "AS" clause for
4528** that column, if there is an AS clause. If there is no AS clause
4529** then the name of the column is unspecified and may change from
4530** one release of SQLite to the next.
4531*/
4532SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4533SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4534
4535/*
4536** CAPI3REF: Source Of Data In A Query Result
4537** METHOD: sqlite3_stmt
4538**
4539** ^These routines provide a means to determine the database, table, and
4540** table column that is the origin of a particular result column in
4541** [SELECT] statement.
4542** ^The name of the database or table or column can be returned as
4543** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4544** the database name, the _table_ routines return the table name, and
4545** the origin_ routines return the column name.
4546** ^The returned string is valid until the [prepared statement] is destroyed
4547** using [sqlite3_finalize()] or until the statement is automatically
4548** reprepared by the first call to [sqlite3_step()] for a particular run
4549** or until the same information is requested
4550** again in a different encoding.
4551**
4552** ^The names returned are the original un-aliased names of the
4553** database, table, and column.
4554**
4555** ^The first argument to these interfaces is a [prepared statement].
4556** ^These functions return information about the Nth result column returned by
4557** the statement, where N is the second function argument.
4558** ^The left-most column is column 0 for these routines.
4559**
4560** ^If the Nth column returned by the statement is an expression or
4561** subquery and is not a column value, then all of these functions return
4562** NULL. ^These routines might also return NULL if a memory allocation error
4563** occurs. ^Otherwise, they return the name of the attached database, table,
4564** or column that query result column was extracted from.
4565**
4566** ^As with all other SQLite APIs, those whose names end with "16" return
4567** UTF-16 encoded strings and the other functions return UTF-8.
4568**
4569** ^These APIs are only available if the library was compiled with the
4570** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4571**
4572** If two or more threads call one or more
4573** [sqlite3_column_database_name | column metadata interfaces]
4574** for the same [prepared statement] and result column
4575** at the same time then the results are undefined.
4576*/
4577SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4578SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4579SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4580SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4581SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4582SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4583
4584/*
4585** CAPI3REF: Declared Datatype Of A Query Result
4586** METHOD: sqlite3_stmt
4587**
4588** ^(The first parameter is a [prepared statement].
4589** If this statement is a [SELECT] statement and the Nth column of the
4590** returned result set of that [SELECT] is a table column (not an
4591** expression or subquery) then the declared type of the table
4592** column is returned.)^ ^If the Nth column of the result set is an
4593** expression or subquery, then a NULL pointer is returned.
4594** ^The returned string is always UTF-8 encoded.
4595**
4596** ^(For example, given the database schema:
4597**
4598** CREATE TABLE t1(c1 VARIANT);
4599**
4600** and the following statement to be compiled:
4601**
4602** SELECT c1 + 1, c1 FROM t1;
4603**
4604** this routine would return the string "VARIANT" for the second result
4605** column (i==1), and a NULL pointer for the first result column (i==0).)^
4606**
4607** ^SQLite uses dynamic run-time typing. ^So just because a column
4608** is declared to contain a particular type does not mean that the
4609** data stored in that column is of the declared type. SQLite is
4610** strongly typed, but the typing is dynamic not static. ^Type
4611** is associated with individual values, not with the containers
4612** used to hold those values.
4613*/
4614SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4615SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4616
4617/*
4618** CAPI3REF: Evaluate An SQL Statement
4619** METHOD: sqlite3_stmt
4620**
4621** After a [prepared statement] has been prepared using any of
4622** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4623** or [sqlite3_prepare16_v3()] or one of the legacy
4624** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4625** must be called one or more times to evaluate the statement.
4626**
4627** The details of the behavior of the sqlite3_step() interface depend
4628** on whether the statement was prepared using the newer "vX" interfaces
4629** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4630** [sqlite3_prepare16_v2()] or the older legacy
4631** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4632** new "vX" interface is recommended for new applications but the legacy
4633** interface will continue to be supported.
4634**
4635** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4636** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4637** ^With the "v2" interface, any of the other [result codes] or
4638** [extended result codes] might be returned as well.
4639**
4640** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4641** database locks it needs to do its job. ^If the statement is a [COMMIT]
4642** or occurs outside of an explicit transaction, then you can retry the
4643** statement. If the statement is not a [COMMIT] and occurs within an
4644** explicit transaction then you should rollback the transaction before
4645** continuing.
4646**
4647** ^[SQLITE_DONE] means that the statement has finished executing
4648** successfully. sqlite3_step() should not be called again on this virtual
4649** machine without first calling [sqlite3_reset()] to reset the virtual
4650** machine back to its initial state.
4651**
4652** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4653** is returned each time a new row of data is ready for processing by the
4654** caller. The values may be accessed using the [column access functions].
4655** sqlite3_step() is called again to retrieve the next row of data.
4656**
4657** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4658** violation) has occurred. sqlite3_step() should not be called again on
4659** the VM. More information may be found by calling [sqlite3_errmsg()].
4660** ^With the legacy interface, a more specific error code (for example,
4661** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4662** can be obtained by calling [sqlite3_reset()] on the
4663** [prepared statement]. ^In the "v2" interface,
4664** the more specific error code is returned directly by sqlite3_step().
4665**
4666** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4667** Perhaps it was called on a [prepared statement] that has
4668** already been [sqlite3_finalize | finalized] or on one that had
4669** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4670** be the case that the same database connection is being used by two or
4671** more threads at the same moment in time.
4672**
4673** For all versions of SQLite up to and including 3.6.23.1, a call to
4674** [sqlite3_reset()] was required after sqlite3_step() returned anything
4675** other than [SQLITE_ROW] before any subsequent invocation of
4676** sqlite3_step(). Failure to reset the prepared statement using
4677** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4678** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4679** sqlite3_step() began
4680** calling [sqlite3_reset()] automatically in this circumstance rather
4681** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4682** break because any application that ever receives an SQLITE_MISUSE error
4683** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4684** can be used to restore the legacy behavior.
4685**
4686** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4687** API always returns a generic error code, [SQLITE_ERROR], following any
4688** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4689** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4690** specific [error codes] that better describes the error.
4691** We admit that this is a goofy design. The problem has been fixed
4692** with the "v2" interface. If you prepare all of your SQL statements
4693** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4694** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4695** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4696** then the more specific [error codes] are returned directly
4697** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4698*/
4699SQLITE_API int sqlite3_step(sqlite3_stmt*);
4700
4701/*
4702** CAPI3REF: Number of columns in a result set
4703** METHOD: sqlite3_stmt
4704**
4705** ^The sqlite3_data_count(P) interface returns the number of columns in the
4706** current row of the result set of [prepared statement] P.
4707** ^If prepared statement P does not have results ready to return
4708** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4709** interfaces) then sqlite3_data_count(P) returns 0.
4710** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4711** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4712** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4713** will return non-zero if previous call to [sqlite3_step](P) returned
4714** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4715** where it always returns zero since each step of that multi-step
4716** pragma returns 0 columns of data.
4717**
4718** See also: [sqlite3_column_count()]
4719*/
4720SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4721
4722/*
4723** CAPI3REF: Fundamental Datatypes
4724** KEYWORDS: SQLITE_TEXT
4725**
4726** ^(Every value in SQLite has one of five fundamental datatypes:
4727**
4728** <ul>
4729** <li> 64-bit signed integer
4730** <li> 64-bit IEEE floating point number
4731** <li> string
4732** <li> BLOB
4733** <li> NULL
4734** </ul>)^
4735**
4736** These constants are codes for each of those types.
4737**
4738** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4739** for a completely different meaning. Software that links against both
4740** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4741** SQLITE_TEXT.
4742*/
4743#define SQLITE_INTEGER 1
4744#define SQLITE_FLOAT 2
4745#define SQLITE_BLOB 4
4746#define SQLITE_NULL 5
4747#ifdef SQLITE_TEXT
4748# undef SQLITE_TEXT
4749#else
4750# define SQLITE_TEXT 3
4751#endif
4752#define SQLITE3_TEXT 3
4753
4754/*
4755** CAPI3REF: Result Values From A Query
4756** KEYWORDS: {column access functions}
4757** METHOD: sqlite3_stmt
4758**
4759** <b>Summary:</b>
4760** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4761** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4762** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4763** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4764** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4765** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4766** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4767** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4768** [sqlite3_value|unprotected sqlite3_value] object.
4769** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4770** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4771** or a UTF-8 TEXT result in bytes
4772** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4773** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4774** TEXT in bytes
4775** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4776** datatype of the result
4777** </table></blockquote>
4778**
4779** <b>Details:</b>
4780**
4781** ^These routines return information about a single column of the current
4782** result row of a query. ^In every case the first argument is a pointer
4783** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4784** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4785** and the second argument is the index of the column for which information
4786** should be returned. ^The leftmost column of the result set has the index 0.
4787** ^The number of columns in the result can be determined using
4788** [sqlite3_column_count()].
4789**
4790** If the SQL statement does not currently point to a valid row, or if the
4791** column index is out of range, the result is undefined.
4792** These routines may only be called when the most recent call to
4793** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4794** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4795** If any of these routines are called after [sqlite3_reset()] or
4796** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4797** something other than [SQLITE_ROW], the results are undefined.
4798** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4799** are called from a different thread while any of these routines
4800** are pending, then the results are undefined.
4801**
4802** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4803** each return the value of a result column in a specific data format. If
4804** the result column is not initially in the requested format (for example,
4805** if the query returns an integer but the sqlite3_column_text() interface
4806** is used to extract the value) then an automatic type conversion is performed.
4807**
4808** ^The sqlite3_column_type() routine returns the
4809** [SQLITE_INTEGER | datatype code] for the initial data type
4810** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4811** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4812** The return value of sqlite3_column_type() can be used to decide which
4813** of the first six interface should be used to extract the column value.
4814** The value returned by sqlite3_column_type() is only meaningful if no
4815** automatic type conversions have occurred for the value in question.
4816** After a type conversion, the result of calling sqlite3_column_type()
4817** is undefined, though harmless. Future
4818** versions of SQLite may change the behavior of sqlite3_column_type()
4819** following a type conversion.
4820**
4821** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4822** or sqlite3_column_bytes16() interfaces can be used to determine the size
4823** of that BLOB or string.
4824**
4825** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4826** routine returns the number of bytes in that BLOB or string.
4827** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4828** the string to UTF-8 and then returns the number of bytes.
4829** ^If the result is a numeric value then sqlite3_column_bytes() uses
4830** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4831** the number of bytes in that string.
4832** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4833**
4834** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4835** routine returns the number of bytes in that BLOB or string.
4836** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4837** the string to UTF-16 and then returns the number of bytes.
4838** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4839** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4840** the number of bytes in that string.
4841** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4842**
4843** ^The values returned by [sqlite3_column_bytes()] and
4844** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4845** of the string. ^For clarity: the values returned by
4846** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4847** bytes in the string, not the number of characters.
4848**
4849** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4850** even empty strings, are always zero-terminated. ^The return
4851** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4852**
4853** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4854** [unprotected sqlite3_value] object. In a multithreaded environment,
4855** an unprotected sqlite3_value object may only be used safely with
4856** [sqlite3_bind_value()] and [sqlite3_result_value()].
4857** If the [unprotected sqlite3_value] object returned by
4858** [sqlite3_column_value()] is used in any other way, including calls
4859** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4860** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4861** Hence, the sqlite3_column_value() interface
4862** is normally only useful within the implementation of
4863** [application-defined SQL functions] or [virtual tables], not within
4864** top-level application code.
4865**
4866** The these routines may attempt to convert the datatype of the result.
4867** ^For example, if the internal representation is FLOAT and a text result
4868** is requested, [sqlite3_snprintf()] is used internally to perform the
4869** conversion automatically. ^(The following table details the conversions
4870** that are applied:
4871**
4872** <blockquote>
4873** <table border="1">
4874** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4875**
4876** <tr><td> NULL <td> INTEGER <td> Result is 0
4877** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4878** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4879** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4880** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4881** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4882** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4883** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4884** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4885** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4886** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4887** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4888** <tr><td> TEXT <td> BLOB <td> No change
4889** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4890** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4891** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4892** </table>
4893** </blockquote>)^
4894**
4895** Note that when type conversions occur, pointers returned by prior
4896** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4897** sqlite3_column_text16() may be invalidated.
4898** Type conversions and pointer invalidations might occur
4899** in the following cases:
4900**
4901** <ul>
4902** <li> The initial content is a BLOB and sqlite3_column_text() or
4903** sqlite3_column_text16() is called. A zero-terminator might
4904** need to be added to the string.</li>
4905** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4906** sqlite3_column_text16() is called. The content must be converted
4907** to UTF-16.</li>
4908** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4909** sqlite3_column_text() is called. The content must be converted
4910** to UTF-8.</li>
4911** </ul>
4912**
4913** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4914** not invalidate a prior pointer, though of course the content of the buffer
4915** that the prior pointer references will have been modified. Other kinds
4916** of conversion are done in place when it is possible, but sometimes they
4917** are not possible and in those cases prior pointers are invalidated.
4918**
4919** The safest policy is to invoke these routines
4920** in one of the following ways:
4921**
4922** <ul>
4923** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4924** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4925** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4926** </ul>
4927**
4928** In other words, you should call sqlite3_column_text(),
4929** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4930** into the desired format, then invoke sqlite3_column_bytes() or
4931** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4932** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4933** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4934** with calls to sqlite3_column_bytes().
4935**
4936** ^The pointers returned are valid until a type conversion occurs as
4937** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4938** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4939** and BLOBs is freed automatically. Do not pass the pointers returned
4940** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4941** [sqlite3_free()].
4942**
4943** As long as the input parameters are correct, these routines will only
4944** fail if an out-of-memory error occurs during a format conversion.
4945** Only the following subset of interfaces are subject to out-of-memory
4946** errors:
4947**
4948** <ul>
4949** <li> sqlite3_column_blob()
4950** <li> sqlite3_column_text()
4951** <li> sqlite3_column_text16()
4952** <li> sqlite3_column_bytes()
4953** <li> sqlite3_column_bytes16()
4954** </ul>
4955**
4956** If an out-of-memory error occurs, then the return value from these
4957** routines is the same as if the column had contained an SQL NULL value.
4958** Valid SQL NULL returns can be distinguished from out-of-memory errors
4959** by invoking the [sqlite3_errcode()] immediately after the suspect
4960** return value is obtained and before any
4961** other SQLite interface is called on the same [database connection].
4962*/
4963SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4964SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4965SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4966SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4967SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4968SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4969SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4970SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4971SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4972SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4973
4974/*
4975** CAPI3REF: Destroy A Prepared Statement Object
4976** DESTRUCTOR: sqlite3_stmt
4977**
4978** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4979** ^If the most recent evaluation of the statement encountered no errors
4980** or if the statement is never been evaluated, then sqlite3_finalize() returns
4981** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4982** sqlite3_finalize(S) returns the appropriate [error code] or
4983** [extended error code].
4984**
4985** ^The sqlite3_finalize(S) routine can be called at any point during
4986** the life cycle of [prepared statement] S:
4987** before statement S is ever evaluated, after
4988** one or more calls to [sqlite3_reset()], or after any call
4989** to [sqlite3_step()] regardless of whether or not the statement has
4990** completed execution.
4991**
4992** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4993**
4994** The application must finalize every [prepared statement] in order to avoid
4995** resource leaks. It is a grievous error for the application to try to use
4996** a prepared statement after it has been finalized. Any use of a prepared
4997** statement after it has been finalized can result in undefined and
4998** undesirable behavior such as segfaults and heap corruption.
4999*/
5000SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5001
5002/*
5003** CAPI3REF: Reset A Prepared Statement Object
5004** METHOD: sqlite3_stmt
5005**
5006** The sqlite3_reset() function is called to reset a [prepared statement]
5007** object back to its initial state, ready to be re-executed.
5008** ^Any SQL statement variables that had values bound to them using
5009** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5010** Use [sqlite3_clear_bindings()] to reset the bindings.
5011**
5012** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5013** back to the beginning of its program.
5014**
5015** ^If the most recent call to [sqlite3_step(S)] for the
5016** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5017** or if [sqlite3_step(S)] has never before been called on S,
5018** then [sqlite3_reset(S)] returns [SQLITE_OK].
5019**
5020** ^If the most recent call to [sqlite3_step(S)] for the
5021** [prepared statement] S indicated an error, then
5022** [sqlite3_reset(S)] returns an appropriate [error code].
5023**
5024** ^The [sqlite3_reset(S)] interface does not change the values
5025** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5026*/
5027SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5028
5029/*
5030** CAPI3REF: Create Or Redefine SQL Functions
5031** KEYWORDS: {function creation routines}
5032** METHOD: sqlite3
5033**
5034** ^These functions (collectively known as "function creation routines")
5035** are used to add SQL functions or aggregates or to redefine the behavior
5036** of existing SQL functions or aggregates. The only differences between
5037** the three "sqlite3_create_function*" routines are the text encoding
5038** expected for the second parameter (the name of the function being
5039** created) and the presence or absence of a destructor callback for
5040** the application data pointer. Function sqlite3_create_window_function()
5041** is similar, but allows the user to supply the extra callback functions
5042** needed by [aggregate window functions].
5043**
5044** ^The first parameter is the [database connection] to which the SQL
5045** function is to be added. ^If an application uses more than one database
5046** connection then application-defined SQL functions must be added
5047** to each database connection separately.
5048**
5049** ^The second parameter is the name of the SQL function to be created or
5050** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5051** representation, exclusive of the zero-terminator. ^Note that the name
5052** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5053** ^Any attempt to create a function with a longer name
5054** will result in [SQLITE_MISUSE] being returned.
5055**
5056** ^The third parameter (nArg)
5057** is the number of arguments that the SQL function or
5058** aggregate takes. ^If this parameter is -1, then the SQL function or
5059** aggregate may take any number of arguments between 0 and the limit
5060** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5061** parameter is less than -1 or greater than 127 then the behavior is
5062** undefined.
5063**
5064** ^The fourth parameter, eTextRep, specifies what
5065** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5066** its parameters. The application should set this parameter to
5067** [SQLITE_UTF16LE] if the function implementation invokes
5068** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5069** implementation invokes [sqlite3_value_text16be()] on an input, or
5070** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5071** otherwise. ^The same SQL function may be registered multiple times using
5072** different preferred text encodings, with different implementations for
5073** each encoding.
5074** ^When multiple implementations of the same function are available, SQLite
5075** will pick the one that involves the least amount of data conversion.
5076**
5077** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5078** to signal that the function will always return the same result given
5079** the same inputs within a single SQL statement. Most SQL functions are
5080** deterministic. The built-in [random()] SQL function is an example of a
5081** function that is not deterministic. The SQLite query planner is able to
5082** perform additional optimizations on deterministic functions, so use
5083** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5084**
5085** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5086** flag, which if present prevents the function from being invoked from
5087** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5088** index expressions, or the WHERE clause of partial indexes.
5089**
5090** <span style="background-color:#ffff90;">
5091** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5092** all application-defined SQL functions that do not need to be
5093** used inside of triggers, view, CHECK constraints, or other elements of
5094** the database schema. This flags is especially recommended for SQL
5095** functions that have side effects or reveal internal application state.
5096** Without this flag, an attacker might be able to modify the schema of
5097** a database file to include invocations of the function with parameters
5098** chosen by the attacker, which the application will then execute when
5099** the database file is opened and read.
5100** </span>
5101**
5102** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5103** function can gain access to this pointer using [sqlite3_user_data()].)^
5104**
5105** ^The sixth, seventh and eighth parameters passed to the three
5106** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5107** pointers to C-language functions that implement the SQL function or
5108** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5109** callback only; NULL pointers must be passed as the xStep and xFinal
5110** parameters. ^An aggregate SQL function requires an implementation of xStep
5111** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5112** SQL function or aggregate, pass NULL pointers for all three function
5113** callbacks.
5114**
5115** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5116** and xInverse) passed to sqlite3_create_window_function are pointers to
5117** C-language callbacks that implement the new function. xStep and xFinal
5118** must both be non-NULL. xValue and xInverse may either both be NULL, in
5119** which case a regular aggregate function is created, or must both be
5120** non-NULL, in which case the new function may be used as either an aggregate
5121** or aggregate window function. More details regarding the implementation
5122** of aggregate window functions are
5123** [user-defined window functions|available here].
5124**
5125** ^(If the final parameter to sqlite3_create_function_v2() or
5126** sqlite3_create_window_function() is not NULL, then it is destructor for
5127** the application data pointer. The destructor is invoked when the function
5128** is deleted, either by being overloaded or when the database connection
5129** closes.)^ ^The destructor is also invoked if the call to
5130** sqlite3_create_function_v2() fails. ^When the destructor callback is
5131** invoked, it is passed a single argument which is a copy of the application
5132** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5133**
5134** ^It is permitted to register multiple implementations of the same
5135** functions with the same name but with either differing numbers of
5136** arguments or differing preferred text encodings. ^SQLite will use
5137** the implementation that most closely matches the way in which the
5138** SQL function is used. ^A function implementation with a non-negative
5139** nArg parameter is a better match than a function implementation with
5140** a negative nArg. ^A function where the preferred text encoding
5141** matches the database encoding is a better
5142** match than a function where the encoding is different.
5143** ^A function where the encoding difference is between UTF16le and UTF16be
5144** is a closer match than a function where the encoding difference is
5145** between UTF8 and UTF16.
5146**
5147** ^Built-in functions may be overloaded by new application-defined functions.
5148**
5149** ^An application-defined function is permitted to call other
5150** SQLite interfaces. However, such calls must not
5151** close the database connection nor finalize or reset the prepared
5152** statement in which the function is running.
5153*/
5154SQLITE_API int sqlite3_create_function(
5155 sqlite3 *db,
5156 const char *zFunctionName,
5157 int nArg,
5158 int eTextRep,
5159 void *pApp,
5160 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5161 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5162 void (*xFinal)(sqlite3_context*)
5163);
5164SQLITE_API int sqlite3_create_function16(
5165 sqlite3 *db,
5166 const void *zFunctionName,
5167 int nArg,
5168 int eTextRep,
5169 void *pApp,
5170 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5171 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5172 void (*xFinal)(sqlite3_context*)
5173);
5174SQLITE_API int sqlite3_create_function_v2(
5175 sqlite3 *db,
5176 const char *zFunctionName,
5177 int nArg,
5178 int eTextRep,
5179 void *pApp,
5180 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5181 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5182 void (*xFinal)(sqlite3_context*),
5183 void(*xDestroy)(void*)
5184);
5185SQLITE_API int sqlite3_create_window_function(
5186 sqlite3 *db,
5187 const char *zFunctionName,
5188 int nArg,
5189 int eTextRep,
5190 void *pApp,
5191 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5192 void (*xFinal)(sqlite3_context*),
5193 void (*xValue)(sqlite3_context*),
5194 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5195 void(*xDestroy)(void*)
5196);
5197
5198/*
5199** CAPI3REF: Text Encodings
5200**
5201** These constant define integer codes that represent the various
5202** text encodings supported by SQLite.
5203*/
5204#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5205#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5206#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5207#define SQLITE_UTF16 4 /* Use native byte order */
5208#define SQLITE_ANY 5 /* Deprecated */
5209#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5210
5211/*
5212** CAPI3REF: Function Flags
5213**
5214** These constants may be ORed together with the
5215** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5216** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5217** [sqlite3_create_function_v2()].
5218**
5219** <dl>
5220** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5221** The SQLITE_DETERMINISTIC flag means that the new function always gives
5222** the same output when the input parameters are the same.
5223** The [abs|abs() function] is deterministic, for example, but
5224** [randomblob|randomblob()] is not. Functions must
5225** be deterministic in order to be used in certain contexts such as
5226** with the WHERE clause of [partial indexes] or in [generated columns].
5227** SQLite might also optimize deterministic functions by factoring them
5228** out of inner loops.
5229** </dd>
5230**
5231** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5232** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5233** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5234** schema structures such as [CHECK constraints], [DEFAULT clauses],
5235** [expression indexes], [partial indexes], or [generated columns].
5236** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5237** for all [application-defined SQL functions], and especially for functions
5238** that have side-effects or that could potentially leak sensitive
5239** information.
5240** </dd>
5241**
5242** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5243** The SQLITE_INNOCUOUS flag means that the function is unlikely
5244** to cause problems even if misused. An innocuous function should have
5245** no side effects and should not depend on any values other than its
5246** input parameters. The [abs|abs() function] is an example of an
5247** innocuous function.
5248** The [load_extension() SQL function] is not innocuous because of its
5249** side effects.
5250** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5251** exactly the same. The [random|random() function] is an example of a
5252** function that is innocuous but not deterministic.
5253** <p>Some heightened security settings
5254** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5255** disable the use of SQL functions inside views and triggers and in
5256** schema structures such as [CHECK constraints], [DEFAULT clauses],
5257** [expression indexes], [partial indexes], and [generated columns] unless
5258** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5259** are innocuous. Developers are advised to avoid using the
5260** SQLITE_INNOCUOUS flag for application-defined functions unless the
5261** function has been carefully audited and found to be free of potentially
5262** security-adverse side-effects and information-leaks.
5263** </dd>
5264**
5265** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5266** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5267** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5268** Specifying this flag makes no difference for scalar or aggregate user
5269** functions. However, if it is not specified for a user-defined window
5270** function, then any sub-types belonging to arguments passed to the window
5271** function may be discarded before the window function is called (i.e.
5272** sqlite3_value_subtype() will always return 0).
5273** </dd>
5274** </dl>
5275*/
5276#define SQLITE_DETERMINISTIC 0x000000800
5277#define SQLITE_DIRECTONLY 0x000080000
5278#define SQLITE_SUBTYPE 0x000100000
5279#define SQLITE_INNOCUOUS 0x000200000
5280
5281/*
5282** CAPI3REF: Deprecated Functions
5283** DEPRECATED
5284**
5285** These functions are [deprecated]. In order to maintain
5286** backwards compatibility with older code, these functions continue
5287** to be supported. However, new applications should avoid
5288** the use of these functions. To encourage programmers to avoid
5289** these functions, we will not explain what they do.
5290*/
5291#ifndef SQLITE_OMIT_DEPRECATED
5292SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5293SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5294SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5295SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5296SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5297SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5298 void*,sqlite3_int64);
5299#endif
5300
5301/*
5302** CAPI3REF: Obtaining SQL Values
5303** METHOD: sqlite3_value
5304**
5305** <b>Summary:</b>
5306** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5307** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5308** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5309** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5310** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5311** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5312** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5313** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5314** the native byteorder
5315** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5316** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5317** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5318** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5319** or a UTF-8 TEXT in bytes
5320** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5321** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5322** TEXT in bytes
5323** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5324** datatype of the value
5325** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5326** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5327** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5328** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5329** against a virtual table.
5330** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5331** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5332** </table></blockquote>
5333**
5334** <b>Details:</b>
5335**
5336** These routines extract type, size, and content information from
5337** [protected sqlite3_value] objects. Protected sqlite3_value objects
5338** are used to pass parameter information into the functions that
5339** implement [application-defined SQL functions] and [virtual tables].
5340**
5341** These routines work only with [protected sqlite3_value] objects.
5342** Any attempt to use these routines on an [unprotected sqlite3_value]
5343** is not threadsafe.
5344**
5345** ^These routines work just like the corresponding [column access functions]
5346** except that these routines take a single [protected sqlite3_value] object
5347** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5348**
5349** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5350** in the native byte-order of the host machine. ^The
5351** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5352** extract UTF-16 strings as big-endian and little-endian respectively.
5353**
5354** ^If [sqlite3_value] object V was initialized
5355** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5356** and if X and Y are strings that compare equal according to strcmp(X,Y),
5357** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5358** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5359** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5360**
5361** ^(The sqlite3_value_type(V) interface returns the
5362** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5363** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5364** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5365** Other interfaces might change the datatype for an sqlite3_value object.
5366** For example, if the datatype is initially SQLITE_INTEGER and
5367** sqlite3_value_text(V) is called to extract a text value for that
5368** integer, then subsequent calls to sqlite3_value_type(V) might return
5369** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5370** occurs is undefined and may change from one release of SQLite to the next.
5371**
5372** ^(The sqlite3_value_numeric_type() interface attempts to apply
5373** numeric affinity to the value. This means that an attempt is
5374** made to convert the value to an integer or floating point. If
5375** such a conversion is possible without loss of information (in other
5376** words, if the value is a string that looks like a number)
5377** then the conversion is performed. Otherwise no conversion occurs.
5378** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5379**
5380** ^Within the [xUpdate] method of a [virtual table], the
5381** sqlite3_value_nochange(X) interface returns true if and only if
5382** the column corresponding to X is unchanged by the UPDATE operation
5383** that the xUpdate method call was invoked to implement and if
5384** and the prior [xColumn] method call that was invoked to extracted
5385** the value for that column returned without setting a result (probably
5386** because it queried [sqlite3_vtab_nochange()] and found that the column
5387** was unchanging). ^Within an [xUpdate] method, any value for which
5388** sqlite3_value_nochange(X) is true will in all other respects appear
5389** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5390** than within an [xUpdate] method call for an UPDATE statement, then
5391** the return value is arbitrary and meaningless.
5392**
5393** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5394** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5395** interfaces. ^If X comes from an SQL literal value, or a table column,
5396** or an expression, then sqlite3_value_frombind(X) returns zero.
5397**
5398** Please pay particular attention to the fact that the pointer returned
5399** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5400** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5401** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5402** or [sqlite3_value_text16()].
5403**
5404** These routines must be called from the same thread as
5405** the SQL function that supplied the [sqlite3_value*] parameters.
5406**
5407** As long as the input parameter is correct, these routines can only
5408** fail if an out-of-memory error occurs during a format conversion.
5409** Only the following subset of interfaces are subject to out-of-memory
5410** errors:
5411**
5412** <ul>
5413** <li> sqlite3_value_blob()
5414** <li> sqlite3_value_text()
5415** <li> sqlite3_value_text16()
5416** <li> sqlite3_value_text16le()
5417** <li> sqlite3_value_text16be()
5418** <li> sqlite3_value_bytes()
5419** <li> sqlite3_value_bytes16()
5420** </ul>
5421**
5422** If an out-of-memory error occurs, then the return value from these
5423** routines is the same as if the column had contained an SQL NULL value.
5424** Valid SQL NULL returns can be distinguished from out-of-memory errors
5425** by invoking the [sqlite3_errcode()] immediately after the suspect
5426** return value is obtained and before any
5427** other SQLite interface is called on the same [database connection].
5428*/
5429SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5430SQLITE_API double sqlite3_value_double(sqlite3_value*);
5431SQLITE_API int sqlite3_value_int(sqlite3_value*);
5432SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5433SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5434SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5435SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5436SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5437SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5438SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5439SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5440SQLITE_API int sqlite3_value_type(sqlite3_value*);
5441SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5442SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5443SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5444
5445/*
5446** CAPI3REF: Finding The Subtype Of SQL Values
5447** METHOD: sqlite3_value
5448**
5449** The sqlite3_value_subtype(V) function returns the subtype for
5450** an [application-defined SQL function] argument V. The subtype
5451** information can be used to pass a limited amount of context from
5452** one SQL function to another. Use the [sqlite3_result_subtype()]
5453** routine to set the subtype for the return value of an SQL function.
5454*/
5455SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5456
5457/*
5458** CAPI3REF: Copy And Free SQL Values
5459** METHOD: sqlite3_value
5460**
5461** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5462** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5463** is a [protected sqlite3_value] object even if the input is not.
5464** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5465** memory allocation fails.
5466**
5467** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5468** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5469** then sqlite3_value_free(V) is a harmless no-op.
5470*/
5471SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5472SQLITE_API void sqlite3_value_free(sqlite3_value*);
5473
5474/*
5475** CAPI3REF: Obtain Aggregate Function Context
5476** METHOD: sqlite3_context
5477**
5478** Implementations of aggregate SQL functions use this
5479** routine to allocate memory for storing their state.
5480**
5481** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5482** for a particular aggregate function, SQLite allocates
5483** N bytes of memory, zeroes out that memory, and returns a pointer
5484** to the new memory. ^On second and subsequent calls to
5485** sqlite3_aggregate_context() for the same aggregate function instance,
5486** the same buffer is returned. Sqlite3_aggregate_context() is normally
5487** called once for each invocation of the xStep callback and then one
5488** last time when the xFinal callback is invoked. ^(When no rows match
5489** an aggregate query, the xStep() callback of the aggregate function
5490** implementation is never called and xFinal() is called exactly once.
5491** In those cases, sqlite3_aggregate_context() might be called for the
5492** first time from within xFinal().)^
5493**
5494** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5495** when first called if N is less than or equal to zero or if a memory
5496** allocate error occurs.
5497**
5498** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5499** determined by the N parameter on first successful call. Changing the
5500** value of N in any subsequent call to sqlite3_aggregate_context() within
5501** the same aggregate function instance will not resize the memory
5502** allocation.)^ Within the xFinal callback, it is customary to set
5503** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5504** pointless memory allocations occur.
5505**
5506** ^SQLite automatically frees the memory allocated by
5507** sqlite3_aggregate_context() when the aggregate query concludes.
5508**
5509** The first parameter must be a copy of the
5510** [sqlite3_context | SQL function context] that is the first parameter
5511** to the xStep or xFinal callback routine that implements the aggregate
5512** function.
5513**
5514** This routine must be called from the same thread in which
5515** the aggregate SQL function is running.
5516*/
5517SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5518
5519/*
5520** CAPI3REF: User Data For Functions
5521** METHOD: sqlite3_context
5522**
5523** ^The sqlite3_user_data() interface returns a copy of
5524** the pointer that was the pUserData parameter (the 5th parameter)
5525** of the [sqlite3_create_function()]
5526** and [sqlite3_create_function16()] routines that originally
5527** registered the application defined function.
5528**
5529** This routine must be called from the same thread in which
5530** the application-defined function is running.
5531*/
5532SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5533
5534/*
5535** CAPI3REF: Database Connection For Functions
5536** METHOD: sqlite3_context
5537**
5538** ^The sqlite3_context_db_handle() interface returns a copy of
5539** the pointer to the [database connection] (the 1st parameter)
5540** of the [sqlite3_create_function()]
5541** and [sqlite3_create_function16()] routines that originally
5542** registered the application defined function.
