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 "3.25.2"
127#define SQLITE_VERSION_NUMBER 3025002
128#define SQLITE_SOURCE_ID "2018-09-25 19:08:10 fb90e7189ae6d62e77ba3a308ca5d683f90bbe633cf681865365b8e92792d1c7"
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#endif
193
194/*
195** CAPI3REF: Test To See If The Library Is Threadsafe
196**
197** ^The sqlite3_threadsafe() function returns zero if and only if
198** SQLite was compiled with mutexing code omitted due to the
199** [SQLITE_THREADSAFE] compile-time option being set to 0.
200**
201** SQLite can be compiled with or without mutexes. When
202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
203** are enabled and SQLite is threadsafe. When the
204** [SQLITE_THREADSAFE] macro is 0,
205** the mutexes are omitted. Without the mutexes, it is not safe
206** to use SQLite concurrently from more than one thread.
207**
208** Enabling mutexes incurs a measurable performance penalty.
209** So if speed is of utmost importance, it makes sense to disable
210** the mutexes. But for maximum safety, mutexes should be enabled.
211** ^The default behavior is for mutexes to be enabled.
212**
213** This interface can be used by an application to make sure that the
214** version of SQLite that it is linking against was compiled with
215** the desired setting of the [SQLITE_THREADSAFE] macro.
216**
217** This interface only reports on the compile-time mutex setting
218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
220** can be fully or partially disabled using a call to [sqlite3_config()]
221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
223** sqlite3_threadsafe() function shows only the compile-time setting of
224** thread safety, not any run-time changes to that setting made by
225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
226** is unchanged by calls to sqlite3_config().)^
227**
228** See the [threading mode] documentation for additional information.
229*/
230SQLITE_API int sqlite3_threadsafe(void);
231
232/*
233** CAPI3REF: Database Connection Handle
234** KEYWORDS: {database connection} {database connections}
235**
236** Each open SQLite database is represented by a pointer to an instance of
237** the opaque structure named "sqlite3". It is useful to think of an sqlite3
238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
240** and [sqlite3_close_v2()] are its destructors. There are many other
241** interfaces (such as
242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
243** [sqlite3_busy_timeout()] to name but three) that are methods on an
244** sqlite3 object.
245*/
246typedef struct sqlite3 sqlite3;
247
248/*
249** CAPI3REF: 64-Bit Integer Types
250** KEYWORDS: sqlite_int64 sqlite_uint64
251**
252** Because there is no cross-platform way to specify 64-bit integer types
253** SQLite includes typedefs for 64-bit signed and unsigned integers.
254**
255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
256** The sqlite_int64 and sqlite_uint64 types are supported for backwards
257** compatibility only.
258**
259** ^The sqlite3_int64 and sqlite_int64 types can store integer values
260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
261** sqlite3_uint64 and sqlite_uint64 types can store integer values
262** between 0 and +18446744073709551615 inclusive.
263*/
264#ifdef SQLITE_INT64_TYPE
265 typedef SQLITE_INT64_TYPE sqlite_int64;
266# ifdef SQLITE_UINT64_TYPE
267 typedef SQLITE_UINT64_TYPE sqlite_uint64;
268# else
269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
270# endif
271#elif defined(_MSC_VER) || defined(__BORLANDC__)
272 typedef __int64 sqlite_int64;
273 typedef unsigned __int64 sqlite_uint64;
274#else
275 typedef long long int sqlite_int64;
276 typedef unsigned long long int sqlite_uint64;
277#endif
278typedef sqlite_int64 sqlite3_int64;
279typedef sqlite_uint64 sqlite3_uint64;
280
281/*
282** If compiling for a processor that lacks floating point support,
283** substitute integer for floating-point.
284*/
285#ifdef SQLITE_OMIT_FLOATING_POINT
286# define double sqlite3_int64
287#endif
288
289/*
290** CAPI3REF: Closing A Database Connection
291** DESTRUCTOR: sqlite3
292**
293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
294** for the [sqlite3] object.
295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
296** the [sqlite3] object is successfully destroyed and all associated
297** resources are deallocated.
298**
299** ^If the database connection is associated with unfinalized prepared
300** statements or unfinished sqlite3_backup objects then sqlite3_close()
301** will leave the database connection open and return [SQLITE_BUSY].
302** ^If sqlite3_close_v2() is called with unfinalized prepared statements
303** and/or unfinished sqlite3_backups, then the database connection becomes
304** an unusable "zombie" which will automatically be deallocated when the
305** last prepared statement is finalized or the last sqlite3_backup is
306** finished. The sqlite3_close_v2() interface is intended for use with
307** host languages that are garbage collected, and where the order in which
308** destructors are called is arbitrary.
309**
310** Applications should [sqlite3_finalize | finalize] all [prepared statements],
311** [sqlite3_blob_close | close] all [BLOB handles], and
312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
313** with the [sqlite3] object prior to attempting to close the object. ^If
314** sqlite3_close_v2() is called on a [database connection] that still has
315** outstanding [prepared statements], [BLOB handles], and/or
316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
317** of resources is deferred until all [prepared statements], [BLOB handles],
318** and [sqlite3_backup] objects are also destroyed.
319**
320** ^If an [sqlite3] object is destroyed while a transaction is open,
321** the transaction is automatically rolled back.
322**
323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
324** must be either a NULL
325** pointer or an [sqlite3] object pointer obtained
326** from [sqlite3_open()], [sqlite3_open16()], or
327** [sqlite3_open_v2()], and not previously closed.
328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
329** argument is a harmless no-op.
330*/
331SQLITE_API int sqlite3_close(sqlite3*);
332SQLITE_API int sqlite3_close_v2(sqlite3*);
333
334/*
335** The type for a callback function.
336** This is legacy and deprecated. It is included for historical
337** compatibility and is not documented.
338*/
339typedef int (*sqlite3_callback)(void*,int,char**, char**);
340
341/*
342** CAPI3REF: One-Step Query Execution Interface
343** METHOD: sqlite3
344**
345** The sqlite3_exec() interface is a convenience wrapper around
346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
347** that allows an application to run multiple statements of SQL
348** without having to use a lot of C code.
349**
350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
351** semicolon-separate SQL statements passed into its 2nd argument,
352** in the context of the [database connection] passed in as its 1st
353** argument. ^If the callback function of the 3rd argument to
354** sqlite3_exec() is not NULL, then it is invoked for each result row
355** coming out of the evaluated SQL statements. ^The 4th argument to
356** sqlite3_exec() is relayed through to the 1st argument of each
357** callback invocation. ^If the callback pointer to sqlite3_exec()
358** is NULL, then no callback is ever invoked and result rows are
359** ignored.
360**
361** ^If an error occurs while evaluating the SQL statements passed into
362** sqlite3_exec(), then execution of the current statement stops and
363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
364** is not NULL then any error message is written into memory obtained
365** from [sqlite3_malloc()] and passed back through the 5th parameter.
366** To avoid memory leaks, the application should invoke [sqlite3_free()]
367** on error message strings returned through the 5th parameter of
368** sqlite3_exec() after the error message string is no longer needed.
369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
371** NULL before returning.
372**
373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
374** routine returns SQLITE_ABORT without invoking the callback again and
375** without running any subsequent SQL statements.
376**
377** ^The 2nd argument to the sqlite3_exec() callback function is the
378** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
379** callback is an array of pointers to strings obtained as if from
380** [sqlite3_column_text()], one for each column. ^If an element of a
381** result row is NULL then the corresponding string pointer for the
382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
383** sqlite3_exec() callback is an array of pointers to strings where each
384** entry represents the name of corresponding result column as obtained
385** from [sqlite3_column_name()].
386**
387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
388** to an empty string, or a pointer that contains only whitespace and/or
389** SQL comments, then no SQL statements are evaluated and the database
390** is not changed.
391**
392** Restrictions:
393**
394** <ul>
395** <li> The application must ensure that the 1st parameter to sqlite3_exec()
396** is a valid and open [database connection].
397** <li> The application must not close the [database connection] specified by
398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
399** <li> The application must not modify the SQL statement text passed into
400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
401** </ul>
402*/
403SQLITE_API int sqlite3_exec(
404 sqlite3*, /* An open database */
405 const char *sql, /* SQL to be evaluated */
406 int (*callback)(void*,int,char**,char**), /* Callback function */
407 void *, /* 1st argument to callback */
408 char **errmsg /* Error msg written here */
409);
410
411/*
412** CAPI3REF: Result Codes
413** KEYWORDS: {result code definitions}
414**
415** Many SQLite functions return an integer result code from the set shown
416** here in order to indicate success or failure.
417**
418** New error codes may be added in future versions of SQLite.
419**
420** See also: [extended result code definitions]
421*/
422#define SQLITE_OK 0 /* Successful result */
423/* beginning-of-error-codes */
424#define SQLITE_ERROR 1 /* Generic error */
425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
426#define SQLITE_PERM 3 /* Access permission denied */
427#define SQLITE_ABORT 4 /* Callback routine requested an abort */
428#define SQLITE_BUSY 5 /* The database file is locked */
429#define SQLITE_LOCKED 6 /* A table in the database is locked */
430#define SQLITE_NOMEM 7 /* A malloc() failed */
431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
436#define SQLITE_FULL 13 /* Insertion failed because database is full */
437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
439#define SQLITE_EMPTY 16 /* Internal use only */
440#define SQLITE_SCHEMA 17 /* The database schema changed */
441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
443#define SQLITE_MISMATCH 20 /* Data type mismatch */
444#define SQLITE_MISUSE 21 /* Library used incorrectly */
445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
446#define SQLITE_AUTH 23 /* Authorization denied */
447#define SQLITE_FORMAT 24 /* Not used */
448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
449#define SQLITE_NOTADB 26 /* File opened that is not a database file */
450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
454/* end-of-error-codes */
455
456/*
457** CAPI3REF: Extended Result Codes
458** KEYWORDS: {extended result code definitions}
459**
460** In its default configuration, SQLite API routines return one of 30 integer
461** [result codes]. However, experience has shown that many of
462** these result codes are too coarse-grained. They do not provide as
463** much information about problems as programmers might like. In an effort to
464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
465** and later) include
466** support for additional result codes that provide more detailed information
467** about errors. These [extended result codes] are enabled or disabled
468** on a per database connection basis using the
469** [sqlite3_extended_result_codes()] API. Or, the extended code for
470** the most recent error can be obtained using
471** [sqlite3_extended_errcode()].
472*/
473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
475#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
476#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
477#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
478#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
479#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
480#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
481#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
482#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
483#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
484#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
485#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
486#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
487#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
488#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
489#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
490#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
491#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
492#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
493#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
494#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
495#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
496#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
497#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
498#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
499#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
500#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
501#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
502#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
503#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
504#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
505#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
506#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<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_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
512#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
513#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
514#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
515#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
516#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
517#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
518#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
519#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
520#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
521#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
522#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
523#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
524#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
525#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
526#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
527#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
528#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
529#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
530#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
531#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
532#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
533#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
534#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
535#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
536#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
537#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
538#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
539#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
540
541/*
542** CAPI3REF: Flags For File Open Operations
543**
544** These bit values are intended for use in the
545** 3rd parameter to the [sqlite3_open_v2()] interface and
546** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
547*/
548#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
549#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
550#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
551#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
552#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
553#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
554#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
555#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
556#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
557#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
558#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
559#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
560#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
561#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
562#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
563#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
564#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
565#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
566#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
567#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
568
569/* Reserved: 0x00F00000 */
570
571/*
572** CAPI3REF: Device Characteristics
573**
574** The xDeviceCharacteristics method of the [sqlite3_io_methods]
575** object returns an integer which is a vector of these
576** bit values expressing I/O characteristics of the mass storage
577** device that holds the file that the [sqlite3_io_methods]
578** refers to.
579**
580** The SQLITE_IOCAP_ATOMIC property means that all writes of
581** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
582** mean that writes of blocks that are nnn bytes in size and
583** are aligned to an address which is an integer multiple of
584** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
585** that when data is appended to a file, the data is appended
586** first then the size of the file is extended, never the other
587** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
588** information is written to disk in the same order as calls
589** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
590** after reboot following a crash or power loss, the only bytes in a
591** file that were written at the application level might have changed
592** and that adjacent bytes, even bytes within the same sector are
593** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
594** flag indicates that a file cannot be deleted when open. The
595** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
596** read-only media and cannot be changed even by processes with
597** elevated privileges.
598**
599** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
600** filesystem supports doing multiple write operations atomically when those
601** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
602** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
603*/
604#define SQLITE_IOCAP_ATOMIC 0x00000001
605#define SQLITE_IOCAP_ATOMIC512 0x00000002
606#define SQLITE_IOCAP_ATOMIC1K 0x00000004
607#define SQLITE_IOCAP_ATOMIC2K 0x00000008
608#define SQLITE_IOCAP_ATOMIC4K 0x00000010
609#define SQLITE_IOCAP_ATOMIC8K 0x00000020
610#define SQLITE_IOCAP_ATOMIC16K 0x00000040
611#define SQLITE_IOCAP_ATOMIC32K 0x00000080
612#define SQLITE_IOCAP_ATOMIC64K 0x00000100
613#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
614#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
615#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
616#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
617#define SQLITE_IOCAP_IMMUTABLE 0x00002000
618#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
619
620/*
621** CAPI3REF: File Locking Levels
622**
623** SQLite uses one of these integer values as the second
624** argument to calls it makes to the xLock() and xUnlock() methods
625** of an [sqlite3_io_methods] object.
626*/
627#define SQLITE_LOCK_NONE 0
628#define SQLITE_LOCK_SHARED 1
629#define SQLITE_LOCK_RESERVED 2
630#define SQLITE_LOCK_PENDING 3
631#define SQLITE_LOCK_EXCLUSIVE 4
632
633/*
634** CAPI3REF: Synchronization Type Flags
635**
636** When SQLite invokes the xSync() method of an
637** [sqlite3_io_methods] object it uses a combination of
638** these integer values as the second argument.