5543*/
5544SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5545
5546/*
5547** CAPI3REF: Function Auxiliary Data
5548** METHOD: sqlite3_context
5549**
5550** These functions may be used by (non-aggregate) SQL functions to
5551** associate metadata with argument values. If the same value is passed to
5552** multiple invocations of the same SQL function during query execution, under
5553** some circumstances the associated metadata may be preserved. An example
5554** of where this might be useful is in a regular-expression matching
5555** function. The compiled version of the regular expression can be stored as
5556** metadata associated with the pattern string.
5557** Then as long as the pattern string remains the same,
5558** the compiled regular expression can be reused on multiple
5559** invocations of the same function.
5560**
5561** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5562** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5563** value to the application-defined function. ^N is zero for the left-most
5564** function argument. ^If there is no metadata
5565** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5566** returns a NULL pointer.
5567**
5568** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5569** argument of the application-defined function. ^Subsequent
5570** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5571** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5572** NULL if the metadata has been discarded.
5573** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5574** SQLite will invoke the destructor function X with parameter P exactly
5575** once, when the metadata is discarded.
5576** SQLite is free to discard the metadata at any time, including: <ul>
5577** <li> ^(when the corresponding function parameter changes)^, or
5578** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5579** SQL statement)^, or
5580** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5581** parameter)^, or
5582** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5583** allocation error occurs.)^ </ul>
5584**
5585** Note the last bullet in particular. The destructor X in
5586** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5587** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5588** should be called near the end of the function implementation and the
5589** function implementation should not make any use of P after
5590** sqlite3_set_auxdata() has been called.
5591**
5592** ^(In practice, metadata is preserved between function calls for
5593** function parameters that are compile-time constants, including literal
5594** values and [parameters] and expressions composed from the same.)^
5595**
5596** The value of the N parameter to these interfaces should be non-negative.
5597** Future enhancements may make use of negative N values to define new
5598** kinds of function caching behavior.
5599**
5600** These routines must be called from the same thread in which
5601** the SQL function is running.
5602*/
5603SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5604SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5605
5606
5607/*
5608** CAPI3REF: Constants Defining Special Destructor Behavior
5609**
5610** These are special values for the destructor that is passed in as the
5611** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5612** argument is SQLITE_STATIC, it means that the content pointer is constant
5613** and will never change. It does not need to be destroyed. ^The
5614** SQLITE_TRANSIENT value means that the content will likely change in
5615** the near future and that SQLite should make its own private copy of
5616** the content before returning.
5617**
5618** The typedef is necessary to work around problems in certain
5619** C++ compilers.
5620*/
5621typedef void (*sqlite3_destructor_type)(void*);
5622#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5623#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5624
5625/*
5626** CAPI3REF: Setting The Result Of An SQL Function
5627** METHOD: sqlite3_context
5628**
5629** These routines are used by the xFunc or xFinal callbacks that
5630** implement SQL functions and aggregates. See
5631** [sqlite3_create_function()] and [sqlite3_create_function16()]
5632** for additional information.
5633**
5634** These functions work very much like the [parameter binding] family of
5635** functions used to bind values to host parameters in prepared statements.
5636** Refer to the [SQL parameter] documentation for additional information.
5637**
5638** ^The sqlite3_result_blob() interface sets the result from
5639** an application-defined function to be the BLOB whose content is pointed
5640** to by the second parameter and which is N bytes long where N is the
5641** third parameter.
5642**
5643** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5644** interfaces set the result of the application-defined function to be
5645** a BLOB containing all zero bytes and N bytes in size.
5646**
5647** ^The sqlite3_result_double() interface sets the result from
5648** an application-defined function to be a floating point value specified
5649** by its 2nd argument.
5650**
5651** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5652** cause the implemented SQL function to throw an exception.
5653** ^SQLite uses the string pointed to by the
5654** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5655** as the text of an error message. ^SQLite interprets the error
5656** message string from sqlite3_result_error() as UTF-8. ^SQLite
5657** interprets the string from sqlite3_result_error16() as UTF-16 using
5658** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5659** ^If the third parameter to sqlite3_result_error()
5660** or sqlite3_result_error16() is negative then SQLite takes as the error
5661** message all text up through the first zero character.
5662** ^If the third parameter to sqlite3_result_error() or
5663** sqlite3_result_error16() is non-negative then SQLite takes that many
5664** bytes (not characters) from the 2nd parameter as the error message.
5665** ^The sqlite3_result_error() and sqlite3_result_error16()
5666** routines make a private copy of the error message text before
5667** they return. Hence, the calling function can deallocate or
5668** modify the text after they return without harm.
5669** ^The sqlite3_result_error_code() function changes the error code
5670** returned by SQLite as a result of an error in a function. ^By default,
5671** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5672** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5673**
5674** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5675** error indicating that a string or BLOB is too long to represent.
5676**
5677** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5678** error indicating that a memory allocation failed.
5679**
5680** ^The sqlite3_result_int() interface sets the return value
5681** of the application-defined function to be the 32-bit signed integer
5682** value given in the 2nd argument.
5683** ^The sqlite3_result_int64() interface sets the return value
5684** of the application-defined function to be the 64-bit signed integer
5685** value given in the 2nd argument.
5686**
5687** ^The sqlite3_result_null() interface sets the return value
5688** of the application-defined function to be NULL.
5689**
5690** ^The sqlite3_result_text(), sqlite3_result_text16(),
5691** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5692** set the return value of the application-defined function to be
5693** a text string which is represented as UTF-8, UTF-16 native byte order,
5694** UTF-16 little endian, or UTF-16 big endian, respectively.
5695** ^The sqlite3_result_text64() interface sets the return value of an
5696** application-defined function to be a text string in an encoding
5697** specified by the fifth (and last) parameter, which must be one
5698** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5699** ^SQLite takes the text result from the application from
5700** the 2nd parameter of the sqlite3_result_text* interfaces.
5701** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5702** is negative, then SQLite takes result text from the 2nd parameter
5703** through the first zero character.
5704** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5705** is non-negative, then as many bytes (not characters) of the text
5706** pointed to by the 2nd parameter are taken as the application-defined
5707** function result. If the 3rd parameter is non-negative, then it
5708** must be the byte offset into the string where the NUL terminator would
5709** appear if the string where NUL terminated. If any NUL characters occur
5710** in the string at a byte offset that is less than the value of the 3rd
5711** parameter, then the resulting string will contain embedded NULs and the
5712** result of expressions operating on strings with embedded NULs is undefined.
5713** ^If the 4th parameter to the sqlite3_result_text* interfaces
5714** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5715** function as the destructor on the text or BLOB result when it has
5716** finished using that result.
5717** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5718** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5719** assumes that the text or BLOB result is in constant space and does not
5720** copy the content of the parameter nor call a destructor on the content
5721** when it has finished using that result.
5722** ^If the 4th parameter to the sqlite3_result_text* interfaces
5723** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5724** then SQLite makes a copy of the result into space obtained
5725** from [sqlite3_malloc()] before it returns.
5726**
5727** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5728** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5729** when the encoding is not UTF8, if the input UTF16 begins with a
5730** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5731** string and the rest of the string is interpreted according to the
5732** byte-order specified by the BOM. ^The byte-order specified by
5733** the BOM at the beginning of the text overrides the byte-order
5734** specified by the interface procedure. ^So, for example, if
5735** sqlite3_result_text16le() is invoked with text that begins
5736** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5737** first two bytes of input are skipped and the remaining input
5738** is interpreted as UTF16BE text.
5739**
5740** ^For UTF16 input text to the sqlite3_result_text16(),
5741** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5742** sqlite3_result_text64() routines, if the text contains invalid
5743** UTF16 characters, the invalid characters might be converted
5744** into the unicode replacement character, U+FFFD.
5745**
5746** ^The sqlite3_result_value() interface sets the result of
5747** the application-defined function to be a copy of the
5748** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5749** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5750** so that the [sqlite3_value] specified in the parameter may change or
5751** be deallocated after sqlite3_result_value() returns without harm.
5752** ^A [protected sqlite3_value] object may always be used where an
5753** [unprotected sqlite3_value] object is required, so either
5754** kind of [sqlite3_value] object can be used with this interface.
5755**
5756** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5757** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5758** also associates the host-language pointer P or type T with that
5759** NULL value such that the pointer can be retrieved within an
5760** [application-defined SQL function] using [sqlite3_value_pointer()].
5761** ^If the D parameter is not NULL, then it is a pointer to a destructor
5762** for the P parameter. ^SQLite invokes D with P as its only argument
5763** when SQLite is finished with P. The T parameter should be a static
5764** string and preferably a string literal. The sqlite3_result_pointer()
5765** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5766**
5767** If these routines are called from within the different thread
5768** than the one containing the application-defined function that received
5769** the [sqlite3_context] pointer, the results are undefined.
5770*/
5771SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5772SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5773 sqlite3_uint64,void(*)(void*));
5774SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5775SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5776SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5777SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5778SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5779SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5780SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5781SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5782SQLITE_API void sqlite3_result_null(sqlite3_context*);
5783SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5784SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5785 void(*)(void*), unsigned char encoding);
5786SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5787SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5788SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5789SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5790SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5791SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5792SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5793
5794
5795/*
5796** CAPI3REF: Setting The Subtype Of An SQL Function
5797** METHOD: sqlite3_context
5798**
5799** The sqlite3_result_subtype(C,T) function causes the subtype of
5800** the result from the [application-defined SQL function] with
5801** [sqlite3_context] C to be the value T. Only the lower 8 bits
5802** of the subtype T are preserved in current versions of SQLite;
5803** higher order bits are discarded.
5804** The number of subtype bytes preserved by SQLite might increase
5805** in future releases of SQLite.
5806*/
5807SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5808
5809/*
5810** CAPI3REF: Define New Collating Sequences
5811** METHOD: sqlite3
5812**
5813** ^These functions add, remove, or modify a [collation] associated
5814** with the [database connection] specified as the first argument.
5815**
5816** ^The name of the collation is a UTF-8 string
5817** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5818** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5819** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5820** considered to be the same name.
5821**
5822** ^(The third argument (eTextRep) must be one of the constants:
5823** <ul>
5824** <li> [SQLITE_UTF8],
5825** <li> [SQLITE_UTF16LE],
5826** <li> [SQLITE_UTF16BE],
5827** <li> [SQLITE_UTF16], or
5828** <li> [SQLITE_UTF16_ALIGNED].
5829** </ul>)^
5830** ^The eTextRep argument determines the encoding of strings passed
5831** to the collating function callback, xCompare.
5832** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5833** force strings to be UTF16 with native byte order.
5834** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5835** on an even byte address.
5836**
5837** ^The fourth argument, pArg, is an application data pointer that is passed
5838** through as the first argument to the collating function callback.
5839**
5840** ^The fifth argument, xCompare, is a pointer to the collating function.
5841** ^Multiple collating functions can be registered using the same name but
5842** with different eTextRep parameters and SQLite will use whichever
5843** function requires the least amount of data transformation.
5844** ^If the xCompare argument is NULL then the collating function is
5845** deleted. ^When all collating functions having the same name are deleted,
5846** that collation is no longer usable.
5847**
5848** ^The collating function callback is invoked with a copy of the pArg
5849** application data pointer and with two strings in the encoding specified
5850** by the eTextRep argument. The two integer parameters to the collating
5851** function callback are the length of the two strings, in bytes. The collating
5852** function must return an integer that is negative, zero, or positive
5853** if the first string is less than, equal to, or greater than the second,
5854** respectively. A collating function must always return the same answer
5855** given the same inputs. If two or more collating functions are registered
5856** to the same collation name (using different eTextRep values) then all
5857** must give an equivalent answer when invoked with equivalent strings.
5858** The collating function must obey the following properties for all
5859** strings A, B, and C:
5860**
5861** <ol>
5862** <li> If A==B then B==A.
5863** <li> If A==B and B==C then A==C.
5864** <li> If A&lt;B THEN B&gt;A.
5865** <li> If A&lt;B and B&lt;C then A&lt;C.
5866** </ol>
5867**
5868** If a collating function fails any of the above constraints and that
5869** collating function is registered and used, then the behavior of SQLite
5870** is undefined.
5871**
5872** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5873** with the addition that the xDestroy callback is invoked on pArg when
5874** the collating function is deleted.
5875** ^Collating functions are deleted when they are overridden by later
5876** calls to the collation creation functions or when the
5877** [database connection] is closed using [sqlite3_close()].
5878**
5879** ^The xDestroy callback is <u>not</u> called if the
5880** sqlite3_create_collation_v2() function fails. Applications that invoke
5881** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5882** check the return code and dispose of the application data pointer
5883** themselves rather than expecting SQLite to deal with it for them.
5884** This is different from every other SQLite interface. The inconsistency
5885** is unfortunate but cannot be changed without breaking backwards
5886** compatibility.
5887**
5888** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5889*/
5890SQLITE_API int sqlite3_create_collation(
5891 sqlite3*,
5892 const char *zName,
5893 int eTextRep,
5894 void *pArg,
5895 int(*xCompare)(void*,int,const void*,int,const void*)
5896);
5897SQLITE_API int sqlite3_create_collation_v2(
5898 sqlite3*,
5899 const char *zName,
5900 int eTextRep,
5901 void *pArg,
5902 int(*xCompare)(void*,int,const void*,int,const void*),
5903 void(*xDestroy)(void*)
5904);
5905SQLITE_API int sqlite3_create_collation16(
5906 sqlite3*,
5907 const void *zName,
5908 int eTextRep,
5909 void *pArg,
5910 int(*xCompare)(void*,int,const void*,int,const void*)
5911);
5912
5913/*
5914** CAPI3REF: Collation Needed Callbacks
5915** METHOD: sqlite3
5916**
5917** ^To avoid having to register all collation sequences before a database
5918** can be used, a single callback function may be registered with the
5919** [database connection] to be invoked whenever an undefined collation
5920** sequence is required.
5921**
5922** ^If the function is registered using the sqlite3_collation_needed() API,
5923** then it is passed the names of undefined collation sequences as strings
5924** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5925** the names are passed as UTF-16 in machine native byte order.
5926** ^A call to either function replaces the existing collation-needed callback.
5927**
5928** ^(When the callback is invoked, the first argument passed is a copy
5929** of the second argument to sqlite3_collation_needed() or
5930** sqlite3_collation_needed16(). The second argument is the database
5931** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5932** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5933** sequence function required. The fourth parameter is the name of the
5934** required collation sequence.)^
5935**
5936** The callback function should register the desired collation using
5937** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5938** [sqlite3_create_collation_v2()].
5939*/
5940SQLITE_API int sqlite3_collation_needed(
5941 sqlite3*,
5942 void*,
5943 void(*)(void*,sqlite3*,int eTextRep,const char*)
5944);
5945SQLITE_API int sqlite3_collation_needed16(
5946 sqlite3*,
5947 void*,
5948 void(*)(void*,sqlite3*,int eTextRep,const void*)
5949);
5950
5951#ifdef SQLITE_ENABLE_CEROD
5952/*
5953** Specify the activation key for a CEROD database. Unless
5954** activated, none of the CEROD routines will work.
5955*/
5956SQLITE_API void sqlite3_activate_cerod(
5957 const char *zPassPhrase /* Activation phrase */
5958);
5959#endif
5960
5961/*
5962** CAPI3REF: Suspend Execution For A Short Time
5963**
5964** The sqlite3_sleep() function causes the current thread to suspend execution
5965** for at least a number of milliseconds specified in its parameter.
5966**
5967** If the operating system does not support sleep requests with
5968** millisecond time resolution, then the time will be rounded up to
5969** the nearest second. The number of milliseconds of sleep actually
5970** requested from the operating system is returned.
5971**
5972** ^SQLite implements this interface by calling the xSleep()
5973** method of the default [sqlite3_vfs] object. If the xSleep() method
5974** of the default VFS is not implemented correctly, or not implemented at
5975** all, then the behavior of sqlite3_sleep() may deviate from the description
5976** in the previous paragraphs.
5977*/
5978SQLITE_API int sqlite3_sleep(int);
5979
5980/*
5981** CAPI3REF: Name Of The Folder Holding Temporary Files
5982**
5983** ^(If this global variable is made to point to a string which is
5984** the name of a folder (a.k.a. directory), then all temporary files
5985** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5986** will be placed in that directory.)^ ^If this variable
5987** is a NULL pointer, then SQLite performs a search for an appropriate
5988** temporary file directory.
5989**
5990** Applications are strongly discouraged from using this global variable.
5991** It is required to set a temporary folder on Windows Runtime (WinRT).
5992** But for all other platforms, it is highly recommended that applications
5993** neither read nor write this variable. This global variable is a relic
5994** that exists for backwards compatibility of legacy applications and should
5995** be avoided in new projects.
5996**
5997** It is not safe to read or modify this variable in more than one
5998** thread at a time. It is not safe to read or modify this variable
5999** if a [database connection] is being used at the same time in a separate
6000** thread.
6001** It is intended that this variable be set once
6002** as part of process initialization and before any SQLite interface
6003** routines have been called and that this variable remain unchanged
6004** thereafter.
6005**
6006** ^The [temp_store_directory pragma] may modify this variable and cause
6007** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6008** the [temp_store_directory pragma] always assumes that any string
6009** that this variable points to is held in memory obtained from
6010** [sqlite3_malloc] and the pragma may attempt to free that memory
6011** using [sqlite3_free].
6012** Hence, if this variable is modified directly, either it should be
6013** made NULL or made to point to memory obtained from [sqlite3_malloc]
6014** or else the use of the [temp_store_directory pragma] should be avoided.
6015** Except when requested by the [temp_store_directory pragma], SQLite
6016** does not free the memory that sqlite3_temp_directory points to. If
6017** the application wants that memory to be freed, it must do
6018** so itself, taking care to only do so after all [database connection]
6019** objects have been destroyed.
6020**
6021** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6022** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6023** features that require the use of temporary files may fail. Here is an
6024** example of how to do this using C++ with the Windows Runtime:
6025**
6026** <blockquote><pre>
6027** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6028** &nbsp; TemporaryFolder->Path->Data();
6029** char zPathBuf&#91;MAX_PATH + 1&#93;;
6030** memset(zPathBuf, 0, sizeof(zPathBuf));
6031** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6032** &nbsp; NULL, NULL);
6033** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6034** </pre></blockquote>
6035*/
6036SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6037
6038/*
6039** CAPI3REF: Name Of The Folder Holding Database Files
6040**
6041** ^(If this global variable is made to point to a string which is
6042** the name of a folder (a.k.a. directory), then all database files
6043** specified with a relative pathname and created or accessed by
6044** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6045** to be relative to that directory.)^ ^If this variable is a NULL
6046** pointer, then SQLite assumes that all database files specified
6047** with a relative pathname are relative to the current directory
6048** for the process. Only the windows VFS makes use of this global
6049** variable; it is ignored by the unix VFS.
6050**
6051** Changing the value of this variable while a database connection is
6052** open can result in a corrupt database.
6053**
6054** It is not safe to read or modify this variable in more than one
6055** thread at a time. It is not safe to read or modify this variable
6056** if a [database connection] is being used at the same time in a separate
6057** thread.
6058** It is intended that this variable be set once
6059** as part of process initialization and before any SQLite interface
6060** routines have been called and that this variable remain unchanged
6061** thereafter.
6062**
6063** ^The [data_store_directory pragma] may modify this variable and cause
6064** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6065** the [data_store_directory pragma] always assumes that any string
6066** that this variable points to is held in memory obtained from
6067** [sqlite3_malloc] and the pragma may attempt to free that memory
6068** using [sqlite3_free].
6069** Hence, if this variable is modified directly, either it should be
6070** made NULL or made to point to memory obtained from [sqlite3_malloc]
6071** or else the use of the [data_store_directory pragma] should be avoided.
6072*/
6073SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6074
6075/*
6076** CAPI3REF: Win32 Specific Interface
6077**
6078** These interfaces are available only on Windows. The
6079** [sqlite3_win32_set_directory] interface is used to set the value associated
6080** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6081** zValue, depending on the value of the type parameter. The zValue parameter
6082** should be NULL to cause the previous value to be freed via [sqlite3_free];
6083** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6084** prior to being used. The [sqlite3_win32_set_directory] interface returns
6085** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6086** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6087** [sqlite3_data_directory] variable is intended to act as a replacement for
6088** the current directory on the sub-platforms of Win32 where that concept is
6089** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6090** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6091** sqlite3_win32_set_directory interface except the string parameter must be
6092** UTF-8 or UTF-16, respectively.
6093*/
6094SQLITE_API int sqlite3_win32_set_directory(
6095 unsigned long type, /* Identifier for directory being set or reset */
6096 void *zValue /* New value for directory being set or reset */
6097);
6098SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6099SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6100
6101/*
6102** CAPI3REF: Win32 Directory Types
6103**
6104** These macros are only available on Windows. They define the allowed values
6105** for the type argument to the [sqlite3_win32_set_directory] interface.
6106*/
6107#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6108#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6109
6110/*
6111** CAPI3REF: Test For Auto-Commit Mode
6112** KEYWORDS: {autocommit mode}
6113** METHOD: sqlite3
6114**
6115** ^The sqlite3_get_autocommit() interface returns non-zero or
6116** zero if the given database connection is or is not in autocommit mode,
6117** respectively. ^Autocommit mode is on by default.
6118** ^Autocommit mode is disabled by a [BEGIN] statement.
6119** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6120**
6121** If certain kinds of errors occur on a statement within a multi-statement
6122** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6123** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6124** transaction might be rolled back automatically. The only way to
6125** find out whether SQLite automatically rolled back the transaction after
6126** an error is to use this function.
6127**
6128** If another thread changes the autocommit status of the database
6129** connection while this routine is running, then the return value
6130** is undefined.
6131*/
6132SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6133
6134/*
6135** CAPI3REF: Find The Database Handle Of A Prepared Statement
6136** METHOD: sqlite3_stmt
6137**
6138** ^The sqlite3_db_handle interface returns the [database connection] handle
6139** to which a [prepared statement] belongs. ^The [database connection]
6140** returned by sqlite3_db_handle is the same [database connection]
6141** that was the first argument
6142** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6143** create the statement in the first place.
6144*/
6145SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6146
6147/*
6148** CAPI3REF: Return The Filename For A Database Connection
6149** METHOD: sqlite3
6150**
6151** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6152** associated with database N of connection D.
6153** ^If there is no attached database N on the database
6154** connection D, or if database N is a temporary or in-memory database, then
6155** this function will return either a NULL pointer or an empty string.
6156**
6157** ^The string value returned by this routine is owned and managed by
6158** the database connection. ^The value will be valid until the database N
6159** is [DETACH]-ed or until the database connection closes.
6160**
6161** ^The filename returned by this function is the output of the
6162** xFullPathname method of the [VFS]. ^In other words, the filename
6163** will be an absolute pathname, even if the filename used
6164** to open the database originally was a URI or relative pathname.
6165**
6166** If the filename pointer returned by this routine is not NULL, then it
6167** can be used as the filename input parameter to these routines:
6168** <ul>
6169** <li> [sqlite3_uri_parameter()]
6170** <li> [sqlite3_uri_boolean()]
6171** <li> [sqlite3_uri_int64()]
6172** <li> [sqlite3_filename_database()]
6173** <li> [sqlite3_filename_journal()]
6174** <li> [sqlite3_filename_wal()]
6175** </ul>
6176*/
6177SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6178
6179/*
6180** CAPI3REF: Determine if a database is read-only
6181** METHOD: sqlite3
6182**
6183** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6184** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6185** the name of a database on connection D.
6186*/
6187SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6188
6189/*
6190** CAPI3REF: Find the next prepared statement
6191** METHOD: sqlite3
6192**
6193** ^This interface returns a pointer to the next [prepared statement] after
6194** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6195** then this interface returns a pointer to the first prepared statement
6196** associated with the database connection pDb. ^If no prepared statement
6197** satisfies the conditions of this routine, it returns NULL.
6198**
6199** The [database connection] pointer D in a call to
6200** [sqlite3_next_stmt(D,S)] must refer to an open database
6201** connection and in particular must not be a NULL pointer.
6202*/
6203SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6204
6205/*
6206** CAPI3REF: Commit And Rollback Notification Callbacks
6207** METHOD: sqlite3
6208**
6209** ^The sqlite3_commit_hook() interface registers a callback
6210** function to be invoked whenever a transaction is [COMMIT | committed].
6211** ^Any callback set by a previous call to sqlite3_commit_hook()
6212** for the same database connection is overridden.
6213** ^The sqlite3_rollback_hook() interface registers a callback
6214** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6215** ^Any callback set by a previous call to sqlite3_rollback_hook()
6216** for the same database connection is overridden.
6217** ^The pArg argument is passed through to the callback.
6218** ^If the callback on a commit hook function returns non-zero,
6219** then the commit is converted into a rollback.
6220**
6221** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6222** return the P argument from the previous call of the same function
6223** on the same [database connection] D, or NULL for
6224** the first call for each function on D.
6225**
6226** The commit and rollback hook callbacks are not reentrant.
6227** The callback implementation must not do anything that will modify
6228** the database connection that invoked the callback. Any actions
6229** to modify the database connection must be deferred until after the
6230** completion of the [sqlite3_step()] call that triggered the commit
6231** or rollback hook in the first place.
6232** Note that running any other SQL statements, including SELECT statements,
6233** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6234** the database connections for the meaning of "modify" in this paragraph.
6235**
6236** ^Registering a NULL function disables the callback.
6237**
6238** ^When the commit hook callback routine returns zero, the [COMMIT]
6239** operation is allowed to continue normally. ^If the commit hook
6240** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6241** ^The rollback hook is invoked on a rollback that results from a commit
6242** hook returning non-zero, just as it would be with any other rollback.
6243**
6244** ^For the purposes of this API, a transaction is said to have been
6245** rolled back if an explicit "ROLLBACK" statement is executed, or
6246** an error or constraint causes an implicit rollback to occur.
6247** ^The rollback callback is not invoked if a transaction is
6248** automatically rolled back because the database connection is closed.
6249**
6250** See also the [sqlite3_update_hook()] interface.
6251*/
6252SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6253SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6254
6255/*
6256** CAPI3REF: Data Change Notification Callbacks
6257** METHOD: sqlite3
6258**
6259** ^The sqlite3_update_hook() interface registers a callback function
6260** with the [database connection] identified by the first argument
6261** to be invoked whenever a row is updated, inserted or deleted in
6262** a [rowid table].
6263** ^Any callback set by a previous call to this function
6264** for the same database connection is overridden.
6265**
6266** ^The second argument is a pointer to the function to invoke when a
6267** row is updated, inserted or deleted in a rowid table.
6268** ^The first argument to the callback is a copy of the third argument
6269** to sqlite3_update_hook().
6270** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6271** or [SQLITE_UPDATE], depending on the operation that caused the callback
6272** to be invoked.
6273** ^The third and fourth arguments to the callback contain pointers to the
6274** database and table name containing the affected row.
6275** ^The final callback parameter is the [rowid] of the row.
6276** ^In the case of an update, this is the [rowid] after the update takes place.
6277**
6278** ^(The update hook is not invoked when internal system tables are
6279** modified (i.e. sqlite_sequence).)^
6280** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6281**
6282** ^In the current implementation, the update hook
6283** is not invoked when conflicting rows are deleted because of an
6284** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6285** invoked when rows are deleted using the [truncate optimization].
6286** The exceptions defined in this paragraph might change in a future
6287** release of SQLite.
6288**
6289** The update hook implementation must not do anything that will modify
6290** the database connection that invoked the update hook. Any actions
6291** to modify the database connection must be deferred until after the
6292** completion of the [sqlite3_step()] call that triggered the update hook.
6293** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6294** database connections for the meaning of "modify" in this paragraph.
6295**
6296** ^The sqlite3_update_hook(D,C,P) function
6297** returns the P argument from the previous call
6298** on the same [database connection] D, or NULL for
6299** the first call on D.
6300**
6301** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6302** and [sqlite3_preupdate_hook()] interfaces.
6303*/
6304SQLITE_API void *sqlite3_update_hook(
6305 sqlite3*,
6306 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6307 void*
6308);
6309
6310/*
6311** CAPI3REF: Enable Or Disable Shared Pager Cache
6312**
6313** ^(This routine enables or disables the sharing of the database cache
6314** and schema data structures between [database connection | connections]
6315** to the same database. Sharing is enabled if the argument is true
6316** and disabled if the argument is false.)^
6317**
6318** ^Cache sharing is enabled and disabled for an entire process.
6319** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6320** In prior versions of SQLite,
6321** sharing was enabled or disabled for each thread separately.
6322**
6323** ^(The cache sharing mode set by this interface effects all subsequent
6324** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6325** Existing database connections continue to use the sharing mode
6326** that was in effect at the time they were opened.)^
6327**
6328** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6329** successfully. An [error code] is returned otherwise.)^
6330**
6331** ^Shared cache is disabled by default. It is recommended that it stay
6332** that way. In other words, do not use this routine. This interface
6333** continues to be provided for historical compatibility, but its use is
6334** discouraged. Any use of shared cache is discouraged. If shared cache
6335** must be used, it is recommended that shared cache only be enabled for
6336** individual database connections using the [sqlite3_open_v2()] interface
6337** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6338**
6339** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6340** and will always return SQLITE_MISUSE. On those systems,
6341** shared cache mode should be enabled per-database connection via
6342** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6343**
6344** This interface is threadsafe on processors where writing a
6345** 32-bit integer is atomic.
6346**
6347** See Also: [SQLite Shared-Cache Mode]
6348*/
6349SQLITE_API int sqlite3_enable_shared_cache(int);
6350
6351/*
6352** CAPI3REF: Attempt To Free Heap Memory
6353**
6354** ^The sqlite3_release_memory() interface attempts to free N bytes
6355** of heap memory by deallocating non-essential memory allocations
6356** held by the database library. Memory used to cache database
6357** pages to improve performance is an example of non-essential memory.
6358** ^sqlite3_release_memory() returns the number of bytes actually freed,
6359** which might be more or less than the amount requested.
6360** ^The sqlite3_release_memory() routine is a no-op returning zero
6361** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6362**
6363** See also: [sqlite3_db_release_memory()]
6364*/
6365SQLITE_API int sqlite3_release_memory(int);
6366
6367/*
6368** CAPI3REF: Free Memory Used By A Database Connection
6369** METHOD: sqlite3
6370**
6371** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6372** memory as possible from database connection D. Unlike the
6373** [sqlite3_release_memory()] interface, this interface is in effect even
6374** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6375** omitted.
6376**
6377** See also: [sqlite3_release_memory()]
6378*/
6379SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6380
6381/*
6382** CAPI3REF: Impose A Limit On Heap Size
6383**
6384** These interfaces impose limits on the amount of heap memory that will be
6385** by all database connections within a single process.
6386**
6387** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6388** soft limit on the amount of heap memory that may be allocated by SQLite.
6389** ^SQLite strives to keep heap memory utilization below the soft heap
6390** limit by reducing the number of pages held in the page cache
6391** as heap memory usages approaches the limit.
6392** ^The soft heap limit is "soft" because even though SQLite strives to stay
6393** below the limit, it will exceed the limit rather than generate
6394** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6395** is advisory only.
6396**
6397** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6398** N bytes on the amount of memory that will be allocated. ^The
6399** sqlite3_hard_heap_limit64(N) interface is similar to
6400** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6401** when the hard heap limit is reached.
6402**
6403** ^The return value from both sqlite3_soft_heap_limit64() and
6404** sqlite3_hard_heap_limit64() is the size of
6405** the heap limit prior to the call, or negative in the case of an
6406** error. ^If the argument N is negative
6407** then no change is made to the heap limit. Hence, the current
6408** size of heap limits can be determined by invoking
6409** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6410**
6411** ^Setting the heap limits to zero disables the heap limiter mechanism.
6412**
6413** ^The soft heap limit may not be greater than the hard heap limit.
6414** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6415** is invoked with a value of N that is greater than the hard heap limit,
6416** the the soft heap limit is set to the value of the hard heap limit.
6417** ^The soft heap limit is automatically enabled whenever the hard heap
6418** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6419** the soft heap limit is outside the range of 1..N, then the soft heap
6420** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6421** hard heap limit is enabled makes the soft heap limit equal to the
6422** hard heap limit.
6423**
6424** The memory allocation limits can also be adjusted using
6425** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6426**
6427** ^(The heap limits are not enforced in the current implementation
6428** if one or more of following conditions are true:
6429**
6430** <ul>
6431** <li> The limit value is set to zero.
6432** <li> Memory accounting is disabled using a combination of the
6433** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6434** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6435** <li> An alternative page cache implementation is specified using
6436** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6437** <li> The page cache allocates from its own memory pool supplied
6438** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6439** from the heap.
6440** </ul>)^
6441**
6442** The circumstances under which SQLite will enforce the heap limits may
6443** changes in future releases of SQLite.
6444*/
6445SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6446SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6447
6448/*
6449** CAPI3REF: Deprecated Soft Heap Limit Interface
6450** DEPRECATED
6451**
6452** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6453** interface. This routine is provided for historical compatibility
6454** only. All new applications should use the
6455** [sqlite3_soft_heap_limit64()] interface rather than this one.
6456*/
6457SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6458
6459
6460/*
6461** CAPI3REF: Extract Metadata About A Column Of A Table
6462** METHOD: sqlite3
6463**
6464** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6465** information about column C of table T in database D
6466** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6467** interface returns SQLITE_OK and fills in the non-NULL pointers in
6468** the final five arguments with appropriate values if the specified
6469** column exists. ^The sqlite3_table_column_metadata() interface returns
6470** SQLITE_ERROR if the specified column does not exist.
6471** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6472** NULL pointer, then this routine simply checks for the existence of the
6473** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6474** does not. If the table name parameter T in a call to
6475** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6476** undefined behavior.
6477**
6478** ^The column is identified by the second, third and fourth parameters to
6479** this function. ^(The second parameter is either the name of the database
6480** (i.e. "main", "temp", or an attached database) containing the specified
6481** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6482** for the table using the same algorithm used by the database engine to
6483** resolve unqualified table references.
6484**
6485** ^The third and fourth parameters to this function are the table and column
6486** name of the desired column, respectively.
6487**
6488** ^Metadata is returned by writing to the memory locations passed as the 5th
6489** and subsequent parameters to this function. ^Any of these arguments may be
6490** NULL, in which case the corresponding element of metadata is omitted.
6491**
6492** ^(<blockquote>
6493** <table border="1">
6494** <tr><th> Parameter <th> Output<br>Type <th> Description
6495**
6496** <tr><td> 5th <td> const char* <td> Data type
6497** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6498** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6499** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6500** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6501** </table>
6502** </blockquote>)^
6503**
6504** ^The memory pointed to by the character pointers returned for the
6505** declaration type and collation sequence is valid until the next
6506** call to any SQLite API function.
6507**
6508** ^If the specified table is actually a view, an [error code] is returned.
6509**
6510** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6511** is not a [WITHOUT ROWID] table and an
6512** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6513** parameters are set for the explicitly declared column. ^(If there is no
6514** [INTEGER PRIMARY KEY] column, then the outputs
6515** for the [rowid] are set as follows:
6516**
6517** <pre>
6518** data type: "INTEGER"
6519** collation sequence: "BINARY"
6520** not null: 0
6521** primary key: 1
6522** auto increment: 0
6523** </pre>)^
6524**
6525** ^This function causes all database schemas to be read from disk and
6526** parsed, if that has not already been done, and returns an error if
6527** any errors are encountered while loading the schema.
6528*/
6529SQLITE_API int sqlite3_table_column_metadata(
6530 sqlite3 *db, /* Connection handle */
6531 const char *zDbName, /* Database name or NULL */
6532 const char *zTableName, /* Table name */
6533 const char *zColumnName, /* Column name */
6534 char const **pzDataType, /* OUTPUT: Declared data type */
6535 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6536 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6537 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6538 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6539);
6540
6541/*
6542** CAPI3REF: Load An Extension
6543** METHOD: sqlite3
6544**
6545** ^This interface loads an SQLite extension library from the named file.
6546**
6547** ^The sqlite3_load_extension() interface attempts to load an
6548** [SQLite extension] library contained in the file zFile. If
6549** the file cannot be loaded directly, attempts are made to load
6550** with various operating-system specific extensions added.
6551** So for example, if "samplelib" cannot be loaded, then names like
6552** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6553** be tried also.
6554**
6555** ^The entry point is zProc.
6556** ^(zProc may be 0, in which case SQLite will try to come up with an
6557** entry point name on its own. It first tries "sqlite3_extension_init".
6558** If that does not work, it constructs a name "sqlite3_X_init" where the
6559** X is consists of the lower-case equivalent of all ASCII alphabetic
6560** characters in the filename from the last "/" to the first following
6561** "." and omitting any initial "lib".)^
6562** ^The sqlite3_load_extension() interface returns
6563** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6564** ^If an error occurs and pzErrMsg is not 0, then the
6565** [sqlite3_load_extension()] interface shall attempt to
6566** fill *pzErrMsg with error message text stored in memory
6567** obtained from [sqlite3_malloc()]. The calling function
6568** should free this memory by calling [sqlite3_free()].
6569**
6570** ^Extension loading must be enabled using
6571** [sqlite3_enable_load_extension()] or
6572** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6573** prior to calling this API,
6574** otherwise an error will be returned.
6575**
6576** <b>Security warning:</b> It is recommended that the
6577** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6578** interface. The use of the [sqlite3_enable_load_extension()] interface
6579** should be avoided. This will keep the SQL function [load_extension()]
6580** disabled and prevent SQL injections from giving attackers
6581** access to extension loading capabilities.
6582**
6583** See also the [load_extension() SQL function].
6584*/
6585SQLITE_API int sqlite3_load_extension(
6586 sqlite3 *db, /* Load the extension into this database connection */
6587 const char *zFile, /* Name of the shared library containing extension */
6588 const char *zProc, /* Entry point. Derived from zFile if 0 */
6589 char **pzErrMsg /* Put error message here if not 0 */
6590);
6591
6592/*
6593** CAPI3REF: Enable Or Disable Extension Loading
6594** METHOD: sqlite3
6595**
6596** ^So as not to open security holes in older applications that are
6597** unprepared to deal with [extension loading], and as a means of disabling
6598** [extension loading] while evaluating user-entered SQL, the following API
6599** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6600**
6601** ^Extension loading is off by default.
6602** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6603** to turn extension loading on and call it with onoff==0 to turn
6604** it back off again.
6605**
6606** ^This interface enables or disables both the C-API
6607** [sqlite3_load_extension()] and the SQL function [load_extension()].
6608** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6609** to enable or disable only the C-API.)^
6610**
6611** <b>Security warning:</b> It is recommended that extension loading
6612** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6613** rather than this interface, so the [load_extension()] SQL function
6614** remains disabled. This will prevent SQL injections from giving attackers
6615** access to extension loading capabilities.
6616*/
6617SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6618
6619/*
6620** CAPI3REF: Automatically Load Statically Linked Extensions
6621**
6622** ^This interface causes the xEntryPoint() function to be invoked for
6623** each new [database connection] that is created. The idea here is that
6624** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6625** that is to be automatically loaded into all new database connections.
6626**
6627** ^(Even though the function prototype shows that xEntryPoint() takes
6628** no arguments and returns void, SQLite invokes xEntryPoint() with three
6629** arguments and expects an integer result as if the signature of the
6630** entry point where as follows:
6631**
6632** <blockquote><pre>
6633** &nbsp; int xEntryPoint(
6634** &nbsp; sqlite3 *db,
6635** &nbsp; const char **pzErrMsg,
6636** &nbsp; const struct sqlite3_api_routines *pThunk
6637** &nbsp; );
6638** </pre></blockquote>)^
6639**
6640** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6641** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6642** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6643** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6644** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6645** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6646** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6647**
6648** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6649** on the list of automatic extensions is a harmless no-op. ^No entry point
6650** will be called more than once for each database connection that is opened.
6651**
6652** See also: [sqlite3_reset_auto_extension()]
6653** and [sqlite3_cancel_auto_extension()]
6654*/
6655SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6656
6657/*
6658** CAPI3REF: Cancel Automatic Extension Loading
6659**
6660** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6661** initialization routine X that was registered using a prior call to
6662** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6663** routine returns 1 if initialization routine X was successfully
6664** unregistered and it returns 0 if X was not on the list of initialization
6665** routines.
6666*/
6667SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6668
6669/*
6670** CAPI3REF: Reset Automatic Extension Loading
6671**
6672** ^This interface disables all automatic extensions previously
6673** registered using [sqlite3_auto_extension()].
6674*/
6675SQLITE_API void sqlite3_reset_auto_extension(void);
6676
6677/*
6678** The interface to the virtual-table mechanism is currently considered
6679** to be experimental. The interface might change in incompatible ways.
6680** If this is a problem for you, do not use the interface at this time.
6681**
6682** When the virtual-table mechanism stabilizes, we will declare the
6683** interface fixed, support it indefinitely, and remove this comment.
6684*/
6685
6686/*
6687** Structures used by the virtual table interface
6688*/
6689typedef struct sqlite3_vtab sqlite3_vtab;
6690typedef struct sqlite3_index_info sqlite3_index_info;
6691typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6692typedef struct sqlite3_module sqlite3_module;
6693
6694/*
6695** CAPI3REF: Virtual Table Object
6696** KEYWORDS: sqlite3_module {virtual table module}
6697**
6698** This structure, sometimes called a "virtual table module",
6699** defines the implementation of a [virtual table].
6700** This structure consists mostly of methods for the module.
6701**
6702** ^A virtual table module is created by filling in a persistent
6703** instance of this structure and passing a pointer to that instance
6704** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6705** ^The registration remains valid until it is replaced by a different
6706** module or until the [database connection] closes. The content
6707** of this structure must not change while it is registered with
6708** any database connection.
6709*/
6710struct sqlite3_module {
6711 int iVersion;
6712 int (*xCreate)(sqlite3*, void *pAux,
6713 int argc, const char *const*argv,
6714 sqlite3_vtab **ppVTab, char**);
6715 int (*xConnect)(sqlite3*, void *pAux,
6716 int argc, const char *const*argv,
6717 sqlite3_vtab **ppVTab, char**);
6718 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6719 int (*xDisconnect)(sqlite3_vtab *pVTab);
6720 int (*xDestroy)(sqlite3_vtab *pVTab);
6721 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6722 int (*xClose)(sqlite3_vtab_cursor*);
6723 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6724 int argc, sqlite3_value **argv);
6725 int (*xNext)(sqlite3_vtab_cursor*);
6726 int (*xEof)(sqlite3_vtab_cursor*);
6727 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6728 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6729 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6730 int (*xBegin)(sqlite3_vtab *pVTab);
6731 int (*xSync)(sqlite3_vtab *pVTab);
6732 int (*xCommit)(sqlite3_vtab *pVTab);
6733 int (*xRollback)(sqlite3_vtab *pVTab);
6734 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6735 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6736 void **ppArg);
6737 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6738 /* The methods above are in version 1 of the sqlite_module object. Those
6739 ** below are for version 2 and greater. */
6740 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6741 int (*xRelease)(sqlite3_vtab *pVTab, int);
6742 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6743 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6744 ** Those below are for version 3 and greater. */
6745 int (*xShadowName)(const char*);
6746};
6747
6748/*
6749** CAPI3REF: Virtual Table Indexing Information
6750** KEYWORDS: sqlite3_index_info
6751**
6752** The sqlite3_index_info structure and its substructures is used as part
6753** of the [virtual table] interface to
6754** pass information into and receive the reply from the [xBestIndex]
6755** method of a [virtual table module]. The fields under **Inputs** are the
6756** inputs to xBestIndex and are read-only. xBestIndex inserts its
6757** results into the **Outputs** fields.
6758**
6759** ^(The aConstraint[] array records WHERE clause constraints of the form:
6760**
6761** <blockquote>column OP expr</blockquote>
6762**
6763** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6764** stored in aConstraint[].op using one of the
6765** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6766** ^(The index of the column is stored in
6767** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6768** expr on the right-hand side can be evaluated (and thus the constraint
6769** is usable) and false if it cannot.)^
6770**
6771** ^The optimizer automatically inverts terms of the form "expr OP column"
6772** and makes other simplifications to the WHERE clause in an attempt to
6773** get as many WHERE clause terms into the form shown above as possible.
6774** ^The aConstraint[] array only reports WHERE clause terms that are
6775** relevant to the particular virtual table being queried.
6776**
6777** ^Information about the ORDER BY clause is stored in aOrderBy[].
6778** ^Each term of aOrderBy records a column of the ORDER BY clause.
6779**
6780** The colUsed field indicates which columns of the virtual table may be
6781** required by the current scan. Virtual table columns are numbered from
6782** zero in the order in which they appear within the CREATE TABLE statement
6783** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6784** the corresponding bit is set within the colUsed mask if the column may be
6785** required by SQLite. If the table has at least 64 columns and any column
6786** to the right of the first 63 is required, then bit 63 of colUsed is also
6787** set. In other words, column iCol may be required if the expression
6788** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6789** non-zero.
6790**
6791** The [xBestIndex] method must fill aConstraintUsage[] with information
6792** about what parameters to pass to xFilter. ^If argvIndex>0 then
6793** the right-hand side of the corresponding aConstraint[] is evaluated
6794** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6795** is true, then the constraint is assumed to be fully handled by the
6796** virtual table and might not be checked again by the byte code.)^ ^(The
6797** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
6798** is left in its default setting of false, the constraint will always be
6799** checked separately in byte code. If the omit flag is change to true, then
6800** the constraint may or may not be checked in byte code. In other words,
6801** when the omit flag is true there is no guarantee that the constraint will
6802** not be checked again using byte code.)^
6803**
6804** ^The idxNum and idxPtr values are recorded and passed into the
6805** [xFilter] method.
6806** ^[sqlite3_free()] is used to free idxPtr if and only if
6807** needToFreeIdxPtr is true.
6808**
6809** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6810** the correct order to satisfy the ORDER BY clause so that no separate
6811** sorting step is required.
6812**
6813** ^The estimatedCost value is an estimate of the cost of a particular
6814** strategy. A cost of N indicates that the cost of the strategy is similar
6815** to a linear scan of an SQLite table with N rows. A cost of log(N)
6816** indicates that the expense of the operation is similar to that of a
6817** binary search on a unique indexed field of an SQLite table with N rows.
6818**
6819** ^The estimatedRows value is an estimate of the number of rows that
6820** will be returned by the strategy.
6821**
6822** The xBestIndex method may optionally populate the idxFlags field with a
6823** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6824** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6825** assumes that the strategy may visit at most one row.
6826**
6827** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6828** SQLite also assumes that if a call to the xUpdate() method is made as
6829** part of the same statement to delete or update a virtual table row and the
6830** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6831** any database changes. In other words, if the xUpdate() returns
6832** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6833** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6834** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6835** the xUpdate method are automatically rolled back by SQLite.
6836**
6837** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6838** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6839** If a virtual table extension is
6840** used with an SQLite version earlier than 3.8.2, the results of attempting
6841** to read or write the estimatedRows field are undefined (but are likely
6842** to include crashing the application). The estimatedRows field should
6843** therefore only be used if [sqlite3_libversion_number()] returns a
6844** value greater than or equal to 3008002. Similarly, the idxFlags field
6845** was added for [version 3.9.0] ([dateof:3.9.0]).
6846** It may therefore only be used if
6847** sqlite3_libversion_number() returns a value greater than or equal to
6848** 3009000.
6849*/
6850struct sqlite3_index_info {
6851 /* Inputs */
6852 int nConstraint; /* Number of entries in aConstraint */
6853 struct sqlite3_index_constraint {
6854 int iColumn; /* Column constrained. -1 for ROWID */
6855 unsigned char op; /* Constraint operator */
6856 unsigned char usable; /* True if this constraint is usable */
6857 int iTermOffset; /* Used internally - xBestIndex should ignore */
6858 } *aConstraint; /* Table of WHERE clause constraints */
6859 int nOrderBy; /* Number of terms in the ORDER BY clause */
6860 struct sqlite3_index_orderby {
6861 int iColumn; /* Column number */
6862 unsigned char desc; /* True for DESC. False for ASC. */
6863 } *aOrderBy; /* The ORDER BY clause */
6864 /* Outputs */
6865 struct sqlite3_index_constraint_usage {
6866 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6867 unsigned char omit; /* Do not code a test for this constraint */
6868 } *aConstraintUsage;
6869 int idxNum; /* Number used to identify the index */
6870 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6871 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6872 int orderByConsumed; /* True if output is already ordered */
6873 double estimatedCost; /* Estimated cost of using this index */
6874 /* Fields below are only available in SQLite 3.8.2 and later */
6875 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6876 /* Fields below are only available in SQLite 3.9.0 and later */
6877 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6878 /* Fields below are only available in SQLite 3.10.0 and later */
6879 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6880};
6881
6882/*
6883** CAPI3REF: Virtual Table Scan Flags
6884**
6885** Virtual table implementations are allowed to set the
6886** [sqlite3_index_info].idxFlags field to some combination of
6887** these bits.
6888*/
6889#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6890
6891/*
6892** CAPI3REF: Virtual Table Constraint Operator Codes
6893**
6894** These macros define the allowed values for the
6895** [sqlite3_index_info].aConstraint[].op field. Each value represents
6896** an operator that is part of a constraint term in the wHERE clause of
6897** a query that uses a [virtual table].
6898*/
6899#define SQLITE_INDEX_CONSTRAINT_EQ 2
6900#define SQLITE_INDEX_CONSTRAINT_GT 4
6901#define SQLITE_INDEX_CONSTRAINT_LE 8
6902#define SQLITE_INDEX_CONSTRAINT_LT 16
6903#define SQLITE_INDEX_CONSTRAINT_GE 32
6904#define SQLITE_INDEX_CONSTRAINT_MATCH 64
6905#define SQLITE_INDEX_CONSTRAINT_LIKE 65
6906#define SQLITE_INDEX_CONSTRAINT_GLOB 66
6907#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6908#define SQLITE_INDEX_CONSTRAINT_NE 68
6909#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6910#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6911#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6912#define SQLITE_INDEX_CONSTRAINT_IS 72
6913#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
6914
6915/*
6916** CAPI3REF: Register A Virtual Table Implementation
6917** METHOD: sqlite3
6918**
6919** ^These routines are used to register a new [virtual table module] name.
6920** ^Module names must be registered before
6921** creating a new [virtual table] using the module and before using a
6922** preexisting [virtual table] for the module.
6923**
6924** ^The module name is registered on the [database connection] specified
6925** by the first parameter. ^The name of the module is given by the
6926** second parameter. ^The third parameter is a pointer to
6927** the implementation of the [virtual table module]. ^The fourth
6928** parameter is an arbitrary client data pointer that is passed through
6929** into the [xCreate] and [xConnect] methods of the virtual table module
6930** when a new virtual table is be being created or reinitialized.
6931**
6932** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6933** is a pointer to a destructor for the pClientData. ^SQLite will
6934** invoke the destructor function (if it is not NULL) when SQLite
6935** no longer needs the pClientData pointer. ^The destructor will also
6936** be invoked if the call to sqlite3_create_module_v2() fails.
6937** ^The sqlite3_create_module()
6938** interface is equivalent to sqlite3_create_module_v2() with a NULL
6939** destructor.
6940**
6941** ^If the third parameter (the pointer to the sqlite3_module object) is
6942** NULL then no new module is create and any existing modules with the
6943** same name are dropped.
6944**
6945** See also: [sqlite3_drop_modules()]
6946*/
6947SQLITE_API int sqlite3_create_module(
6948 sqlite3 *db, /* SQLite connection to register module with */
6949 const char *zName, /* Name of the module */
6950 const sqlite3_module *p, /* Methods for the module */
6951 void *pClientData /* Client data for xCreate/xConnect */
6952);
6953SQLITE_API int sqlite3_create_module_v2(
6954 sqlite3 *db, /* SQLite connection to register module with */
6955 const char *zName, /* Name of the module */
6956 const sqlite3_module *p, /* Methods for the module */
6957 void *pClientData, /* Client data for xCreate/xConnect */
6958 void(*xDestroy)(void*) /* Module destructor function */
6959);
6960
6961/*
6962** CAPI3REF: Remove Unnecessary Virtual Table Implementations
6963** METHOD: sqlite3
6964**
6965** ^The sqlite3_drop_modules(D,L) interface removes all virtual
6966** table modules from database connection D except those named on list L.
6967** The L parameter must be either NULL or a pointer to an array of pointers
6968** to strings where the array is terminated by a single NULL pointer.
6969** ^If the L parameter is NULL, then all virtual table modules are removed.
6970**
6971** See also: [sqlite3_create_module()]
6972*/
6973SQLITE_API int sqlite3_drop_modules(
6974 sqlite3 *db, /* Remove modules from this connection */
6975 const char **azKeep /* Except, do not remove the ones named here */
6976);
6977
6978/*
6979** CAPI3REF: Virtual Table Instance Object
6980** KEYWORDS: sqlite3_vtab
6981**
6982** Every [virtual table module] implementation uses a subclass
6983** of this object to describe a particular instance
6984** of the [virtual table]. Each subclass will
6985** be tailored to the specific needs of the module implementation.
6986** The purpose of this superclass is to define certain fields that are
6987** common to all module implementations.
6988**
6989** ^Virtual tables methods can set an error message by assigning a
6990** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6991** take care that any prior string is freed by a call to [sqlite3_free()]
6992** prior to assigning a new string to zErrMsg. ^After the error message
6993** is delivered up to the client application, the string will be automatically
6994** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6995*/
6996struct sqlite3_vtab {
6997 const sqlite3_module *pModule; /* The module for this virtual table */
6998 int nRef; /* Number of open cursors */
6999 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7000 /* Virtual table implementations will typically add additional fields */
7001};
7002
7003/*
7004** CAPI3REF: Virtual Table Cursor Object
7005** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7006**
7007** Every [virtual table module] implementation uses a subclass of the
7008** following structure to describe cursors that point into the
7009** [virtual table] and are used
7010** to loop through the virtual table. Cursors are created using the
7011** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7012** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7013** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7014** of the module. Each module implementation will define
7015** the content of a cursor structure to suit its own needs.
7016**
7017** This superclass exists in order to define fields of the cursor that
7018** are common to all implementations.
7019*/
7020struct sqlite3_vtab_cursor {
7021 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7022 /* Virtual table implementations will typically add additional fields */
7023};
7024
7025/*
7026** CAPI3REF: Declare The Schema Of A Virtual Table
7027**
7028** ^The [xCreate] and [xConnect] methods of a
7029** [virtual table module] call this interface
7030** to declare the format (the names and datatypes of the columns) of
7031** the virtual tables they implement.
7032*/
7033SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7034
7035/*
7036** CAPI3REF: Overload A Function For A Virtual Table
7037** METHOD: sqlite3
7038**
7039** ^(Virtual tables can provide alternative implementations of functions
7040** using the [xFindFunction] method of the [virtual table module].
7041** But global versions of those functions
7042** must exist in order to be overloaded.)^
7043**
7044** ^(This API makes sure a global version of a function with a particular
7045** name and number of parameters exists. If no such function exists
7046** before this API is called, a new function is created.)^ ^The implementation
7047** of the new function always causes an exception to be thrown. So
7048** the new function is not good for anything by itself. Its only
7049** purpose is to be a placeholder function that can be overloaded
7050** by a [virtual table].
7051*/
7052SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7053
7054/*
7055** The interface to the virtual-table mechanism defined above (back up
7056** to a comment remarkably similar to this one) is currently considered
7057** to be experimental. The interface might change in incompatible ways.
7058** If this is a problem for you, do not use the interface at this time.
7059**
7060** When the virtual-table mechanism stabilizes, we will declare the
7061** interface fixed, support it indefinitely, and remove this comment.
7062*/
7063
7064/*
7065** CAPI3REF: A Handle To An Open BLOB
7066** KEYWORDS: {BLOB handle} {BLOB handles}
7067**
7068** An instance of this object represents an open BLOB on which
7069** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7070** ^Objects of this type are created by [sqlite3_blob_open()]
7071** and destroyed by [sqlite3_blob_close()].
7072** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7073** can be used to read or write small subsections of the BLOB.
7074** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7075*/
7076typedef struct sqlite3_blob sqlite3_blob;
7077
7078/*
7079** CAPI3REF: Open A BLOB For Incremental I/O
7080** METHOD: sqlite3
7081** CONSTRUCTOR: sqlite3_blob
7082**
7083** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7084** in row iRow, column zColumn, table zTable in database zDb;
7085** in other words, the same BLOB that would be selected by:
7086**
7087** <pre>
7088** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7089** </pre>)^
7090**
7091** ^(Parameter zDb is not the filename that contains the database, but
7092** rather the symbolic name of the database. For attached databases, this is
7093** the name that appears after the AS keyword in the [ATTACH] statement.
7094** For the main database file, the database name is "main". For TEMP
7095** tables, the database name is "temp".)^
7096**
7097** ^If the flags parameter is non-zero, then the BLOB is opened for read
7098** and write access. ^If the flags parameter is zero, the BLOB is opened for
7099** read-only access.
7100**
7101** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7102** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7103** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7104** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7105** on *ppBlob after this function it returns.
7106**
7107** This function fails with SQLITE_ERROR if any of the following are true:
7108** <ul>
7109** <li> ^(Database zDb does not exist)^,
7110** <li> ^(Table zTable does not exist within database zDb)^,
7111** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7112** <li> ^(Column zColumn does not exist)^,
7113** <li> ^(Row iRow is not present in the table)^,
7114** <li> ^(The specified column of row iRow contains a value that is not
7115** a TEXT or BLOB value)^,
7116** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7117** constraint and the blob is being opened for read/write access)^,
7118** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7119** column zColumn is part of a [child key] definition and the blob is
7120** being opened for read/write access)^.
7121** </ul>
7122**
7123** ^Unless it returns SQLITE_MISUSE, this function sets the
7124** [database connection] error code and message accessible via
7125** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7126**
7127** A BLOB referenced by sqlite3_blob_open() may be read using the
7128** [sqlite3_blob_read()] interface and modified by using
7129** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7130** different row of the same table using the [sqlite3_blob_reopen()]
7131** interface. However, the column, table, or database of a [BLOB handle]
7132** cannot be changed after the [BLOB handle] is opened.
7133**
7134** ^(If the row that a BLOB handle points to is modified by an
7135** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7136** then the BLOB handle is marked as "expired".
7137** This is true if any column of the row is changed, even a column
7138** other than the one the BLOB handle is open on.)^
7139** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7140** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7141** ^(Changes written into a BLOB prior to the BLOB expiring are not
7142** rolled back by the expiration of the BLOB. Such changes will eventually
7143** commit if the transaction continues to completion.)^
7144**
7145** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7146** the opened blob. ^The size of a blob may not be changed by this
7147** interface. Use the [UPDATE] SQL command to change the size of a
7148** blob.
7149**
7150** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7151** and the built-in [zeroblob] SQL function may be used to create a
7152** zero-filled blob to read or write using the incremental-blob interface.
7153**
7154** To avoid a resource leak, every open [BLOB handle] should eventually
7155** be released by a call to [sqlite3_blob_close()].
7156**
7157** See also: [sqlite3_blob_close()],
7158** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7159** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7160*/
7161SQLITE_API int sqlite3_blob_open(
7162 sqlite3*,
7163 const char *zDb,
7164 const char *zTable,
7165 const char *zColumn,
7166 sqlite3_int64 iRow,
7167 int flags,
7168 sqlite3_blob **ppBlob
7169);
7170
7171/*
7172** CAPI3REF: Move a BLOB Handle to a New Row
7173** METHOD: sqlite3_blob
7174**
7175** ^This function is used to move an existing [BLOB handle] so that it points
7176** to a different row of the same database table. ^The new row is identified
7177** by the rowid value passed as the second argument. Only the row can be
7178** changed. ^The database, table and column on which the blob handle is open
7179** remain the same. Moving an existing [BLOB handle] to a new row is
7180** faster than closing the existing handle and opening a new one.
7181**
7182** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7183** it must exist and there must be either a blob or text value stored in
7184** the nominated column.)^ ^If the new row is not present in the table, or if
7185** it does not contain a blob or text value, or if another error occurs, an
7186** SQLite error code is returned and the blob handle is considered aborted.
7187** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7188** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7189** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7190** always returns zero.
7191**
7192** ^This function sets the database handle error code and message.
7193*/
7194SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7195
7196/*
7197** CAPI3REF: Close A BLOB Handle
7198** DESTRUCTOR: sqlite3_blob
7199**
7200** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7201** unconditionally. Even if this routine returns an error code, the
7202** handle is still closed.)^
7203**
7204** ^If the blob handle being closed was opened for read-write access, and if
7205** the database is in auto-commit mode and there are no other open read-write
7206** blob handles or active write statements, the current transaction is
7207** committed. ^If an error occurs while committing the transaction, an error
7208** code is returned and the transaction rolled back.
7209**
7210** Calling this function with an argument that is not a NULL pointer or an
7211** open blob handle results in undefined behaviour. ^Calling this routine
7212** with a null pointer (such as would be returned by a failed call to
7213** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7214** is passed a valid open blob handle, the values returned by the
7215** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7216*/
7217SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7218
7219/*
7220** CAPI3REF: Return The Size Of An Open BLOB
7221** METHOD: sqlite3_blob
7222**
7223** ^Returns the size in bytes of the BLOB accessible via the
7224** successfully opened [BLOB handle] in its only argument. ^The
7225** incremental blob I/O routines can only read or overwriting existing
7226** blob content; they cannot change the size of a blob.
7227**
7228** This routine only works on a [BLOB handle] which has been created
7229** by a prior successful call to [sqlite3_blob_open()] and which has not
7230** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7231** to this routine results in undefined and probably undesirable behavior.
7232*/
7233SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7234
7235/*
7236** CAPI3REF: Read Data From A BLOB Incrementally
7237** METHOD: sqlite3_blob
7238**
7239** ^(This function is used to read data from an open [BLOB handle] into a
7240** caller-supplied buffer. N bytes of data are copied into buffer Z
7241** from the open BLOB, starting at offset iOffset.)^
7242**
7243** ^If offset iOffset is less than N bytes from the end of the BLOB,
7244** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7245** less than zero, [SQLITE_ERROR] is returned and no data is read.
7246** ^The size of the blob (and hence the maximum value of N+iOffset)
7247** can be determined using the [sqlite3_blob_bytes()] interface.
7248**
7249** ^An attempt to read from an expired [BLOB handle] fails with an
7250** error code of [SQLITE_ABORT].
7251**
7252** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7253** Otherwise, an [error code] or an [extended error code] is returned.)^
7254**
7255** This routine only works on a [BLOB handle] which has been created
7256** by a prior successful call to [sqlite3_blob_open()] and which has not
7257** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7258** to this routine results in undefined and probably undesirable behavior.
7259**
7260** See also: [sqlite3_blob_write()].
7261*/
7262SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7263
7264/*
7265** CAPI3REF: Write Data Into A BLOB Incrementally
7266** METHOD: sqlite3_blob
7267**
7268** ^(This function is used to write data into an open [BLOB handle] from a
7269** caller-supplied buffer. N bytes of data are copied from the buffer Z
7270** into the open BLOB, starting at offset iOffset.)^
7271**
7272** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7273** Otherwise, an [error code] or an [extended error code] is returned.)^
7274** ^Unless SQLITE_MISUSE is returned, this function sets the
7275** [database connection] error code and message accessible via
7276** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7277**
7278** ^If the [BLOB handle] passed as the first argument was not opened for
7279** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7280** this function returns [SQLITE_READONLY].
7281**
7282** This function may only modify the contents of the BLOB; it is
7283** not possible to increase the size of a BLOB using this API.
7284** ^If offset iOffset is less than N bytes from the end of the BLOB,
7285** [SQLITE_ERROR] is returned and no data is written. The size of the
7286** BLOB (and hence the maximum value of N+iOffset) can be determined
7287** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7288** than zero [SQLITE_ERROR] is returned and no data is written.
7289**
7290** ^An attempt to write to an expired [BLOB handle] fails with an
7291** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7292** before the [BLOB handle] expired are not rolled back by the
7293** expiration of the handle, though of course those changes might
7294** have been overwritten by the statement that expired the BLOB handle
7295** or by other independent statements.
7296**
7297** This routine only works on a [BLOB handle] which has been created
7298** by a prior successful call to [sqlite3_blob_open()] and which has not
7299** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7300** to this routine results in undefined and probably undesirable behavior.
7301**
7302** See also: [sqlite3_blob_read()].
7303*/
7304SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7305
7306/*
7307** CAPI3REF: Virtual File System Objects
7308**
7309** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7310** that SQLite uses to interact
7311** with the underlying operating system. Most SQLite builds come with a
7312** single default VFS that is appropriate for the host computer.
7313** New VFSes can be registered and existing VFSes can be unregistered.
7314** The following interfaces are provided.
7315**
7316** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7317** ^Names are case sensitive.
7318** ^Names are zero-terminated UTF-8 strings.
7319** ^If there is no match, a NULL pointer is returned.
7320** ^If zVfsName is NULL then the default VFS is returned.
7321**
7322** ^New VFSes are registered with sqlite3_vfs_register().
7323** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7324** ^The same VFS can be registered multiple times without injury.
7325** ^To make an existing VFS into the default VFS, register it again
7326** with the makeDflt flag set. If two different VFSes with the
7327** same name are registered, the behavior is undefined. If a
7328** VFS is registered with a name that is NULL or an empty string,
7329** then the behavior is undefined.
7330**
7331** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7332** ^(If the default VFS is unregistered, another VFS is chosen as
7333** the default. The choice for the new VFS is arbitrary.)^
7334*/
7335SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7336SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7337SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7338
7339/*
7340** CAPI3REF: Mutexes
7341**
7342** The SQLite core uses these routines for thread
7343** synchronization. Though they are intended for internal
7344** use by SQLite, code that links against SQLite is
7345** permitted to use any of these routines.
7346**
7347** The SQLite source code contains multiple implementations
7348** of these mutex routines. An appropriate implementation
7349** is selected automatically at compile-time. The following
7350** implementations are available in the SQLite core:
7351**
7352** <ul>
7353** <li> SQLITE_MUTEX_PTHREADS
7354** <li> SQLITE_MUTEX_W32
7355** <li> SQLITE_MUTEX_NOOP
7356** </ul>
7357**
7358** The SQLITE_MUTEX_NOOP implementation is a set of routines
7359** that does no real locking and is appropriate for use in
7360** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7361** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7362** and Windows.
7363**
7364** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7365** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7366** implementation is included with the library. In this case the
7367** application must supply a custom mutex implementation using the
7368** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7369** before calling sqlite3_initialize() or any other public sqlite3_
7370** function that calls sqlite3_initialize().
7371**
7372** ^The sqlite3_mutex_alloc() routine allocates a new
7373** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7374** routine returns NULL if it is unable to allocate the requested
7375** mutex. The argument to sqlite3_mutex_alloc() must one of these
7376** integer constants:
7377**
7378** <ul>
7379** <li> SQLITE_MUTEX_FAST
7380** <li> SQLITE_MUTEX_RECURSIVE
7381** <li> SQLITE_MUTEX_STATIC_MAIN
7382** <li> SQLITE_MUTEX_STATIC_MEM
7383** <li> SQLITE_MUTEX_STATIC_OPEN
7384** <li> SQLITE_MUTEX_STATIC_PRNG
7385** <li> SQLITE_MUTEX_STATIC_LRU
7386** <li> SQLITE_MUTEX_STATIC_PMEM
7387** <li> SQLITE_MUTEX_STATIC_APP1
7388** <li> SQLITE_MUTEX_STATIC_APP2
7389** <li> SQLITE_MUTEX_STATIC_APP3
7390** <li> SQLITE_MUTEX_STATIC_VFS1
7391** <li> SQLITE_MUTEX_STATIC_VFS2
7392** <li> SQLITE_MUTEX_STATIC_VFS3
7393** </ul>
7394**
7395** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7396** cause sqlite3_mutex_alloc() to create
7397** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7398** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7399** The mutex implementation does not need to make a distinction
7400** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7401** not want to. SQLite will only request a recursive mutex in
7402** cases where it really needs one. If a faster non-recursive mutex
7403** implementation is available on the host platform, the mutex subsystem
7404** might return such a mutex in response to SQLITE_MUTEX_FAST.
7405**
7406** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7407** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7408** a pointer to a static preexisting mutex. ^Nine static mutexes are
7409** used by the current version of SQLite. Future versions of SQLite
7410** may add additional static mutexes. Static mutexes are for internal
7411** use by SQLite only. Applications that use SQLite mutexes should
7412** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7413** SQLITE_MUTEX_RECURSIVE.
7414**
7415** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7416** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7417** returns a different mutex on every call. ^For the static
7418** mutex types, the same mutex is returned on every call that has
7419** the same type number.