639**
640** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
641** sync operation only needs to flush data to mass storage. Inode
642** information need not be flushed. If the lower four bits of the flag
643** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
644** If the lower four bits equal SQLITE_SYNC_FULL, that means
645** to use Mac OS X style fullsync instead of fsync().
646**
647** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
648** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
649** settings. The [synchronous pragma] determines when calls to the
650** xSync VFS method occur and applies uniformly across all platforms.
651** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
652** energetic or rigorous or forceful the sync operations are and
653** only make a difference on Mac OSX for the default SQLite code.
654** (Third-party VFS implementations might also make the distinction
655** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
656** operating systems natively supported by SQLite, only Mac OSX
657** cares about the difference.)
658*/
659#define SQLITE_SYNC_NORMAL 0x00002
660#define SQLITE_SYNC_FULL 0x00003
661#define SQLITE_SYNC_DATAONLY 0x00010
662
663/*
664** CAPI3REF: OS Interface Open File Handle
665**
666** An [sqlite3_file] object represents an open file in the
667** [sqlite3_vfs | OS interface layer]. Individual OS interface
668** implementations will
669** want to subclass this object by appending additional fields
670** for their own use. The pMethods entry is a pointer to an
671** [sqlite3_io_methods] object that defines methods for performing
672** I/O operations on the open file.
673*/
674typedef struct sqlite3_file sqlite3_file;
675struct sqlite3_file {
676 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
677};
678
679/*
680** CAPI3REF: OS Interface File Virtual Methods Object
681**
682** Every file opened by the [sqlite3_vfs.xOpen] method populates an
683** [sqlite3_file] object (or, more commonly, a subclass of the
684** [sqlite3_file] object) with a pointer to an instance of this object.
685** This object defines the methods used to perform various operations
686** against the open file represented by the [sqlite3_file] object.
687**
688** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
689** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
690** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
691** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
692** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
693** to NULL.
694**
695** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
696** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
697** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
698** flag may be ORed in to indicate that only the data of the file
699** and not its inode needs to be synced.
700**
701** The integer values to xLock() and xUnlock() are one of
702** <ul>
703** <li> [SQLITE_LOCK_NONE],
704** <li> [SQLITE_LOCK_SHARED],
705** <li> [SQLITE_LOCK_RESERVED],
706** <li> [SQLITE_LOCK_PENDING], or
707** <li> [SQLITE_LOCK_EXCLUSIVE].
708** </ul>
709** xLock() increases the lock. xUnlock() decreases the lock.
710** The xCheckReservedLock() method checks whether any database connection,
711** either in this process or in some other process, is holding a RESERVED,
712** PENDING, or EXCLUSIVE lock on the file. It returns true
713** if such a lock exists and false otherwise.
714**
715** The xFileControl() method is a generic interface that allows custom
716** VFS implementations to directly control an open file using the
717** [sqlite3_file_control()] interface. The second "op" argument is an
718** integer opcode. The third argument is a generic pointer intended to
719** point to a structure that may contain arguments or space in which to
720** write return values. Potential uses for xFileControl() might be
721** functions to enable blocking locks with timeouts, to change the
722** locking strategy (for example to use dot-file locks), to inquire
723** about the status of a lock, or to break stale locks. The SQLite
724** core reserves all opcodes less than 100 for its own use.
725** A [file control opcodes | list of opcodes] less than 100 is available.
726** Applications that define a custom xFileControl method should use opcodes
727** greater than 100 to avoid conflicts. VFS implementations should
728** return [SQLITE_NOTFOUND] for file control opcodes that they do not
729** recognize.
730**
731** The xSectorSize() method returns the sector size of the
732** device that underlies the file. The sector size is the
733** minimum write that can be performed without disturbing
734** other bytes in the file. The xDeviceCharacteristics()
735** method returns a bit vector describing behaviors of the
736** underlying device:
737**
738** <ul>
739** <li> [SQLITE_IOCAP_ATOMIC]
740** <li> [SQLITE_IOCAP_ATOMIC512]
741** <li> [SQLITE_IOCAP_ATOMIC1K]
742** <li> [SQLITE_IOCAP_ATOMIC2K]
743** <li> [SQLITE_IOCAP_ATOMIC4K]
744** <li> [SQLITE_IOCAP_ATOMIC8K]
745** <li> [SQLITE_IOCAP_ATOMIC16K]
746** <li> [SQLITE_IOCAP_ATOMIC32K]
747** <li> [SQLITE_IOCAP_ATOMIC64K]
748** <li> [SQLITE_IOCAP_SAFE_APPEND]
749** <li> [SQLITE_IOCAP_SEQUENTIAL]
750** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
751** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
752** <li> [SQLITE_IOCAP_IMMUTABLE]
753** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
754** </ul>
755**
756** The SQLITE_IOCAP_ATOMIC property means that all writes of
757** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
758** mean that writes of blocks that are nnn bytes in size and
759** are aligned to an address which is an integer multiple of
760** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
761** that when data is appended to a file, the data is appended
762** first then the size of the file is extended, never the other
763** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
764** information is written to disk in the same order as calls
765** to xWrite().
766**
767** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
768** in the unread portions of the buffer with zeros. A VFS that
769** fails to zero-fill short reads might seem to work. However,
770** failure to zero-fill short reads will eventually lead to
771** database corruption.
772*/
773typedef struct sqlite3_io_methods sqlite3_io_methods;
774struct sqlite3_io_methods {
775 int iVersion;
776 int (*xClose)(sqlite3_file*);
777 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
778 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
779 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
780 int (*xSync)(sqlite3_file*, int flags);
781 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
782 int (*xLock)(sqlite3_file*, int);
783 int (*xUnlock)(sqlite3_file*, int);
784 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
785 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
786 int (*xSectorSize)(sqlite3_file*);
787 int (*xDeviceCharacteristics)(sqlite3_file*);
788 /* Methods above are valid for version 1 */
789 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
790 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
791 void (*xShmBarrier)(sqlite3_file*);
792 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
793 /* Methods above are valid for version 2 */
794 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
795 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
796 /* Methods above are valid for version 3 */
797 /* Additional methods may be added in future releases */
798};
799
800/*
801** CAPI3REF: Standard File Control Opcodes
802** KEYWORDS: {file control opcodes} {file control opcode}
803**
804** These integer constants are opcodes for the xFileControl method
805** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
806** interface.
807**
808** <ul>
809** <li>[[SQLITE_FCNTL_LOCKSTATE]]
810** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
811** opcode causes the xFileControl method to write the current state of
812** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
813** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
814** into an integer that the pArg argument points to. This capability
815** is used during testing and is only available when the SQLITE_TEST
816** compile-time option is used.
817**
818** <li>[[SQLITE_FCNTL_SIZE_HINT]]
819** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
820** layer a hint of how large the database file will grow to be during the
821** current transaction. This hint is not guaranteed to be accurate but it
822** is often close. The underlying VFS might choose to preallocate database
823** file space based on this hint in order to help writes to the database
824** file run faster.
825**
826** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
827** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
828** extends and truncates the database file in chunks of a size specified
829** by the user. The fourth argument to [sqlite3_file_control()] should
830** point to an integer (type int) containing the new chunk-size to use
831** for the nominated database. Allocating database file space in large
832** chunks (say 1MB at a time), may reduce file-system fragmentation and
833** improve performance on some systems.
834**
835** <li>[[SQLITE_FCNTL_FILE_POINTER]]
836** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
837** to the [sqlite3_file] object associated with a particular database
838** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
839**
840** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
841** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
842** to the [sqlite3_file] object associated with the journal file (either
843** the [rollback journal] or the [write-ahead log]) for a particular database
844** connection. See also [SQLITE_FCNTL_FILE_POINTER].
845**
846** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
847** No longer in use.
848**
849** <li>[[SQLITE_FCNTL_SYNC]]
850** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
851** sent to the VFS immediately before the xSync method is invoked on a
852** database file descriptor. Or, if the xSync method is not invoked
853** because the user has configured SQLite with
854** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
855** of the xSync method. In most cases, the pointer argument passed with
856** this file-control is NULL. However, if the database file is being synced
857** as part of a multi-database commit, the argument points to a nul-terminated
858** string containing the transactions master-journal file name. VFSes that
859** do not need this signal should silently ignore this opcode. Applications
860** should not call [sqlite3_file_control()] with this opcode as doing so may
861** disrupt the operation of the specialized VFSes that do require it.
862**
863** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
864** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
865** and sent to the VFS after a transaction has been committed immediately
866** but before the database is unlocked. VFSes that do not need this signal
867** should silently ignore this opcode. Applications should not call
868** [sqlite3_file_control()] with this opcode as doing so may disrupt the
869** operation of the specialized VFSes that do require it.
870**
871** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
872** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
873** retry counts and intervals for certain disk I/O operations for the
874** windows [VFS] in order to provide robustness in the presence of
875** anti-virus programs. By default, the windows VFS will retry file read,
876** file write, and file delete operations up to 10 times, with a delay
877** of 25 milliseconds before the first retry and with the delay increasing
878** by an additional 25 milliseconds with each subsequent retry. This
879** opcode allows these two values (10 retries and 25 milliseconds of delay)
880** to be adjusted. The values are changed for all database connections
881** within the same process. The argument is a pointer to an array of two
882** integers where the first integer is the new retry count and the second
883** integer is the delay. If either integer is negative, then the setting
884** is not changed but instead the prior value of that setting is written
885** into the array entry, allowing the current retry settings to be
886** interrogated. The zDbName parameter is ignored.
887**
888** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
889** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
890** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
891** write ahead log ([WAL file]) and shared memory
892** files used for transaction control
893** are automatically deleted when the latest connection to the database
894** closes. Setting persistent WAL mode causes those files to persist after
895** close. Persisting the files is useful when other processes that do not
896** have write permission on the directory containing the database file want
897** to read the database file, as the WAL and shared memory files must exist
898** in order for the database to be readable. The fourth parameter to
899** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
900** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
901** WAL mode. If the integer is -1, then it is overwritten with the current
902** WAL persistence setting.
903**
904** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
905** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
906** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
907** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
908** xDeviceCharacteristics methods. The fourth parameter to
909** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
910** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
911** mode. If the integer is -1, then it is overwritten with the current
912** zero-damage mode setting.
913**
914** <li>[[SQLITE_FCNTL_OVERWRITE]]
915** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
916** a write transaction to indicate that, unless it is rolled back for some
917** reason, the entire database file will be overwritten by the current
918** transaction. This is used by VACUUM operations.
919**
920** <li>[[SQLITE_FCNTL_VFSNAME]]
921** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
922** all [VFSes] in the VFS stack. The names are of all VFS shims and the
923** final bottom-level VFS are written into memory obtained from
924** [sqlite3_malloc()] and the result is stored in the char* variable
925** that the fourth parameter of [sqlite3_file_control()] points to.
926** The caller is responsible for freeing the memory when done. As with
927** all file-control actions, there is no guarantee that this will actually
928** do anything. Callers should initialize the char* variable to a NULL
929** pointer in case this file-control is not implemented. This file-control
930** is intended for diagnostic use only.
931**
932** <li>[[SQLITE_FCNTL_VFS_POINTER]]
933** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
934** [VFSes] currently in use. ^(The argument X in
935** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
936** of type "[sqlite3_vfs] **". This opcodes will set *X
937** to a pointer to the top-level VFS.)^
938** ^When there are multiple VFS shims in the stack, this opcode finds the
939** upper-most shim only.
940**
941** <li>[[SQLITE_FCNTL_PRAGMA]]
942** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
943** file control is sent to the open [sqlite3_file] object corresponding
944** to the database file to which the pragma statement refers. ^The argument
945** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
946** pointers to strings (char**) in which the second element of the array
947** is the name of the pragma and the third element is the argument to the
948** pragma or NULL if the pragma has no argument. ^The handler for an
949** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
950** of the char** argument point to a string obtained from [sqlite3_mprintf()]
951** or the equivalent and that string will become the result of the pragma or
952** the error message if the pragma fails. ^If the
953** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
954** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
955** file control returns [SQLITE_OK], then the parser assumes that the
956** VFS has handled the PRAGMA itself and the parser generates a no-op
957** prepared statement if result string is NULL, or that returns a copy
958** of the result string if the string is non-NULL.
959** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
960** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
961** that the VFS encountered an error while handling the [PRAGMA] and the
962** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
963** file control occurs at the beginning of pragma statement analysis and so
964** it is able to override built-in [PRAGMA] statements.
965**
966** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
967** ^The [SQLITE_FCNTL_BUSYHANDLER]
968** file-control may be invoked by SQLite on the database file handle
969** shortly after it is opened in order to provide a custom VFS with access
970** to the connections busy-handler callback. The argument is of type (void **)
971** - an array of two (void *) values. The first (void *) actually points
972** to a function of type (int (*)(void *)). In order to invoke the connections
973** busy-handler, this function should be invoked with the second (void *) in
974** the array as the only argument. If it returns non-zero, then the operation
975** should be retried. If it returns zero, the custom VFS should abandon the
976** current operation.
977**
978** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
979** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
980** to have SQLite generate a
981** temporary filename using the same algorithm that is followed to generate
982** temporary filenames for TEMP tables and other internal uses. The
983** argument should be a char** which will be filled with the filename
984** written into memory obtained from [sqlite3_malloc()]. The caller should
985** invoke [sqlite3_free()] on the result to avoid a memory leak.
986**
987** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
988** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
989** maximum number of bytes that will be used for memory-mapped I/O.
990** The argument is a pointer to a value of type sqlite3_int64 that
991** is an advisory maximum number of bytes in the file to memory map. The
992** pointer is overwritten with the old value. The limit is not changed if
993** the value originally pointed to is negative, and so the current limit
994** can be queried by passing in a pointer to a negative number. This
995** file-control is used internally to implement [PRAGMA mmap_size].