7420**
7421** ^The sqlite3_mutex_free() routine deallocates a previously
7422** allocated dynamic mutex. Attempting to deallocate a static
7423** mutex results in undefined behavior.
7424**
7425** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7426** to enter a mutex. ^If another thread is already within the mutex,
7427** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7428** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7429** upon successful entry. ^(Mutexes created using
7430** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7431** In such cases, the
7432** mutex must be exited an equal number of times before another thread
7433** can enter.)^ If the same thread tries to enter any mutex other
7434** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7435**
7436** ^(Some systems (for example, Windows 95) do not support the operation
7437** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7438** will always return SQLITE_BUSY. The SQLite core only ever uses
7439** sqlite3_mutex_try() as an optimization so this is acceptable
7440** behavior.)^
7441**
7442** ^The sqlite3_mutex_leave() routine exits a mutex that was
7443** previously entered by the same thread. The behavior
7444** is undefined if the mutex is not currently entered by the
7445** calling thread or is not currently allocated.
7446**
7447** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7448** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7449** behave as no-ops.
7450**
7451** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7452*/
7453SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7454SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7455SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7456SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7457SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7458
7459/*
7460** CAPI3REF: Mutex Methods Object
7461**
7462** An instance of this structure defines the low-level routines
7463** used to allocate and use mutexes.
7464**
7465** Usually, the default mutex implementations provided by SQLite are
7466** sufficient, however the application has the option of substituting a custom
7467** implementation for specialized deployments or systems for which SQLite
7468** does not provide a suitable implementation. In this case, the application
7469** creates and populates an instance of this structure to pass
7470** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7471** Additionally, an instance of this structure can be used as an
7472** output variable when querying the system for the current mutex
7473** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7474**
7475** ^The xMutexInit method defined by this structure is invoked as
7476** part of system initialization by the sqlite3_initialize() function.
7477** ^The xMutexInit routine is called by SQLite exactly once for each
7478** effective call to [sqlite3_initialize()].
7479**
7480** ^The xMutexEnd method defined by this structure is invoked as
7481** part of system shutdown by the sqlite3_shutdown() function. The
7482** implementation of this method is expected to release all outstanding
7483** resources obtained by the mutex methods implementation, especially
7484** those obtained by the xMutexInit method. ^The xMutexEnd()
7485** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7486**
7487** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7488** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7489** xMutexNotheld) implement the following interfaces (respectively):
7490**
7491** <ul>
7492** <li> [sqlite3_mutex_alloc()] </li>
7493** <li> [sqlite3_mutex_free()] </li>
7494** <li> [sqlite3_mutex_enter()] </li>
7495** <li> [sqlite3_mutex_try()] </li>
7496** <li> [sqlite3_mutex_leave()] </li>
7497** <li> [sqlite3_mutex_held()] </li>
7498** <li> [sqlite3_mutex_notheld()] </li>
7499** </ul>)^
7500**
7501** The only difference is that the public sqlite3_XXX functions enumerated
7502** above silently ignore any invocations that pass a NULL pointer instead
7503** of a valid mutex handle. The implementations of the methods defined
7504** by this structure are not required to handle this case. The results
7505** of passing a NULL pointer instead of a valid mutex handle are undefined
7506** (i.e. it is acceptable to provide an implementation that segfaults if
7507** it is passed a NULL pointer).
7508**
7509** The xMutexInit() method must be threadsafe. It must be harmless to
7510** invoke xMutexInit() multiple times within the same process and without
7511** intervening calls to xMutexEnd(). Second and subsequent calls to
7512** xMutexInit() must be no-ops.
7513**
7514** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7515** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7516** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7517** memory allocation for a fast or recursive mutex.
7518**
7519** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7520** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7521** If xMutexInit fails in any way, it is expected to clean up after itself
7522** prior to returning.
7523*/
7524typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7525struct sqlite3_mutex_methods {
7526 int (*xMutexInit)(void);
7527 int (*xMutexEnd)(void);
7528 sqlite3_mutex *(*xMutexAlloc)(int);
7529 void (*xMutexFree)(sqlite3_mutex *);
7530 void (*xMutexEnter)(sqlite3_mutex *);
7531 int (*xMutexTry)(sqlite3_mutex *);
7532 void (*xMutexLeave)(sqlite3_mutex *);
7533 int (*xMutexHeld)(sqlite3_mutex *);
7534 int (*xMutexNotheld)(sqlite3_mutex *);
7535};
7536
7537/*
7538** CAPI3REF: Mutex Verification Routines
7539**
7540** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7541** are intended for use inside assert() statements. The SQLite core
7542** never uses these routines except inside an assert() and applications
7543** are advised to follow the lead of the core. The SQLite core only
7544** provides implementations for these routines when it is compiled
7545** with the SQLITE_DEBUG flag. External mutex implementations
7546** are only required to provide these routines if SQLITE_DEBUG is
7547** defined and if NDEBUG is not defined.
7548**
7549** These routines should return true if the mutex in their argument
7550** is held or not held, respectively, by the calling thread.
7551**
7552** The implementation is not required to provide versions of these
7553** routines that actually work. If the implementation does not provide working
7554** versions of these routines, it should at least provide stubs that always
7555** return true so that one does not get spurious assertion failures.
7556**
7557** If the argument to sqlite3_mutex_held() is a NULL pointer then
7558** the routine should return 1. This seems counter-intuitive since
7559** clearly the mutex cannot be held if it does not exist. But
7560** the reason the mutex does not exist is because the build is not
7561** using mutexes. And we do not want the assert() containing the
7562** call to sqlite3_mutex_held() to fail, so a non-zero return is
7563** the appropriate thing to do. The sqlite3_mutex_notheld()
7564** interface should also return 1 when given a NULL pointer.
7565*/
7566#ifndef NDEBUG
7567SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7568SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7569#endif
7570
7571/*
7572** CAPI3REF: Mutex Types
7573**
7574** The [sqlite3_mutex_alloc()] interface takes a single argument
7575** which is one of these integer constants.
7576**
7577** The set of static mutexes may change from one SQLite release to the
7578** next. Applications that override the built-in mutex logic must be
7579** prepared to accommodate additional static mutexes.
7580*/
7581#define SQLITE_MUTEX_FAST 0
7582#define SQLITE_MUTEX_RECURSIVE 1
7583#define SQLITE_MUTEX_STATIC_MAIN 2
7584#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7585#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7586#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7587#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7588#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7589#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7590#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7591#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7592#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7593#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7594#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7595#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7596#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7597
7598/* Legacy compatibility: */
7599#define SQLITE_MUTEX_STATIC_MASTER 2
7600
7601
7602/*
7603** CAPI3REF: Retrieve the mutex for a database connection
7604** METHOD: sqlite3
7605**
7606** ^This interface returns a pointer the [sqlite3_mutex] object that
7607** serializes access to the [database connection] given in the argument
7608** when the [threading mode] is Serialized.
7609** ^If the [threading mode] is Single-thread or Multi-thread then this
7610** routine returns a NULL pointer.
7611*/
7612SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7613
7614/*
7615** CAPI3REF: Low-Level Control Of Database Files
7616** METHOD: sqlite3
7617** KEYWORDS: {file control}
7618**
7619** ^The [sqlite3_file_control()] interface makes a direct call to the
7620** xFileControl method for the [sqlite3_io_methods] object associated
7621** with a particular database identified by the second argument. ^The
7622** name of the database is "main" for the main database or "temp" for the
7623** TEMP database, or the name that appears after the AS keyword for
7624** databases that are added using the [ATTACH] SQL command.
7625** ^A NULL pointer can be used in place of "main" to refer to the
7626** main database file.
7627** ^The third and fourth parameters to this routine
7628** are passed directly through to the second and third parameters of
7629** the xFileControl method. ^The return value of the xFileControl
7630** method becomes the return value of this routine.
7631**
7632** A few opcodes for [sqlite3_file_control()] are handled directly
7633** by the SQLite core and never invoke the
7634** sqlite3_io_methods.xFileControl method.
7635** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7636** a pointer to the underlying [sqlite3_file] object to be written into
7637** the space pointed to by the 4th parameter. The
7638** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7639** the [sqlite3_file] object associated with the journal file instead of
7640** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7641** a pointer to the underlying [sqlite3_vfs] object for the file.
7642** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7643** from the pager.
7644**
7645** ^If the second parameter (zDbName) does not match the name of any
7646** open database file, then SQLITE_ERROR is returned. ^This error
7647** code is not remembered and will not be recalled by [sqlite3_errcode()]
7648** or [sqlite3_errmsg()]. The underlying xFileControl method might
7649** also return SQLITE_ERROR. There is no way to distinguish between
7650** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7651** xFileControl method.
7652**
7653** See also: [file control opcodes]
7654*/
7655SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7656
7657/*
7658** CAPI3REF: Testing Interface
7659**
7660** ^The sqlite3_test_control() interface is used to read out internal
7661** state of SQLite and to inject faults into SQLite for testing
7662** purposes. ^The first parameter is an operation code that determines
7663** the number, meaning, and operation of all subsequent parameters.
7664**
7665** This interface is not for use by applications. It exists solely
7666** for verifying the correct operation of the SQLite library. Depending
7667** on how the SQLite library is compiled, this interface might not exist.
7668**
7669** The details of the operation codes, their meanings, the parameters
7670** they take, and what they do are all subject to change without notice.
7671** Unlike most of the SQLite API, this function is not guaranteed to
7672** operate consistently from one release to the next.
7673*/
7674SQLITE_API int sqlite3_test_control(int op, ...);
7675
7676/*
7677** CAPI3REF: Testing Interface Operation Codes
7678**
7679** These constants are the valid operation code parameters used
7680** as the first argument to [sqlite3_test_control()].
7681**
7682** These parameters and their meanings are subject to change
7683** without notice. These values are for testing purposes only.
7684** Applications should not use any of these parameters or the
7685** [sqlite3_test_control()] interface.
7686*/
7687#define SQLITE_TESTCTRL_FIRST 5
7688#define SQLITE_TESTCTRL_PRNG_SAVE 5
7689#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7690#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
7691#define SQLITE_TESTCTRL_BITVEC_TEST 8
7692#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7693#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7694#define SQLITE_TESTCTRL_PENDING_BYTE 11
7695#define SQLITE_TESTCTRL_ASSERT 12
7696#define SQLITE_TESTCTRL_ALWAYS 13
7697#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
7698#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7699#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7700#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7701#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7702#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7703#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7704#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7705#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7706#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7707#define SQLITE_TESTCTRL_BYTEORDER 22
7708#define SQLITE_TESTCTRL_ISINIT 23
7709#define SQLITE_TESTCTRL_SORTER_MMAP 24
7710#define SQLITE_TESTCTRL_IMPOSTER 25
7711#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7712#define SQLITE_TESTCTRL_RESULT_INTREAL 27
7713#define SQLITE_TESTCTRL_PRNG_SEED 28
7714#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
7715#define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */
7716
7717/*
7718** CAPI3REF: SQL Keyword Checking
7719**
7720** These routines provide access to the set of SQL language keywords
7721** recognized by SQLite. Applications can uses these routines to determine
7722** whether or not a specific identifier needs to be escaped (for example,
7723** by enclosing in double-quotes) so as not to confuse the parser.
7724**
7725** The sqlite3_keyword_count() interface returns the number of distinct
7726** keywords understood by SQLite.
7727**
7728** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7729** makes *Z point to that keyword expressed as UTF8 and writes the number
7730** of bytes in the keyword into *L. The string that *Z points to is not
7731** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7732** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7733** or L are NULL or invalid pointers then calls to
7734** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7735**
7736** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7737** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7738** if it is and zero if not.
7739**
7740** The parser used by SQLite is forgiving. It is often possible to use
7741** a keyword as an identifier as long as such use does not result in a
7742** parsing ambiguity. For example, the statement
7743** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7744** creates a new table named "BEGIN" with three columns named
7745** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7746** using keywords as identifiers. Common techniques used to avoid keyword
7747** name collisions include:
7748** <ul>
7749** <li> Put all identifier names inside double-quotes. This is the official
7750** SQL way to escape identifier names.
7751** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
7752** but it is what SQL Server does and so lots of programmers use this
7753** technique.
7754** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7755** with "Z".
7756** <li> Include a digit somewhere in every identifier name.
7757** </ul>
7758**
7759** Note that the number of keywords understood by SQLite can depend on
7760** compile-time options. For example, "VACUUM" is not a keyword if
7761** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7762** new keywords may be added to future releases of SQLite.
7763*/
7764SQLITE_API int sqlite3_keyword_count(void);
7765SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7766SQLITE_API int sqlite3_keyword_check(const char*,int);
7767
7768/*
7769** CAPI3REF: Dynamic String Object
7770** KEYWORDS: {dynamic string}
7771**
7772** An instance of the sqlite3_str object contains a dynamically-sized
7773** string under construction.
7774**
7775** The lifecycle of an sqlite3_str object is as follows:
7776** <ol>
7777** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7778** <li> ^Text is appended to the sqlite3_str object using various
7779** methods, such as [sqlite3_str_appendf()].
7780** <li> ^The sqlite3_str object is destroyed and the string it created
7781** is returned using the [sqlite3_str_finish()] interface.
7782** </ol>
7783*/
7784typedef struct sqlite3_str sqlite3_str;
7785
7786/*
7787** CAPI3REF: Create A New Dynamic String Object
7788** CONSTRUCTOR: sqlite3_str
7789**
7790** ^The [sqlite3_str_new(D)] interface allocates and initializes
7791** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7792** [sqlite3_str_new()] must be freed by a subsequent call to
7793** [sqlite3_str_finish(X)].
7794**
7795** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7796** valid [sqlite3_str] object, though in the event of an out-of-memory
7797** error the returned object might be a special singleton that will
7798** silently reject new text, always return SQLITE_NOMEM from
7799** [sqlite3_str_errcode()], always return 0 for
7800** [sqlite3_str_length()], and always return NULL from
7801** [sqlite3_str_finish(X)]. It is always safe to use the value
7802** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7803** to any of the other [sqlite3_str] methods.
7804**
7805** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7806** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7807** length of the string contained in the [sqlite3_str] object will be
7808** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7809** of [SQLITE_MAX_LENGTH].
7810*/
7811SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7812
7813/*
7814** CAPI3REF: Finalize A Dynamic String
7815** DESTRUCTOR: sqlite3_str
7816**
7817** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7818** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7819** that contains the constructed string. The calling application should
7820** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7821** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7822** errors were encountered during construction of the string. ^The
7823** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7824** string in [sqlite3_str] object X is zero bytes long.
7825*/
7826SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7827
7828/*
7829** CAPI3REF: Add Content To A Dynamic String
7830** METHOD: sqlite3_str
7831**
7832** These interfaces add content to an sqlite3_str object previously obtained
7833** from [sqlite3_str_new()].
7834**
7835** ^The [sqlite3_str_appendf(X,F,...)] and
7836** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7837** functionality of SQLite to append formatted text onto the end of
7838** [sqlite3_str] object X.
7839**
7840** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7841** onto the end of the [sqlite3_str] object X. N must be non-negative.
7842** S must contain at least N non-zero bytes of content. To append a
7843** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7844** method instead.
7845**
7846** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7847** zero-terminated string S onto the end of [sqlite3_str] object X.
7848**
7849** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7850** single-byte character C onto the end of [sqlite3_str] object X.
7851** ^This method can be used, for example, to add whitespace indentation.
7852**
7853** ^The [sqlite3_str_reset(X)] method resets the string under construction
7854** inside [sqlite3_str] object X back to zero bytes in length.
7855**
7856** These methods do not return a result code. ^If an error occurs, that fact
7857** is recorded in the [sqlite3_str] object and can be recovered by a
7858** subsequent call to [sqlite3_str_errcode(X)].
7859*/
7860SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7861SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7862SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7863SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7864SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7865SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7866
7867/*
7868** CAPI3REF: Status Of A Dynamic String
7869** METHOD: sqlite3_str
7870**
7871** These interfaces return the current status of an [sqlite3_str] object.
7872**
7873** ^If any prior errors have occurred while constructing the dynamic string
7874** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7875** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7876** [SQLITE_NOMEM] following any out-of-memory error, or
7877** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7878** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7879**
7880** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7881** of the dynamic string under construction in [sqlite3_str] object X.
7882** ^The length returned by [sqlite3_str_length(X)] does not include the
7883** zero-termination byte.
7884**
7885** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7886** content of the dynamic string under construction in X. The value
7887** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7888** and might be freed or altered by any subsequent method on the same
7889** [sqlite3_str] object. Applications must not used the pointer returned
7890** [sqlite3_str_value(X)] after any subsequent method call on the same
7891** object. ^Applications may change the content of the string returned
7892** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7893** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7894** write any byte after any subsequent sqlite3_str method call.
7895*/
7896SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7897SQLITE_API int sqlite3_str_length(sqlite3_str*);
7898SQLITE_API char *sqlite3_str_value(sqlite3_str*);
7899
7900/*
7901** CAPI3REF: SQLite Runtime Status
7902**
7903** ^These interfaces are used to retrieve runtime status information
7904** about the performance of SQLite, and optionally to reset various
7905** highwater marks. ^The first argument is an integer code for
7906** the specific parameter to measure. ^(Recognized integer codes
7907** are of the form [status parameters | SQLITE_STATUS_...].)^
7908** ^The current value of the parameter is returned into *pCurrent.
7909** ^The highest recorded value is returned in *pHighwater. ^If the
7910** resetFlag is true, then the highest record value is reset after
7911** *pHighwater is written. ^(Some parameters do not record the highest
7912** value. For those parameters
7913** nothing is written into *pHighwater and the resetFlag is ignored.)^
7914** ^(Other parameters record only the highwater mark and not the current
7915** value. For these latter parameters nothing is written into *pCurrent.)^
7916**
7917** ^The sqlite3_status() and sqlite3_status64() routines return
7918** SQLITE_OK on success and a non-zero [error code] on failure.
7919**
7920** If either the current value or the highwater mark is too large to
7921** be represented by a 32-bit integer, then the values returned by
7922** sqlite3_status() are undefined.
7923**
7924** See also: [sqlite3_db_status()]
7925*/
7926SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7927SQLITE_API int sqlite3_status64(
7928 int op,
7929 sqlite3_int64 *pCurrent,
7930 sqlite3_int64 *pHighwater,
7931 int resetFlag
7932);
7933
7934
7935/*
7936** CAPI3REF: Status Parameters
7937** KEYWORDS: {status parameters}
7938**
7939** These integer constants designate various run-time status parameters
7940** that can be returned by [sqlite3_status()].
7941**
7942** <dl>
7943** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7944** <dd>This parameter is the current amount of memory checked out
7945** using [sqlite3_malloc()], either directly or indirectly. The
7946** figure includes calls made to [sqlite3_malloc()] by the application
7947** and internal memory usage by the SQLite library. Auxiliary page-cache
7948** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
7949** this parameter. The amount returned is the sum of the allocation
7950** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
7951**
7952** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
7953** <dd>This parameter records the largest memory allocation request
7954** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
7955** internal equivalents). Only the value returned in the
7956** *pHighwater parameter to [sqlite3_status()] is of interest.
7957** The value written into the *pCurrent parameter is undefined.</dd>)^
7958**
7959** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
7960** <dd>This parameter records the number of separate memory allocations
7961** currently checked out.</dd>)^
7962**
7963** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
7964** <dd>This parameter returns the number of pages used out of the
7965** [pagecache memory allocator] that was configured using
7966** [SQLITE_CONFIG_PAGECACHE]. The
7967** value returned is in pages, not in bytes.</dd>)^
7968**
7969** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
7970** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
7971** <dd>This parameter returns the number of bytes of page cache
7972** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
7973** buffer and where forced to overflow to [sqlite3_malloc()]. The
7974** returned value includes allocations that overflowed because they
7975** where too large (they were larger than the "sz" parameter to
7976** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
7977** no space was left in the page cache.</dd>)^
7978**
7979** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
7980** <dd>This parameter records the largest memory allocation request
7981** handed to the [pagecache memory allocator]. Only the value returned in the
7982** *pHighwater parameter to [sqlite3_status()] is of interest.
7983** The value written into the *pCurrent parameter is undefined.</dd>)^
7984**
7985** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
7986** <dd>No longer used.</dd>
7987**
7988** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
7989** <dd>No longer used.</dd>
7990**
7991** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
7992** <dd>No longer used.</dd>
7993**
7994** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
7995** <dd>The *pHighwater parameter records the deepest parser stack.
7996** The *pCurrent value is undefined. The *pHighwater value is only
7997** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
7998** </dl>
7999**
8000** New status parameters may be added from time to time.
8001*/
8002#define SQLITE_STATUS_MEMORY_USED 0
8003#define SQLITE_STATUS_PAGECACHE_USED 1
8004#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8005#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8006#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8007#define SQLITE_STATUS_MALLOC_SIZE 5
8008#define SQLITE_STATUS_PARSER_STACK 6
8009#define SQLITE_STATUS_PAGECACHE_SIZE 7
8010#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8011#define SQLITE_STATUS_MALLOC_COUNT 9
8012
8013/*
8014** CAPI3REF: Database Connection Status
8015** METHOD: sqlite3
8016**
8017** ^This interface is used to retrieve runtime status information
8018** about a single [database connection]. ^The first argument is the
8019** database connection object to be interrogated. ^The second argument
8020** is an integer constant, taken from the set of
8021** [SQLITE_DBSTATUS options], that
8022** determines the parameter to interrogate. The set of
8023** [SQLITE_DBSTATUS options] is likely
8024** to grow in future releases of SQLite.
8025**
8026** ^The current value of the requested parameter is written into *pCur
8027** and the highest instantaneous value is written into *pHiwtr. ^If
8028** the resetFlg is true, then the highest instantaneous value is
8029** reset back down to the current value.
8030**
8031** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8032** non-zero [error code] on failure.
8033**
8034** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8035*/
8036SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8037
8038/*
8039** CAPI3REF: Status Parameters for database connections
8040** KEYWORDS: {SQLITE_DBSTATUS options}
8041**
8042** These constants are the available integer "verbs" that can be passed as
8043** the second argument to the [sqlite3_db_status()] interface.
8044**
8045** New verbs may be added in future releases of SQLite. Existing verbs
8046** might be discontinued. Applications should check the return code from
8047** [sqlite3_db_status()] to make sure that the call worked.
8048** The [sqlite3_db_status()] interface will return a non-zero error code
8049** if a discontinued or unsupported verb is invoked.
8050**
8051** <dl>
8052** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8053** <dd>This parameter returns the number of lookaside memory slots currently
8054** checked out.</dd>)^
8055**
8056** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8057** <dd>This parameter returns the number of malloc attempts that were
8058** satisfied using lookaside memory. Only the high-water value is meaningful;
8059** the current value is always zero.)^
8060**
8061** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8062** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8063** <dd>This parameter returns the number malloc attempts that might have
8064** been satisfied using lookaside memory but failed due to the amount of
8065** memory requested being larger than the lookaside slot size.
8066** Only the high-water value is meaningful;
8067** the current value is always zero.)^
8068**
8069** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8070** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8071** <dd>This parameter returns the number malloc attempts that might have
8072** been satisfied using lookaside memory but failed due to all lookaside
8073** memory already being in use.
8074** Only the high-water value is meaningful;
8075** the current value is always zero.)^
8076**
8077** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8078** <dd>This parameter returns the approximate number of bytes of heap
8079** memory used by all pager caches associated with the database connection.)^
8080** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8081**
8082** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8083** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8084** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8085** pager cache is shared between two or more connections the bytes of heap
8086** memory used by that pager cache is divided evenly between the attached
8087** connections.)^ In other words, if none of the pager caches associated
8088** with the database connection are shared, this request returns the same
8089** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8090** shared, the value returned by this call will be smaller than that returned
8091** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8092** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8093**
8094** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8095** <dd>This parameter returns the approximate number of bytes of heap
8096** memory used to store the schema for all databases associated
8097** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8098** ^The full amount of memory used by the schemas is reported, even if the
8099** schema memory is shared with other database connections due to
8100** [shared cache mode] being enabled.
8101** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8102**
8103** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8104** <dd>This parameter returns the approximate number of bytes of heap
8105** and lookaside memory used by all prepared statements associated with
8106** the database connection.)^
8107** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8108** </dd>
8109**
8110** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8111** <dd>This parameter returns the number of pager cache hits that have
8112** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8113** is always 0.
8114** </dd>
8115**
8116** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8117** <dd>This parameter returns the number of pager cache misses that have
8118** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8119** is always 0.
8120** </dd>
8121**
8122** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8123** <dd>This parameter returns the number of dirty cache entries that have
8124** been written to disk. Specifically, the number of pages written to the
8125** wal file in wal mode databases, or the number of pages written to the
8126** database file in rollback mode databases. Any pages written as part of
8127** transaction rollback or database recovery operations are not included.
8128** If an IO or other error occurs while writing a page to disk, the effect
8129** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8130** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8131** </dd>
8132**
8133** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8134** <dd>This parameter returns the number of dirty cache entries that have
8135** been written to disk in the middle of a transaction due to the page
8136** cache overflowing. Transactions are more efficient if they are written
8137** to disk all at once. When pages spill mid-transaction, that introduces
8138** additional overhead. This parameter can be used help identify
8139** inefficiencies that can be resolved by increasing the cache size.
8140** </dd>
8141**
8142** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8143** <dd>This parameter returns zero for the current value if and only if
8144** all foreign key constraints (deferred or immediate) have been
8145** resolved.)^ ^The highwater mark is always 0.
8146** </dd>
8147** </dl>
8148*/
8149#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8150#define SQLITE_DBSTATUS_CACHE_USED 1
8151#define SQLITE_DBSTATUS_SCHEMA_USED 2
8152#define SQLITE_DBSTATUS_STMT_USED 3
8153#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8154#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8155#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8156#define SQLITE_DBSTATUS_CACHE_HIT 7
8157#define SQLITE_DBSTATUS_CACHE_MISS 8
8158#define SQLITE_DBSTATUS_CACHE_WRITE 9
8159#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8160#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8161#define SQLITE_DBSTATUS_CACHE_SPILL 12
8162#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8163
8164
8165/*
8166** CAPI3REF: Prepared Statement Status
8167** METHOD: sqlite3_stmt
8168**
8169** ^(Each prepared statement maintains various
8170** [SQLITE_STMTSTATUS counters] that measure the number
8171** of times it has performed specific operations.)^ These counters can
8172** be used to monitor the performance characteristics of the prepared
8173** statements. For example, if the number of table steps greatly exceeds
8174** the number of table searches or result rows, that would tend to indicate
8175** that the prepared statement is using a full table scan rather than
8176** an index.
8177**
8178** ^(This interface is used to retrieve and reset counter values from
8179** a [prepared statement]. The first argument is the prepared statement
8180** object to be interrogated. The second argument
8181** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8182** to be interrogated.)^
8183** ^The current value of the requested counter is returned.
8184** ^If the resetFlg is true, then the counter is reset to zero after this
8185** interface call returns.
8186**
8187** See also: [sqlite3_status()] and [sqlite3_db_status()].
8188*/
8189SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8190
8191/*
8192** CAPI3REF: Status Parameters for prepared statements
8193** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8194**
8195** These preprocessor macros define integer codes that name counter
8196** values associated with the [sqlite3_stmt_status()] interface.
8197** The meanings of the various counters are as follows:
8198**
8199** <dl>
8200** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8201** <dd>^This is the number of times that SQLite has stepped forward in
8202** a table as part of a full table scan. Large numbers for this counter
8203** may indicate opportunities for performance improvement through
8204** careful use of indices.</dd>
8205**
8206** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8207** <dd>^This is the number of sort operations that have occurred.
8208** A non-zero value in this counter may indicate an opportunity to
8209** improvement performance through careful use of indices.</dd>
8210**
8211** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8212** <dd>^This is the number of rows inserted into transient indices that
8213** were created automatically in order to help joins run faster.
8214** A non-zero value in this counter may indicate an opportunity to
8215** improvement performance by adding permanent indices that do not
8216** need to be reinitialized each time the statement is run.</dd>
8217**
8218** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8219** <dd>^This is the number of virtual machine operations executed
8220** by the prepared statement if that number is less than or equal
8221** to 2147483647. The number of virtual machine operations can be
8222** used as a proxy for the total work done by the prepared statement.
8223** If the number of virtual machine operations exceeds 2147483647
8224** then the value returned by this statement status code is undefined.
8225**
8226** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8227** <dd>^This is the number of times that the prepare statement has been
8228** automatically regenerated due to schema changes or changes to
8229** [bound parameters] that might affect the query plan.
8230**
8231** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8232** <dd>^This is the number of times that the prepared statement has
8233** been run. A single "run" for the purposes of this counter is one
8234** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8235** The counter is incremented on the first [sqlite3_step()] call of each
8236** cycle.
8237**
8238** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8239** <dd>^This is the approximate number of bytes of heap memory
8240** used to store the prepared statement. ^This value is not actually
8241** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8242** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8243** </dd>
8244** </dl>
8245*/
8246#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8247#define SQLITE_STMTSTATUS_SORT 2
8248#define SQLITE_STMTSTATUS_AUTOINDEX 3
8249#define SQLITE_STMTSTATUS_VM_STEP 4
8250#define SQLITE_STMTSTATUS_REPREPARE 5
8251#define SQLITE_STMTSTATUS_RUN 6
8252#define SQLITE_STMTSTATUS_MEMUSED 99
8253
8254/*
8255** CAPI3REF: Custom Page Cache Object
8256**
8257** The sqlite3_pcache type is opaque. It is implemented by
8258** the pluggable module. The SQLite core has no knowledge of
8259** its size or internal structure and never deals with the
8260** sqlite3_pcache object except by holding and passing pointers
8261** to the object.
8262**
8263** See [sqlite3_pcache_methods2] for additional information.
8264*/
8265typedef struct sqlite3_pcache sqlite3_pcache;
8266
8267/*
8268** CAPI3REF: Custom Page Cache Object
8269**
8270** The sqlite3_pcache_page object represents a single page in the
8271** page cache. The page cache will allocate instances of this
8272** object. Various methods of the page cache use pointers to instances
8273** of this object as parameters or as their return value.
8274**
8275** See [sqlite3_pcache_methods2] for additional information.
8276*/
8277typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8278struct sqlite3_pcache_page {
8279 void *pBuf; /* The content of the page */
8280 void *pExtra; /* Extra information associated with the page */
8281};
8282
8283/*
8284** CAPI3REF: Application Defined Page Cache.
8285** KEYWORDS: {page cache}
8286**
8287** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8288** register an alternative page cache implementation by passing in an
8289** instance of the sqlite3_pcache_methods2 structure.)^
8290** In many applications, most of the heap memory allocated by
8291** SQLite is used for the page cache.
8292** By implementing a
8293** custom page cache using this API, an application can better control
8294** the amount of memory consumed by SQLite, the way in which
8295** that memory is allocated and released, and the policies used to
8296** determine exactly which parts of a database file are cached and for
8297** how long.
8298**
8299** The alternative page cache mechanism is an
8300** extreme measure that is only needed by the most demanding applications.
8301** The built-in page cache is recommended for most uses.
8302**
8303** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8304** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8305** the application may discard the parameter after the call to
8306** [sqlite3_config()] returns.)^
8307**
8308** [[the xInit() page cache method]]
8309** ^(The xInit() method is called once for each effective
8310** call to [sqlite3_initialize()])^
8311** (usually only once during the lifetime of the process). ^(The xInit()
8312** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8313** The intent of the xInit() method is to set up global data structures
8314** required by the custom page cache implementation.
8315** ^(If the xInit() method is NULL, then the
8316** built-in default page cache is used instead of the application defined
8317** page cache.)^
8318**
8319** [[the xShutdown() page cache method]]
8320** ^The xShutdown() method is called by [sqlite3_shutdown()].
8321** It can be used to clean up
8322** any outstanding resources before process shutdown, if required.
8323** ^The xShutdown() method may be NULL.
8324**
8325** ^SQLite automatically serializes calls to the xInit method,
8326** so the xInit method need not be threadsafe. ^The
8327** xShutdown method is only called from [sqlite3_shutdown()] so it does
8328** not need to be threadsafe either. All other methods must be threadsafe
8329** in multithreaded applications.
8330**
8331** ^SQLite will never invoke xInit() more than once without an intervening
8332** call to xShutdown().
8333**
8334** [[the xCreate() page cache methods]]
8335** ^SQLite invokes the xCreate() method to construct a new cache instance.
8336** SQLite will typically create one cache instance for each open database file,
8337** though this is not guaranteed. ^The
8338** first parameter, szPage, is the size in bytes of the pages that must
8339** be allocated by the cache. ^szPage will always a power of two. ^The
8340** second parameter szExtra is a number of bytes of extra storage
8341** associated with each page cache entry. ^The szExtra parameter will
8342** a number less than 250. SQLite will use the
8343** extra szExtra bytes on each page to store metadata about the underlying
8344** database page on disk. The value passed into szExtra depends
8345** on the SQLite version, the target platform, and how SQLite was compiled.
8346** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8347** created will be used to cache database pages of a file stored on disk, or
8348** false if it is used for an in-memory database. The cache implementation
8349** does not have to do anything special based with the value of bPurgeable;
8350** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8351** never invoke xUnpin() except to deliberately delete a page.
8352** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8353** false will always have the "discard" flag set to true.
8354** ^Hence, a cache created with bPurgeable false will
8355** never contain any unpinned pages.
8356**
8357** [[the xCachesize() page cache method]]
8358** ^(The xCachesize() method may be called at any time by SQLite to set the
8359** suggested maximum cache-size (number of pages stored by) the cache
8360** instance passed as the first argument. This is the value configured using
8361** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8362** parameter, the implementation is not required to do anything with this
8363** value; it is advisory only.
8364**
8365** [[the xPagecount() page cache methods]]
8366** The xPagecount() method must return the number of pages currently
8367** stored in the cache, both pinned and unpinned.
8368**
8369** [[the xFetch() page cache methods]]
8370** The xFetch() method locates a page in the cache and returns a pointer to
8371** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8372** The pBuf element of the returned sqlite3_pcache_page object will be a
8373** pointer to a buffer of szPage bytes used to store the content of a
8374** single database page. The pExtra element of sqlite3_pcache_page will be
8375** a pointer to the szExtra bytes of extra storage that SQLite has requested
8376** for each entry in the page cache.
8377**
8378** The page to be fetched is determined by the key. ^The minimum key value
8379** is 1. After it has been retrieved using xFetch, the page is considered
8380** to be "pinned".
8381**
8382** If the requested page is already in the page cache, then the page cache
8383** implementation must return a pointer to the page buffer with its content
8384** intact. If the requested page is not already in the cache, then the
8385** cache implementation should use the value of the createFlag
8386** parameter to help it determined what action to take:
8387**
8388** <table border=1 width=85% align=center>
8389** <tr><th> createFlag <th> Behavior when page is not already in cache
8390** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8391** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8392** Otherwise return NULL.
8393** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8394** NULL if allocating a new page is effectively impossible.
8395** </table>
8396**
8397** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8398** will only use a createFlag of 2 after a prior call with a createFlag of 1
8399** failed.)^ In between the xFetch() calls, SQLite may
8400** attempt to unpin one or more cache pages by spilling the content of
8401** pinned pages to disk and synching the operating system disk cache.
8402**
8403** [[the xUnpin() page cache method]]
8404** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8405** as its second argument. If the third parameter, discard, is non-zero,
8406** then the page must be evicted from the cache.
8407** ^If the discard parameter is
8408** zero, then the page may be discarded or retained at the discretion of
8409** page cache implementation. ^The page cache implementation
8410** may choose to evict unpinned pages at any time.
8411**
8412** The cache must not perform any reference counting. A single
8413** call to xUnpin() unpins the page regardless of the number of prior calls
8414** to xFetch().
8415**
8416** [[the xRekey() page cache methods]]
8417** The xRekey() method is used to change the key value associated with the
8418** page passed as the second argument. If the cache
8419** previously contains an entry associated with newKey, it must be
8420** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8421** to be pinned.
8422**
8423** When SQLite calls the xTruncate() method, the cache must discard all
8424** existing cache entries with page numbers (keys) greater than or equal
8425** to the value of the iLimit parameter passed to xTruncate(). If any
8426** of these pages are pinned, they are implicitly unpinned, meaning that
8427** they can be safely discarded.
8428**
8429** [[the xDestroy() page cache method]]
8430** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8431** All resources associated with the specified cache should be freed. ^After
8432** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8433** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8434** functions.
8435**
8436** [[the xShrink() page cache method]]
8437** ^SQLite invokes the xShrink() method when it wants the page cache to
8438** free up as much of heap memory as possible. The page cache implementation
8439** is not obligated to free any memory, but well-behaved implementations should
8440** do their best.
8441*/
8442typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8443struct sqlite3_pcache_methods2 {
8444 int iVersion;
8445 void *pArg;
8446 int (*xInit)(void*);
8447 void (*xShutdown)(void*);
8448 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8449 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8450 int (*xPagecount)(sqlite3_pcache*);
8451 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8452 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8453 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8454 unsigned oldKey, unsigned newKey);
8455 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8456 void (*xDestroy)(sqlite3_pcache*);
8457 void (*xShrink)(sqlite3_pcache*);
8458};
8459
8460/*
8461** This is the obsolete pcache_methods object that has now been replaced
8462** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8463** retained in the header file for backwards compatibility only.
8464*/
8465typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8466struct sqlite3_pcache_methods {
8467 void *pArg;
8468 int (*xInit)(void*);
8469 void (*xShutdown)(void*);
8470 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8471 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8472 int (*xPagecount)(sqlite3_pcache*);
8473 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8474 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8475 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8476 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8477 void (*xDestroy)(sqlite3_pcache*);
8478};
8479
8480
8481/*
8482** CAPI3REF: Online Backup Object
8483**
8484** The sqlite3_backup object records state information about an ongoing
8485** online backup operation. ^The sqlite3_backup object is created by
8486** a call to [sqlite3_backup_init()] and is destroyed by a call to
8487** [sqlite3_backup_finish()].
8488**
8489** See Also: [Using the SQLite Online Backup API]
8490*/
8491typedef struct sqlite3_backup sqlite3_backup;
8492
8493/*
8494** CAPI3REF: Online Backup API.
8495**
8496** The backup API copies the content of one database into another.
8497** It is useful either for creating backups of databases or
8498** for copying in-memory databases to or from persistent files.
8499**
8500** See Also: [Using the SQLite Online Backup API]
8501**
8502** ^SQLite holds a write transaction open on the destination database file
8503** for the duration of the backup operation.
8504** ^The source database is read-locked only while it is being read;
8505** it is not locked continuously for the entire backup operation.
8506** ^Thus, the backup may be performed on a live source database without
8507** preventing other database connections from
8508** reading or writing to the source database while the backup is underway.
8509**
8510** ^(To perform a backup operation:
8511** <ol>
8512** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8513** backup,
8514** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8515** the data between the two databases, and finally
8516** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8517** associated with the backup operation.
8518** </ol>)^
8519** There should be exactly one call to sqlite3_backup_finish() for each
8520** successful call to sqlite3_backup_init().
8521**
8522** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8523**
8524** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8525** [database connection] associated with the destination database
8526** and the database name, respectively.
8527** ^The database name is "main" for the main database, "temp" for the
8528** temporary database, or the name specified after the AS keyword in
8529** an [ATTACH] statement for an attached database.
8530** ^The S and M arguments passed to
8531** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8532** and database name of the source database, respectively.
8533** ^The source and destination [database connections] (parameters S and D)
8534** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8535** an error.
8536**
8537** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8538** there is already a read or read-write transaction open on the
8539** destination database.
8540**
8541** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8542** returned and an error code and error message are stored in the
8543** destination [database connection] D.
8544** ^The error code and message for the failed call to sqlite3_backup_init()
8545** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8546** [sqlite3_errmsg16()] functions.
8547** ^A successful call to sqlite3_backup_init() returns a pointer to an
8548** [sqlite3_backup] object.
8549** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8550** sqlite3_backup_finish() functions to perform the specified backup
8551** operation.
8552**
8553** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8554**
8555** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8556** the source and destination databases specified by [sqlite3_backup] object B.
8557** ^If N is negative, all remaining source pages are copied.
8558** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8559** are still more pages to be copied, then the function returns [SQLITE_OK].
8560** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8561** from source to destination, then it returns [SQLITE_DONE].
8562** ^If an error occurs while running sqlite3_backup_step(B,N),
8563** then an [error code] is returned. ^As well as [SQLITE_OK] and
8564** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8565** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8566** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8567**
8568** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8569** <ol>
8570** <li> the destination database was opened read-only, or
8571** <li> the destination database is using write-ahead-log journaling
8572** and the destination and source page sizes differ, or
8573** <li> the destination database is an in-memory database and the
8574** destination and source page sizes differ.
8575** </ol>)^
8576**
8577** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8578** the [sqlite3_busy_handler | busy-handler function]
8579** is invoked (if one is specified). ^If the
8580** busy-handler returns non-zero before the lock is available, then
8581** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8582** sqlite3_backup_step() can be retried later. ^If the source
8583** [database connection]
8584** is being used to write to the source database when sqlite3_backup_step()
8585** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8586** case the call to sqlite3_backup_step() can be retried later on. ^(If
8587** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8588** [SQLITE_READONLY] is returned, then
8589** there is no point in retrying the call to sqlite3_backup_step(). These
8590** errors are considered fatal.)^ The application must accept
8591** that the backup operation has failed and pass the backup operation handle
8592** to the sqlite3_backup_finish() to release associated resources.
8593**
8594** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8595** on the destination file. ^The exclusive lock is not released until either
8596** sqlite3_backup_finish() is called or the backup operation is complete
8597** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8598** sqlite3_backup_step() obtains a [shared lock] on the source database that
8599** lasts for the duration of the sqlite3_backup_step() call.
8600** ^Because the source database is not locked between calls to
8601** sqlite3_backup_step(), the source database may be modified mid-way
8602** through the backup process. ^If the source database is modified by an
8603** external process or via a database connection other than the one being
8604** used by the backup operation, then the backup will be automatically
8605** restarted by the next call to sqlite3_backup_step(). ^If the source
8606** database is modified by the using the same database connection as is used
8607** by the backup operation, then the backup database is automatically
8608** updated at the same time.
8609**
8610** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8611**
8612** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8613** application wishes to abandon the backup operation, the application
8614** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8615** ^The sqlite3_backup_finish() interfaces releases all
8616** resources associated with the [sqlite3_backup] object.
8617** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8618** active write-transaction on the destination database is rolled back.
8619** The [sqlite3_backup] object is invalid
8620** and may not be used following a call to sqlite3_backup_finish().
8621**
8622** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8623** sqlite3_backup_step() errors occurred, regardless or whether or not
8624** sqlite3_backup_step() completed.
8625** ^If an out-of-memory condition or IO error occurred during any prior
8626** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8627** sqlite3_backup_finish() returns the corresponding [error code].
8628**
8629** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8630** is not a permanent error and does not affect the return value of
8631** sqlite3_backup_finish().
8632**
8633** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8634** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8635**
8636** ^The sqlite3_backup_remaining() routine returns the number of pages still
8637** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8638** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8639** in the source database at the conclusion of the most recent
8640** sqlite3_backup_step().
8641** ^(The values returned by these functions are only updated by
8642** sqlite3_backup_step(). If the source database is modified in a way that
8643** changes the size of the source database or the number of pages remaining,
8644** those changes are not reflected in the output of sqlite3_backup_pagecount()
8645** and sqlite3_backup_remaining() until after the next
8646** sqlite3_backup_step().)^
8647**
8648** <b>Concurrent Usage of Database Handles</b>
8649**
8650** ^The source [database connection] may be used by the application for other
8651** purposes while a backup operation is underway or being initialized.
8652** ^If SQLite is compiled and configured to support threadsafe database
8653** connections, then the source database connection may be used concurrently
8654** from within other threads.
8655**
8656** However, the application must guarantee that the destination
8657** [database connection] is not passed to any other API (by any thread) after
8658** sqlite3_backup_init() is called and before the corresponding call to
8659** sqlite3_backup_finish(). SQLite does not currently check to see
8660** if the application incorrectly accesses the destination [database connection]
8661** and so no error code is reported, but the operations may malfunction
8662** nevertheless. Use of the destination database connection while a
8663** backup is in progress might also also cause a mutex deadlock.
8664**
8665** If running in [shared cache mode], the application must
8666** guarantee that the shared cache used by the destination database
8667** is not accessed while the backup is running. In practice this means
8668** that the application must guarantee that the disk file being
8669** backed up to is not accessed by any connection within the process,
8670** not just the specific connection that was passed to sqlite3_backup_init().
8671**
8672** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8673** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8674** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8675** APIs are not strictly speaking threadsafe. If they are invoked at the
8676** same time as another thread is invoking sqlite3_backup_step() it is
8677** possible that they return invalid values.
8678*/
8679SQLITE_API sqlite3_backup *sqlite3_backup_init(
8680 sqlite3 *pDest, /* Destination database handle */
8681 const char *zDestName, /* Destination database name */
8682 sqlite3 *pSource, /* Source database handle */
8683 const char *zSourceName /* Source database name */
8684);
8685SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8686SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8687SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8688SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8689
8690/*
8691** CAPI3REF: Unlock Notification
8692** METHOD: sqlite3
8693**
8694** ^When running in shared-cache mode, a database operation may fail with
8695** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8696** individual tables within the shared-cache cannot be obtained. See
8697** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8698** ^This API may be used to register a callback that SQLite will invoke
8699** when the connection currently holding the required lock relinquishes it.
8700** ^This API is only available if the library was compiled with the
8701** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8702**
8703** See Also: [Using the SQLite Unlock Notification Feature].
8704**
8705** ^Shared-cache locks are released when a database connection concludes
8706** its current transaction, either by committing it or rolling it back.
8707**
8708** ^When a connection (known as the blocked connection) fails to obtain a
8709** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8710** identity of the database connection (the blocking connection) that
8711** has locked the required resource is stored internally. ^After an
8712** application receives an SQLITE_LOCKED error, it may call the
8713** sqlite3_unlock_notify() method with the blocked connection handle as
8714** the first argument to register for a callback that will be invoked
8715** when the blocking connections current transaction is concluded. ^The
8716** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8717** call that concludes the blocking connection's transaction.
8718**
8719** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8720** there is a chance that the blocking connection will have already
8721** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8722** If this happens, then the specified callback is invoked immediately,
8723** from within the call to sqlite3_unlock_notify().)^
8724**
8725** ^If the blocked connection is attempting to obtain a write-lock on a
8726** shared-cache table, and more than one other connection currently holds
8727** a read-lock on the same table, then SQLite arbitrarily selects one of
8728** the other connections to use as the blocking connection.
8729**
8730** ^(There may be at most one unlock-notify callback registered by a
8731** blocked connection. If sqlite3_unlock_notify() is called when the
8732** blocked connection already has a registered unlock-notify callback,
8733** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8734** called with a NULL pointer as its second argument, then any existing
8735** unlock-notify callback is canceled. ^The blocked connections
8736** unlock-notify callback may also be canceled by closing the blocked
8737** connection using [sqlite3_close()].
8738**
8739** The unlock-notify callback is not reentrant. If an application invokes
8740** any sqlite3_xxx API functions from within an unlock-notify callback, a
8741** crash or deadlock may be the result.
8742**
8743** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8744** returns SQLITE_OK.
8745**
8746** <b>Callback Invocation Details</b>
8747**
8748** When an unlock-notify callback is registered, the application provides a
8749** single void* pointer that is passed to the callback when it is invoked.
8750** However, the signature of the callback function allows SQLite to pass
8751** it an array of void* context pointers. The first argument passed to
8752** an unlock-notify callback is a pointer to an array of void* pointers,
8753** and the second is the number of entries in the array.
8754**
8755** When a blocking connection's transaction is concluded, there may be
8756** more than one blocked connection that has registered for an unlock-notify
8757** callback. ^If two or more such blocked connections have specified the
8758** same callback function, then instead of invoking the callback function
8759** multiple times, it is invoked once with the set of void* context pointers
8760** specified by the blocked connections bundled together into an array.
8761** This gives the application an opportunity to prioritize any actions
8762** related to the set of unblocked database connections.
8763**
8764** <b>Deadlock Detection</b>
8765**
8766** Assuming that after registering for an unlock-notify callback a
8767** database waits for the callback to be issued before taking any further
8768** action (a reasonable assumption), then using this API may cause the
8769** application to deadlock. For example, if connection X is waiting for
8770** connection Y's transaction to be concluded, and similarly connection
8771** Y is waiting on connection X's transaction, then neither connection
8772** will proceed and the system may remain deadlocked indefinitely.
8773**
8774** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8775** detection. ^If a given call to sqlite3_unlock_notify() would put the
8776** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8777** unlock-notify callback is registered. The system is said to be in
8778** a deadlocked state if connection A has registered for an unlock-notify
8779** callback on the conclusion of connection B's transaction, and connection
8780** B has itself registered for an unlock-notify callback when connection
8781** A's transaction is concluded. ^Indirect deadlock is also detected, so
8782** the system is also considered to be deadlocked if connection B has
8783** registered for an unlock-notify callback on the conclusion of connection
8784** C's transaction, where connection C is waiting on connection A. ^Any
8785** number of levels of indirection are allowed.
8786**
8787** <b>The "DROP TABLE" Exception</b>
8788**
8789** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
8790** always appropriate to call sqlite3_unlock_notify(). There is however,
8791** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8792** SQLite checks if there are any currently executing SELECT statements
8793** that belong to the same connection. If there are, SQLITE_LOCKED is
8794** returned. In this case there is no "blocking connection", so invoking
8795** sqlite3_unlock_notify() results in the unlock-notify callback being
8796** invoked immediately. If the application then re-attempts the "DROP TABLE"
8797** or "DROP INDEX" query, an infinite loop might be the result.
8798**
8799** One way around this problem is to check the extended error code returned
8800** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8801** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
8802** the special "DROP TABLE/INDEX" case, the extended error code is just
8803** SQLITE_LOCKED.)^
8804*/
8805SQLITE_API int sqlite3_unlock_notify(
8806 sqlite3 *pBlocked, /* Waiting connection */
8807 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8808 void *pNotifyArg /* Argument to pass to xNotify */
8809);
8810
8811
8812/*
8813** CAPI3REF: String Comparison
8814**
8815** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8816** and extensions to compare the contents of two buffers containing UTF-8
8817** strings in a case-independent fashion, using the same definition of "case
8818** independence" that SQLite uses internally when comparing identifiers.
8819*/
8820SQLITE_API int sqlite3_stricmp(const char *, const char *);
8821SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8822
8823/*
8824** CAPI3REF: String Globbing
8825*
8826** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8827** string X matches the [GLOB] pattern P.
8828** ^The definition of [GLOB] pattern matching used in
8829** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8830** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8831** is case sensitive.
8832**
8833** Note that this routine returns zero on a match and non-zero if the strings
8834** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8835**
8836** See also: [sqlite3_strlike()].
8837*/
8838SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8839
8840/*
8841** CAPI3REF: String LIKE Matching
8842*
8843** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8844** string X matches the [LIKE] pattern P with escape character E.
8845** ^The definition of [LIKE] pattern matching used in
8846** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8847** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8848** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8849** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8850** insensitive - equivalent upper and lower case ASCII characters match
8851** one another.
8852**
8853** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8854** only ASCII characters are case folded.
8855**
8856** Note that this routine returns zero on a match and non-zero if the strings
8857** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8858**
8859** See also: [sqlite3_strglob()].
8860*/
8861SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8862
8863/*
8864** CAPI3REF: Error Logging Interface
8865**
8866** ^The [sqlite3_log()] interface writes a message into the [error log]
8867** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8868** ^If logging is enabled, the zFormat string and subsequent arguments are
8869** used with [sqlite3_snprintf()] to generate the final output string.
8870**
8871** The sqlite3_log() interface is intended for use by extensions such as
8872** virtual tables, collating functions, and SQL functions. While there is
8873** nothing to prevent an application from calling sqlite3_log(), doing so
8874** is considered bad form.
8875**
8876** The zFormat string must not be NULL.
8877**
8878** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8879** will not use dynamically allocated memory. The log message is stored in
8880** a fixed-length buffer on the stack. If the log message is longer than
8881** a few hundred characters, it will be truncated to the length of the
8882** buffer.
8883*/
8884SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8885
8886/*
8887** CAPI3REF: Write-Ahead Log Commit Hook
8888** METHOD: sqlite3
8889**
8890** ^The [sqlite3_wal_hook()] function is used to register a callback that
8891** is invoked each time data is committed to a database in wal mode.
8892**
8893** ^(The callback is invoked by SQLite after the commit has taken place and
8894** the associated write-lock on the database released)^, so the implementation
8895** may read, write or [checkpoint] the database as required.
8896**
8897** ^The first parameter passed to the callback function when it is invoked
8898** is a copy of the third parameter passed to sqlite3_wal_hook() when
8899** registering the callback. ^The second is a copy of the database handle.
8900** ^The third parameter is the name of the database that was written to -
8901** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8902** is the number of pages currently in the write-ahead log file,
8903** including those that were just committed.
8904**
8905** The callback function should normally return [SQLITE_OK]. ^If an error
8906** code is returned, that error will propagate back up through the
8907** SQLite code base to cause the statement that provoked the callback
8908** to report an error, though the commit will have still occurred. If the
8909** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8910** that does not correspond to any valid SQLite error code, the results
8911** are undefined.
8912**
8913** A single database handle may have at most a single write-ahead log callback
8914** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8915** previously registered write-ahead log callback. ^Note that the
8916** [sqlite3_wal_autocheckpoint()] interface and the
8917** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8918** overwrite any prior [sqlite3_wal_hook()] settings.
8919*/
8920SQLITE_API void *sqlite3_wal_hook(
8921 sqlite3*,
8922 int(*)(void *,sqlite3*,const char*,int),
8923 void*
8924);
8925
8926/*
8927** CAPI3REF: Configure an auto-checkpoint
8928** METHOD: sqlite3
8929**
8930** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8931** [sqlite3_wal_hook()] that causes any database on [database connection] D
8932** to automatically [checkpoint]
8933** after committing a transaction if there are N or
8934** more frames in the [write-ahead log] file. ^Passing zero or
8935** a negative value as the nFrame parameter disables automatic
8936** checkpoints entirely.
8937**
8938** ^The callback registered by this function replaces any existing callback
8939** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8940** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8941** configured by this function.
8942**
8943** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8944** from SQL.
8945**
8946** ^Checkpoints initiated by this mechanism are
8947** [sqlite3_wal_checkpoint_v2|PASSIVE].
8948**
8949** ^Every new [database connection] defaults to having the auto-checkpoint
8950** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
8951** pages. The use of this interface
8952** is only necessary if the default setting is found to be suboptimal
8953** for a particular application.
8954*/
8955SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
8956
8957/*
8958** CAPI3REF: Checkpoint a database
8959** METHOD: sqlite3
8960**
8961** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
8962** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
8963**
8964** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
8965** [write-ahead log] for database X on [database connection] D to be
8966** transferred into the database file and for the write-ahead log to
8967** be reset. See the [checkpointing] documentation for addition
8968** information.
8969**
8970** This interface used to be the only way to cause a checkpoint to
8971** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
8972** interface was added. This interface is retained for backwards
8973** compatibility and as a convenience for applications that need to manually
8974** start a callback but which do not need the full power (and corresponding
8975** complication) of [sqlite3_wal_checkpoint_v2()].
8976*/
8977SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
8978
8979/*
8980** CAPI3REF: Checkpoint a database
8981** METHOD: sqlite3
8982**
8983** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
8984** operation on database X of [database connection] D in mode M. Status
8985** information is written back into integers pointed to by L and C.)^
8986** ^(The M parameter must be a valid [checkpoint mode]:)^
8987**
8988** <dl>
8989** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
8990** ^Checkpoint as many frames as possible without waiting for any database
8991** readers or writers to finish, then sync the database file if all frames
8992** in the log were checkpointed. ^The [busy-handler callback]
8993** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
8994** ^On the other hand, passive mode might leave the checkpoint unfinished
8995** if there are concurrent readers or writers.
8996**
8997** <dt>SQLITE_CHECKPOINT_FULL<dd>
8998** ^This mode blocks (it invokes the
8999** [sqlite3_busy_handler|busy-handler callback]) until there is no
9000** database writer and all readers are reading from the most recent database
9001** snapshot. ^It then checkpoints all frames in the log file and syncs the
9002** database file. ^This mode blocks new database writers while it is pending,
9003** but new database readers are allowed to continue unimpeded.
9004**
9005** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9006** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9007** that after checkpointing the log file it blocks (calls the
9008** [busy-handler callback])
9009** until all readers are reading from the database file only. ^This ensures
9010** that the next writer will restart the log file from the beginning.
9011** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9012** database writer attempts while it is pending, but does not impede readers.
9013**
9014** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9015** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9016** addition that it also truncates the log file to zero bytes just prior
9017** to a successful return.
9018** </dl>
9019**
9020** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9021** the log file or to -1 if the checkpoint could not run because
9022** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9023** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9024** log file (including any that were already checkpointed before the function
9025** was called) or to -1 if the checkpoint could not run due to an error or
9026** because the database is not in WAL mode. ^Note that upon successful
9027** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9028** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9029**
9030** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9031** any other process is running a checkpoint operation at the same time, the
9032** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9033** busy-handler configured, it will not be invoked in this case.
9034**
9035** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9036** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9037** obtained immediately, and a busy-handler is configured, it is invoked and
9038** the writer lock retried until either the busy-handler returns 0 or the lock
9039** is successfully obtained. ^The busy-handler is also invoked while waiting for
9040** database readers as described above. ^If the busy-handler returns 0 before
9041** the writer lock is obtained or while waiting for database readers, the
9042** checkpoint operation proceeds from that point in the same way as
9043** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9044** without blocking any further. ^SQLITE_BUSY is returned in this case.
9045**
9046** ^If parameter zDb is NULL or points to a zero length string, then the
9047** specified operation is attempted on all WAL databases [attached] to
9048** [database connection] db. In this case the
9049** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9050** an SQLITE_BUSY error is encountered when processing one or more of the
9051** attached WAL databases, the operation is still attempted on any remaining
9052** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9053** error occurs while processing an attached database, processing is abandoned
9054** and the error code is returned to the caller immediately. ^If no error
9055** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9056** databases, SQLITE_OK is returned.
9057**
9058** ^If database zDb is the name of an attached database that is not in WAL
9059** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9060** zDb is not NULL (or a zero length string) and is not the name of any
9061** attached database, SQLITE_ERROR is returned to the caller.
9062**
9063** ^Unless it returns SQLITE_MISUSE,
9064** the sqlite3_wal_checkpoint_v2() interface
9065** sets the error information that is queried by
9066** [sqlite3_errcode()] and [sqlite3_errmsg()].
9067**
9068** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9069** from SQL.
9070*/
9071SQLITE_API int sqlite3_wal_checkpoint_v2(
9072 sqlite3 *db, /* Database handle */
9073 const char *zDb, /* Name of attached database (or NULL) */
9074 int eMode, /* SQLITE_CHECKPOINT_* value */
9075 int *pnLog, /* OUT: Size of WAL log in frames */
9076 int *pnCkpt /* OUT: Total number of frames checkpointed */
9077);
9078
9079/*
9080** CAPI3REF: Checkpoint Mode Values
9081** KEYWORDS: {checkpoint mode}
9082**
9083** These constants define all valid values for the "checkpoint mode" passed
9084** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9085** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9086** meaning of each of these checkpoint modes.
9087*/
9088#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9089#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9090#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
9091#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9092
9093/*
9094** CAPI3REF: Virtual Table Interface Configuration
9095**
9096** This function may be called by either the [xConnect] or [xCreate] method
9097** of a [virtual table] implementation to configure
9098** various facets of the virtual table interface.
9099**
9100** If this interface is invoked outside the context of an xConnect or
9101** xCreate virtual table method then the behavior is undefined.
9102**
9103** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9104** [database connection] in which the virtual table is being created and
9105** which is passed in as the first argument to the [xConnect] or [xCreate]
9106** method that is invoking sqlite3_vtab_config(). The C parameter is one
9107** of the [virtual table configuration options]. The presence and meaning
9108** of parameters after C depend on which [virtual table configuration option]
9109** is used.
9110*/
9111SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9112
9113/*
9114** CAPI3REF: Virtual Table Configuration Options
9115** KEYWORDS: {virtual table configuration options}
9116** KEYWORDS: {virtual table configuration option}
9117**
9118** These macros define the various options to the
9119** [sqlite3_vtab_config()] interface that [virtual table] implementations
9120** can use to customize and optimize their behavior.
9121**
9122** <dl>
9123** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9124** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9125** <dd>Calls of the form
9126** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9127** where X is an integer. If X is zero, then the [virtual table] whose
9128** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9129** support constraints. In this configuration (which is the default) if
9130** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9131** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9132** specified as part of the users SQL statement, regardless of the actual
9133** ON CONFLICT mode specified.
9134**
9135** If X is non-zero, then the virtual table implementation guarantees
9136** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9137** any modifications to internal or persistent data structures have been made.
9138** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9139** is able to roll back a statement or database transaction, and abandon
9140** or continue processing the current SQL statement as appropriate.
9141** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9142** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9143** had been ABORT.
9144**
9145** Virtual table implementations that are required to handle OR REPLACE
9146** must do so within the [xUpdate] method. If a call to the
9147** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9148** CONFLICT policy is REPLACE, the virtual table implementation should
9149** silently replace the appropriate rows within the xUpdate callback and
9150** return SQLITE_OK. Or, if this is not possible, it may return
9151** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9152** constraint handling.
9153** </dd>
9154**
9155** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9156** <dd>Calls of the form
9157** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9158** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9159** prohibits that virtual table from being used from within triggers and
9160** views.
9161** </dd>
9162**
9163** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9164** <dd>Calls of the form
9165** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9166** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9167** identify that virtual table as being safe to use from within triggers
9168** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9169** virtual table can do no serious harm even if it is controlled by a
9170** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9171** flag unless absolutely necessary.
9172** </dd>
9173** </dl>
9174*/
9175#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9176#define SQLITE_VTAB_INNOCUOUS 2
9177#define SQLITE_VTAB_DIRECTONLY 3
9178
9179/*
9180** CAPI3REF: Determine The Virtual Table Conflict Policy
9181**
9182** This function may only be called from within a call to the [xUpdate] method
9183** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9184** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9185** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9186** of the SQL statement that triggered the call to the [xUpdate] method of the
9187** [virtual table].
9188*/
9189SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9190
9191/*
9192** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9193**
9194** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9195** method of a [virtual table], then it returns true if and only if the
9196** column is being fetched as part of an UPDATE operation during which the
9197** column value will not change. Applications might use this to substitute
9198** a return value that is less expensive to compute and that the corresponding
9199** [xUpdate] method understands as a "no-change" value.
9200**
9201** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9202** the column is not changed by the UPDATE statement, then the xColumn
9203** method can optionally return without setting a result, without calling
9204** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9205** In that case, [sqlite3_value_nochange(X)] will return true for the
9206** same column in the [xUpdate] method.
9207*/
9208SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9209
9210/*
9211** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9212**
9213** This function may only be called from within a call to the [xBestIndex]
9214** method of a [virtual table].
9215**
9216** The first argument must be the sqlite3_index_info object that is the
9217** first parameter to the xBestIndex() method. The second argument must be
9218** an index into the aConstraint[] array belonging to the sqlite3_index_info
9219** structure passed to xBestIndex. This function returns a pointer to a buffer
9220** containing the name of the collation sequence for the corresponding
9221** constraint.
9222*/
9223SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9224
9225/*
9226** CAPI3REF: Conflict resolution modes
9227** KEYWORDS: {conflict resolution mode}
9228**
9229** These constants are returned by [sqlite3_vtab_on_conflict()] to
9230** inform a [virtual table] implementation what the [ON CONFLICT] mode
9231** is for the SQL statement being evaluated.
9232**
9233** Note that the [SQLITE_IGNORE] constant is also used as a potential
9234** return value from the [sqlite3_set_authorizer()] callback and that
9235** [SQLITE_ABORT] is also a [result code].
9236*/
9237#define SQLITE_ROLLBACK 1
9238/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9239#define SQLITE_FAIL 3
9240/* #define SQLITE_ABORT 4 // Also an error code */
9241#define SQLITE_REPLACE 5
9242
9243/*
9244** CAPI3REF: Prepared Statement Scan Status Opcodes
9245** KEYWORDS: {scanstatus options}
9246**
9247** The following constants can be used for the T parameter to the
9248** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9249** different metric for sqlite3_stmt_scanstatus() to return.
9250**
9251** When the value returned to V is a string, space to hold that string is
9252** managed by the prepared statement S and will be automatically freed when
9253** S is finalized.
9254**
9255** <dl>
9256** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
9257** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
9258** set to the total number of times that the X-th loop has run.</dd>
9259**
9260** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
9261** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
9262** to the total number of rows examined by all iterations of the X-th loop.</dd>
9263**
9264** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
9265** <dd>^The "double" variable pointed to by the V parameter will be set to the
9266** query planner's estimate for the average number of rows output from each
9267** iteration of the X-th loop. If the query planner's estimates was accurate,
9268** then this value will approximate the quotient NVISIT/NLOOP and the
9269** product of this value for all prior loops with the same SELECTID will
9270** be the NLOOP value for the current loop.
9271**
9272** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
9273** <dd>^The "const char *" variable pointed to by the V parameter will be set
9274** to a zero-terminated UTF-8 string containing the name of the index or table
9275** used for the X-th loop.
9276**
9277** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
9278** <dd>^The "const char *" variable pointed to by the V parameter will be set
9279** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9280** description for the X-th loop.
9281**
9282** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
9283** <dd>^The "int" variable pointed to by the V parameter will be set to the
9284** "select-id" for the X-th loop. The select-id identifies which query or
9285** subquery the loop is part of. The main query has a select-id of zero.
9286** The select-id is the same value as is output in the first column
9287** of an [EXPLAIN QUERY PLAN] query.
9288** </dl>
9289*/
9290#define SQLITE_SCANSTAT_NLOOP 0
9291#define SQLITE_SCANSTAT_NVISIT 1
9292#define SQLITE_SCANSTAT_EST 2
9293#define SQLITE_SCANSTAT_NAME 3
9294#define SQLITE_SCANSTAT_EXPLAIN 4
9295#define SQLITE_SCANSTAT_SELECTID 5
9296
9297/*
9298** CAPI3REF: Prepared Statement Scan Status
9299** METHOD: sqlite3_stmt
9300**
9301** This interface returns information about the predicted and measured
9302** performance for pStmt. Advanced applications can use this
9303** interface to compare the predicted and the measured performance and
9304** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9305**
9306** Since this interface is expected to be rarely used, it is only
9307** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9308** compile-time option.
9309**
9310** The "iScanStatusOp" parameter determines which status information to return.
9311** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9312** of this interface is undefined.
9313** ^The requested measurement is written into a variable pointed to by
9314** the "pOut" parameter.
9315** Parameter "idx" identifies the specific loop to retrieve statistics for.
9316** Loops are numbered starting from zero. ^If idx is out of range - less than
9317** zero or greater than or equal to the total number of loops used to implement
9318** the statement - a non-zero value is returned and the variable that pOut
9319** points to is unchanged.
9320**
9321** ^Statistics might not be available for all loops in all statements. ^In cases
9322** where there exist loops with no available statistics, this function behaves
9323** as if the loop did not exist - it returns non-zero and leave the variable
9324** that pOut points to unchanged.
9325**
9326** See also: [sqlite3_stmt_scanstatus_reset()]
9327*/
9328SQLITE_API int sqlite3_stmt_scanstatus(
9329 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9330 int idx, /* Index of loop to report on */
9331 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9332 void *pOut /* Result written here */
9333);
9334
9335/*
9336** CAPI3REF: Zero Scan-Status Counters
9337** METHOD: sqlite3_stmt
9338**
9339** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9340**
9341** This API is only available if the library is built with pre-processor
9342** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9343*/
9344SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9345
9346/*
9347** CAPI3REF: Flush caches to disk mid-transaction
9348**
9349** ^If a write-transaction is open on [database connection] D when the
9350** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
9351** pages in the pager-cache that are not currently in use are written out
9352** to disk. A dirty page may be in use if a database cursor created by an
9353** active SQL statement is reading from it, or if it is page 1 of a database
9354** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9355** interface flushes caches for all schemas - "main", "temp", and
9356** any [attached] databases.