996**
997** <li>[[SQLITE_FCNTL_TRACE]]
998** The [SQLITE_FCNTL_TRACE] file control provides advisory information
999** to the VFS about what the higher layers of the SQLite stack are doing.
1000** This file control is used by some VFS activity tracing [shims].
1001** The argument is a zero-terminated string. Higher layers in the
1002** SQLite stack may generate instances of this file control if
1003** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1004**
1005** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1006** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1007** pointer to an integer and it writes a boolean into that integer depending
1008** on whether or not the file has been renamed, moved, or deleted since it
1009** was first opened.
1010**
1011** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1012** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1013** underlying native file handle associated with a file handle. This file
1014** control interprets its argument as a pointer to a native file handle and
1015** writes the resulting value there.
1016**
1017** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1018** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1019** opcode causes the xFileControl method to swap the file handle with the one
1020** pointed to by the pArg argument. This capability is used during testing
1021** and only needs to be supported when SQLITE_TEST is defined.
1022**
1023** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1024** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1025** be advantageous to block on the next WAL lock if the lock is not immediately
1026** available. The WAL subsystem issues this signal during rare
1027** circumstances in order to fix a problem with priority inversion.
1028** Applications should <em>not</em> use this file-control.
1029**
1030** <li>[[SQLITE_FCNTL_ZIPVFS]]
1031** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1032** VFS should return SQLITE_NOTFOUND for this opcode.
1033**
1034** <li>[[SQLITE_FCNTL_RBU]]
1035** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1036** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1037** this opcode.
1038**
1039** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1040** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1041** the file descriptor is placed in "batch write mode", which
1042** means all subsequent write operations will be deferred and done
1043** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1044** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1045** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1046** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1047** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1048** no VFS interface calls on the same [sqlite3_file] file descriptor
1049** except for calls to the xWrite method and the xFileControl method
1050** with [SQLITE_FCNTL_SIZE_HINT].
1051**
1052** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1053** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1054** operations since the previous successful call to
1055** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1056** This file control returns [SQLITE_OK] if and only if the writes were
1057** all performed successfully and have been committed to persistent storage.
1058** ^Regardless of whether or not it is successful, this file control takes
1059** the file descriptor out of batch write mode so that all subsequent
1060** write operations are independent.
1061** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1062** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1063**
1064** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1065** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1066** operations since the previous successful call to
1067** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1068** ^This file control takes the file descriptor out of batch write mode
1069** so that all subsequent write operations are independent.
1070** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1071** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1072**
1073** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1074** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
1075** a file lock using the xLock or xShmLock methods of the VFS to wait
1076** for up to M milliseconds before failing, where M is the single
1077** unsigned integer parameter.
1078**
1079** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1080** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1081** a database file. The argument is a pointer to a 32-bit unsigned integer.
1082** The "data version" for the pager is written into the pointer. The
1083** "data version" changes whenever any change occurs to the corresponding
1084** database file, either through SQL statements on the same database
1085** connection or through transactions committed by separate database
1086** connections possibly in other processes. The [sqlite3_total_changes()]
1087** interface can be used to find if any database on the connection has changed,
1088** but that interface responds to changes on TEMP as well as MAIN and does
1089** not provide a mechanism to detect changes to MAIN only. Also, the
1090** [sqlite3_total_changes()] interface responds to internal changes only and
1091** omits changes made by other database connections. The
1092** [PRAGMA data_version] command provide a mechanism to detect changes to
1093** a single attached database that occur due to other database connections,
1094** but omits changes implemented by the database connection on which it is
1095** called. This file control is the only mechanism to detect changes that
1096** happen either internally or externally and that are associated with
1097** a particular attached database.
1098** </ul>
1099*/
1100#define SQLITE_FCNTL_LOCKSTATE 1
1101#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1102#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1103#define SQLITE_FCNTL_LAST_ERRNO 4
1104#define SQLITE_FCNTL_SIZE_HINT 5
1105#define SQLITE_FCNTL_CHUNK_SIZE 6
1106#define SQLITE_FCNTL_FILE_POINTER 7
1107#define SQLITE_FCNTL_SYNC_OMITTED 8
1108#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1109#define SQLITE_FCNTL_PERSIST_WAL 10
1110#define SQLITE_FCNTL_OVERWRITE 11
1111#define SQLITE_FCNTL_VFSNAME 12
1112#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1113#define SQLITE_FCNTL_PRAGMA 14
1114#define SQLITE_FCNTL_BUSYHANDLER 15
1115#define SQLITE_FCNTL_TEMPFILENAME 16
1116#define SQLITE_FCNTL_MMAP_SIZE 18
1117#define SQLITE_FCNTL_TRACE 19
1118#define SQLITE_FCNTL_HAS_MOVED 20
1119#define SQLITE_FCNTL_SYNC 21
1120#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1121#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1122#define SQLITE_FCNTL_WAL_BLOCK 24
1123#define SQLITE_FCNTL_ZIPVFS 25
1124#define SQLITE_FCNTL_RBU 26
1125#define SQLITE_FCNTL_VFS_POINTER 27
1126#define SQLITE_FCNTL_JOURNAL_POINTER 28
1127#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1128#define SQLITE_FCNTL_PDB 30
1129#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1130#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1131#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1132#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1133#define SQLITE_FCNTL_DATA_VERSION 35
1134
1135/* deprecated names */
1136#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1137#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1138#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1139
1140
1141/*
1142** CAPI3REF: Mutex Handle
1143**
1144** The mutex module within SQLite defines [sqlite3_mutex] to be an
1145** abstract type for a mutex object. The SQLite core never looks
1146** at the internal representation of an [sqlite3_mutex]. It only
1147** deals with pointers to the [sqlite3_mutex] object.
1148**
1149** Mutexes are created using [sqlite3_mutex_alloc()].
1150*/
1151typedef struct sqlite3_mutex sqlite3_mutex;
1152
1153/*
1154** CAPI3REF: Loadable Extension Thunk
1155**
1156** A pointer to the opaque sqlite3_api_routines structure is passed as
1157** the third parameter to entry points of [loadable extensions]. This
1158** structure must be typedefed in order to work around compiler warnings
1159** on some platforms.
1160*/
1161typedef struct sqlite3_api_routines sqlite3_api_routines;
1162
1163/*
1164** CAPI3REF: OS Interface Object
1165**
1166** An instance of the sqlite3_vfs object defines the interface between
1167** the SQLite core and the underlying operating system. The "vfs"
1168** in the name of the object stands for "virtual file system". See
1169** the [VFS | VFS documentation] for further information.
1170**
1171** The VFS interface is sometimes extended by adding new methods onto
1172** the end. Each time such an extension occurs, the iVersion field
1173** is incremented. The iVersion value started out as 1 in
1174** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1175** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1176** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1177** may be appended to the sqlite3_vfs object and the iVersion value
1178** may increase again in future versions of SQLite.
1179** Note that the structure
1180** of the sqlite3_vfs object changes in the transition from
1181** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1182** and yet the iVersion field was not modified.
1183**
1184** The szOsFile field is the size of the subclassed [sqlite3_file]
1185** structure used by this VFS. mxPathname is the maximum length of
1186** a pathname in this VFS.
1187**
1188** Registered sqlite3_vfs objects are kept on a linked list formed by
1189** the pNext pointer. The [sqlite3_vfs_register()]
1190** and [sqlite3_vfs_unregister()] interfaces manage this list
1191** in a thread-safe way. The [sqlite3_vfs_find()] interface
1192** searches the list. Neither the application code nor the VFS
1193** implementation should use the pNext pointer.
1194**
1195** The pNext field is the only field in the sqlite3_vfs
1196** structure that SQLite will ever modify. SQLite will only access
1197** or modify this field while holding a particular static mutex.
1198** The application should never modify anything within the sqlite3_vfs
1199** object once the object has been registered.
1200**
1201** The zName field holds the name of the VFS module. The name must
1202** be unique across all VFS modules.
1203**
1204** [[sqlite3_vfs.xOpen]]
1205** ^SQLite guarantees that the zFilename parameter to xOpen
1206** is either a NULL pointer or string obtained
1207** from xFullPathname() with an optional suffix added.
1208** ^If a suffix is added to the zFilename parameter, it will
1209** consist of a single "-" character followed by no more than
1210** 11 alphanumeric and/or "-" characters.
1211** ^SQLite further guarantees that
1212** the string will be valid and unchanged until xClose() is
1213** called. Because of the previous sentence,
1214** the [sqlite3_file] can safely store a pointer to the
1215** filename if it needs to remember the filename for some reason.
1216** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1217** must invent its own temporary name for the file. ^Whenever the
1218** xFilename parameter is NULL it will also be the case that the
1219** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1220**
1221** The flags argument to xOpen() includes all bits set in
1222** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1223** or [sqlite3_open16()] is used, then flags includes at least
1224** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1225** If xOpen() opens a file read-only then it sets *pOutFlags to
1226** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1227**
1228** ^(SQLite will also add one of the following flags to the xOpen()
1229** call, depending on the object being opened:
1230**
1231** <ul>
1232** <li> [SQLITE_OPEN_MAIN_DB]
1233** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1234** <li> [SQLITE_OPEN_TEMP_DB]
1235** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1236** <li> [SQLITE_OPEN_TRANSIENT_DB]
1237** <li> [SQLITE_OPEN_SUBJOURNAL]
1238** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1239** <li> [SQLITE_OPEN_WAL]
1240** </ul>)^
1241**
1242** The file I/O implementation can use the object type flags to
1243** change the way it deals with files. For example, an application
1244** that does not care about crash recovery or rollback might make
1245** the open of a journal file a no-op. Writes to this journal would
1246** also be no-ops, and any attempt to read the journal would return
1247** SQLITE_IOERR. Or the implementation might recognize that a database
1248** file will be doing page-aligned sector reads and writes in a random
1249** order and set up its I/O subsystem accordingly.
1250**
1251** SQLite might also add one of the following flags to the xOpen method:
1252**
1253** <ul>
1254** <li> [SQLITE_OPEN_DELETEONCLOSE]
1255** <li> [SQLITE_OPEN_EXCLUSIVE]
1256** </ul>
1257**
1258** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1259** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1260** will be set for TEMP databases and their journals, transient
1261** databases, and subjournals.
1262**
1263** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1264** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1265** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1266** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1267** SQLITE_OPEN_CREATE, is used to indicate that file should always
1268** be created, and that it is an error if it already exists.
1269** It is <i>not</i> used to indicate the file should be opened
1270** for exclusive access.
1271**
1272** ^At least szOsFile bytes of memory are allocated by SQLite
1273** to hold the [sqlite3_file] structure passed as the third
1274** argument to xOpen. The xOpen method does not have to
1275** allocate the structure; it should just fill it in. Note that
1276** the xOpen method must set the sqlite3_file.pMethods to either
1277** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1278** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1279** element will be valid after xOpen returns regardless of the success
1280** or failure of the xOpen call.
1281**
1282** [[sqlite3_vfs.xAccess]]
1283** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1284** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1285** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1286** to test whether a file is at least readable. The file can be a
1287** directory.
1288**
1289** ^SQLite will always allocate at least mxPathname+1 bytes for the
1290** output buffer xFullPathname. The exact size of the output buffer
1291** is also passed as a parameter to both methods. If the output buffer
1292** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1293** handled as a fatal error by SQLite, vfs implementations should endeavor
1294** to prevent this by setting mxPathname to a sufficiently large value.
1295**
1296** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1297** interfaces are not strictly a part of the filesystem, but they are
1298** included in the VFS structure for completeness.
1299** The xRandomness() function attempts to return nBytes bytes
1300** of good-quality randomness into zOut. The return value is
1301** the actual number of bytes of randomness obtained.
1302** The xSleep() method causes the calling thread to sleep for at
1303** least the number of microseconds given. ^The xCurrentTime()
1304** method returns a Julian Day Number for the current date and time as
1305** a floating point value.
1306** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1307** Day Number multiplied by 86400000 (the number of milliseconds in
1308** a 24-hour day).
1309** ^SQLite will use the xCurrentTimeInt64() method to get the current
1310** date and time if that method is available (if iVersion is 2 or
1311** greater and the function pointer is not NULL) and will fall back
1312** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1313**
1314** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1315** are not used by the SQLite core. These optional interfaces are provided
1316** by some VFSes to facilitate testing of the VFS code. By overriding
1317** system calls with functions under its control, a test program can
1318** simulate faults and error conditions that would otherwise be difficult
1319** or impossible to induce. The set of system calls that can be overridden
1320** varies from one VFS to another, and from one version of the same VFS to the
1321** next. Applications that use these interfaces must be prepared for any
1322** or all of these interfaces to be NULL or for their behavior to change
1323** from one release to the next. Applications must not attempt to access
1324** any of these methods if the iVersion of the VFS is less than 3.
1325*/
1326typedef struct sqlite3_vfs sqlite3_vfs;
1327typedef void (*sqlite3_syscall_ptr)(void);
1328struct sqlite3_vfs {
1329 int iVersion; /* Structure version number (currently 3) */
1330 int szOsFile; /* Size of subclassed sqlite3_file */
1331 int mxPathname; /* Maximum file pathname length */
1332 sqlite3_vfs *pNext; /* Next registered VFS */
1333 const char *zName; /* Name of this virtual file system */
1334 void *pAppData; /* Pointer to application-specific data */
1335 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1336 int flags, int *pOutFlags);
1337 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1338 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1339 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1340 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1341 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1342 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1343 void (*xDlClose)(sqlite3_vfs*, void*);
1344 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1345 int (*xSleep)(sqlite3_vfs*, int microseconds);
1346 int (*xCurrentTime)(sqlite3_vfs*, double*);
1347 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1348 /*
1349 ** The methods above are in version 1 of the sqlite_vfs object
1350 ** definition. Those that follow are added in version 2 or later
1351 */
1352 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1353 /*
1354 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1355 ** Those below are for version 3 and greater.