9357**
9358** ^If this function needs to obtain extra database locks before dirty pages
9359** can be flushed to disk, it does so. ^If those locks cannot be obtained
9360** immediately and there is a busy-handler callback configured, it is invoked
9361** in the usual manner. ^If the required lock still cannot be obtained, then
9362** the database is skipped and an attempt made to flush any dirty pages
9363** belonging to the next (if any) database. ^If any databases are skipped
9364** because locks cannot be obtained, but no other error occurs, this
9365** function returns SQLITE_BUSY.
9366**
9367** ^If any other error occurs while flushing dirty pages to disk (for
9368** example an IO error or out-of-memory condition), then processing is
9369** abandoned and an SQLite [error code] is returned to the caller immediately.
9370**
9371** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
9372**
9373** ^This function does not set the database handle error code or message
9374** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
9375*/
9376SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
9377
9378/*
9379** CAPI3REF: The pre-update hook.
9380**
9381** ^These interfaces are only available if SQLite is compiled using the
9382** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
9383**
9384** ^The [sqlite3_preupdate_hook()] interface registers a callback function
9385** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
9386** on a database table.
9387** ^At most one preupdate hook may be registered at a time on a single
9388** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
9389** the previous setting.
9390** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
9391** with a NULL pointer as the second parameter.
9392** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
9393** the first parameter to callbacks.
9394**
9395** ^The preupdate hook only fires for changes to real database tables; the
9396** preupdate hook is not invoked for changes to [virtual tables] or to
9397** system tables like sqlite_sequence or sqlite_stat1.
9398**
9399** ^The second parameter to the preupdate callback is a pointer to
9400** the [database connection] that registered the preupdate hook.
9401** ^The third parameter to the preupdate callback is one of the constants
9402** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
9403** kind of update operation that is about to occur.
9404** ^(The fourth parameter to the preupdate callback is the name of the
9405** database within the database connection that is being modified. This
9406** will be "main" for the main database or "temp" for TEMP tables or
9407** the name given after the AS keyword in the [ATTACH] statement for attached
9408** databases.)^
9409** ^The fifth parameter to the preupdate callback is the name of the
9410** table that is being modified.
9411**
9412** For an UPDATE or DELETE operation on a [rowid table], the sixth
9413** parameter passed to the preupdate callback is the initial [rowid] of the
9414** row being modified or deleted. For an INSERT operation on a rowid table,
9415** or any operation on a WITHOUT ROWID table, the value of the sixth
9416** parameter is undefined. For an INSERT or UPDATE on a rowid table the
9417** seventh parameter is the final rowid value of the row being inserted
9418** or updated. The value of the seventh parameter passed to the callback
9419** function is not defined for operations on WITHOUT ROWID tables, or for
9420** INSERT operations on rowid tables.
9421**
9422** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
9423** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
9424** provide additional information about a preupdate event. These routines
9425** may only be called from within a preupdate callback. Invoking any of
9426** these routines from outside of a preupdate callback or with a
9427** [database connection] pointer that is different from the one supplied
9428** to the preupdate callback results in undefined and probably undesirable
9429** behavior.
9430**
9431** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
9432** in the row that is being inserted, updated, or deleted.
9433**
9434** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
9435** a [protected sqlite3_value] that contains the value of the Nth column of
9436** the table row before it is updated. The N parameter must be between 0
9437** and one less than the number of columns or the behavior will be
9438** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
9439** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
9440** behavior is undefined. The [sqlite3_value] that P points to
9441** will be destroyed when the preupdate callback returns.
9442**
9443** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
9444** a [protected sqlite3_value] that contains the value of the Nth column of
9445** the table row after it is updated. The N parameter must be between 0
9446** and one less than the number of columns or the behavior will be
9447** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
9448** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
9449** behavior is undefined. The [sqlite3_value] that P points to
9450** will be destroyed when the preupdate callback returns.
9451**
9452** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
9453** callback was invoked as a result of a direct insert, update, or delete
9454** operation; or 1 for inserts, updates, or deletes invoked by top-level
9455** triggers; or 2 for changes resulting from triggers called by top-level
9456** triggers; and so forth.
9457**
9458** See also: [sqlite3_update_hook()]
9459*/
9460#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9461SQLITE_API void *sqlite3_preupdate_hook(
9462 sqlite3 *db,
9463 void(*xPreUpdate)(
9464 void *pCtx, /* Copy of third arg to preupdate_hook() */
9465 sqlite3 *db, /* Database handle */
9466 int op, /* SQLITE_UPDATE, DELETE or INSERT */
9467 char const *zDb, /* Database name */
9468 char const *zName, /* Table name */
9469 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9470 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9471 ),
9472 void*
9473);
9474SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9475SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9476SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9477SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9478#endif
9479
9480/*
9481** CAPI3REF: Low-level system error code
9482**
9483** ^Attempt to return the underlying operating system error code or error
9484** number that caused the most recent I/O error or failure to open a file.
9485** The return value is OS-dependent. For example, on unix systems, after
9486** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9487** called to get back the underlying "errno" that caused the problem, such
9488** as ENOSPC, EAUTH, EISDIR, and so forth.
9489*/
9490SQLITE_API int sqlite3_system_errno(sqlite3*);
9491
9492/*
9493** CAPI3REF: Database Snapshot
9494** KEYWORDS: {snapshot} {sqlite3_snapshot}
9495**
9496** An instance of the snapshot object records the state of a [WAL mode]
9497** database for some specific point in history.
9498**
9499** In [WAL mode], multiple [database connections] that are open on the
9500** same database file can each be reading a different historical version
9501** of the database file. When a [database connection] begins a read
9502** transaction, that connection sees an unchanging copy of the database
9503** as it existed for the point in time when the transaction first started.
9504** Subsequent changes to the database from other connections are not seen
9505** by the reader until a new read transaction is started.
9506**
9507** The sqlite3_snapshot object records state information about an historical
9508** version of the database file so that it is possible to later open a new read
9509** transaction that sees that historical version of the database rather than
9510** the most recent version.
9511*/
9512typedef struct sqlite3_snapshot {
9513 unsigned char hidden[48];
9514} sqlite3_snapshot;
9515
9516/*
9517** CAPI3REF: Record A Database Snapshot
9518** CONSTRUCTOR: sqlite3_snapshot
9519**
9520** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9521** new [sqlite3_snapshot] object that records the current state of
9522** schema S in database connection D. ^On success, the
9523** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9524** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9525** If there is not already a read-transaction open on schema S when
9526** this function is called, one is opened automatically.
9527**
9528** The following must be true for this function to succeed. If any of
9529** the following statements are false when sqlite3_snapshot_get() is
9530** called, SQLITE_ERROR is returned. The final value of *P is undefined
9531** in this case.
9532**
9533** <ul>
9534** <li> The database handle must not be in [autocommit mode].
9535**
9536** <li> Schema S of [database connection] D must be a [WAL mode] database.
9537**
9538** <li> There must not be a write transaction open on schema S of database
9539** connection D.
9540**
9541** <li> One or more transactions must have been written to the current wal
9542** file since it was created on disk (by any connection). This means
9543** that a snapshot cannot be taken on a wal mode database with no wal
9544** file immediately after it is first opened. At least one transaction
9545** must be written to it first.
9546** </ul>
9547**
9548** This function may also return SQLITE_NOMEM. If it is called with the
9549** database handle in autocommit mode but fails for some other reason,
9550** whether or not a read transaction is opened on schema S is undefined.
9551**
9552** The [sqlite3_snapshot] object returned from a successful call to
9553** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9554** to avoid a memory leak.
9555**
9556** The [sqlite3_snapshot_get()] interface is only available when the
9557** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9558*/
9559SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9560 sqlite3 *db,
9561 const char *zSchema,
9562 sqlite3_snapshot **ppSnapshot
9563);
9564
9565/*
9566** CAPI3REF: Start a read transaction on an historical snapshot
9567** METHOD: sqlite3_snapshot
9568**
9569** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9570** transaction or upgrades an existing one for schema S of
9571** [database connection] D such that the read transaction refers to
9572** historical [snapshot] P, rather than the most recent change to the
9573** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9574** on success or an appropriate [error code] if it fails.
9575**
9576** ^In order to succeed, the database connection must not be in
9577** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9578** is already a read transaction open on schema S, then the database handle
9579** must have no active statements (SELECT statements that have been passed
9580** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9581** SQLITE_ERROR is returned if either of these conditions is violated, or
9582** if schema S does not exist, or if the snapshot object is invalid.
9583**
9584** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9585** snapshot has been overwritten by a [checkpoint]. In this case
9586** SQLITE_ERROR_SNAPSHOT is returned.
9587**
9588** If there is already a read transaction open when this function is
9589** invoked, then the same read transaction remains open (on the same
9590** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9591** is returned. If another error code - for example SQLITE_PROTOCOL or an
9592** SQLITE_IOERR error code - is returned, then the final state of the
9593** read transaction is undefined. If SQLITE_OK is returned, then the
9594** read transaction is now open on database snapshot P.
9595**
9596** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9597** database connection D does not know that the database file for
9598** schema S is in [WAL mode]. A database connection might not know
9599** that the database file is in [WAL mode] if there has been no prior
9600** I/O on that database connection, or if the database entered [WAL mode]
9601** after the most recent I/O on the database connection.)^
9602** (Hint: Run "[PRAGMA application_id]" against a newly opened
9603** database connection in order to make it ready to use snapshots.)
9604**
9605** The [sqlite3_snapshot_open()] interface is only available when the
9606** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9607*/
9608SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9609 sqlite3 *db,
9610 const char *zSchema,
9611 sqlite3_snapshot *pSnapshot
9612);
9613
9614/*
9615** CAPI3REF: Destroy a snapshot
9616** DESTRUCTOR: sqlite3_snapshot
9617**
9618** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9619** The application must eventually free every [sqlite3_snapshot] object
9620** using this routine to avoid a memory leak.
9621**
9622** The [sqlite3_snapshot_free()] interface is only available when the
9623** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9624*/
9625SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9626
9627/*
9628** CAPI3REF: Compare the ages of two snapshot handles.
9629** METHOD: sqlite3_snapshot
9630**
9631** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9632** of two valid snapshot handles.
9633**
9634** If the two snapshot handles are not associated with the same database
9635** file, the result of the comparison is undefined.
9636**
9637** Additionally, the result of the comparison is only valid if both of the
9638** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9639** last time the wal file was deleted. The wal file is deleted when the
9640** database is changed back to rollback mode or when the number of database
9641** clients drops to zero. If either snapshot handle was obtained before the
9642** wal file was last deleted, the value returned by this function
9643** is undefined.
9644**
9645** Otherwise, this API returns a negative value if P1 refers to an older
9646** snapshot than P2, zero if the two handles refer to the same database
9647** snapshot, and a positive value if P1 is a newer snapshot than P2.
9648**
9649** This interface is only available if SQLite is compiled with the
9650** [SQLITE_ENABLE_SNAPSHOT] option.
9651*/
9652SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9653 sqlite3_snapshot *p1,
9654 sqlite3_snapshot *p2
9655);
9656
9657/*
9658** CAPI3REF: Recover snapshots from a wal file
9659** METHOD: sqlite3_snapshot
9660**
9661** If a [WAL file] remains on disk after all database connections close
9662** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9663** or because the last process to have the database opened exited without
9664** calling [sqlite3_close()]) and a new connection is subsequently opened
9665** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9666** will only be able to open the last transaction added to the WAL file
9667** even though the WAL file contains other valid transactions.
9668**
9669** This function attempts to scan the WAL file associated with database zDb
9670** of database handle db and make all valid snapshots available to
9671** sqlite3_snapshot_open(). It is an error if there is already a read
9672** transaction open on the database, or if the database is not a WAL mode
9673** database.
9674**
9675** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9676**
9677** This interface is only available if SQLite is compiled with the
9678** [SQLITE_ENABLE_SNAPSHOT] option.
9679*/
9680SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9681
9682/*
9683** CAPI3REF: Serialize a database
9684**
9685** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9686** that is a serialization of the S database on [database connection] D.
9687** If P is not a NULL pointer, then the size of the database in bytes
9688** is written into *P.
9689**
9690** For an ordinary on-disk database file, the serialization is just a
9691** copy of the disk file. For an in-memory database or a "TEMP" database,
9692** the serialization is the same sequence of bytes which would be written
9693** to disk if that database where backed up to disk.
9694**
9695** The usual case is that sqlite3_serialize() copies the serialization of
9696** the database into memory obtained from [sqlite3_malloc64()] and returns
9697** a pointer to that memory. The caller is responsible for freeing the
9698** returned value to avoid a memory leak. However, if the F argument
9699** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9700** are made, and the sqlite3_serialize() function will return a pointer
9701** to the contiguous memory representation of the database that SQLite
9702** is currently using for that database, or NULL if the no such contiguous
9703** memory representation of the database exists. A contiguous memory
9704** representation of the database will usually only exist if there has
9705** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9706** values of D and S.
9707** The size of the database is written into *P even if the
9708** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9709** of the database exists.
9710**
9711** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9712** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9713** allocation error occurs.
9714**
9715** This interface is only available if SQLite is compiled with the
9716** [SQLITE_ENABLE_DESERIALIZE] option.
9717*/
9718SQLITE_API unsigned char *sqlite3_serialize(
9719 sqlite3 *db, /* The database connection */
9720 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9721 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9722 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9723);
9724
9725/*
9726** CAPI3REF: Flags for sqlite3_serialize
9727**
9728** Zero or more of the following constants can be OR-ed together for
9729** the F argument to [sqlite3_serialize(D,S,P,F)].
9730**
9731** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9732** a pointer to contiguous in-memory database that it is currently using,
9733** without making a copy of the database. If SQLite is not currently using
9734** a contiguous in-memory database, then this option causes
9735** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9736** using a contiguous in-memory database if it has been initialized by a
9737** prior call to [sqlite3_deserialize()].
9738*/
9739#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9740
9741/*
9742** CAPI3REF: Deserialize a database
9743**
9744** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9745** [database connection] D to disconnect from database S and then
9746** reopen S as an in-memory database based on the serialization contained
9747** in P. The serialized database P is N bytes in size. M is the size of
9748** the buffer P, which might be larger than N. If M is larger than N, and
9749** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9750** permitted to add content to the in-memory database as long as the total
9751** size does not exceed M bytes.
9752**
9753** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9754** invoke sqlite3_free() on the serialization buffer when the database
9755** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9756** SQLite will try to increase the buffer size using sqlite3_realloc64()
9757** if writes on the database cause it to grow larger than M bytes.
9758**
9759** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9760** database is currently in a read transaction or is involved in a backup
9761** operation.
9762**
9763** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9764** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9765** [sqlite3_free()] is invoked on argument P prior to returning.
9766**
9767** This interface is only available if SQLite is compiled with the
9768** [SQLITE_ENABLE_DESERIALIZE] option.
9769*/
9770SQLITE_API int sqlite3_deserialize(
9771 sqlite3 *db, /* The database connection */
9772 const char *zSchema, /* Which DB to reopen with the deserialization */
9773 unsigned char *pData, /* The serialized database content */
9774 sqlite3_int64 szDb, /* Number bytes in the deserialization */
9775 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9776 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9777);
9778
9779/*
9780** CAPI3REF: Flags for sqlite3_deserialize()
9781**
9782** The following are allowed values for 6th argument (the F argument) to
9783** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9784**
9785** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9786** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9787** and that SQLite should take ownership of this memory and automatically
9788** free it when it has finished using it. Without this flag, the caller
9789** is responsible for freeing any dynamically allocated memory.
9790**
9791** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9792** grow the size of the database using calls to [sqlite3_realloc64()]. This
9793** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9794** Without this flag, the deserialized database cannot increase in size beyond
9795** the number of bytes specified by the M parameter.
9796**
9797** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9798** should be treated as read-only.
9799*/
9800#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9801#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9802#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9803
9804/*
9805** Undo the hack that converts floating point types to integer for
9806** builds on processors without floating point support.
9807*/
9808#ifdef SQLITE_OMIT_FLOATING_POINT
9809# undef double
9810#endif
9811
9812#ifdef __cplusplus
9813} /* End of the 'extern "C"' block */
9814#endif
9815#endif /* SQLITE3_H */
9816
9817/******** Begin file sqlite3rtree.h *********/
9818/*
9819** 2010 August 30
9820**
9821** The author disclaims copyright to this source code. In place of
9822** a legal notice, here is a blessing:
9823**
9824** May you do good and not evil.
9825** May you find forgiveness for yourself and forgive others.
9826** May you share freely, never taking more than you give.
9827**
9828*************************************************************************
9829*/
9830
9831#ifndef _SQLITE3RTREE_H_
9832#define _SQLITE3RTREE_H_
9833
9834
9835#ifdef __cplusplus
9836extern "C" {
9837#endif
9838
9839typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
9840typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9841
9842/* The double-precision datatype used by RTree depends on the
9843** SQLITE_RTREE_INT_ONLY compile-time option.
9844*/
9845#ifdef SQLITE_RTREE_INT_ONLY
9846 typedef sqlite3_int64 sqlite3_rtree_dbl;
9847#else
9848 typedef double sqlite3_rtree_dbl;
9849#endif
9850
9851/*
9852** Register a geometry callback named zGeom that can be used as part of an
9853** R-Tree geometry query as follows:
9854**
9855** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9856*/
9857SQLITE_API int sqlite3_rtree_geometry_callback(
9858 sqlite3 *db,
9859 const char *zGeom,
9860 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
9861 void *pContext
9862);
9863
9864
9865/*
9866** A pointer to a structure of the following type is passed as the first
9867** argument to callbacks registered using rtree_geometry_callback().
9868*/
9869struct sqlite3_rtree_geometry {
9870 void *pContext; /* Copy of pContext passed to s_r_g_c() */
9871 int nParam; /* Size of array aParam[] */
9872 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
9873 void *pUser; /* Callback implementation user data */
9874 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9875};
9876
9877/*
9878** Register a 2nd-generation geometry callback named zScore that can be
9879** used as part of an R-Tree geometry query as follows:
9880**
9881** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9882*/
9883SQLITE_API int sqlite3_rtree_query_callback(
9884 sqlite3 *db,
9885 const char *zQueryFunc,
9886 int (*xQueryFunc)(sqlite3_rtree_query_info*),
9887 void *pContext,
9888 void (*xDestructor)(void*)
9889);
9890
9891
9892/*
9893** A pointer to a structure of the following type is passed as the
9894** argument to scored geometry callback registered using
9895** sqlite3_rtree_query_callback().
9896**
9897** Note that the first 5 fields of this structure are identical to
9898** sqlite3_rtree_geometry. This structure is a subclass of
9899** sqlite3_rtree_geometry.
9900*/
9901struct sqlite3_rtree_query_info {
9902 void *pContext; /* pContext from when function registered */
9903 int nParam; /* Number of function parameters */
9904 sqlite3_rtree_dbl *aParam; /* value of function parameters */
9905 void *pUser; /* callback can use this, if desired */
9906 void (*xDelUser)(void*); /* function to free pUser */
9907 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9908 unsigned int *anQueue; /* Number of pending entries in the queue */
9909 int nCoord; /* Number of coordinates */
9910 int iLevel; /* Level of current node or entry */
9911 int mxLevel; /* The largest iLevel value in the tree */
9912 sqlite3_int64 iRowid; /* Rowid for current entry */
9913 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9914 int eParentWithin; /* Visibility of parent node */
9915 int eWithin; /* OUT: Visibility */
9916 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9917 /* The following fields are only available in 3.8.11 and later */
9918 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9919};
9920
9921/*
9922** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9923*/
9924#define NOT_WITHIN 0 /* Object completely outside of query region */
9925#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9926#define FULLY_WITHIN 2 /* Object fully contained within query region */
9927
9928
9929#ifdef __cplusplus
9930} /* end of the 'extern "C"' block */
9931#endif
9932
9933#endif /* ifndef _SQLITE3RTREE_H_ */
9934
9935/******** End of sqlite3rtree.h *********/
9936/******** Begin file sqlite3session.h *********/
9937
9938#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
9939#define __SQLITESESSION_H_ 1
9940
9941/*
9942** Make sure we can call this stuff from C++.
9943*/
9944#ifdef __cplusplus
9945extern "C" {
9946#endif
9947
9948
9949/*
9950** CAPI3REF: Session Object Handle
9951**
9952** An instance of this object is a [session] that can be used to
9953** record changes to a database.
9954*/
9955typedef struct sqlite3_session sqlite3_session;
9956
9957/*
9958** CAPI3REF: Changeset Iterator Handle
9959**
9960** An instance of this object acts as a cursor for iterating
9961** over the elements of a [changeset] or [patchset].
9962*/
9963typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
9964
9965/*
9966** CAPI3REF: Create A New Session Object
9967** CONSTRUCTOR: sqlite3_session
9968**
9969** Create a new session object attached to database handle db. If successful,
9970** a pointer to the new object is written to *ppSession and SQLITE_OK is
9971** returned. If an error occurs, *ppSession is set to NULL and an SQLite
9972** error code (e.g. SQLITE_NOMEM) is returned.
9973**
9974** It is possible to create multiple session objects attached to a single
9975** database handle.
9976**
9977** Session objects created using this function should be deleted using the
9978** [sqlite3session_delete()] function before the database handle that they
9979** are attached to is itself closed. If the database handle is closed before
9980** the session object is deleted, then the results of calling any session
9981** module function, including [sqlite3session_delete()] on the session object
9982** are undefined.
9983**
9984** Because the session module uses the [sqlite3_preupdate_hook()] API, it
9985** is not possible for an application to register a pre-update hook on a
9986** database handle that has one or more session objects attached. Nor is
9987** it possible to create a session object attached to a database handle for
9988** which a pre-update hook is already defined. The results of attempting
9989** either of these things are undefined.
9990**
9991** The session object will be used to create changesets for tables in
9992** database zDb, where zDb is either "main", or "temp", or the name of an
9993** attached database. It is not an error if database zDb is not attached
9994** to the database when the session object is created.
9995*/
9996SQLITE_API int sqlite3session_create(
9997 sqlite3 *db, /* Database handle */
9998 const char *zDb, /* Name of db (e.g. "main") */
9999 sqlite3_session **ppSession /* OUT: New session object */
10000);
10001
10002/*
10003** CAPI3REF: Delete A Session Object
10004** DESTRUCTOR: sqlite3_session
10005**
10006** Delete a session object previously allocated using
10007** [sqlite3session_create()]. Once a session object has been deleted, the
10008** results of attempting to use pSession with any other session module
10009** function are undefined.
10010**
10011** Session objects must be deleted before the database handle to which they
10012** are attached is closed. Refer to the documentation for
10013** [sqlite3session_create()] for details.
10014*/
10015SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10016
10017
10018/*
10019** CAPI3REF: Enable Or Disable A Session Object
10020** METHOD: sqlite3_session
10021**
10022** Enable or disable the recording of changes by a session object. When
10023** enabled, a session object records changes made to the database. When
10024** disabled - it does not. A newly created session object is enabled.
10025** Refer to the documentation for [sqlite3session_changeset()] for further
10026** details regarding how enabling and disabling a session object affects
10027** the eventual changesets.
10028**
10029** Passing zero to this function disables the session. Passing a value
10030** greater than zero enables it. Passing a value less than zero is a
10031** no-op, and may be used to query the current state of the session.
10032**
10033** The return value indicates the final state of the session object: 0 if
10034** the session is disabled, or 1 if it is enabled.
10035*/
10036SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10037
10038/*
10039** CAPI3REF: Set Or Clear the Indirect Change Flag
10040** METHOD: sqlite3_session
10041**
10042** Each change recorded by a session object is marked as either direct or
10043** indirect. A change is marked as indirect if either:
10044**
10045** <ul>
10046** <li> The session object "indirect" flag is set when the change is
10047** made, or
10048** <li> The change is made by an SQL trigger or foreign key action
10049** instead of directly as a result of a users SQL statement.
10050** </ul>
10051**
10052** If a single row is affected by more than one operation within a session,
10053** then the change is considered indirect if all operations meet the criteria
10054** for an indirect change above, or direct otherwise.
10055**
10056** This function is used to set, clear or query the session object indirect
10057** flag. If the second argument passed to this function is zero, then the
10058** indirect flag is cleared. If it is greater than zero, the indirect flag
10059** is set. Passing a value less than zero does not modify the current value
10060** of the indirect flag, and may be used to query the current state of the
10061** indirect flag for the specified session object.
10062**
10063** The return value indicates the final state of the indirect flag: 0 if
10064** it is clear, or 1 if it is set.
10065*/
10066SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10067
10068/*
10069** CAPI3REF: Attach A Table To A Session Object
10070** METHOD: sqlite3_session
10071**
10072** If argument zTab is not NULL, then it is the name of a table to attach
10073** to the session object passed as the first argument. All subsequent changes
10074** made to the table while the session object is enabled will be recorded. See
10075** documentation for [sqlite3session_changeset()] for further details.
10076**
10077** Or, if argument zTab is NULL, then changes are recorded for all tables
10078** in the database. If additional tables are added to the database (by
10079** executing "CREATE TABLE" statements) after this call is made, changes for
10080** the new tables are also recorded.
10081**
10082** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10083** defined as part of their CREATE TABLE statement. It does not matter if the
10084** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10085** KEY may consist of a single column, or may be a composite key.
10086**
10087** It is not an error if the named table does not exist in the database. Nor
10088** is it an error if the named table does not have a PRIMARY KEY. However,
10089** no changes will be recorded in either of these scenarios.
10090**
10091** Changes are not recorded for individual rows that have NULL values stored
10092** in one or more of their PRIMARY KEY columns.
10093**
10094** SQLITE_OK is returned if the call completes without error. Or, if an error
10095** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10096**
10097** <h3>Special sqlite_stat1 Handling</h3>
10098**
10099** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10100** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10101** <pre>
10102** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
10103** </pre>
10104**
10105** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10106** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10107** are recorded for rows for which (idx IS NULL) is true. However, for such
10108** rows a zero-length blob (SQL value X'') is stored in the changeset or
10109** patchset instead of a NULL value. This allows such changesets to be
10110** manipulated by legacy implementations of sqlite3changeset_invert(),
10111** concat() and similar.
10112**
10113** The sqlite3changeset_apply() function automatically converts the
10114** zero-length blob back to a NULL value when updating the sqlite_stat1
10115** table. However, if the application calls sqlite3changeset_new(),
10116** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10117** iterator directly (including on a changeset iterator passed to a
10118** conflict-handler callback) then the X'' value is returned. The application
10119** must translate X'' to NULL itself if required.
10120**
10121** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10122** changes made to the sqlite_stat1 table. Legacy versions of the
10123** sqlite3changeset_apply() function silently ignore any modifications to the
10124** sqlite_stat1 table that are part of a changeset or patchset.
10125*/
10126SQLITE_API int sqlite3session_attach(
10127 sqlite3_session *pSession, /* Session object */
10128 const char *zTab /* Table name */
10129);
10130
10131/*
10132** CAPI3REF: Set a table filter on a Session Object.
10133** METHOD: sqlite3_session
10134**
10135** The second argument (xFilter) is the "filter callback". For changes to rows
10136** in tables that are not attached to the Session object, the filter is called
10137** to determine whether changes to the table's rows should be tracked or not.
10138** If xFilter returns 0, changes are not tracked. Note that once a table is
10139** attached, xFilter will not be called again.
10140*/
10141SQLITE_API void sqlite3session_table_filter(
10142 sqlite3_session *pSession, /* Session object */
10143 int(*xFilter)(
10144 void *pCtx, /* Copy of third arg to _filter_table() */
10145 const char *zTab /* Table name */
10146 ),
10147 void *pCtx /* First argument passed to xFilter */
10148);
10149
10150/*
10151** CAPI3REF: Generate A Changeset From A Session Object
10152** METHOD: sqlite3_session
10153**
10154** Obtain a changeset containing changes to the tables attached to the
10155** session object passed as the first argument. If successful,
10156** set *ppChangeset to point to a buffer containing the changeset
10157** and *pnChangeset to the size of the changeset in bytes before returning
10158** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10159** zero and return an SQLite error code.
10160**
10161** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10162** each representing a change to a single row of an attached table. An INSERT
10163** change contains the values of each field of a new database row. A DELETE
10164** contains the original values of each field of a deleted database row. An
10165** UPDATE change contains the original values of each field of an updated
10166** database row along with the updated values for each updated non-primary-key
10167** column. It is not possible for an UPDATE change to represent a change that
10168** modifies the values of primary key columns. If such a change is made, it
10169** is represented in a changeset as a DELETE followed by an INSERT.
10170**
10171** Changes are not recorded for rows that have NULL values stored in one or
10172** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10173** no corresponding change is present in the changesets returned by this
10174** function. If an existing row with one or more NULL values stored in
10175** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10176** only an INSERT is appears in the changeset. Similarly, if an existing row
10177** with non-NULL PRIMARY KEY values is updated so that one or more of its
10178** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10179** DELETE change only.
10180**
10181** The contents of a changeset may be traversed using an iterator created
10182** using the [sqlite3changeset_start()] API. A changeset may be applied to
10183** a database with a compatible schema using the [sqlite3changeset_apply()]
10184** API.
10185**
10186** Within a changeset generated by this function, all changes related to a
10187** single table are grouped together. In other words, when iterating through
10188** a changeset or when applying a changeset to a database, all changes related
10189** to a single table are processed before moving on to the next table. Tables
10190** are sorted in the same order in which they were attached (or auto-attached)
10191** to the sqlite3_session object. The order in which the changes related to
10192** a single table are stored is undefined.
10193**
10194** Following a successful call to this function, it is the responsibility of
10195** the caller to eventually free the buffer that *ppChangeset points to using
10196** [sqlite3_free()].
10197**
10198** <h3>Changeset Generation</h3>
10199**
10200** Once a table has been attached to a session object, the session object
10201** records the primary key values of all new rows inserted into the table.
10202** It also records the original primary key and other column values of any
10203** deleted or updated rows. For each unique primary key value, data is only
10204** recorded once - the first time a row with said primary key is inserted,
10205** updated or deleted in the lifetime of the session.
10206**
10207** There is one exception to the previous paragraph: when a row is inserted,
10208** updated or deleted, if one or more of its primary key columns contain a
10209** NULL value, no record of the change is made.
10210**
10211** The session object therefore accumulates two types of records - those
10212** that consist of primary key values only (created when the user inserts
10213** a new record) and those that consist of the primary key values and the
10214** original values of other table columns (created when the users deletes
10215** or updates a record).
10216**
10217** When this function is called, the requested changeset is created using
10218** both the accumulated records and the current contents of the database
10219** file. Specifically:
10220**
10221** <ul>
10222** <li> For each record generated by an insert, the database is queried
10223** for a row with a matching primary key. If one is found, an INSERT
10224** change is added to the changeset. If no such row is found, no change
10225** is added to the changeset.
10226**
10227** <li> For each record generated by an update or delete, the database is
10228** queried for a row with a matching primary key. If such a row is
10229** found and one or more of the non-primary key fields have been
10230** modified from their original values, an UPDATE change is added to
10231** the changeset. Or, if no such row is found in the table, a DELETE
10232** change is added to the changeset. If there is a row with a matching
10233** primary key in the database, but all fields contain their original
10234** values, no change is added to the changeset.
10235** </ul>
10236**
10237** This means, amongst other things, that if a row is inserted and then later
10238** deleted while a session object is active, neither the insert nor the delete
10239** will be present in the changeset. Or if a row is deleted and then later a
10240** row with the same primary key values inserted while a session object is
10241** active, the resulting changeset will contain an UPDATE change instead of
10242** a DELETE and an INSERT.
10243**
10244** When a session object is disabled (see the [sqlite3session_enable()] API),
10245** it does not accumulate records when rows are inserted, updated or deleted.
10246** This may appear to have some counter-intuitive effects if a single row
10247** is written to more than once during a session. For example, if a row
10248** is inserted while a session object is enabled, then later deleted while
10249** the same session object is disabled, no INSERT record will appear in the
10250** changeset, even though the delete took place while the session was disabled.
10251** Or, if one field of a row is updated while a session is disabled, and
10252** another field of the same row is updated while the session is enabled, the
10253** resulting changeset will contain an UPDATE change that updates both fields.
10254*/
10255SQLITE_API int sqlite3session_changeset(
10256 sqlite3_session *pSession, /* Session object */
10257 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10258 void **ppChangeset /* OUT: Buffer containing changeset */
10259);
10260
10261/*
10262** CAPI3REF: Load The Difference Between Tables Into A Session
10263** METHOD: sqlite3_session
10264**
10265** If it is not already attached to the session object passed as the first
10266** argument, this function attaches table zTbl in the same manner as the
10267** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10268** does not have a primary key, this function is a no-op (but does not return
10269** an error).
10270**
10271** Argument zFromDb must be the name of a database ("main", "temp" etc.)
10272** attached to the same database handle as the session object that contains
10273** a table compatible with the table attached to the session by this function.
10274** A table is considered compatible if it:
10275**
10276** <ul>
10277** <li> Has the same name,
10278** <li> Has the same set of columns declared in the same order, and
10279** <li> Has the same PRIMARY KEY definition.
10280** </ul>
10281**
10282** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10283** are compatible but do not have any PRIMARY KEY columns, it is not an error
10284** but no changes are added to the session object. As with other session
10285** APIs, tables without PRIMARY KEYs are simply ignored.
10286**
10287** This function adds a set of changes to the session object that could be
10288** used to update the table in database zFrom (call this the "from-table")
10289** so that its content is the same as the table attached to the session
10290** object (call this the "to-table"). Specifically:
10291**
10292** <ul>
10293** <li> For each row (primary key) that exists in the to-table but not in
10294** the from-table, an INSERT record is added to the session object.
10295**
10296** <li> For each row (primary key) that exists in the to-table but not in
10297** the from-table, a DELETE record is added to the session object.
10298**
10299** <li> For each row (primary key) that exists in both tables, but features
10300** different non-PK values in each, an UPDATE record is added to the
10301** session.
10302** </ul>
10303**
10304** To clarify, if this function is called and then a changeset constructed
10305** using [sqlite3session_changeset()], then after applying that changeset to
10306** database zFrom the contents of the two compatible tables would be
10307** identical.
10308**
10309** It an error if database zFrom does not exist or does not contain the
10310** required compatible table.
10311**
10312** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
10313** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
10314** may be set to point to a buffer containing an English language error
10315** message. It is the responsibility of the caller to free this buffer using
10316** sqlite3_free().