1356 */
1357 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1358 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1359 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1360 /*
1361 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1362 ** New fields may be appended in future versions. The iVersion
1363 ** value will increment whenever this happens.
1364 */
1365};
1366
1367/*
1368** CAPI3REF: Flags for the xAccess VFS method
1369**
1370** These integer constants can be used as the third parameter to
1371** the xAccess method of an [sqlite3_vfs] object. They determine
1372** what kind of permissions the xAccess method is looking for.
1373** With SQLITE_ACCESS_EXISTS, the xAccess method
1374** simply checks whether the file exists.
1375** With SQLITE_ACCESS_READWRITE, the xAccess method
1376** checks whether the named directory is both readable and writable
1377** (in other words, if files can be added, removed, and renamed within
1378** the directory).
1379** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1380** [temp_store_directory pragma], though this could change in a future
1381** release of SQLite.
1382** With SQLITE_ACCESS_READ, the xAccess method
1383** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1384** currently unused, though it might be used in a future release of
1385** SQLite.
1386*/
1387#define SQLITE_ACCESS_EXISTS 0
1388#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1389#define SQLITE_ACCESS_READ 2 /* Unused */
1390
1391/*
1392** CAPI3REF: Flags for the xShmLock VFS method
1393**
1394** These integer constants define the various locking operations
1395** allowed by the xShmLock method of [sqlite3_io_methods]. The
1396** following are the only legal combinations of flags to the
1397** xShmLock method:
1398**
1399** <ul>
1400** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1401** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1402** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1403** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1404** </ul>
1405**
1406** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1407** was given on the corresponding lock.
1408**
1409** The xShmLock method can transition between unlocked and SHARED or
1410** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1411** and EXCLUSIVE.
1412*/
1413#define SQLITE_SHM_UNLOCK 1
1414#define SQLITE_SHM_LOCK 2
1415#define SQLITE_SHM_SHARED 4
1416#define SQLITE_SHM_EXCLUSIVE 8
1417
1418/*
1419** CAPI3REF: Maximum xShmLock index
1420**
1421** The xShmLock method on [sqlite3_io_methods] may use values
1422** between 0 and this upper bound as its "offset" argument.
1423** The SQLite core will never attempt to acquire or release a
1424** lock outside of this range
1425*/
1426#define SQLITE_SHM_NLOCK 8
1427
1428
1429/*
1430** CAPI3REF: Initialize The SQLite Library
1431**
1432** ^The sqlite3_initialize() routine initializes the
1433** SQLite library. ^The sqlite3_shutdown() routine
1434** deallocates any resources that were allocated by sqlite3_initialize().
1435** These routines are designed to aid in process initialization and
1436** shutdown on embedded systems. Workstation applications using
1437** SQLite normally do not need to invoke either of these routines.
1438**
1439** A call to sqlite3_initialize() is an "effective" call if it is
1440** the first time sqlite3_initialize() is invoked during the lifetime of
1441** the process, or if it is the first time sqlite3_initialize() is invoked
1442** following a call to sqlite3_shutdown(). ^(Only an effective call
1443** of sqlite3_initialize() does any initialization. All other calls
1444** are harmless no-ops.)^
1445**
1446** A call to sqlite3_shutdown() is an "effective" call if it is the first
1447** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1448** an effective call to sqlite3_shutdown() does any deinitialization.
1449** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1450**
1451** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1452** is not. The sqlite3_shutdown() interface must only be called from a
1453** single thread. All open [database connections] must be closed and all
1454** other SQLite resources must be deallocated prior to invoking
1455** sqlite3_shutdown().
1456**
1457** Among other things, ^sqlite3_initialize() will invoke
1458** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1459** will invoke sqlite3_os_end().
1460**
1461** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1462** ^If for some reason, sqlite3_initialize() is unable to initialize
1463** the library (perhaps it is unable to allocate a needed resource such
1464** as a mutex) it returns an [error code] other than [SQLITE_OK].
1465**
1466** ^The sqlite3_initialize() routine is called internally by many other
1467** SQLite interfaces so that an application usually does not need to
1468** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1469** calls sqlite3_initialize() so the SQLite library will be automatically
1470** initialized when [sqlite3_open()] is called if it has not be initialized
1471** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1472** compile-time option, then the automatic calls to sqlite3_initialize()
1473** are omitted and the application must call sqlite3_initialize() directly
1474** prior to using any other SQLite interface. For maximum portability,
1475** it is recommended that applications always invoke sqlite3_initialize()
1476** directly prior to using any other SQLite interface. Future releases
1477** of SQLite may require this. In other words, the behavior exhibited
1478** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1479** default behavior in some future release of SQLite.
1480**
1481** The sqlite3_os_init() routine does operating-system specific
1482** initialization of the SQLite library. The sqlite3_os_end()
1483** routine undoes the effect of sqlite3_os_init(). Typical tasks
1484** performed by these routines include allocation or deallocation
1485** of static resources, initialization of global variables,
1486** setting up a default [sqlite3_vfs] module, or setting up
1487** a default configuration using [sqlite3_config()].
1488**
1489** The application should never invoke either sqlite3_os_init()
1490** or sqlite3_os_end() directly. The application should only invoke
1491** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1492** interface is called automatically by sqlite3_initialize() and
1493** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1494** implementations for sqlite3_os_init() and sqlite3_os_end()
1495** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1496** When [custom builds | built for other platforms]
1497** (using the [SQLITE_OS_OTHER=1] compile-time
1498** option) the application must supply a suitable implementation for
1499** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1500** implementation of sqlite3_os_init() or sqlite3_os_end()
1501** must return [SQLITE_OK] on success and some other [error code] upon
1502** failure.
1503*/
1504SQLITE_API int sqlite3_initialize(void);
1505SQLITE_API int sqlite3_shutdown(void);
1506SQLITE_API int sqlite3_os_init(void);
1507SQLITE_API int sqlite3_os_end(void);
1508
1509/*
1510** CAPI3REF: Configuring The SQLite Library
1511**
1512** The sqlite3_config() interface is used to make global configuration
1513** changes to SQLite in order to tune SQLite to the specific needs of
1514** the application. The default configuration is recommended for most
1515** applications and so this routine is usually not necessary. It is
1516** provided to support rare applications with unusual needs.
1517**
1518** <b>The sqlite3_config() interface is not threadsafe. The application
1519** must ensure that no other SQLite interfaces are invoked by other
1520** threads while sqlite3_config() is running.</b>
1521**
1522** The sqlite3_config() interface
1523** may only be invoked prior to library initialization using
1524** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1525** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1526** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1527** Note, however, that ^sqlite3_config() can be called as part of the
1528** implementation of an application-defined [sqlite3_os_init()].
1529**
1530** The first argument to sqlite3_config() is an integer
1531** [configuration option] that determines
1532** what property of SQLite is to be configured. Subsequent arguments
1533** vary depending on the [configuration option]
1534** in the first argument.
1535**
1536** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1537** ^If the option is unknown or SQLite is unable to set the option
1538** then this routine returns a non-zero [error code].
1539*/
1540SQLITE_API int sqlite3_config(int, ...);
1541
1542/*
1543** CAPI3REF: Configure database connections
1544** METHOD: sqlite3
1545**
1546** The sqlite3_db_config() interface is used to make configuration
1547** changes to a [database connection]. The interface is similar to
1548** [sqlite3_config()] except that the changes apply to a single
1549** [database connection] (specified in the first argument).
1550**
1551** The second argument to sqlite3_db_config(D,V,...) is the
1552** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1553** that indicates what aspect of the [database connection] is being configured.
1554** Subsequent arguments vary depending on the configuration verb.
1555**
1556** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1557** the call is considered successful.
1558*/
1559SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1560
1561/*
1562** CAPI3REF: Memory Allocation Routines
1563**
1564** An instance of this object defines the interface between SQLite
1565** and low-level memory allocation routines.
1566**
1567** This object is used in only one place in the SQLite interface.
1568** A pointer to an instance of this object is the argument to
1569** [sqlite3_config()] when the configuration option is
1570** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1571** By creating an instance of this object
1572** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1573** during configuration, an application can specify an alternative
1574** memory allocation subsystem for SQLite to use for all of its
1575** dynamic memory needs.
1576**
1577** Note that SQLite comes with several [built-in memory allocators]
1578** that are perfectly adequate for the overwhelming majority of applications
1579** and that this object is only useful to a tiny minority of applications
1580** with specialized memory allocation requirements. This object is
1581** also used during testing of SQLite in order to specify an alternative
1582** memory allocator that simulates memory out-of-memory conditions in
1583** order to verify that SQLite recovers gracefully from such
1584** conditions.
1585**
1586** The xMalloc, xRealloc, and xFree methods must work like the
1587** malloc(), realloc() and free() functions from the standard C library.
1588** ^SQLite guarantees that the second argument to
1589** xRealloc is always a value returned by a prior call to xRoundup.
1590**
1591** xSize should return the allocated size of a memory allocation
1592** previously obtained from xMalloc or xRealloc. The allocated size
1593** is always at least as big as the requested size but may be larger.
1594**
1595** The xRoundup method returns what would be the allocated size of
1596** a memory allocation given a particular requested size. Most memory
1597** allocators round up memory allocations at least to the next multiple
1598** of 8. Some allocators round up to a larger multiple or to a power of 2.
1599** Every memory allocation request coming in through [sqlite3_malloc()]
1600** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1601** that causes the corresponding memory allocation to fail.
1602**
1603** The xInit method initializes the memory allocator. For example,
1604** it might allocate any require mutexes or initialize internal data
1605** structures. The xShutdown method is invoked (indirectly) by
1606** [sqlite3_shutdown()] and should deallocate any resources acquired
1607** by xInit. The pAppData pointer is used as the only parameter to
1608** xInit and xShutdown.
1609**
1610** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1611** the xInit method, so the xInit method need not be threadsafe. The
1612** xShutdown method is only called from [sqlite3_shutdown()] so it does
1613** not need to be threadsafe either. For all other methods, SQLite
1614** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1615** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1616** it is by default) and so the methods are automatically serialized.
1617** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1618** methods must be threadsafe or else make their own arrangements for
1619** serialization.
1620**
1621** SQLite will never invoke xInit() more than once without an intervening
1622** call to xShutdown().
1623*/
1624typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1625struct sqlite3_mem_methods {
1626 void *(*xMalloc)(int); /* Memory allocation function */
1627 void (*xFree)(void*); /* Free a prior allocation */
1628 void *(*xRealloc)(void*,int); /* Resize an allocation */
1629 int (*xSize)(void*); /* Return the size of an allocation */
1630 int (*xRoundup)(int); /* Round up request size to allocation size */
1631 int (*xInit)(void*); /* Initialize the memory allocator */
1632 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1633 void *pAppData; /* Argument to xInit() and xShutdown() */
1634};
1635
1636/*
1637** CAPI3REF: Configuration Options
1638** KEYWORDS: {configuration option}
1639**
1640** These constants are the available integer configuration options that
1641** can be passed as the first argument to the [sqlite3_config()] interface.
1642**
1643** New configuration options may be added in future releases of SQLite.
1644** Existing configuration options might be discontinued. Applications
1645** should check the return code from [sqlite3_config()] to make sure that
1646** the call worked. The [sqlite3_config()] interface will return a
1647** non-zero [error code] if a discontinued or unsupported configuration option
1648** is invoked.
1649**
1650** <dl>
1651** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1652** <dd>There are no arguments to this option. ^This option sets the
1653** [threading mode] to Single-thread. In other words, it disables
1654** all mutexing and puts SQLite into a mode where it can only be used
1655** by a single thread. ^If SQLite is compiled with
1656** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1657** it is not possible to change the [threading mode] from its default
1658** value of Single-thread and so [sqlite3_config()] will return
1659** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1660** configuration option.</dd>
1661**
1662** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1663** <dd>There are no arguments to this option. ^This option sets the
1664** [threading mode] to Multi-thread. In other words, it disables
1665** mutexing on [database connection] and [prepared statement] objects.
1666** The application is responsible for serializing access to
1667** [database connections] and [prepared statements]. But other mutexes
1668** are enabled so that SQLite will be safe to use in a multi-threaded
1669** environment as long as no two threads attempt to use the same
1670** [database connection] at the same time. ^If SQLite is compiled with
1671** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1672** it is not possible to set the Multi-thread [threading mode] and
1673** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1674** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1675**
1676** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1677** <dd>There are no arguments to this option. ^This option sets the
1678** [threading mode] to Serialized. In other words, this option enables
1679** all mutexes including the recursive
1680** mutexes on [database connection] and [prepared statement] objects.
1681** In this mode (which is the default when SQLite is compiled with
1682** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1683** to [database connections] and [prepared statements] so that the
1684** application is free to use the same [database connection] or the
1685** same [prepared statement] in different threads at the same time.
1686** ^If SQLite is compiled with
1687** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1688** it is not possible to set the Serialized [threading mode] and
1689** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1690** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1691**
1692** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1693** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1694** a pointer to an instance of the [sqlite3_mem_methods] structure.
1695** The argument specifies
1696** alternative low-level memory allocation routines to be used in place of
1697** the memory allocation routines built into SQLite.)^ ^SQLite makes
1698** its own private copy of the content of the [sqlite3_mem_methods] structure
1699** before the [sqlite3_config()] call returns.</dd>
1700**
1701** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1702** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1703** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1704** The [sqlite3_mem_methods]
1705** structure is filled with the currently defined memory allocation routines.)^
1706** This option can be used to overload the default memory allocation
1707** routines with a wrapper that simulations memory allocation failure or
1708** tracks memory usage, for example. </dd>
1709**
1710** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1711** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1712** type int, interpreted as a boolean, which if true provides a hint to
1713** SQLite that it should avoid large memory allocations if possible.
1714** SQLite will run faster if it is free to make large memory allocations,
1715** but some application might prefer to run slower in exchange for
1716** guarantees about memory fragmentation that are possible if large
1717** allocations are avoided. This hint is normally off.
1718** </dd>
1719**
1720** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1721** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1722** interpreted as a boolean, which enables or disables the collection of
1723** memory allocation statistics. ^(When memory allocation statistics are
1724** disabled, the following SQLite interfaces become non-operational:
1725** <ul>
1726** <li> [sqlite3_memory_used()]
1727** <li> [sqlite3_memory_highwater()]
1728** <li> [sqlite3_soft_heap_limit64()]
1729** <li> [sqlite3_status64()]
1730** </ul>)^
1731** ^Memory allocation statistics are enabled by default unless SQLite is
1732** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1733** allocation statistics are disabled by default.
1734** </dd>
1735**
1736** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1737** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1738** </dd>
1739**
1740** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1741** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1742** that SQLite can use for the database page cache with the default page
1743** cache implementation.
1744** This configuration option is a no-op if an application-define page
1745** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1746** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1747** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1748** and the number of cache lines (N).
1749** The sz argument should be the size of the largest database page
1750** (a power of two between 512 and 65536) plus some extra bytes for each
1751** page header. ^The number of extra bytes needed by the page header
1752** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1753** ^It is harmless, apart from the wasted memory,
1754** for the sz parameter to be larger than necessary. The pMem
1755** argument must be either a NULL pointer or a pointer to an 8-byte
1756** aligned block of memory of at least sz*N bytes, otherwise
1757** subsequent behavior is undefined.
1758** ^When pMem is not NULL, SQLite will strive to use the memory provided
1759** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1760** a page cache line is larger than sz bytes or if all of the pMem buffer
1761** is exhausted.
1762** ^If pMem is NULL and N is non-zero, then each database connection
1763** does an initial bulk allocation for page cache memory
1764** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1765** of -1024*N bytes if N is negative, . ^If additional
1766** page cache memory is needed beyond what is provided by the initial
1767** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1768** additional cache line. </dd>
1769**
1770** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1771** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1772** that SQLite will use for all of its dynamic memory allocation needs
1773** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1774** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1775** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1776** [SQLITE_ERROR] if invoked otherwise.
1777** ^There are three arguments to SQLITE_CONFIG_HEAP:
1778** An 8-byte aligned pointer to the memory,
1779** the number of bytes in the memory buffer, and the minimum allocation size.
1780** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1781** to using its default memory allocator (the system malloc() implementation),
1782** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1783** memory pointer is not NULL then the alternative memory
1784** allocator is engaged to handle all of SQLites memory allocation needs.
1785** The first pointer (the memory pointer) must be aligned to an 8-byte
1786** boundary or subsequent behavior of SQLite will be undefined.
1787** The minimum allocation size is capped at 2**12. Reasonable values
1788** for the minimum allocation size are 2**5 through 2**8.</dd>
1789**
1790** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1791** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1792** pointer to an instance of the [sqlite3_mutex_methods] structure.
1793** The argument specifies alternative low-level mutex routines to be used
1794** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1795** the content of the [sqlite3_mutex_methods] structure before the call to
1796** [sqlite3_config()] returns. ^If SQLite is compiled with
1797** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1798** the entire mutexing subsystem is omitted from the build and hence calls to
1799** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1800** return [SQLITE_ERROR].</dd>
1801**
1802** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1803** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1804** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1805** [sqlite3_mutex_methods]
1806** structure is filled with the currently defined mutex routines.)^
1807** This option can be used to overload the default mutex allocation
1808** routines with a wrapper used to track mutex usage for performance
1809** profiling or testing, for example. ^If SQLite is compiled with
1810** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1811** the entire mutexing subsystem is omitted from the build and hence calls to
1812** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1813** return [SQLITE_ERROR].</dd>
1814**
1815** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1816** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1817** the default size of lookaside memory on each [database connection].
1818** The first argument is the
1819** size of each lookaside buffer slot and the second is the number of
1820** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1821** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1822** option to [sqlite3_db_config()] can be used to change the lookaside
1823** configuration on individual connections.)^ </dd>
1824**
1825** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1826** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1827** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1828** the interface to a custom page cache implementation.)^
1829** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1830**
1831** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1832** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1833** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1834** the current page cache implementation into that object.)^ </dd>
1835**
1836** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1837** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1838** global [error log].
1839** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1840** function with a call signature of void(*)(void*,int,const char*),
1841** and a pointer to void. ^If the function pointer is not NULL, it is
1842** invoked by [sqlite3_log()] to process each logging event. ^If the
1843** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1844** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1845** passed through as the first parameter to the application-defined logger
1846** function whenever that function is invoked. ^The second parameter to
1847** the logger function is a copy of the first parameter to the corresponding
1848** [sqlite3_log()] call and is intended to be a [result code] or an
1849** [extended result code]. ^The third parameter passed to the logger is
1850** log message after formatting via [sqlite3_snprintf()].
1851** The SQLite logging interface is not reentrant; the logger function
1852** supplied by the application must not invoke any SQLite interface.
1853** In a multi-threaded application, the application-defined logger
1854** function must be threadsafe. </dd>
1855**
1856** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1857** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1858** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1859** then URI handling is globally disabled.)^ ^If URI handling is globally
1860** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1861** [sqlite3_open16()] or
1862** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1863** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1864** connection is opened. ^If it is globally disabled, filenames are
1865** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1866** database connection is opened. ^(By default, URI handling is globally
1867** disabled. The default value may be changed by compiling with the
1868** [SQLITE_USE_URI] symbol defined.)^
1869**
1870** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1871** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1872** argument which is interpreted as a boolean in order to enable or disable
1873** the use of covering indices for full table scans in the query optimizer.
1874** ^The default setting is determined
1875** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1876** if that compile-time option is omitted.
1877** The ability to disable the use of covering indices for full table scans
1878** is because some incorrectly coded legacy applications might malfunction
1879** when the optimization is enabled. Providing the ability to
1880** disable the optimization allows the older, buggy application code to work
1881** without change even with newer versions of SQLite.
1882**
1883** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1884** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1885** <dd> These options are obsolete and should not be used by new code.
1886** They are retained for backwards compatibility but are now no-ops.
1887** </dd>
1888**
1889** [[SQLITE_CONFIG_SQLLOG]]
1890** <dt>SQLITE_CONFIG_SQLLOG
1891** <dd>This option is only available if sqlite is compiled with the
1892** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1893** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1894** The second should be of type (void*). The callback is invoked by the library
1895** in three separate circumstances, identified by the value passed as the
1896** fourth parameter. If the fourth parameter is 0, then the database connection
1897** passed as the second argument has just been opened. The third argument
1898** points to a buffer containing the name of the main database file. If the
1899** fourth parameter is 1, then the SQL statement that the third parameter
1900** points to has just been executed. Or, if the fourth parameter is 2, then
1901** the connection being passed as the second parameter is being closed. The
1902** third parameter is passed NULL In this case. An example of using this
1903** configuration option can be seen in the "test_sqllog.c" source file in
1904** the canonical SQLite source tree.</dd>
1905**
1906** [[SQLITE_CONFIG_MMAP_SIZE]]
1907** <dt>SQLITE_CONFIG_MMAP_SIZE
1908** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1909** that are the default mmap size limit (the default setting for
1910** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1911** ^The default setting can be overridden by each database connection using
1912** either the [PRAGMA mmap_size] command, or by using the
1913** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1914** will be silently truncated if necessary so that it does not exceed the
1915** compile-time maximum mmap size set by the
1916** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1917** ^If either argument to this option is negative, then that argument is
1918** changed to its compile-time default.
1919**
1920** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1921** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1922** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1923** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1924** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1925** that specifies the maximum size of the created heap.
1926**
1927** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1928** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1929** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1930** is a pointer to an integer and writes into that integer the number of extra
1931** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1932** The amount of extra space required can change depending on the compiler,
1933** target platform, and SQLite version.
1934**
1935** [[SQLITE_CONFIG_PMASZ]]
1936** <dt>SQLITE_CONFIG_PMASZ
1937** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1938** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1939** sorter to that integer. The default minimum PMA Size is set by the
1940** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1941** to help with sort operations when multithreaded sorting
1942** is enabled (using the [PRAGMA threads] command) and the amount of content
1943** to be sorted exceeds the page size times the minimum of the
1944** [PRAGMA cache_size] setting and this value.
1945**
1946** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1947** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1948** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1949** becomes the [statement journal] spill-to-disk threshold.
1950** [Statement journals] are held in memory until their size (in bytes)
1951** exceeds this threshold, at which point they are written to disk.
1952** Or if the threshold is -1, statement journals are always held
1953** exclusively in memory.
1954** Since many statement journals never become large, setting the spill
1955** threshold to a value such as 64KiB can greatly reduce the amount of
1956** I/O required to support statement rollback.
1957** The default value for this setting is controlled by the
1958** [SQLITE_STMTJRNL_SPILL] compile-time option.
1959**
1960** [[SQLITE_CONFIG_SORTERREF_SIZE]]
1961** <dt>SQLITE_CONFIG_SORTERREF_SIZE
1962** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
1963** of type (int) - the new value of the sorter-reference size threshold.
1964** Usually, when SQLite uses an external sort to order records according
1965** to an ORDER BY clause, all fields required by the caller are present in the
1966** sorted records. However, if SQLite determines based on the declared type
1967** of a table column that its values are likely to be very large - larger
1968** than the configured sorter-reference size threshold - then a reference
1969** is stored in each sorted record and the required column values loaded
1970** from the database as records are returned in sorted order. The default
1971** value for this option is to never use this optimization. Specifying a
1972** negative value for this option restores the default behaviour.
1973** This option is only available if SQLite is compiled with the
1974** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
1975** </dl>
1976*/
1977#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1978#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1979#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1980#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1981#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1982#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
1983#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1984#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1985#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1986#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1987#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1988/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1989#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1990#define SQLITE_CONFIG_PCACHE 14 /* no-op */
1991#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1992#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1993#define SQLITE_CONFIG_URI 17 /* int */
1994#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1995#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1996#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1997#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1998#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1999#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2000#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2001#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2002#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2003#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2004#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2005
2006/*
2007** CAPI3REF: Database Connection Configuration Options
2008**
2009** These constants are the available integer configuration options that
2010** can be passed as the second argument to the [sqlite3_db_config()] interface.
2011**
2012** New configuration options may be added in future releases of SQLite.
2013** Existing configuration options might be discontinued. Applications
2014** should check the return code from [sqlite3_db_config()] to make sure that
2015** the call worked. ^The [sqlite3_db_config()] interface will return a
2016** non-zero [error code] if a discontinued or unsupported configuration option
2017** is invoked.
2018**
2019** <dl>
2020** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2021** <dd> ^This option takes three additional arguments that determine the
2022** [lookaside memory allocator] configuration for the [database connection].
2023** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2024** pointer to a memory buffer to use for lookaside memory.
2025** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2026** may be NULL in which case SQLite will allocate the
2027** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2028** size of each lookaside buffer slot. ^The third argument is the number of
2029** slots. The size of the buffer in the first argument must be greater than
2030** or equal to the product of the second and third arguments. The buffer
2031** must be aligned to an 8-byte boundary. ^If the second argument to
2032** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2033** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2034** configuration for a database connection can only be changed when that
2035** connection is not currently using lookaside memory, or in other words
2036** when the "current value" returned by
2037** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2038** Any attempt to change the lookaside memory configuration when lookaside
2039** memory is in use leaves the configuration unchanged and returns
2040** [SQLITE_BUSY].)^</dd>
2041**
2042** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2043** <dd> ^This option is used to enable or disable the enforcement of
2044** [foreign key constraints]. There should be two additional arguments.
2045** The first argument is an integer which is 0 to disable FK enforcement,
2046** positive to enable FK enforcement or negative to leave FK enforcement
2047** unchanged. The second parameter is a pointer to an integer into which
2048** is written 0 or 1 to indicate whether FK enforcement is off or on
2049** following this call. The second parameter may be a NULL pointer, in
2050** which case the FK enforcement setting is not reported back. </dd>
2051**
2052** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2053** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2054** There should be two additional arguments.
2055** The first argument is an integer which is 0 to disable triggers,
2056** positive to enable triggers or negative to leave the setting unchanged.
2057** The second parameter is a pointer to an integer into which
2058** is written 0 or 1 to indicate whether triggers are disabled or enabled
2059** following this call. The second parameter may be a NULL pointer, in
2060** which case the trigger setting is not reported back. </dd>
2061**
2062** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2063** <dd> ^This option is used to enable or disable the two-argument
2064** version of the [fts3_tokenizer()] function which is part of the
2065** [FTS3] full-text search engine extension.
2066** There should be two additional arguments.
2067** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2068** positive to enable fts3_tokenizer() or negative to leave the setting
2069** unchanged.
2070** The second parameter is a pointer to an integer into which
2071** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2072** following this call. The second parameter may be a NULL pointer, in
2073** which case the new setting is not reported back. </dd>
2074**
2075** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2076** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2077** interface independently of the [load_extension()] SQL function.
2078** The [sqlite3_enable_load_extension()] API enables or disables both the
2079** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2080** There should be two additional arguments.
2081** When the first argument to this interface is 1, then only the C-API is
2082** enabled and the SQL function remains disabled. If the first argument to
2083** this interface is 0, then both the C-API and the SQL function are disabled.
2084** If the first argument is -1, then no changes are made to state of either the
2085** C-API or the SQL function.
2086** The second parameter is a pointer to an integer into which
2087** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2088** is disabled or enabled following this call. The second parameter may
2089** be a NULL pointer, in which case the new setting is not reported back.