10317*/
10318SQLITE_API int sqlite3session_diff(
10319 sqlite3_session *pSession,
10320 const char *zFromDb,
10321 const char *zTbl,
10322 char **pzErrMsg
10323);
10324
10325
10326/*
10327** CAPI3REF: Generate A Patchset From A Session Object
10328** METHOD: sqlite3_session
10329**
10330** The differences between a patchset and a changeset are that:
10331**
10332** <ul>
10333** <li> DELETE records consist of the primary key fields only. The
10334** original values of other fields are omitted.
10335** <li> The original values of any modified fields are omitted from
10336** UPDATE records.
10337** </ul>
10338**
10339** A patchset blob may be used with up to date versions of all
10340** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
10341** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
10342** attempting to use a patchset blob with old versions of the
10343** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
10344**
10345** Because the non-primary key "old.*" fields are omitted, no
10346** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
10347** is passed to the sqlite3changeset_apply() API. Other conflict types work
10348** in the same way as for changesets.
10349**
10350** Changes within a patchset are ordered in the same way as for changesets
10351** generated by the sqlite3session_changeset() function (i.e. all changes for
10352** a single table are grouped together, tables appear in the order in which
10353** they were attached to the session object).
10354*/
10355SQLITE_API int sqlite3session_patchset(
10356 sqlite3_session *pSession, /* Session object */
10357 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
10358 void **ppPatchset /* OUT: Buffer containing patchset */
10359);
10360
10361/*
10362** CAPI3REF: Test if a changeset has recorded any changes.
10363**
10364** Return non-zero if no changes to attached tables have been recorded by
10365** the session object passed as the first argument. Otherwise, if one or
10366** more changes have been recorded, return zero.
10367**
10368** Even if this function returns zero, it is possible that calling
10369** [sqlite3session_changeset()] on the session handle may still return a
10370** changeset that contains no changes. This can happen when a row in
10371** an attached table is modified and then later on the original values
10372** are restored. However, if this function returns non-zero, then it is
10373** guaranteed that a call to sqlite3session_changeset() will return a
10374** changeset containing zero changes.
10375*/
10376SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
10377
10378/*
10379** CAPI3REF: Create An Iterator To Traverse A Changeset
10380** CONSTRUCTOR: sqlite3_changeset_iter
10381**
10382** Create an iterator used to iterate through the contents of a changeset.
10383** If successful, *pp is set to point to the iterator handle and SQLITE_OK
10384** is returned. Otherwise, if an error occurs, *pp is set to zero and an
10385** SQLite error code is returned.
10386**
10387** The following functions can be used to advance and query a changeset
10388** iterator created by this function:
10389**
10390** <ul>
10391** <li> [sqlite3changeset_next()]
10392** <li> [sqlite3changeset_op()]
10393** <li> [sqlite3changeset_new()]
10394** <li> [sqlite3changeset_old()]
10395** </ul>
10396**
10397** It is the responsibility of the caller to eventually destroy the iterator
10398** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
10399** changeset (pChangeset) must remain valid until after the iterator is
10400** destroyed.
10401**
10402** Assuming the changeset blob was created by one of the
10403** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
10404** [sqlite3changeset_invert()] functions, all changes within the changeset
10405** that apply to a single table are grouped together. This means that when
10406** an application iterates through a changeset using an iterator created by
10407** this function, all changes that relate to a single table are visited
10408** consecutively. There is no chance that the iterator will visit a change
10409** the applies to table X, then one for table Y, and then later on visit
10410** another change for table X.
10411**
10412** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
10413** may be modified by passing a combination of
10414** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
10415**
10416** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
10417** and therefore subject to change.
10418*/
10419SQLITE_API int sqlite3changeset_start(
10420 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10421 int nChangeset, /* Size of changeset blob in bytes */
10422 void *pChangeset /* Pointer to blob containing changeset */
10423);
10424SQLITE_API int sqlite3changeset_start_v2(
10425 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10426 int nChangeset, /* Size of changeset blob in bytes */
10427 void *pChangeset, /* Pointer to blob containing changeset */
10428 int flags /* SESSION_CHANGESETSTART_* flags */
10429);
10430
10431/*
10432** CAPI3REF: Flags for sqlite3changeset_start_v2
10433**
10434** The following flags may passed via the 4th parameter to
10435** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
10436**
10437** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10438** Invert the changeset while iterating through it. This is equivalent to
10439** inverting a changeset using sqlite3changeset_invert() before applying it.
10440** It is an error to specify this flag with a patchset.
10441*/
10442#define SQLITE_CHANGESETSTART_INVERT 0x0002
10443
10444
10445/*
10446** CAPI3REF: Advance A Changeset Iterator
10447** METHOD: sqlite3_changeset_iter
10448**
10449** This function may only be used with iterators created by the function
10450** [sqlite3changeset_start()]. If it is called on an iterator passed to
10451** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
10452** is returned and the call has no effect.
10453**
10454** Immediately after an iterator is created by sqlite3changeset_start(), it
10455** does not point to any change in the changeset. Assuming the changeset
10456** is not empty, the first call to this function advances the iterator to
10457** point to the first change in the changeset. Each subsequent call advances
10458** the iterator to point to the next change in the changeset (if any). If
10459** no error occurs and the iterator points to a valid change after a call
10460** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
10461** Otherwise, if all changes in the changeset have already been visited,
10462** SQLITE_DONE is returned.
10463**
10464** If an error occurs, an SQLite error code is returned. Possible error
10465** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
10466** SQLITE_NOMEM.
10467*/
10468SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
10469
10470/*
10471** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
10472** METHOD: sqlite3_changeset_iter
10473**
10474** The pIter argument passed to this function may either be an iterator
10475** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10476** created by [sqlite3changeset_start()]. In the latter case, the most recent
10477** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10478** is not the case, this function returns [SQLITE_MISUSE].
10479**
10480** If argument pzTab is not NULL, then *pzTab is set to point to a
10481** nul-terminated utf-8 encoded string containing the name of the table
10482** affected by the current change. The buffer remains valid until either
10483** sqlite3changeset_next() is called on the iterator or until the
10484** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
10485** set to the number of columns in the table affected by the change. If
10486** pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
10487** is an indirect change, or false (0) otherwise. See the documentation for
10488** [sqlite3session_indirect()] for a description of direct and indirect
10489** changes. Finally, if pOp is not NULL, then *pOp is set to one of
10490** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
10491** type of change that the iterator currently points to.
10492**
10493** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10494** SQLite error code is returned. The values of the output variables may not
10495** be trusted in this case.
10496*/
10497SQLITE_API int sqlite3changeset_op(
10498 sqlite3_changeset_iter *pIter, /* Iterator object */
10499 const char **pzTab, /* OUT: Pointer to table name */
10500 int *pnCol, /* OUT: Number of columns in table */
10501 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10502 int *pbIndirect /* OUT: True for an 'indirect' change */
10503);
10504
10505/*
10506** CAPI3REF: Obtain The Primary Key Definition Of A Table
10507** METHOD: sqlite3_changeset_iter
10508**
10509** For each modified table, a changeset includes the following:
10510**
10511** <ul>
10512** <li> The number of columns in the table, and
10513** <li> Which of those columns make up the tables PRIMARY KEY.
10514** </ul>
10515**
10516** This function is used to find which columns comprise the PRIMARY KEY of
10517** the table modified by the change that iterator pIter currently points to.
10518** If successful, *pabPK is set to point to an array of nCol entries, where
10519** nCol is the number of columns in the table. Elements of *pabPK are set to
10520** 0x01 if the corresponding column is part of the tables primary key, or
10521** 0x00 if it is not.
10522**
10523** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10524** in the table.
10525**
10526** If this function is called when the iterator does not point to a valid
10527** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10528** SQLITE_OK is returned and the output variables populated as described
10529** above.
10530*/
10531SQLITE_API int sqlite3changeset_pk(
10532 sqlite3_changeset_iter *pIter, /* Iterator object */
10533 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10534 int *pnCol /* OUT: Number of entries in output array */
10535);
10536
10537/*
10538** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10539** METHOD: sqlite3_changeset_iter
10540**
10541** The pIter argument passed to this function may either be an iterator
10542** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10543** created by [sqlite3changeset_start()]. In the latter case, the most recent
10544** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10545** Furthermore, it may only be called if the type of change that the iterator
10546** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10547** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10548**
10549** Argument iVal must be greater than or equal to 0, and less than the number
10550** of columns in the table affected by the current change. Otherwise,
10551** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10552**
10553** If successful, this function sets *ppValue to point to a protected
10554** sqlite3_value object containing the iVal'th value from the vector of
10555** original row values stored as part of the UPDATE or DELETE change and
10556** returns SQLITE_OK. The name of the function comes from the fact that this
10557** is similar to the "old.*" columns available to update or delete triggers.
10558**
10559** If some other error occurs (e.g. an OOM condition), an SQLite error code
10560** is returned and *ppValue is set to NULL.
10561*/
10562SQLITE_API int sqlite3changeset_old(
10563 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10564 int iVal, /* Column number */
10565 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10566);
10567
10568/*
10569** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10570** METHOD: sqlite3_changeset_iter
10571**
10572** The pIter argument passed to this function may either be an iterator
10573** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10574** created by [sqlite3changeset_start()]. In the latter case, the most recent
10575** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10576** Furthermore, it may only be called if the type of change that the iterator
10577** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10578** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10579**
10580** Argument iVal must be greater than or equal to 0, and less than the number
10581** of columns in the table affected by the current change. Otherwise,
10582** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10583**
10584** If successful, this function sets *ppValue to point to a protected
10585** sqlite3_value object containing the iVal'th value from the vector of
10586** new row values stored as part of the UPDATE or INSERT change and
10587** returns SQLITE_OK. If the change is an UPDATE and does not include
10588** a new value for the requested column, *ppValue is set to NULL and
10589** SQLITE_OK returned. The name of the function comes from the fact that
10590** this is similar to the "new.*" columns available to update or delete
10591** triggers.
10592**
10593** If some other error occurs (e.g. an OOM condition), an SQLite error code
10594** is returned and *ppValue is set to NULL.
10595*/
10596SQLITE_API int sqlite3changeset_new(
10597 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10598 int iVal, /* Column number */
10599 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10600);
10601
10602/*
10603** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10604** METHOD: sqlite3_changeset_iter
10605**
10606** This function should only be used with iterator objects passed to a
10607** conflict-handler callback by [sqlite3changeset_apply()] with either
10608** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10609** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10610** is set to NULL.
10611**
10612** Argument iVal must be greater than or equal to 0, and less than the number
10613** of columns in the table affected by the current change. Otherwise,
10614** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10615**
10616** If successful, this function sets *ppValue to point to a protected
10617** sqlite3_value object containing the iVal'th value from the
10618** "conflicting row" associated with the current conflict-handler callback
10619** and returns SQLITE_OK.
10620**
10621** If some other error occurs (e.g. an OOM condition), an SQLite error code
10622** is returned and *ppValue is set to NULL.
10623*/
10624SQLITE_API int sqlite3changeset_conflict(
10625 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10626 int iVal, /* Column number */
10627 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10628);
10629
10630/*
10631** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10632** METHOD: sqlite3_changeset_iter
10633**
10634** This function may only be called with an iterator passed to an
10635** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10636** it sets the output variable to the total number of known foreign key
10637** violations in the destination database and returns SQLITE_OK.
10638**
10639** In all other cases this function returns SQLITE_MISUSE.
10640*/
10641SQLITE_API int sqlite3changeset_fk_conflicts(
10642 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10643 int *pnOut /* OUT: Number of FK violations */
10644);
10645
10646
10647/*
10648** CAPI3REF: Finalize A Changeset Iterator
10649** METHOD: sqlite3_changeset_iter
10650**
10651** This function is used to finalize an iterator allocated with
10652** [sqlite3changeset_start()].
10653**
10654** This function should only be called on iterators created using the
10655** [sqlite3changeset_start()] function. If an application calls this
10656** function with an iterator passed to a conflict-handler by
10657** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10658** call has no effect.
10659**
10660** If an error was encountered within a call to an sqlite3changeset_xxx()
10661** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10662** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10663** to that error is returned by this function. Otherwise, SQLITE_OK is
10664** returned. This is to allow the following pattern (pseudo-code):
10665**
10666** <pre>
10667** sqlite3changeset_start();
10668** while( SQLITE_ROW==sqlite3changeset_next() ){
10669** // Do something with change.
10670** }
10671** rc = sqlite3changeset_finalize();
10672** if( rc!=SQLITE_OK ){
10673** // An error has occurred
10674** }
10675** </pre>
10676*/
10677SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10678
10679/*
10680** CAPI3REF: Invert A Changeset
10681**
10682** This function is used to "invert" a changeset object. Applying an inverted
10683** changeset to a database reverses the effects of applying the uninverted
10684** changeset. Specifically:
10685**
10686** <ul>
10687** <li> Each DELETE change is changed to an INSERT, and
10688** <li> Each INSERT change is changed to a DELETE, and
10689** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10690** </ul>
10691**
10692** This function does not change the order in which changes appear within
10693** the changeset. It merely reverses the sense of each individual change.
10694**
10695** If successful, a pointer to a buffer containing the inverted changeset
10696** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10697** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10698** zeroed and an SQLite error code returned.
10699**
10700** It is the responsibility of the caller to eventually call sqlite3_free()
10701** on the *ppOut pointer to free the buffer allocation following a successful
10702** call to this function.
10703**
10704** WARNING/TODO: This function currently assumes that the input is a valid
10705** changeset. If it is not, the results are undefined.
10706*/
10707SQLITE_API int sqlite3changeset_invert(
10708 int nIn, const void *pIn, /* Input changeset */
10709 int *pnOut, void **ppOut /* OUT: Inverse of input */
10710);
10711
10712/*
10713** CAPI3REF: Concatenate Two Changeset Objects
10714**
10715** This function is used to concatenate two changesets, A and B, into a
10716** single changeset. The result is a changeset equivalent to applying
10717** changeset A followed by changeset B.
10718**
10719** This function combines the two input changesets using an
10720** sqlite3_changegroup object. Calling it produces similar results as the
10721** following code fragment:
10722**
10723** <pre>
10724** sqlite3_changegroup *pGrp;
10725** rc = sqlite3_changegroup_new(&pGrp);
10726** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10727** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10728** if( rc==SQLITE_OK ){
10729** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10730** }else{
10731** *ppOut = 0;
10732** *pnOut = 0;
10733** }
10734** </pre>
10735**
10736** Refer to the sqlite3_changegroup documentation below for details.
10737*/
10738SQLITE_API int sqlite3changeset_concat(
10739 int nA, /* Number of bytes in buffer pA */
10740 void *pA, /* Pointer to buffer containing changeset A */
10741 int nB, /* Number of bytes in buffer pB */
10742 void *pB, /* Pointer to buffer containing changeset B */
10743 int *pnOut, /* OUT: Number of bytes in output changeset */
10744 void **ppOut /* OUT: Buffer containing output changeset */
10745);
10746
10747
10748/*
10749** CAPI3REF: Changegroup Handle
10750**
10751** A changegroup is an object used to combine two or more
10752** [changesets] or [patchsets]
10753*/
10754typedef struct sqlite3_changegroup sqlite3_changegroup;
10755
10756/*
10757** CAPI3REF: Create A New Changegroup Object
10758** CONSTRUCTOR: sqlite3_changegroup
10759**
10760** An sqlite3_changegroup object is used to combine two or more changesets
10761** (or patchsets) into a single changeset (or patchset). A single changegroup
10762** object may combine changesets or patchsets, but not both. The output is
10763** always in the same format as the input.
10764**
10765** If successful, this function returns SQLITE_OK and populates (*pp) with
10766** a pointer to a new sqlite3_changegroup object before returning. The caller
10767** should eventually free the returned object using a call to
10768** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10769** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10770**
10771** The usual usage pattern for an sqlite3_changegroup object is as follows:
10772**
10773** <ul>
10774** <li> It is created using a call to sqlite3changegroup_new().
10775**
10776** <li> Zero or more changesets (or patchsets) are added to the object
10777** by calling sqlite3changegroup_add().
10778**
10779** <li> The result of combining all input changesets together is obtained
10780** by the application via a call to sqlite3changegroup_output().
10781**
10782** <li> The object is deleted using a call to sqlite3changegroup_delete().
10783** </ul>
10784**
10785** Any number of calls to add() and output() may be made between the calls to
10786** new() and delete(), and in any order.
10787**
10788** As well as the regular sqlite3changegroup_add() and
10789** sqlite3changegroup_output() functions, also available are the streaming
10790** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10791*/
10792SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
10793
10794/*
10795** CAPI3REF: Add A Changeset To A Changegroup
10796** METHOD: sqlite3_changegroup
10797**
10798** Add all changes within the changeset (or patchset) in buffer pData (size
10799** nData bytes) to the changegroup.
10800**
10801** If the buffer contains a patchset, then all prior calls to this function
10802** on the same changegroup object must also have specified patchsets. Or, if
10803** the buffer contains a changeset, so must have the earlier calls to this
10804** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10805** to the changegroup.
10806**
10807** Rows within the changeset and changegroup are identified by the values in
10808** their PRIMARY KEY columns. A change in the changeset is considered to
10809** apply to the same row as a change already present in the changegroup if
10810** the two rows have the same primary key.
10811**
10812** Changes to rows that do not already appear in the changegroup are
10813** simply copied into it. Or, if both the new changeset and the changegroup
10814** contain changes that apply to a single row, the final contents of the
10815** changegroup depends on the type of each change, as follows:
10816**
10817** <table border=1 style="margin-left:8ex;margin-right:8ex">
10818** <tr><th style="white-space:pre">Existing Change </th>
10819** <th style="white-space:pre">New Change </th>
10820** <th>Output Change
10821** <tr><td>INSERT <td>INSERT <td>
10822** The new change is ignored. This case does not occur if the new
10823** changeset was recorded immediately after the changesets already
10824** added to the changegroup.
10825** <tr><td>INSERT <td>UPDATE <td>
10826** The INSERT change remains in the changegroup. The values in the
10827** INSERT change are modified as if the row was inserted by the
10828** existing change and then updated according to the new change.
10829** <tr><td>INSERT <td>DELETE <td>
10830** The existing INSERT is removed from the changegroup. The DELETE is
10831** not added.
10832** <tr><td>UPDATE <td>INSERT <td>
10833** The new change is ignored. This case does not occur if the new
10834** changeset was recorded immediately after the changesets already
10835** added to the changegroup.
10836** <tr><td>UPDATE <td>UPDATE <td>
10837** The existing UPDATE remains within the changegroup. It is amended
10838** so that the accompanying values are as if the row was updated once
10839** by the existing change and then again by the new change.
10840** <tr><td>UPDATE <td>DELETE <td>
10841** The existing UPDATE is replaced by the new DELETE within the
10842** changegroup.
10843** <tr><td>DELETE <td>INSERT <td>
10844** If one or more of the column values in the row inserted by the
10845** new change differ from those in the row deleted by the existing
10846** change, the existing DELETE is replaced by an UPDATE within the
10847** changegroup. Otherwise, if the inserted row is exactly the same
10848** as the deleted row, the existing DELETE is simply discarded.
10849** <tr><td>DELETE <td>UPDATE <td>
10850** The new change is ignored. This case does not occur if the new
10851** changeset was recorded immediately after the changesets already
10852** added to the changegroup.
10853** <tr><td>DELETE <td>DELETE <td>
10854** The new change is ignored. This case does not occur if the new
10855** changeset was recorded immediately after the changesets already
10856** added to the changegroup.
10857** </table>
10858**
10859** If the new changeset contains changes to a table that is already present
10860** in the changegroup, then the number of columns and the position of the
10861** primary key columns for the table must be consistent. If this is not the
10862** case, this function fails with SQLITE_SCHEMA. If the input changeset
10863** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10864** returned. Or, if an out-of-memory condition occurs during processing, this
10865** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
10866** of the final contents of the changegroup is undefined.
10867**
10868** If no error occurs, SQLITE_OK is returned.
10869*/
10870SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
10871
10872/*
10873** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10874** METHOD: sqlite3_changegroup
10875**
10876** Obtain a buffer containing a changeset (or patchset) representing the
10877** current contents of the changegroup. If the inputs to the changegroup
10878** were themselves changesets, the output is a changeset. Or, if the
10879** inputs were patchsets, the output is also a patchset.
10880**
10881** As with the output of the sqlite3session_changeset() and
10882** sqlite3session_patchset() functions, all changes related to a single
10883** table are grouped together in the output of this function. Tables appear
10884** in the same order as for the very first changeset added to the changegroup.
10885** If the second or subsequent changesets added to the changegroup contain
10886** changes for tables that do not appear in the first changeset, they are
10887** appended onto the end of the output changeset, again in the order in
10888** which they are first encountered.
10889**
10890** If an error occurs, an SQLite error code is returned and the output
10891** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
10892** is returned and the output variables are set to the size of and a
10893** pointer to the output buffer, respectively. In this case it is the
10894** responsibility of the caller to eventually free the buffer using a
10895** call to sqlite3_free().
10896*/
10897SQLITE_API int sqlite3changegroup_output(
10898 sqlite3_changegroup*,
10899 int *pnData, /* OUT: Size of output buffer in bytes */
10900 void **ppData /* OUT: Pointer to output buffer */
10901);
10902
10903/*
10904** CAPI3REF: Delete A Changegroup Object
10905** DESTRUCTOR: sqlite3_changegroup
10906*/
10907SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
10908
10909/*
10910** CAPI3REF: Apply A Changeset To A Database
10911**
10912** Apply a changeset or patchset to a database. These functions attempt to
10913** update the "main" database attached to handle db with the changes found in
10914** the changeset passed via the second and third arguments.
10915**
10916** The fourth argument (xFilter) passed to these functions is the "filter
10917** callback". If it is not NULL, then for each table affected by at least one
10918** change in the changeset, the filter callback is invoked with
10919** the table name as the second argument, and a copy of the context pointer
10920** passed as the sixth argument as the first. If the "filter callback"
10921** returns zero, then no attempt is made to apply any changes to the table.
10922** Otherwise, if the return value is non-zero or the xFilter argument to
10923** is NULL, all changes related to the table are attempted.
10924**
10925** For each table that is not excluded by the filter callback, this function
10926** tests that the target database contains a compatible table. A table is
10927** considered compatible if all of the following are true:
10928**
10929** <ul>
10930** <li> The table has the same name as the name recorded in the
10931** changeset, and
10932** <li> The table has at least as many columns as recorded in the
10933** changeset, and
10934** <li> The table has primary key columns in the same position as
10935** recorded in the changeset.
10936** </ul>
10937**
10938** If there is no compatible table, it is not an error, but none of the
10939** changes associated with the table are applied. A warning message is issued
10940** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
10941** one such warning is issued for each table in the changeset.
10942**
10943** For each change for which there is a compatible table, an attempt is made
10944** to modify the table contents according to the UPDATE, INSERT or DELETE
10945** change. If a change cannot be applied cleanly, the conflict handler
10946** function passed as the fifth argument to sqlite3changeset_apply() may be
10947** invoked. A description of exactly when the conflict handler is invoked for
10948** each type of change is below.
10949**
10950** Unlike the xFilter argument, xConflict may not be passed NULL. The results
10951** of passing anything other than a valid function pointer as the xConflict
10952** argument are undefined.
10953**
10954** Each time the conflict handler function is invoked, it must return one
10955** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
10956** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
10957** if the second argument passed to the conflict handler is either
10958** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
10959** returns an illegal value, any changes already made are rolled back and
10960** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
10961** actions are taken by sqlite3changeset_apply() depending on the value
10962** returned by each invocation of the conflict-handler function. Refer to
10963** the documentation for the three
10964** [SQLITE_CHANGESET_OMIT|available return values] for details.
10965**
10966** <dl>
10967** <dt>DELETE Changes<dd>
10968** For each DELETE change, the function checks if the target database
10969** contains a row with the same primary key value (or values) as the
10970** original row values stored in the changeset. If it does, and the values
10971** stored in all non-primary key columns also match the values stored in
10972** the changeset the row is deleted from the target database.
10973**
10974** If a row with matching primary key values is found, but one or more of
10975** the non-primary key fields contains a value different from the original
10976** row value stored in the changeset, the conflict-handler function is
10977** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
10978** database table has more columns than are recorded in the changeset,
10979** only the values of those non-primary key fields are compared against
10980** the current database contents - any trailing database table columns
10981** are ignored.
10982**
10983** If no row with matching primary key values is found in the database,
10984** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10985** passed as the second argument.
10986**
10987** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
10988** (which can only happen if a foreign key constraint is violated), the
10989** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
10990** passed as the second argument. This includes the case where the DELETE
10991** operation is attempted because an earlier call to the conflict handler
10992** function returned [SQLITE_CHANGESET_REPLACE].
10993**
10994** <dt>INSERT Changes<dd>
10995** For each INSERT change, an attempt is made to insert the new row into
10996** the database. If the changeset row contains fewer fields than the
10997** database table, the trailing fields are populated with their default
10998** values.
10999**
11000** If the attempt to insert the row fails because the database already
11001** contains a row with the same primary key values, the conflict handler
11002** function is invoked with the second argument set to
11003** [SQLITE_CHANGESET_CONFLICT].
11004**
11005** If the attempt to insert the row fails because of some other constraint
11006** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11007** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11008** This includes the case where the INSERT operation is re-attempted because
11009** an earlier call to the conflict handler function returned
11010** [SQLITE_CHANGESET_REPLACE].
11011**
11012** <dt>UPDATE Changes<dd>
11013** For each UPDATE change, the function checks if the target database
11014** contains a row with the same primary key value (or values) as the
11015** original row values stored in the changeset. If it does, and the values
11016** stored in all modified non-primary key columns also match the values
11017** stored in the changeset the row is updated within the target database.
11018**
11019** If a row with matching primary key values is found, but one or more of
11020** the modified non-primary key fields contains a value different from an
11021** original row value stored in the changeset, the conflict-handler function
11022** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11023** UPDATE changes only contain values for non-primary key fields that are
11024** to be modified, only those fields need to match the original values to
11025** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11026**
11027** If no row with matching primary key values is found in the database,
11028** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11029** passed as the second argument.
11030**
11031** If the UPDATE operation is attempted, but SQLite returns
11032** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11033** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11034** This includes the case where the UPDATE operation is attempted after
11035** an earlier call to the conflict handler function returned
11036** [SQLITE_CHANGESET_REPLACE].
11037** </dl>
11038**
11039** It is safe to execute SQL statements, including those that write to the
11040** table that the callback related to, from within the xConflict callback.
11041** This can be used to further customize the application's conflict
11042** resolution strategy.
11043**
11044** All changes made by these functions are enclosed in a savepoint transaction.
11045** If any other error (aside from a constraint failure when attempting to
11046** write to the target database) occurs, then the savepoint transaction is
11047** rolled back, restoring the target database to its original state, and an
11048** SQLite error code returned.
11049**
11050** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11051** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11052** may set (*ppRebase) to point to a "rebase" that may be used with the
11053** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11054** is set to the size of the buffer in bytes. It is the responsibility of the
11055** caller to eventually free any such buffer using sqlite3_free(). The buffer
11056** is only allocated and populated if one or more conflicts were encountered
11057** while applying the patchset. See comments surrounding the sqlite3_rebaser
11058** APIs for further details.
11059**
11060** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11061** may be modified by passing a combination of
11062** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11063**
11064** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11065** and therefore subject to change.
11066*/
11067SQLITE_API int sqlite3changeset_apply(
11068 sqlite3 *db, /* Apply change to "main" db of this handle */
11069 int nChangeset, /* Size of changeset in bytes */
11070 void *pChangeset, /* Changeset blob */
11071 int(*xFilter)(
11072 void *pCtx, /* Copy of sixth arg to _apply() */
11073 const char *zTab /* Table name */
11074 ),
11075 int(*xConflict)(
11076 void *pCtx, /* Copy of sixth arg to _apply() */
11077 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11078 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11079 ),
11080 void *pCtx /* First argument passed to xConflict */
11081);
11082SQLITE_API int sqlite3changeset_apply_v2(
11083 sqlite3 *db, /* Apply change to "main" db of this handle */
11084 int nChangeset, /* Size of changeset in bytes */
11085 void *pChangeset, /* Changeset blob */
11086 int(*xFilter)(
11087 void *pCtx, /* Copy of sixth arg to _apply() */
11088 const char *zTab /* Table name */
11089 ),
11090 int(*xConflict)(
11091 void *pCtx, /* Copy of sixth arg to _apply() */
11092 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11093 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11094 ),
11095 void *pCtx, /* First argument passed to xConflict */
11096 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11097 int flags /* SESSION_CHANGESETAPPLY_* flags */
11098);
11099
11100/*
11101** CAPI3REF: Flags for sqlite3changeset_apply_v2
11102**
11103** The following flags may passed via the 9th parameter to
11104** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11105**
11106** <dl>
11107** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11108** Usually, the sessions module encloses all operations performed by
11109** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11110** SAVEPOINT is committed if the changeset or patchset is successfully
11111** applied, or rolled back if an error occurs. Specifying this flag
11112** causes the sessions module to omit this savepoint. In this case, if the
11113** caller has an open transaction or savepoint when apply_v2() is called,
11114** it may revert the partially applied changeset by rolling it back.
11115**
11116** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11117** Invert the changeset before applying it. This is equivalent to inverting
11118** a changeset using sqlite3changeset_invert() before applying it. It is
11119** an error to specify this flag with a patchset.
11120*/
11121#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11122#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11123
11124/*
11125** CAPI3REF: Constants Passed To The Conflict Handler
11126**
11127** Values that may be passed as the second argument to a conflict-handler.
11128**
11129** <dl>
11130** <dt>SQLITE_CHANGESET_DATA<dd>
11131** The conflict handler is invoked with CHANGESET_DATA as the second argument
11132** when processing a DELETE or UPDATE change if a row with the required
11133** PRIMARY KEY fields is present in the database, but one or more other
11134** (non primary-key) fields modified by the update do not contain the
11135** expected "before" values.
11136**
11137** The conflicting row, in this case, is the database row with the matching
11138** primary key.
11139**
11140** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11141** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11142** argument when processing a DELETE or UPDATE change if a row with the
11143** required PRIMARY KEY fields is not present in the database.
11144**
11145** There is no conflicting row in this case. The results of invoking the
11146** sqlite3changeset_conflict() API are undefined.
11147**
11148** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11149** CHANGESET_CONFLICT is passed as the second argument to the conflict
11150** handler while processing an INSERT change if the operation would result
11151** in duplicate primary key values.
11152**
11153** The conflicting row in this case is the database row with the matching
11154** primary key.
11155**
11156** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11157** If foreign key handling is enabled, and applying a changeset leaves the
11158** database in a state containing foreign key violations, the conflict
11159** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11160** exactly once before the changeset is committed. If the conflict handler
11161** returns CHANGESET_OMIT, the changes, including those that caused the
11162** foreign key constraint violation, are committed. Or, if it returns
11163** CHANGESET_ABORT, the changeset is rolled back.
11164**
11165** No current or conflicting row information is provided. The only function
11166** it is possible to call on the supplied sqlite3_changeset_iter handle
11167** is sqlite3changeset_fk_conflicts().
11168**
11169** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
11170** If any other constraint violation occurs while applying a change (i.e.
11171** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
11172** invoked with CHANGESET_CONSTRAINT as the second argument.
11173**
11174** There is no conflicting row in this case. The results of invoking the
11175** sqlite3changeset_conflict() API are undefined.
11176**
11177** </dl>
11178*/
11179#define SQLITE_CHANGESET_DATA 1
11180#define SQLITE_CHANGESET_NOTFOUND 2
11181#define SQLITE_CHANGESET_CONFLICT 3
11182#define SQLITE_CHANGESET_CONSTRAINT 4
11183#define SQLITE_CHANGESET_FOREIGN_KEY 5
11184
11185/*
11186** CAPI3REF: Constants Returned By The Conflict Handler
11187**
11188** A conflict handler callback must return one of the following three values.
11189**
11190** <dl>
11191** <dt>SQLITE_CHANGESET_OMIT<dd>
11192** If a conflict handler returns this value no special action is taken. The
11193** change that caused the conflict is not applied. The session module
11194** continues to the next change in the changeset.
11195**
11196** <dt>SQLITE_CHANGESET_REPLACE<dd>
11197** This value may only be returned if the second argument to the conflict
11198** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
11199** is not the case, any changes applied so far are rolled back and the
11200** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11201**
11202** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11203** handler, then the conflicting row is either updated or deleted, depending
11204** on the type of change.
11205**
11206** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11207** handler, then the conflicting row is removed from the database and a
11208** second attempt to apply the change is made. If this second attempt fails,
11209** the original row is restored to the database before continuing.
11210**
11211** <dt>SQLITE_CHANGESET_ABORT<dd>
11212** If this value is returned, any changes applied so far are rolled back
11213** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11214** </dl>
11215*/
11216#define SQLITE_CHANGESET_OMIT 0
11217#define SQLITE_CHANGESET_REPLACE 1
11218#define SQLITE_CHANGESET_ABORT 2
11219
11220/*
11221** CAPI3REF: Rebasing changesets
11222** EXPERIMENTAL
11223**
11224** Suppose there is a site hosting a database in state S0. And that
11225** modifications are made that move that database to state S1 and a
11226** changeset recorded (the "local" changeset). Then, a changeset based
11227** on S0 is received from another site (the "remote" changeset) and
11228** applied to the database. The database is then in state
11229** (S1+"remote"), where the exact state depends on any conflict
11230** resolution decisions (OMIT or REPLACE) made while applying "remote".
11231** Rebasing a changeset is to update it to take those conflict
11232** resolution decisions into account, so that the same conflicts
11233** do not have to be resolved elsewhere in the network.
11234**
11235** For example, if both the local and remote changesets contain an
11236** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11237**
11238** local: INSERT INTO t1 VALUES(1, 'v1');
11239** remote: INSERT INTO t1 VALUES(1, 'v2');
11240**
11241** and the conflict resolution is REPLACE, then the INSERT change is
11242** removed from the local changeset (it was overridden). Or, if the
11243** conflict resolution was "OMIT", then the local changeset is modified
11244** to instead contain:
11245**
11246** UPDATE t1 SET b = 'v2' WHERE a=1;
11247**
11248** Changes within the local changeset are rebased as follows:
11249**
11250** <dl>
11251** <dt>Local INSERT<dd>
11252** This may only conflict with a remote INSERT. If the conflict
11253** resolution was OMIT, then add an UPDATE change to the rebased
11254** changeset. Or, if the conflict resolution was REPLACE, add
11255** nothing to the rebased changeset.