2090** </dd>
2091**
2092** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2093** <dd> ^This option is used to change the name of the "main" database
2094** schema. ^The sole argument is a pointer to a constant UTF8 string
2095** which will become the new schema name in place of "main". ^SQLite
2096** does not make a copy of the new main schema name string, so the application
2097** must ensure that the argument passed into this DBCONFIG option is unchanged
2098** until after the database connection closes.
2099** </dd>
2100**
2101** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2102** <dd> Usually, when a database in wal mode is closed or detached from a
2103** database handle, SQLite checks if this will mean that there are now no
2104** connections at all to the database. If so, it performs a checkpoint
2105** operation before closing the connection. This option may be used to
2106** override this behaviour. The first parameter passed to this operation
2107** is an integer - positive to disable checkpoints-on-close, or zero (the
2108** default) to enable them, and negative to leave the setting unchanged.
2109** The second parameter is a pointer to an integer
2110** into which is written 0 or 1 to indicate whether checkpoints-on-close
2111** have been disabled - 0 if they are not disabled, 1 if they are.
2112** </dd>
2113**
2114** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2115** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2116** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2117** a single SQL query statement will always use the same algorithm regardless
2118** of values of [bound parameters].)^ The QPSG disables some query optimizations
2119** that look at the values of bound parameters, which can make some queries
2120** slower. But the QPSG has the advantage of more predictable behavior. With
2121** the QPSG active, SQLite will always use the same query plan in the field as
2122** was used during testing in the lab.
2123** The first argument to this setting is an integer which is 0 to disable
2124** the QPSG, positive to enable QPSG, or negative to leave the setting
2125** unchanged. The second parameter is a pointer to an integer into which
2126** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2127** following this call.
2128** </dd>
2129**
2130** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2131** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2132** include output for any operations performed by trigger programs. This
2133** option is used to set or clear (the default) a flag that governs this
2134** behavior. The first parameter passed to this operation is an integer -
2135** positive to enable output for trigger programs, or zero to disable it,
2136** or negative to leave the setting unchanged.
2137** The second parameter is a pointer to an integer into which is written
2138** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2139** it is not disabled, 1 if it is.
2140** </dd>
2141**
2142** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2143** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2144** [VACUUM] in order to reset a database back to an empty database
2145** with no schema and no content. The following process works even for
2146** a badly corrupted database file:
2147** <ol>
2148** <li> If the database connection is newly opened, make sure it has read the
2149** database schema by preparing then discarding some query against the
2150** database, or calling sqlite3_table_column_metadata(), ignoring any
2151** errors. This step is only necessary if the application desires to keep
2152** the database in WAL mode after the reset if it was in WAL mode before
2153** the reset.
2154** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2155** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2156** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2157** </ol>
2158** Because resetting a database is destructive and irreversible, the
2159** process requires the use of this obscure API and multiple steps to help
2160** ensure that it does not happen by accident.
2161** </dd>
2162** </dl>
2163*/
2164#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2165#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2166#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2167#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2168#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2169#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2170#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2171#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2172#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2173#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2174#define SQLITE_DBCONFIG_MAX 1009 /* Largest DBCONFIG */
2175
2176/*
2177** CAPI3REF: Enable Or Disable Extended Result Codes
2178** METHOD: sqlite3
2179**
2180** ^The sqlite3_extended_result_codes() routine enables or disables the
2181** [extended result codes] feature of SQLite. ^The extended result
2182** codes are disabled by default for historical compatibility.
2183*/
2184SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2185
2186/*
2187** CAPI3REF: Last Insert Rowid
2188** METHOD: sqlite3
2189**
2190** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2191** has a unique 64-bit signed
2192** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2193** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2194** names are not also used by explicitly declared columns. ^If
2195** the table has a column of type [INTEGER PRIMARY KEY] then that column
2196** is another alias for the rowid.
2197**
2198** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2199** the most recent successful [INSERT] into a rowid table or [virtual table]
2200** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2201** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2202** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2203** zero.
2204**
2205** As well as being set automatically as rows are inserted into database
2206** tables, the value returned by this function may be set explicitly by
2207** [sqlite3_set_last_insert_rowid()]
2208**
2209** Some virtual table implementations may INSERT rows into rowid tables as
2210** part of committing a transaction (e.g. to flush data accumulated in memory
2211** to disk). In this case subsequent calls to this function return the rowid
2212** associated with these internal INSERT operations, which leads to
2213** unintuitive results. Virtual table implementations that do write to rowid
2214** tables in this way can avoid this problem by restoring the original
2215** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2216** control to the user.
2217**
2218** ^(If an [INSERT] occurs within a trigger then this routine will
2219** return the [rowid] of the inserted row as long as the trigger is
2220** running. Once the trigger program ends, the value returned
2221** by this routine reverts to what it was before the trigger was fired.)^
2222**
2223** ^An [INSERT] that fails due to a constraint violation is not a
2224** successful [INSERT] and does not change the value returned by this
2225** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2226** and INSERT OR ABORT make no changes to the return value of this
2227** routine when their insertion fails. ^(When INSERT OR REPLACE
2228** encounters a constraint violation, it does not fail. The
2229** INSERT continues to completion after deleting rows that caused
2230** the constraint problem so INSERT OR REPLACE will always change
2231** the return value of this interface.)^
2232**
2233** ^For the purposes of this routine, an [INSERT] is considered to
2234** be successful even if it is subsequently rolled back.
2235**
2236** This function is accessible to SQL statements via the
2237** [last_insert_rowid() SQL function].
2238**
2239** If a separate thread performs a new [INSERT] on the same
2240** database connection while the [sqlite3_last_insert_rowid()]
2241** function is running and thus changes the last insert [rowid],
2242** then the value returned by [sqlite3_last_insert_rowid()] is
2243** unpredictable and might not equal either the old or the new
2244** last insert [rowid].
2245*/
2246SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2247
2248/*
2249** CAPI3REF: Set the Last Insert Rowid value.
2250** METHOD: sqlite3
2251**
2252** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2253** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2254** without inserting a row into the database.
2255*/
2256SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2257
2258/*
2259** CAPI3REF: Count The Number Of Rows Modified
2260** METHOD: sqlite3
2261**
2262** ^This function returns the number of rows modified, inserted or
2263** deleted by the most recently completed INSERT, UPDATE or DELETE
2264** statement on the database connection specified by the only parameter.
2265** ^Executing any other type of SQL statement does not modify the value
2266** returned by this function.
2267**
2268** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2269** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2270** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2271**
2272** Changes to a view that are intercepted by
2273** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2274** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2275** DELETE statement run on a view is always zero. Only changes made to real
2276** tables are counted.
2277**
2278** Things are more complicated if the sqlite3_changes() function is
2279** executed while a trigger program is running. This may happen if the
2280** program uses the [changes() SQL function], or if some other callback
2281** function invokes sqlite3_changes() directly. Essentially:
2282**
2283** <ul>
2284** <li> ^(Before entering a trigger program the value returned by
2285** sqlite3_changes() function is saved. After the trigger program
2286** has finished, the original value is restored.)^
2287**
2288** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2289** statement sets the value returned by sqlite3_changes()
2290** upon completion as normal. Of course, this value will not include
2291** any changes performed by sub-triggers, as the sqlite3_changes()
2292** value will be saved and restored after each sub-trigger has run.)^
2293** </ul>
2294**
2295** ^This means that if the changes() SQL function (or similar) is used
2296** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2297** returns the value as set when the calling statement began executing.
2298** ^If it is used by the second or subsequent such statement within a trigger
2299** program, the value returned reflects the number of rows modified by the
2300** previous INSERT, UPDATE or DELETE statement within the same trigger.
2301**
2302** If a separate thread makes changes on the same database connection
2303** while [sqlite3_changes()] is running then the value returned
2304** is unpredictable and not meaningful.
2305**
2306** See also:
2307** <ul>
2308** <li> the [sqlite3_total_changes()] interface
2309** <li> the [count_changes pragma]
2310** <li> the [changes() SQL function]
2311** <li> the [data_version pragma]
2312** </ul>
2313*/
2314SQLITE_API int sqlite3_changes(sqlite3*);
2315
2316/*
2317** CAPI3REF: Total Number Of Rows Modified
2318** METHOD: sqlite3
2319**
2320** ^This function returns the total number of rows inserted, modified or
2321** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2322** since the database connection was opened, including those executed as
2323** part of trigger programs. ^Executing any other type of SQL statement
2324** does not affect the value returned by sqlite3_total_changes().
2325**
2326** ^Changes made as part of [foreign key actions] are included in the
2327** count, but those made as part of REPLACE constraint resolution are
2328** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2329** are not counted.
2330**
2331** This the [sqlite3_total_changes(D)] interface only reports the number
2332** of rows that changed due to SQL statement run against database
2333** connection D. Any changes by other database connections are ignored.
2334** To detect changes against a database file from other database
2335** connections use the [PRAGMA data_version] command or the
2336** [SQLITE_FCNTL_DATA_VERSION] [file control].
2337**
2338** If a separate thread makes changes on the same database connection
2339** while [sqlite3_total_changes()] is running then the value
2340** returned is unpredictable and not meaningful.
2341**
2342** See also:
2343** <ul>
2344** <li> the [sqlite3_changes()] interface
2345** <li> the [count_changes pragma]
2346** <li> the [changes() SQL function]
2347** <li> the [data_version pragma]
2348** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2349** </ul>
2350*/
2351SQLITE_API int sqlite3_total_changes(sqlite3*);
2352
2353/*
2354** CAPI3REF: Interrupt A Long-Running Query
2355** METHOD: sqlite3
2356**
2357** ^This function causes any pending database operation to abort and
2358** return at its earliest opportunity. This routine is typically
2359** called in response to a user action such as pressing "Cancel"
2360** or Ctrl-C where the user wants a long query operation to halt
2361** immediately.
2362**
2363** ^It is safe to call this routine from a thread different from the
2364** thread that is currently running the database operation. But it
2365** is not safe to call this routine with a [database connection] that
2366** is closed or might close before sqlite3_interrupt() returns.
2367**
2368** ^If an SQL operation is very nearly finished at the time when
2369** sqlite3_interrupt() is called, then it might not have an opportunity
2370** to be interrupted and might continue to completion.
2371**
2372** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2373** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2374** that is inside an explicit transaction, then the entire transaction
2375** will be rolled back automatically.
2376**
2377** ^The sqlite3_interrupt(D) call is in effect until all currently running
2378** SQL statements on [database connection] D complete. ^Any new SQL statements
2379** that are started after the sqlite3_interrupt() call and before the
2380** running statements reaches zero are interrupted as if they had been
2381** running prior to the sqlite3_interrupt() call. ^New SQL statements
2382** that are started after the running statement count reaches zero are
2383** not effected by the sqlite3_interrupt().
2384** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2385** SQL statements is a no-op and has no effect on SQL statements
2386** that are started after the sqlite3_interrupt() call returns.
2387*/
2388SQLITE_API void sqlite3_interrupt(sqlite3*);
2389
2390/*
2391** CAPI3REF: Determine If An SQL Statement Is Complete
2392**
2393** These routines are useful during command-line input to determine if the
2394** currently entered text seems to form a complete SQL statement or
2395** if additional input is needed before sending the text into
2396** SQLite for parsing. ^These routines return 1 if the input string
2397** appears to be a complete SQL statement. ^A statement is judged to be
2398** complete if it ends with a semicolon token and is not a prefix of a
2399** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2400** string literals or quoted identifier names or comments are not
2401** independent tokens (they are part of the token in which they are
2402** embedded) and thus do not count as a statement terminator. ^Whitespace
2403** and comments that follow the final semicolon are ignored.
2404**
2405** ^These routines return 0 if the statement is incomplete. ^If a
2406** memory allocation fails, then SQLITE_NOMEM is returned.
2407**
2408** ^These routines do not parse the SQL statements thus
2409** will not detect syntactically incorrect SQL.
2410**
2411** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2412** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2413** automatically by sqlite3_complete16(). If that initialization fails,
2414** then the return value from sqlite3_complete16() will be non-zero
2415** regardless of whether or not the input SQL is complete.)^
2416**
2417** The input to [sqlite3_complete()] must be a zero-terminated
2418** UTF-8 string.
2419**
2420** The input to [sqlite3_complete16()] must be a zero-terminated
2421** UTF-16 string in native byte order.
2422*/
2423SQLITE_API int sqlite3_complete(const char *sql);
2424SQLITE_API int sqlite3_complete16(const void *sql);
2425
2426/*
2427** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2428** KEYWORDS: {busy-handler callback} {busy handler}
2429** METHOD: sqlite3
2430**
2431** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2432** that might be invoked with argument P whenever
2433** an attempt is made to access a database table associated with
2434** [database connection] D when another thread
2435** or process has the table locked.
2436** The sqlite3_busy_handler() interface is used to implement
2437** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2438**
2439** ^If the busy callback is NULL, then [SQLITE_BUSY]
2440** is returned immediately upon encountering the lock. ^If the busy callback
2441** is not NULL, then the callback might be invoked with two arguments.
2442**
2443** ^The first argument to the busy handler is a copy of the void* pointer which
2444** is the third argument to sqlite3_busy_handler(). ^The second argument to
2445** the busy handler callback is the number of times that the busy handler has
2446** been invoked previously for the same locking event. ^If the
2447** busy callback returns 0, then no additional attempts are made to
2448** access the database and [SQLITE_BUSY] is returned
2449** to the application.
2450** ^If the callback returns non-zero, then another attempt
2451** is made to access the database and the cycle repeats.
2452**
2453** The presence of a busy handler does not guarantee that it will be invoked
2454** when there is lock contention. ^If SQLite determines that invoking the busy
2455** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2456** to the application instead of invoking the
2457** busy handler.
2458** Consider a scenario where one process is holding a read lock that
2459** it is trying to promote to a reserved lock and
2460** a second process is holding a reserved lock that it is trying
2461** to promote to an exclusive lock. The first process cannot proceed
2462** because it is blocked by the second and the second process cannot
2463** proceed because it is blocked by the first. If both processes
2464** invoke the busy handlers, neither will make any progress. Therefore,
2465** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2466** will induce the first process to release its read lock and allow
2467** the second process to proceed.
2468**
2469** ^The default busy callback is NULL.
2470**
2471** ^(There can only be a single busy handler defined for each
2472** [database connection]. Setting a new busy handler clears any
2473** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2474** or evaluating [PRAGMA busy_timeout=N] will change the
2475** busy handler and thus clear any previously set busy handler.
2476**
2477** The busy callback should not take any actions which modify the
2478** database connection that invoked the busy handler. In other words,
2479** the busy handler is not reentrant. Any such actions
2480** result in undefined behavior.
2481**
2482** A busy handler must not close the database connection
2483** or [prepared statement] that invoked the busy handler.
2484*/
2485SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2486
2487/*
2488** CAPI3REF: Set A Busy Timeout
2489** METHOD: sqlite3
2490**
2491** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2492** for a specified amount of time when a table is locked. ^The handler
2493** will sleep multiple times until at least "ms" milliseconds of sleeping
2494** have accumulated. ^After at least "ms" milliseconds of sleeping,
2495** the handler returns 0 which causes [sqlite3_step()] to return
2496** [SQLITE_BUSY].
2497**
2498** ^Calling this routine with an argument less than or equal to zero
2499** turns off all busy handlers.
2500**
2501** ^(There can only be a single busy handler for a particular
2502** [database connection] at any given moment. If another busy handler
2503** was defined (using [sqlite3_busy_handler()]) prior to calling
2504** this routine, that other busy handler is cleared.)^
2505**
2506** See also: [PRAGMA busy_timeout]
2507*/
2508SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2509
2510/*
2511** CAPI3REF: Convenience Routines For Running Queries
2512** METHOD: sqlite3
2513**
2514** This is a legacy interface that is preserved for backwards compatibility.
2515** Use of this interface is not recommended.
2516**
2517** Definition: A <b>result table</b> is memory data structure created by the
2518** [sqlite3_get_table()] interface. A result table records the
2519** complete query results from one or more queries.
2520**
2521** The table conceptually has a number of rows and columns. But
2522** these numbers are not part of the result table itself. These
2523** numbers are obtained separately. Let N be the number of rows
2524** and M be the number of columns.
2525**
2526** A result table is an array of pointers to zero-terminated UTF-8 strings.
2527** There are (N+1)*M elements in the array. The first M pointers point
2528** to zero-terminated strings that contain the names of the columns.
2529** The remaining entries all point to query results. NULL values result
2530** in NULL pointers. All other values are in their UTF-8 zero-terminated
2531** string representation as returned by [sqlite3_column_text()].
2532**
2533** A result table might consist of one or more memory allocations.
2534** It is not safe to pass a result table directly to [sqlite3_free()].
2535** A result table should be deallocated using [sqlite3_free_table()].
2536**
2537** ^(As an example of the result table format, suppose a query result
2538** is as follows:
2539**
2540** <blockquote><pre>
2541** Name | Age
2542** -----------------------
2543** Alice | 43
2544** Bob | 28
2545** Cindy | 21
2546** </pre></blockquote>
2547**
2548** There are two column (M==2) and three rows (N==3). Thus the
2549** result table has 8 entries. Suppose the result table is stored
2550** in an array names azResult. Then azResult holds this content:
2551**
2552** <blockquote><pre>
2553** azResult&#91;0] = "Name";
2554** azResult&#91;1] = "Age";
2555** azResult&#91;2] = "Alice";
2556** azResult&#91;3] = "43";
2557** azResult&#91;4] = "Bob";
2558** azResult&#91;5] = "28";
2559** azResult&#91;6] = "Cindy";
2560** azResult&#91;7] = "21";
2561** </pre></blockquote>)^
2562**
2563** ^The sqlite3_get_table() function evaluates one or more
2564** semicolon-separated SQL statements in the zero-terminated UTF-8
2565** string of its 2nd parameter and returns a result table to the
2566** pointer given in its 3rd parameter.
2567**
2568** After the application has finished with the result from sqlite3_get_table(),
2569** it must pass the result table pointer to sqlite3_free_table() in order to
2570** release the memory that was malloced. Because of the way the
2571** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2572** function must not try to call [sqlite3_free()] directly. Only
2573** [sqlite3_free_table()] is able to release the memory properly and safely.
2574**
2575** The sqlite3_get_table() interface is implemented as a wrapper around
2576** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2577** to any internal data structures of SQLite. It uses only the public
2578** interface defined here. As a consequence, errors that occur in the
2579** wrapper layer outside of the internal [sqlite3_exec()] call are not
2580** reflected in subsequent calls to [sqlite3_errcode()] or
2581** [sqlite3_errmsg()].
2582*/
2583SQLITE_API int sqlite3_get_table(
2584 sqlite3 *db, /* An open database */
2585 const char *zSql, /* SQL to be evaluated */
2586 char ***pazResult, /* Results of the query */
2587 int *pnRow, /* Number of result rows written here */
2588 int *pnColumn, /* Number of result columns written here */
2589 char **pzErrmsg /* Error msg written here */
2590);
2591SQLITE_API void sqlite3_free_table(char **result);
2592
2593/*
2594** CAPI3REF: Formatted String Printing Functions
2595**
2596** These routines are work-alikes of the "printf()" family of functions
2597** from the standard C library.
2598** These routines understand most of the common formatting options from
2599** the standard library printf()
2600** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2601** See the [built-in printf()] documentation for details.
2602**
2603** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2604** results into memory obtained from [sqlite3_malloc64()].
2605** The strings returned by these two routines should be
2606** released by [sqlite3_free()]. ^Both routines return a
2607** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2608** memory to hold the resulting string.
2609**
2610** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2611** the standard C library. The result is written into the
2612** buffer supplied as the second parameter whose size is given by
2613** the first parameter. Note that the order of the
2614** first two parameters is reversed from snprintf().)^ This is an
2615** historical accident that cannot be fixed without breaking
2616** backwards compatibility. ^(Note also that sqlite3_snprintf()
2617** returns a pointer to its buffer instead of the number of
2618** characters actually written into the buffer.)^ We admit that
2619** the number of characters written would be a more useful return
2620** value but we cannot change the implementation of sqlite3_snprintf()
2621** now without breaking compatibility.
2622**
2623** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2624** guarantees that the buffer is always zero-terminated. ^The first
2625** parameter "n" is the total size of the buffer, including space for
2626** the zero terminator. So the longest string that can be completely
2627** written will be n-1 characters.
2628**
2629** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2630**
2631** See also: [built-in printf()], [printf() SQL function]
2632*/
2633SQLITE_API char *sqlite3_mprintf(const char*,...);
2634SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2635SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2636SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2637
2638/*
2639** CAPI3REF: Memory Allocation Subsystem
2640**
2641** The SQLite core uses these three routines for all of its own
2642** internal memory allocation needs. "Core" in the previous sentence
2643** does not include operating-system specific VFS implementation. The
2644** Windows VFS uses native malloc() and free() for some operations.
2645**
2646** ^The sqlite3_malloc() routine returns a pointer to a block
2647** of memory at least N bytes in length, where N is the parameter.
2648** ^If sqlite3_malloc() is unable to obtain sufficient free
2649** memory, it returns a NULL pointer. ^If the parameter N to
2650** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2651** a NULL pointer.
2652**
2653** ^The sqlite3_malloc64(N) routine works just like
2654** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2655** of a signed 32-bit integer.
2656**
2657** ^Calling sqlite3_free() with a pointer previously returned
2658** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2659** that it might be reused. ^The sqlite3_free() routine is
2660** a no-op if is called with a NULL pointer. Passing a NULL pointer
2661** to sqlite3_free() is harmless. After being freed, memory
2662** should neither be read nor written. Even reading previously freed
2663** memory might result in a segmentation fault or other severe error.
2664** Memory corruption, a segmentation fault, or other severe error
2665** might result if sqlite3_free() is called with a non-NULL pointer that
2666** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2667**
2668** ^The sqlite3_realloc(X,N) interface attempts to resize a
2669** prior memory allocation X to be at least N bytes.
2670** ^If the X parameter to sqlite3_realloc(X,N)
2671** is a NULL pointer then its behavior is identical to calling
2672** sqlite3_malloc(N).
2673** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2674** negative then the behavior is exactly the same as calling
2675** sqlite3_free(X).
2676** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2677** of at least N bytes in size or NULL if insufficient memory is available.
2678** ^If M is the size of the prior allocation, then min(N,M) bytes
2679** of the prior allocation are copied into the beginning of buffer returned
2680** by sqlite3_realloc(X,N) and the prior allocation is freed.
2681** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2682** prior allocation is not freed.
2683**
2684** ^The sqlite3_realloc64(X,N) interfaces works the same as
2685** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2686** of a 32-bit signed integer.
2687**
2688** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2689** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2690** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2691** ^The value returned by sqlite3_msize(X) might be larger than the number
2692** of bytes requested when X was allocated. ^If X is a NULL pointer then
2693** sqlite3_msize(X) returns zero. If X points to something that is not
2694** the beginning of memory allocation, or if it points to a formerly
2695** valid memory allocation that has now been freed, then the behavior
2696** of sqlite3_msize(X) is undefined and possibly harmful.
2697**
2698** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2699** sqlite3_malloc64(), and sqlite3_realloc64()
2700** is always aligned to at least an 8 byte boundary, or to a
2701** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2702** option is used.
2703**
2704** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2705** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2706** implementation of these routines to be omitted. That capability
2707** is no longer provided. Only built-in memory allocators can be used.
2708**
2709** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2710** the system malloc() and free() directly when converting
2711** filenames between the UTF-8 encoding used by SQLite
2712** and whatever filename encoding is used by the particular Windows
2713** installation. Memory allocation errors were detected, but
2714** they were reported back as [SQLITE_CANTOPEN] or
2715** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2716**
2717** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2718** must be either NULL or else pointers obtained from a prior
2719** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2720** not yet been released.
2721**
2722** The application must not read or write any part of
2723** a block of memory after it has been released using
2724** [sqlite3_free()] or [sqlite3_realloc()].
2725*/
2726SQLITE_API void *sqlite3_malloc(int);
2727SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2728SQLITE_API void *sqlite3_realloc(void*, int);
2729SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2730SQLITE_API void sqlite3_free(void*);
2731SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2732
2733/*
2734** CAPI3REF: Memory Allocator Statistics
2735**
2736** SQLite provides these two interfaces for reporting on the status
2737** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2738** routines, which form the built-in memory allocation subsystem.
2739**
2740** ^The [sqlite3_memory_used()] routine returns the number of bytes
2741** of memory currently outstanding (malloced but not freed).
2742** ^The [sqlite3_memory_highwater()] routine returns the maximum
2743** value of [sqlite3_memory_used()] since the high-water mark
2744** was last reset. ^The values returned by [sqlite3_memory_used()] and
2745** [sqlite3_memory_highwater()] include any overhead
2746** added by SQLite in its implementation of [sqlite3_malloc()],
2747** but not overhead added by the any underlying system library
2748** routines that [sqlite3_malloc()] may call.
2749**
2750** ^The memory high-water mark is reset to the current value of
2751** [sqlite3_memory_used()] if and only if the parameter to
2752** [sqlite3_memory_highwater()] is true. ^The value returned
2753** by [sqlite3_memory_highwater(1)] is the high-water mark
2754** prior to the reset.
2755*/
2756SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2757SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2758
2759/*
2760** CAPI3REF: Pseudo-Random Number Generator
2761**
2762** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2763** select random [ROWID | ROWIDs] when inserting new records into a table that
2764** already uses the largest possible [ROWID]. The PRNG is also used for
2765** the build-in random() and randomblob() SQL functions. This interface allows
2766** applications to access the same PRNG for other purposes.
2767**
2768** ^A call to this routine stores N bytes of randomness into buffer P.
2769** ^The P parameter can be a NULL pointer.
2770**
2771** ^If this routine has not been previously called or if the previous
2772** call had N less than one or a NULL pointer for P, then the PRNG is
2773** seeded using randomness obtained from the xRandomness method of
2774** the default [sqlite3_vfs] object.
2775** ^If the previous call to this routine had an N of 1 or more and a
2776** non-NULL P then the pseudo-randomness is generated
2777** internally and without recourse to the [sqlite3_vfs] xRandomness
2778** method.
2779*/
2780SQLITE_API void sqlite3_randomness(int N, void *P);
2781
2782/*
2783** CAPI3REF: Compile-Time Authorization Callbacks
2784** METHOD: sqlite3
2785** KEYWORDS: {authorizer callback}
2786**
2787** ^This routine registers an authorizer callback with a particular
2788** [database connection], supplied in the first argument.
2789** ^The authorizer callback is invoked as SQL statements are being compiled
2790** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2791** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2792** and [sqlite3_prepare16_v3()]. ^At various
2793** points during the compilation process, as logic is being created
2794** to perform various actions, the authorizer callback is invoked to
2795** see if those actions are allowed. ^The authorizer callback should
2796** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2797** specific action but allow the SQL statement to continue to be
2798** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2799** rejected with an error. ^If the authorizer callback returns
2800** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2801** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2802** the authorizer will fail with an error message.
2803**
2804** When the callback returns [SQLITE_OK], that means the operation
2805** requested is ok. ^When the callback returns [SQLITE_DENY], the
2806** [sqlite3_prepare_v2()] or equivalent call that triggered the
2807** authorizer will fail with an error message explaining that
2808** access is denied.