11256**
11257** <dt>Local DELETE<dd>
11258** This may conflict with a remote UPDATE or DELETE. In both cases the
11259** only possible resolution is OMIT. If the remote operation was a
11260** DELETE, then add no change to the rebased changeset. If the remote
11261** operation was an UPDATE, then the old.* fields of change are updated
11262** to reflect the new.* values in the UPDATE.
11263**
11264** <dt>Local UPDATE<dd>
11265** This may conflict with a remote UPDATE or DELETE. If it conflicts
11266** with a DELETE, and the conflict resolution was OMIT, then the update
11267** is changed into an INSERT. Any undefined values in the new.* record
11268** from the update change are filled in using the old.* values from
11269** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11270** the UPDATE change is simply omitted from the rebased changeset.
11271**
11272** If conflict is with a remote UPDATE and the resolution is OMIT, then
11273** the old.* values are rebased using the new.* values in the remote
11274** change. Or, if the resolution is REPLACE, then the change is copied
11275** into the rebased changeset with updates to columns also updated by
11276** the conflicting remote UPDATE removed. If this means no columns would
11277** be updated, the change is omitted.
11278** </dl>
11279**
11280** A local change may be rebased against multiple remote changes
11281** simultaneously. If a single key is modified by multiple remote
11282** changesets, they are combined as follows before the local changeset
11283** is rebased:
11284**
11285** <ul>
11286** <li> If there has been one or more REPLACE resolutions on a
11287** key, it is rebased according to a REPLACE.
11288**
11289** <li> If there have been no REPLACE resolutions on a key, then
11290** the local changeset is rebased according to the most recent
11291** of the OMIT resolutions.
11292** </ul>
11293**
11294** Note that conflict resolutions from multiple remote changesets are
11295** combined on a per-field basis, not per-row. This means that in the
11296** case of multiple remote UPDATE operations, some fields of a single
11297** local change may be rebased for REPLACE while others are rebased for
11298** OMIT.
11299**
11300** In order to rebase a local changeset, the remote changeset must first
11301** be applied to the local database using sqlite3changeset_apply_v2() and
11302** the buffer of rebase information captured. Then:
11303**
11304** <ol>
11305** <li> An sqlite3_rebaser object is created by calling
11306** sqlite3rebaser_create().
11307** <li> The new object is configured with the rebase buffer obtained from
11308** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
11309** If the local changeset is to be rebased against multiple remote
11310** changesets, then sqlite3rebaser_configure() should be called
11311** multiple times, in the same order that the multiple
11312** sqlite3changeset_apply_v2() calls were made.
11313** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
11314** <li> The sqlite3_rebaser object is deleted by calling
11315** sqlite3rebaser_delete().
11316** </ol>
11317*/
11318typedef struct sqlite3_rebaser sqlite3_rebaser;
11319
11320/*
11321** CAPI3REF: Create a changeset rebaser object.
11322** EXPERIMENTAL
11323**
11324** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
11325** point to the new object and return SQLITE_OK. Otherwise, if an error
11326** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
11327** to NULL.
11328*/
11329SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
11330
11331/*
11332** CAPI3REF: Configure a changeset rebaser object.
11333** EXPERIMENTAL
11334**
11335** Configure the changeset rebaser object to rebase changesets according
11336** to the conflict resolutions described by buffer pRebase (size nRebase
11337** bytes), which must have been obtained from a previous call to
11338** sqlite3changeset_apply_v2().
11339*/
11340SQLITE_API int sqlite3rebaser_configure(
11341 sqlite3_rebaser*,
11342 int nRebase, const void *pRebase
11343);
11344
11345/*
11346** CAPI3REF: Rebase a changeset
11347** EXPERIMENTAL
11348**
11349** Argument pIn must point to a buffer containing a changeset nIn bytes
11350** in size. This function allocates and populates a buffer with a copy
11351** of the changeset rebased according to the configuration of the
11352** rebaser object passed as the first argument. If successful, (*ppOut)
11353** is set to point to the new buffer containing the rebased changeset and
11354** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
11355** responsibility of the caller to eventually free the new buffer using
11356** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
11357** are set to zero and an SQLite error code returned.
11358*/
11359SQLITE_API int sqlite3rebaser_rebase(
11360 sqlite3_rebaser*,
11361 int nIn, const void *pIn,
11362 int *pnOut, void **ppOut
11363);
11364
11365/*
11366** CAPI3REF: Delete a changeset rebaser object.
11367** EXPERIMENTAL
11368**
11369** Delete the changeset rebaser object and all associated resources. There
11370** should be one call to this function for each successful invocation
11371** of sqlite3rebaser_create().
11372*/
11373SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
11374
11375/*
11376** CAPI3REF: Streaming Versions of API functions.
11377**
11378** The six streaming API xxx_strm() functions serve similar purposes to the
11379** corresponding non-streaming API functions:
11380**
11381** <table border=1 style="margin-left:8ex;margin-right:8ex">
11382** <tr><th>Streaming function<th>Non-streaming equivalent</th>
11383** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
11384** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
11385** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
11386** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
11387** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
11388** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
11389** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
11390** </table>
11391**
11392** Non-streaming functions that accept changesets (or patchsets) as input
11393** require that the entire changeset be stored in a single buffer in memory.
11394** Similarly, those that return a changeset or patchset do so by returning
11395** a pointer to a single large buffer allocated using sqlite3_malloc().
11396** Normally this is convenient. However, if an application running in a
11397** low-memory environment is required to handle very large changesets, the
11398** large contiguous memory allocations required can become onerous.
11399**
11400** In order to avoid this problem, instead of a single large buffer, input
11401** is passed to a streaming API functions by way of a callback function that
11402** the sessions module invokes to incrementally request input data as it is
11403** required. In all cases, a pair of API function parameters such as
11404**
11405** <pre>
11406** &nbsp; int nChangeset,
11407** &nbsp; void *pChangeset,
11408** </pre>
11409**
11410** Is replaced by:
11411**
11412** <pre>
11413** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
11414** &nbsp; void *pIn,
11415** </pre>
11416**
11417** Each time the xInput callback is invoked by the sessions module, the first
11418** argument passed is a copy of the supplied pIn context pointer. The second
11419** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
11420** error occurs the xInput method should copy up to (*pnData) bytes of data
11421** into the buffer and set (*pnData) to the actual number of bytes copied
11422** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
11423** should be set to zero to indicate this. Or, if an error occurs, an SQLite
11424** error code should be returned. In all cases, if an xInput callback returns
11425** an error, all processing is abandoned and the streaming API function
11426** returns a copy of the error code to the caller.
11427**
11428** In the case of sqlite3changeset_start_strm(), the xInput callback may be
11429** invoked by the sessions module at any point during the lifetime of the
11430** iterator. If such an xInput callback returns an error, the iterator enters
11431** an error state, whereby all subsequent calls to iterator functions
11432** immediately fail with the same error code as returned by xInput.
11433**
11434** Similarly, streaming API functions that return changesets (or patchsets)
11435** return them in chunks by way of a callback function instead of via a
11436** pointer to a single large buffer. In this case, a pair of parameters such
11437** as:
11438**
11439** <pre>
11440** &nbsp; int *pnChangeset,
11441** &nbsp; void **ppChangeset,
11442** </pre>
11443**
11444** Is replaced by:
11445**
11446** <pre>
11447** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
11448** &nbsp; void *pOut
11449** </pre>
11450**
11451** The xOutput callback is invoked zero or more times to return data to
11452** the application. The first parameter passed to each call is a copy of the
11453** pOut pointer supplied by the application. The second parameter, pData,
11454** points to a buffer nData bytes in size containing the chunk of output
11455** data being returned. If the xOutput callback successfully processes the
11456** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
11457** it should return some other SQLite error code. In this case processing
11458** is immediately abandoned and the streaming API function returns a copy
11459** of the xOutput error code to the application.
11460**
11461** The sessions module never invokes an xOutput callback with the third
11462** parameter set to a value less than or equal to zero. Other than this,
11463** no guarantees are made as to the size of the chunks of data returned.
11464*/
11465SQLITE_API int sqlite3changeset_apply_strm(
11466 sqlite3 *db, /* Apply change to "main" db of this handle */
11467 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11468 void *pIn, /* First arg for xInput */
11469 int(*xFilter)(
11470 void *pCtx, /* Copy of sixth arg to _apply() */
11471 const char *zTab /* Table name */
11472 ),
11473 int(*xConflict)(
11474 void *pCtx, /* Copy of sixth arg to _apply() */
11475 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11476 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11477 ),
11478 void *pCtx /* First argument passed to xConflict */
11479);
11480SQLITE_API int sqlite3changeset_apply_v2_strm(
11481 sqlite3 *db, /* Apply change to "main" db of this handle */
11482 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11483 void *pIn, /* First arg for xInput */
11484 int(*xFilter)(
11485 void *pCtx, /* Copy of sixth arg to _apply() */
11486 const char *zTab /* Table name */
11487 ),
11488 int(*xConflict)(
11489 void *pCtx, /* Copy of sixth arg to _apply() */
11490 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11491 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11492 ),
11493 void *pCtx, /* First argument passed to xConflict */
11494 void **ppRebase, int *pnRebase,
11495 int flags
11496);
11497SQLITE_API int sqlite3changeset_concat_strm(
11498 int (*xInputA)(void *pIn, void *pData, int *pnData),
11499 void *pInA,
11500 int (*xInputB)(void *pIn, void *pData, int *pnData),
11501 void *pInB,
11502 int (*xOutput)(void *pOut, const void *pData, int nData),
11503 void *pOut
11504);
11505SQLITE_API int sqlite3changeset_invert_strm(
11506 int (*xInput)(void *pIn, void *pData, int *pnData),
11507 void *pIn,
11508 int (*xOutput)(void *pOut, const void *pData, int nData),
11509 void *pOut
11510);
11511SQLITE_API int sqlite3changeset_start_strm(
11512 sqlite3_changeset_iter **pp,
11513 int (*xInput)(void *pIn, void *pData, int *pnData),
11514 void *pIn
11515);
11516SQLITE_API int sqlite3changeset_start_v2_strm(
11517 sqlite3_changeset_iter **pp,
11518 int (*xInput)(void *pIn, void *pData, int *pnData),
11519 void *pIn,
11520 int flags
11521);
11522SQLITE_API int sqlite3session_changeset_strm(
11523 sqlite3_session *pSession,
11524 int (*xOutput)(void *pOut, const void *pData, int nData),
11525 void *pOut
11526);
11527SQLITE_API int sqlite3session_patchset_strm(
11528 sqlite3_session *pSession,
11529 int (*xOutput)(void *pOut, const void *pData, int nData),
11530 void *pOut
11531);
11532SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11533 int (*xInput)(void *pIn, void *pData, int *pnData),
11534 void *pIn
11535);
11536SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11537 int (*xOutput)(void *pOut, const void *pData, int nData),
11538 void *pOut
11539);
11540SQLITE_API int sqlite3rebaser_rebase_strm(
11541 sqlite3_rebaser *pRebaser,
11542 int (*xInput)(void *pIn, void *pData, int *pnData),
11543 void *pIn,
11544 int (*xOutput)(void *pOut, const void *pData, int nData),
11545 void *pOut
11546);
11547
11548/*
11549** CAPI3REF: Configure global parameters
11550**
11551** The sqlite3session_config() interface is used to make global configuration
11552** changes to the sessions module in order to tune it to the specific needs
11553** of the application.
11554**
11555** The sqlite3session_config() interface is not threadsafe. If it is invoked
11556** while any other thread is inside any other sessions method then the
11557** results are undefined. Furthermore, if it is invoked after any sessions
11558** related objects have been created, the results are also undefined.
11559**
11560** The first argument to the sqlite3session_config() function must be one
11561** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11562** interpretation of the (void*) value passed as the second parameter and
11563** the effect of calling this function depends on the value of the first
11564** parameter.
11565**
11566** <dl>
11567** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11568** By default, the sessions module streaming interfaces attempt to input
11569** and output data in approximately 1 KiB chunks. This operand may be used
11570** to set and query the value of this configuration setting. The pointer
11571** passed as the second argument must point to a value of type (int).
11572** If this value is greater than 0, it is used as the new streaming data
11573** chunk size for both input and output. Before returning, the (int) value
11574** pointed to by pArg is set to the final value of the streaming interface
11575** chunk size.
11576** </dl>
11577**
11578** This function returns SQLITE_OK if successful, or an SQLite error code
11579** otherwise.
11580*/
11581SQLITE_API int sqlite3session_config(int op, void *pArg);
11582
11583/*
11584** CAPI3REF: Values for sqlite3session_config().
11585*/
11586#define SQLITE_SESSION_CONFIG_STRMSIZE 1
11587
11588/*
11589** Make sure we can call this stuff from C++.
11590*/
11591#ifdef __cplusplus
11592}
11593#endif
11594
11595#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11596
11597/******** End of sqlite3session.h *********/
11598/******** Begin file fts5.h *********/
11599/*
11600** 2014 May 31
11601**
11602** The author disclaims copyright to this source code. In place of
11603** a legal notice, here is a blessing:
11604**
11605** May you do good and not evil.
11606** May you find forgiveness for yourself and forgive others.
11607** May you share freely, never taking more than you give.
11608**
11609******************************************************************************
11610**
11611** Interfaces to extend FTS5. Using the interfaces defined in this file,
11612** FTS5 may be extended with:
11613**
11614** * custom tokenizers, and
11615** * custom auxiliary functions.
11616*/
11617
11618
11619#ifndef _FTS5_H
11620#define _FTS5_H
11621
11622
11623#ifdef __cplusplus
11624extern "C" {
11625#endif
11626
11627/*************************************************************************
11628** CUSTOM AUXILIARY FUNCTIONS
11629**
11630** Virtual table implementations may overload SQL functions by implementing
11631** the sqlite3_module.xFindFunction() method.
11632*/
11633
11634typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11635typedef struct Fts5Context Fts5Context;
11636typedef struct Fts5PhraseIter Fts5PhraseIter;
11637
11638typedef void (*fts5_extension_function)(
11639 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11640 Fts5Context *pFts, /* First arg to pass to pApi functions */
11641 sqlite3_context *pCtx, /* Context for returning result/error */
11642 int nVal, /* Number of values in apVal[] array */
11643 sqlite3_value **apVal /* Array of trailing arguments */
11644);
11645
11646struct Fts5PhraseIter {
11647 const unsigned char *a;
11648 const unsigned char *b;
11649};
11650
11651/*
11652** EXTENSION API FUNCTIONS
11653**
11654** xUserData(pFts):
11655** Return a copy of the context pointer the extension function was
11656** registered with.
11657**
11658** xColumnTotalSize(pFts, iCol, pnToken):
11659** If parameter iCol is less than zero, set output variable *pnToken
11660** to the total number of tokens in the FTS5 table. Or, if iCol is
11661** non-negative but less than the number of columns in the table, return
11662** the total number of tokens in column iCol, considering all rows in
11663** the FTS5 table.
11664**
11665** If parameter iCol is greater than or equal to the number of columns
11666** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11667** an OOM condition or IO error), an appropriate SQLite error code is
11668** returned.
11669**
11670** xColumnCount(pFts):
11671** Return the number of columns in the table.
11672**
11673** xColumnSize(pFts, iCol, pnToken):
11674** If parameter iCol is less than zero, set output variable *pnToken
11675** to the total number of tokens in the current row. Or, if iCol is
11676** non-negative but less than the number of columns in the table, set
11677** *pnToken to the number of tokens in column iCol of the current row.
11678**
11679** If parameter iCol is greater than or equal to the number of columns
11680** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11681** an OOM condition or IO error), an appropriate SQLite error code is
11682** returned.
11683**
11684** This function may be quite inefficient if used with an FTS5 table
11685** created with the "columnsize=0" option.
11686**
11687** xColumnText:
11688** This function attempts to retrieve the text of column iCol of the
11689** current document. If successful, (*pz) is set to point to a buffer
11690** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11691** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11692** if an error occurs, an SQLite error code is returned and the final values
11693** of (*pz) and (*pn) are undefined.
11694**
11695** xPhraseCount:
11696** Returns the number of phrases in the current query expression.
11697**
11698** xPhraseSize:
11699** Returns the number of tokens in phrase iPhrase of the query. Phrases
11700** are numbered starting from zero.
11701**
11702** xInstCount:
11703** Set *pnInst to the total number of occurrences of all phrases within
11704** the query within the current row. Return SQLITE_OK if successful, or
11705** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11706**
11707** This API can be quite slow if used with an FTS5 table created with the
11708** "detail=none" or "detail=column" option. If the FTS5 table is created
11709** with either "detail=none" or "detail=column" and "content=" option
11710** (i.e. if it is a contentless table), then this API always returns 0.
11711**
11712** xInst:
11713** Query for the details of phrase match iIdx within the current row.
11714** Phrase matches are numbered starting from zero, so the iIdx argument
11715** should be greater than or equal to zero and smaller than the value
11716** output by xInstCount().
11717**
11718** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11719** to the column in which it occurs and *piOff the token offset of the
11720** first token of the phrase. Returns SQLITE_OK if successful, or an error
11721** code (i.e. SQLITE_NOMEM) if an error occurs.
11722**
11723** This API can be quite slow if used with an FTS5 table created with the
11724** "detail=none" or "detail=column" option.
11725**
11726** xRowid:
11727** Returns the rowid of the current row.
11728**
11729** xTokenize:
11730** Tokenize text using the tokenizer belonging to the FTS5 table.
11731**
11732** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11733** This API function is used to query the FTS table for phrase iPhrase
11734** of the current query. Specifically, a query equivalent to:
11735**
11736** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11737**
11738** with $p set to a phrase equivalent to the phrase iPhrase of the
11739** current query is executed. Any column filter that applies to
11740** phrase iPhrase of the current query is included in $p. For each
11741** row visited, the callback function passed as the fourth argument
11742** is invoked. The context and API objects passed to the callback
11743** function may be used to access the properties of each matched row.
11744** Invoking Api.xUserData() returns a copy of the pointer passed as
11745** the third argument to pUserData.
11746**
11747** If the callback function returns any value other than SQLITE_OK, the
11748** query is abandoned and the xQueryPhrase function returns immediately.
11749** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11750** Otherwise, the error code is propagated upwards.
11751**
11752** If the query runs to completion without incident, SQLITE_OK is returned.
11753** Or, if some error occurs before the query completes or is aborted by
11754** the callback, an SQLite error code is returned.
11755**
11756**
11757** xSetAuxdata(pFts5, pAux, xDelete)
11758**
11759** Save the pointer passed as the second argument as the extension function's
11760** "auxiliary data". The pointer may then be retrieved by the current or any
11761** future invocation of the same fts5 extension function made as part of
11762** the same MATCH query using the xGetAuxdata() API.
11763**
11764** Each extension function is allocated a single auxiliary data slot for
11765** each FTS query (MATCH expression). If the extension function is invoked
11766** more than once for a single FTS query, then all invocations share a
11767** single auxiliary data context.
11768**
11769** If there is already an auxiliary data pointer when this function is
11770** invoked, then it is replaced by the new pointer. If an xDelete callback
11771** was specified along with the original pointer, it is invoked at this
11772** point.
11773**
11774** The xDelete callback, if one is specified, is also invoked on the
11775** auxiliary data pointer after the FTS5 query has finished.
11776**
11777** If an error (e.g. an OOM condition) occurs within this function,
11778** the auxiliary data is set to NULL and an error code returned. If the
11779** xDelete parameter was not NULL, it is invoked on the auxiliary data
11780** pointer before returning.
11781**
11782**
11783** xGetAuxdata(pFts5, bClear)
11784**
11785** Returns the current auxiliary data pointer for the fts5 extension
11786** function. See the xSetAuxdata() method for details.
11787**
11788** If the bClear argument is non-zero, then the auxiliary data is cleared
11789** (set to NULL) before this function returns. In this case the xDelete,
11790** if any, is not invoked.
11791**
11792**
11793** xRowCount(pFts5, pnRow)
11794**
11795** This function is used to retrieve the total number of rows in the table.
11796** In other words, the same value that would be returned by:
11797**
11798** SELECT count(*) FROM ftstable;
11799**
11800** xPhraseFirst()
11801** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11802** method, to iterate through all instances of a single query phrase within
11803** the current row. This is the same information as is accessible via the
11804** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
11805** to use, this API may be faster under some circumstances. To iterate
11806** through instances of phrase iPhrase, use the following code:
11807**
11808** Fts5PhraseIter iter;
11809** int iCol, iOff;
11810** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11811** iCol>=0;
11812** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11813** ){
11814** // An instance of phrase iPhrase at offset iOff of column iCol
11815** }
11816**
11817** The Fts5PhraseIter structure is defined above. Applications should not
11818** modify this structure directly - it should only be used as shown above
11819** with the xPhraseFirst() and xPhraseNext() API methods (and by
11820** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11821**
11822** This API can be quite slow if used with an FTS5 table created with the
11823** "detail=none" or "detail=column" option. If the FTS5 table is created
11824** with either "detail=none" or "detail=column" and "content=" option
11825** (i.e. if it is a contentless table), then this API always iterates
11826** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11827**
11828** xPhraseNext()
11829** See xPhraseFirst above.
11830**
11831** xPhraseFirstColumn()
11832** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11833** and xPhraseNext() APIs described above. The difference is that instead
11834** of iterating through all instances of a phrase in the current row, these
11835** APIs are used to iterate through the set of columns in the current row
11836** that contain one or more instances of a specified phrase. For example:
11837**
11838** Fts5PhraseIter iter;
11839** int iCol;
11840** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11841** iCol>=0;
11842** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11843** ){
11844** // Column iCol contains at least one instance of phrase iPhrase
11845** }
11846**
11847** This API can be quite slow if used with an FTS5 table created with the
11848** "detail=none" option. If the FTS5 table is created with either
11849** "detail=none" "content=" option (i.e. if it is a contentless table),
11850** then this API always iterates through an empty set (all calls to
11851** xPhraseFirstColumn() set iCol to -1).
11852**
11853** The information accessed using this API and its companion
11854** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11855** (or xInst/xInstCount). The chief advantage of this API is that it is
11856** significantly more efficient than those alternatives when used with
11857** "detail=column" tables.
11858**
11859** xPhraseNextColumn()
11860** See xPhraseFirstColumn above.
11861*/
11862struct Fts5ExtensionApi {
11863 int iVersion; /* Currently always set to 3 */
11864
11865 void *(*xUserData)(Fts5Context*);
11866
11867 int (*xColumnCount)(Fts5Context*);
11868 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11869 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11870
11871 int (*xTokenize)(Fts5Context*,
11872 const char *pText, int nText, /* Text to tokenize */
11873 void *pCtx, /* Context passed to xToken() */
11874 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11875 );
11876
11877 int (*xPhraseCount)(Fts5Context*);
11878 int (*xPhraseSize)(Fts5Context*, int iPhrase);
11879
11880 int (*xInstCount)(Fts5Context*, int *pnInst);
11881 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11882
11883 sqlite3_int64 (*xRowid)(Fts5Context*);
11884 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11885 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11886
11887 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11888 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11889 );
11890 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11891 void *(*xGetAuxdata)(Fts5Context*, int bClear);
11892
11893 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11894 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11895
11896 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11897 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11898};
11899
11900/*
11901** CUSTOM AUXILIARY FUNCTIONS
11902*************************************************************************/
11903
11904/*************************************************************************
11905** CUSTOM TOKENIZERS
11906**
11907** Applications may also register custom tokenizer types. A tokenizer
11908** is registered by providing fts5 with a populated instance of the
11909** following structure. All structure methods must be defined, setting
11910** any member of the fts5_tokenizer struct to NULL leads to undefined
11911** behaviour. The structure methods are expected to function as follows:
11912**
11913** xCreate:
11914** This function is used to allocate and initialize a tokenizer instance.
11915** A tokenizer instance is required to actually tokenize text.
11916**
11917** The first argument passed to this function is a copy of the (void*)
11918** pointer provided by the application when the fts5_tokenizer object
11919** was registered with FTS5 (the third argument to xCreateTokenizer()).
11920** The second and third arguments are an array of nul-terminated strings
11921** containing the tokenizer arguments, if any, specified following the
11922** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
11923** to create the FTS5 table.
11924**
11925** The final argument is an output variable. If successful, (*ppOut)
11926** should be set to point to the new tokenizer handle and SQLITE_OK
11927** returned. If an error occurs, some value other than SQLITE_OK should
11928** be returned. In this case, fts5 assumes that the final value of *ppOut
11929** is undefined.
11930**
11931** xDelete:
11932** This function is invoked to delete a tokenizer handle previously
11933** allocated using xCreate(). Fts5 guarantees that this function will
11934** be invoked exactly once for each successful call to xCreate().
11935**
11936** xTokenize:
11937** This function is expected to tokenize the nText byte string indicated
11938** by argument pText. pText may or may not be nul-terminated. The first
11939** argument passed to this function is a pointer to an Fts5Tokenizer object
11940** returned by an earlier call to xCreate().
11941**
11942** The second argument indicates the reason that FTS5 is requesting
11943** tokenization of the supplied text. This is always one of the following
11944** four values:
11945**
11946** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
11947** or removed from the FTS table. The tokenizer is being invoked to
11948** determine the set of tokens to add to (or delete from) the
11949** FTS index.
11950**
11951** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
11952** against the FTS index. The tokenizer is being called to tokenize
11953** a bareword or quoted string specified as part of the query.
11954**
11955** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
11956** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
11957** followed by a "*" character, indicating that the last token
11958** returned by the tokenizer will be treated as a token prefix.
11959**
11960** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
11961** satisfy an fts5_api.xTokenize() request made by an auxiliary
11962** function. Or an fts5_api.xColumnSize() request made by the same
11963** on a columnsize=0 database.
11964** </ul>
11965**
11966** For each token in the input string, the supplied callback xToken() must
11967** be invoked. The first argument to it should be a copy of the pointer
11968** passed as the second argument to xTokenize(). The third and fourth
11969** arguments are a pointer to a buffer containing the token text, and the
11970** size of the token in bytes. The 4th and 5th arguments are the byte offsets
11971** of the first byte of and first byte immediately following the text from
11972** which the token is derived within the input.
11973**
11974** The second argument passed to the xToken() callback ("tflags") should
11975** normally be set to 0. The exception is if the tokenizer supports
11976** synonyms. In this case see the discussion below for details.
11977**
11978** FTS5 assumes the xToken() callback is invoked for each token in the
11979** order that they occur within the input text.
11980**
11981** If an xToken() callback returns any value other than SQLITE_OK, then
11982** the tokenization should be abandoned and the xTokenize() method should
11983** immediately return a copy of the xToken() return value. Or, if the
11984** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
11985** if an error occurs with the xTokenize() implementation itself, it
11986** may abandon the tokenization and return any error code other than
11987** SQLITE_OK or SQLITE_DONE.
11988**
11989** SYNONYM SUPPORT
11990**
11991** Custom tokenizers may also support synonyms. Consider a case in which a
11992** user wishes to query for a phrase such as "first place". Using the
11993** built-in tokenizers, the FTS5 query 'first + place' will match instances
11994** of "first place" within the document set, but not alternative forms
11995** such as "1st place". In some applications, it would be better to match
11996** all instances of "first place" or "1st place" regardless of which form
11997** the user specified in the MATCH query text.
11998**
11999** There are several ways to approach this in FTS5:
12000**
12001** <ol><li> By mapping all synonyms to a single token. In this case, using
12002** the above example, this means that the tokenizer returns the
12003** same token for inputs "first" and "1st". Say that token is in
12004** fact "first", so that when the user inserts the document "I won
12005** 1st place" entries are added to the index for tokens "i", "won",
12006** "first" and "place". If the user then queries for '1st + place',
12007** the tokenizer substitutes "first" for "1st" and the query works
12008** as expected.
12009**
12010** <li> By querying the index for all synonyms of each query term
12011** separately. In this case, when tokenizing query text, the
12012** tokenizer may provide multiple synonyms for a single term
12013** within the document. FTS5 then queries the index for each
12014** synonym individually. For example, faced with the query:
12015**
12016** <codeblock>
12017** ... MATCH 'first place'</codeblock>
12018**
12019** the tokenizer offers both "1st" and "first" as synonyms for the
12020** first token in the MATCH query and FTS5 effectively runs a query
12021** similar to:
12022**
12023** <codeblock>
12024** ... MATCH '(first OR 1st) place'</codeblock>
12025**
12026** except that, for the purposes of auxiliary functions, the query
12027** still appears to contain just two phrases - "(first OR 1st)"
12028** being treated as a single phrase.
12029**
12030** <li> By adding multiple synonyms for a single term to the FTS index.
12031** Using this method, when tokenizing document text, the tokenizer
12032** provides multiple synonyms for each token. So that when a
12033** document such as "I won first place" is tokenized, entries are
12034** added to the FTS index for "i", "won", "first", "1st" and
12035** "place".
12036**
12037** This way, even if the tokenizer does not provide synonyms
12038** when tokenizing query text (it should not - to do so would be
12039** inefficient), it doesn't matter if the user queries for
12040** 'first + place' or '1st + place', as there are entries in the
12041** FTS index corresponding to both forms of the first token.
12042** </ol>
12043**
12044** Whether it is parsing document or query text, any call to xToken that
12045** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12046** is considered to supply a synonym for the previous token. For example,
12047** when parsing the document "I won first place", a tokenizer that supports
12048** synonyms would call xToken() 5 times, as follows:
12049**
12050** <codeblock>
12051** xToken(pCtx, 0, "i", 1, 0, 1);
12052** xToken(pCtx, 0, "won", 3, 2, 5);
12053** xToken(pCtx, 0, "first", 5, 6, 11);
12054** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12055** xToken(pCtx, 0, "place", 5, 12, 17);
12056**</codeblock>
12057**
12058** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12059** xToken() is called. Multiple synonyms may be specified for a single token
12060** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
12061** There is no limit to the number of synonyms that may be provided for a
12062** single token.
12063**
12064** In many cases, method (1) above is the best approach. It does not add
12065** extra data to the FTS index or require FTS5 to query for multiple terms,
12066** so it is efficient in terms of disk space and query speed. However, it
12067** does not support prefix queries very well. If, as suggested above, the
12068** token "first" is substituted for "1st" by the tokenizer, then the query:
12069**
12070** <codeblock>
12071** ... MATCH '1s*'</codeblock>
12072**
12073** will not match documents that contain the token "1st" (as the tokenizer
12074** will probably not map "1s" to any prefix of "first").
12075**
12076** For full prefix support, method (3) may be preferred. In this case,
12077** because the index contains entries for both "first" and "1st", prefix
12078** queries such as 'fi*' or '1s*' will match correctly. However, because
12079** extra entries are added to the FTS index, this method uses more space
12080** within the database.
12081**
12082** Method (2) offers a midpoint between (1) and (3). Using this method,
12083** a query such as '1s*' will match documents that contain the literal
12084** token "1st", but not "first" (assuming the tokenizer is not able to
12085** provide synonyms for prefixes). However, a non-prefix query like '1st'
12086** will match against "1st" and "first". This method does not require
12087** extra disk space, as no extra entries are added to the FTS index.
12088** On the other hand, it may require more CPU cycles to run MATCH queries,
12089** as separate queries of the FTS index are required for each synonym.
12090**
12091** When using methods (2) or (3), it is important that the tokenizer only
12092** provide synonyms when tokenizing document text (method (2)) or query
12093** text (method (3)), not both. Doing so will not cause any errors, but is
12094** inefficient.
12095*/
12096typedef struct Fts5Tokenizer Fts5Tokenizer;
12097typedef struct fts5_tokenizer fts5_tokenizer;
12098struct fts5_tokenizer {
12099 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12100 void (*xDelete)(Fts5Tokenizer*);
12101 int (*xTokenize)(Fts5Tokenizer*,
12102 void *pCtx,
12103 int flags, /* Mask of FTS5_TOKENIZE_* flags */
12104 const char *pText, int nText,
12105 int (*xToken)(
12106 void *pCtx, /* Copy of 2nd argument to xTokenize() */
12107 int tflags, /* Mask of FTS5_TOKEN_* flags */
12108 const char *pToken, /* Pointer to buffer containing token */
12109 int nToken, /* Size of token in bytes */
12110 int iStart, /* Byte offset of token within input text */
12111 int iEnd /* Byte offset of end of token within input text */
12112 )
12113 );
12114};
12115
12116/* Flags that may be passed as the third argument to xTokenize() */
12117#define FTS5_TOKENIZE_QUERY 0x0001
12118#define FTS5_TOKENIZE_PREFIX 0x0002
12119#define FTS5_TOKENIZE_DOCUMENT 0x0004
12120#define FTS5_TOKENIZE_AUX 0x0008
12121
12122/* Flags that may be passed by the tokenizer implementation back to FTS5
12123** as the third argument to the supplied xToken callback. */
12124#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12125
12126/*
12127** END OF CUSTOM TOKENIZERS
12128*************************************************************************/
12129
12130/*************************************************************************
12131** FTS5 EXTENSION REGISTRATION API
12132*/
12133typedef struct fts5_api fts5_api;
12134struct fts5_api {
12135 int iVersion; /* Currently always set to 2 */
12136
12137 /* Create a new tokenizer */
12138 int (*xCreateTokenizer)(
12139 fts5_api *pApi,
12140 const char *zName,
12141 void *pContext,
12142 fts5_tokenizer *pTokenizer,
12143 void (*xDestroy)(void*)
12144 );
12145
12146 /* Find an existing tokenizer */
12147 int (*xFindTokenizer)(
12148 fts5_api *pApi,
12149 const char *zName,
12150 void **ppContext,
12151 fts5_tokenizer *pTokenizer
12152 );
12153
12154 /* Create a new auxiliary function */
12155 int (*xCreateFunction)(
12156 fts5_api *pApi,
12157 const char *zName,
12158 void *pContext,
12159 fts5_extension_function xFunction,
12160 void (*xDestroy)(void*)
12161 );
12162};
12163
12164/*
12165** END OF REGISTRATION API
12166*************************************************************************/
12167
12168#ifdef __cplusplus
12169} /* end of the 'extern "C"' block */
12170#endif
12171
12172#endif /* _FTS5_H */
12173
12174/******** End of fts5.h *********/
12175