2809**
2810** ^The first parameter to the authorizer callback is a copy of the third
2811** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2812** to the callback is an integer [SQLITE_COPY | action code] that specifies
2813** the particular action to be authorized. ^The third through sixth parameters
2814** to the callback are either NULL pointers or zero-terminated strings
2815** that contain additional details about the action to be authorized.
2816** Applications must always be prepared to encounter a NULL pointer in any
2817** of the third through the sixth parameters of the authorization callback.
2818**
2819** ^If the action code is [SQLITE_READ]
2820** and the callback returns [SQLITE_IGNORE] then the
2821** [prepared statement] statement is constructed to substitute
2822** a NULL value in place of the table column that would have
2823** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2824** return can be used to deny an untrusted user access to individual
2825** columns of a table.
2826** ^When a table is referenced by a [SELECT] but no column values are
2827** extracted from that table (for example in a query like
2828** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2829** is invoked once for that table with a column name that is an empty string.
2830** ^If the action code is [SQLITE_DELETE] and the callback returns
2831** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2832** [truncate optimization] is disabled and all rows are deleted individually.
2833**
2834** An authorizer is used when [sqlite3_prepare | preparing]
2835** SQL statements from an untrusted source, to ensure that the SQL statements
2836** do not try to access data they are not allowed to see, or that they do not
2837** try to execute malicious statements that damage the database. For
2838** example, an application may allow a user to enter arbitrary
2839** SQL queries for evaluation by a database. But the application does
2840** not want the user to be able to make arbitrary changes to the
2841** database. An authorizer could then be put in place while the
2842** user-entered SQL is being [sqlite3_prepare | prepared] that
2843** disallows everything except [SELECT] statements.
2844**
2845** Applications that need to process SQL from untrusted sources
2846** might also consider lowering resource limits using [sqlite3_limit()]
2847** and limiting database size using the [max_page_count] [PRAGMA]
2848** in addition to using an authorizer.
2849**
2850** ^(Only a single authorizer can be in place on a database connection
2851** at a time. Each call to sqlite3_set_authorizer overrides the
2852** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2853** The authorizer is disabled by default.
2854**
2855** The authorizer callback must not do anything that will modify
2856** the database connection that invoked the authorizer callback.
2857** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2858** database connections for the meaning of "modify" in this paragraph.
2859**
2860** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2861** statement might be re-prepared during [sqlite3_step()] due to a
2862** schema change. Hence, the application should ensure that the
2863** correct authorizer callback remains in place during the [sqlite3_step()].
2864**
2865** ^Note that the authorizer callback is invoked only during
2866** [sqlite3_prepare()] or its variants. Authorization is not
2867** performed during statement evaluation in [sqlite3_step()], unless
2868** as stated in the previous paragraph, sqlite3_step() invokes
2869** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2870*/
2871SQLITE_API int sqlite3_set_authorizer(
2872 sqlite3*,
2873 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2874 void *pUserData
2875);
2876
2877/*
2878** CAPI3REF: Authorizer Return Codes
2879**
2880** The [sqlite3_set_authorizer | authorizer callback function] must
2881** return either [SQLITE_OK] or one of these two constants in order
2882** to signal SQLite whether or not the action is permitted. See the
2883** [sqlite3_set_authorizer | authorizer documentation] for additional
2884** information.
2885**
2886** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2887** returned from the [sqlite3_vtab_on_conflict()] interface.
2888*/
2889#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2890#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2891
2892/*
2893** CAPI3REF: Authorizer Action Codes
2894**
2895** The [sqlite3_set_authorizer()] interface registers a callback function
2896** that is invoked to authorize certain SQL statement actions. The
2897** second parameter to the callback is an integer code that specifies
2898** what action is being authorized. These are the integer action codes that
2899** the authorizer callback may be passed.
2900**
2901** These action code values signify what kind of operation is to be
2902** authorized. The 3rd and 4th parameters to the authorization
2903** callback function will be parameters or NULL depending on which of these
2904** codes is used as the second parameter. ^(The 5th parameter to the
2905** authorizer callback is the name of the database ("main", "temp",
2906** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2907** is the name of the inner-most trigger or view that is responsible for
2908** the access attempt or NULL if this access attempt is directly from
2909** top-level SQL code.
2910*/
2911/******************************************* 3rd ************ 4th ***********/
2912#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2913#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2914#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2915#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2916#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2917#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2918#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2919#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2920#define SQLITE_DELETE 9 /* Table Name NULL */
2921#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2922#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2923#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2924#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2925#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2926#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2927#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2928#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2929#define SQLITE_INSERT 18 /* Table Name NULL */
2930#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2931#define SQLITE_READ 20 /* Table Name Column Name */
2932#define SQLITE_SELECT 21 /* NULL NULL */
2933#define SQLITE_TRANSACTION 22 /* Operation NULL */
2934#define SQLITE_UPDATE 23 /* Table Name Column Name */
2935#define SQLITE_ATTACH 24 /* Filename NULL */
2936#define SQLITE_DETACH 25 /* Database Name NULL */
2937#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2938#define SQLITE_REINDEX 27 /* Index Name NULL */
2939#define SQLITE_ANALYZE 28 /* Table Name NULL */
2940#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2941#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2942#define SQLITE_FUNCTION 31 /* NULL Function Name */
2943#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2944#define SQLITE_COPY 0 /* No longer used */
2945#define SQLITE_RECURSIVE 33 /* NULL NULL */
2946
2947/*
2948** CAPI3REF: Tracing And Profiling Functions
2949** METHOD: sqlite3
2950**
2951** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
2952** instead of the routines described here.
2953**
2954** These routines register callback functions that can be used for
2955** tracing and profiling the execution of SQL statements.
2956**
2957** ^The callback function registered by sqlite3_trace() is invoked at
2958** various times when an SQL statement is being run by [sqlite3_step()].
2959** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2960** SQL statement text as the statement first begins executing.
2961** ^(Additional sqlite3_trace() callbacks might occur
2962** as each triggered subprogram is entered. The callbacks for triggers
2963** contain a UTF-8 SQL comment that identifies the trigger.)^
2964**
2965** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2966** the length of [bound parameter] expansion in the output of sqlite3_trace().
2967**
2968** ^The callback function registered by sqlite3_profile() is invoked
2969** as each SQL statement finishes. ^The profile callback contains
2970** the original statement text and an estimate of wall-clock time
2971** of how long that statement took to run. ^The profile callback
2972** time is in units of nanoseconds, however the current implementation
2973** is only capable of millisecond resolution so the six least significant
2974** digits in the time are meaningless. Future versions of SQLite
2975** might provide greater resolution on the profiler callback. The
2976** sqlite3_profile() function is considered experimental and is
2977** subject to change in future versions of SQLite.
2978*/
2979SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
2980 void(*xTrace)(void*,const char*), void*);
2981SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
2982 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2983
2984/*
2985** CAPI3REF: SQL Trace Event Codes
2986** KEYWORDS: SQLITE_TRACE
2987**
2988** These constants identify classes of events that can be monitored
2989** using the [sqlite3_trace_v2()] tracing logic. The M argument
2990** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
2991** the following constants. ^The first argument to the trace callback
2992** is one of the following constants.
2993**
2994** New tracing constants may be added in future releases.
2995**
2996** ^A trace callback has four arguments: xCallback(T,C,P,X).
2997** ^The T argument is one of the integer type codes above.
2998** ^The C argument is a copy of the context pointer passed in as the
2999** fourth argument to [sqlite3_trace_v2()].
3000** The P and X arguments are pointers whose meanings depend on T.
3001**
3002** <dl>
3003** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3004** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3005** first begins running and possibly at other times during the
3006** execution of the prepared statement, such as at the start of each
3007** trigger subprogram. ^The P argument is a pointer to the
3008** [prepared statement]. ^The X argument is a pointer to a string which
3009** is the unexpanded SQL text of the prepared statement or an SQL comment
3010** that indicates the invocation of a trigger. ^The callback can compute
3011** the same text that would have been returned by the legacy [sqlite3_trace()]
3012** interface by using the X argument when X begins with "--" and invoking
3013** [sqlite3_expanded_sql(P)] otherwise.
3014**
3015** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3016** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3017** information as is provided by the [sqlite3_profile()] callback.
3018** ^The P argument is a pointer to the [prepared statement] and the
3019** X argument points to a 64-bit integer which is the estimated of
3020** the number of nanosecond that the prepared statement took to run.
3021** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3022**
3023** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3024** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3025** statement generates a single row of result.
3026** ^The P argument is a pointer to the [prepared statement] and the
3027** X argument is unused.
3028**
3029** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3030** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3031** connection closes.
3032** ^The P argument is a pointer to the [database connection] object
3033** and the X argument is unused.
3034** </dl>
3035*/
3036#define SQLITE_TRACE_STMT 0x01
3037#define SQLITE_TRACE_PROFILE 0x02
3038#define SQLITE_TRACE_ROW 0x04
3039#define SQLITE_TRACE_CLOSE 0x08
3040
3041/*
3042** CAPI3REF: SQL Trace Hook
3043** METHOD: sqlite3
3044**
3045** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3046** function X against [database connection] D, using property mask M
3047** and context pointer P. ^If the X callback is
3048** NULL or if the M mask is zero, then tracing is disabled. The
3049** M argument should be the bitwise OR-ed combination of
3050** zero or more [SQLITE_TRACE] constants.
3051**
3052** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3053** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3054**
3055** ^The X callback is invoked whenever any of the events identified by
3056** mask M occur. ^The integer return value from the callback is currently
3057** ignored, though this may change in future releases. Callback
3058** implementations should return zero to ensure future compatibility.
3059**
3060** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3061** ^The T argument is one of the [SQLITE_TRACE]
3062** constants to indicate why the callback was invoked.
3063** ^The C argument is a copy of the context pointer.
3064** The P and X arguments are pointers whose meanings depend on T.
3065**
3066** The sqlite3_trace_v2() interface is intended to replace the legacy
3067** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3068** are deprecated.
3069*/
3070SQLITE_API int sqlite3_trace_v2(
3071 sqlite3*,
3072 unsigned uMask,
3073 int(*xCallback)(unsigned,void*,void*,void*),
3074 void *pCtx
3075);
3076
3077/*
3078** CAPI3REF: Query Progress Callbacks
3079** METHOD: sqlite3
3080**
3081** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3082** function X to be invoked periodically during long running calls to
3083** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3084** database connection D. An example use for this
3085** interface is to keep a GUI updated during a large query.
3086**
3087** ^The parameter P is passed through as the only parameter to the
3088** callback function X. ^The parameter N is the approximate number of
3089** [virtual machine instructions] that are evaluated between successive
3090** invocations of the callback X. ^If N is less than one then the progress
3091** handler is disabled.
3092**
3093** ^Only a single progress handler may be defined at one time per
3094** [database connection]; setting a new progress handler cancels the
3095** old one. ^Setting parameter X to NULL disables the progress handler.
3096** ^The progress handler is also disabled by setting N to a value less
3097** than 1.
3098**
3099** ^If the progress callback returns non-zero, the operation is
3100** interrupted. This feature can be used to implement a
3101** "Cancel" button on a GUI progress dialog box.
3102**
3103** The progress handler callback must not do anything that will modify
3104** the database connection that invoked the progress handler.
3105** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3106** database connections for the meaning of "modify" in this paragraph.
3107**
3108*/
3109SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3110
3111/*
3112** CAPI3REF: Opening A New Database Connection
3113** CONSTRUCTOR: sqlite3
3114**
3115** ^These routines open an SQLite database file as specified by the
3116** filename argument. ^The filename argument is interpreted as UTF-8 for
3117** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3118** order for sqlite3_open16(). ^(A [database connection] handle is usually
3119** returned in *ppDb, even if an error occurs. The only exception is that
3120** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3121** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3122** object.)^ ^(If the database is opened (and/or created) successfully, then
3123** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3124** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3125** an English language description of the error following a failure of any
3126** of the sqlite3_open() routines.
3127**
3128** ^The default encoding will be UTF-8 for databases created using
3129** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3130** created using sqlite3_open16() will be UTF-16 in the native byte order.
3131**
3132** Whether or not an error occurs when it is opened, resources
3133** associated with the [database connection] handle should be released by
3134** passing it to [sqlite3_close()] when it is no longer required.
3135**
3136** The sqlite3_open_v2() interface works like sqlite3_open()
3137** except that it accepts two additional parameters for additional control
3138** over the new database connection. ^(The flags parameter to
3139** sqlite3_open_v2() can take one of
3140** the following three values, optionally combined with the
3141** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3142** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3143**
3144** <dl>
3145** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3146** <dd>The database is opened in read-only mode. If the database does not
3147** already exist, an error is returned.</dd>)^
3148**
3149** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3150** <dd>The database is opened for reading and writing if possible, or reading
3151** only if the file is write protected by the operating system. In either
3152** case the database must already exist, otherwise an error is returned.</dd>)^
3153**
3154** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3155** <dd>The database is opened for reading and writing, and is created if
3156** it does not already exist. This is the behavior that is always used for
3157** sqlite3_open() and sqlite3_open16().</dd>)^
3158** </dl>
3159**
3160** If the 3rd parameter to sqlite3_open_v2() is not one of the
3161** combinations shown above optionally combined with other
3162** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3163** then the behavior is undefined.
3164**
3165** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3166** opens in the multi-thread [threading mode] as long as the single-thread
3167** mode has not been set at compile-time or start-time. ^If the
3168** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3169** in the serialized [threading mode] unless single-thread was
3170** previously selected at compile-time or start-time.
3171** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3172** eligible to use [shared cache mode], regardless of whether or not shared
3173** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3174** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3175** participate in [shared cache mode] even if it is enabled.
3176**
3177** ^The fourth parameter to sqlite3_open_v2() is the name of the
3178** [sqlite3_vfs] object that defines the operating system interface that
3179** the new database connection should use. ^If the fourth parameter is
3180** a NULL pointer then the default [sqlite3_vfs] object is used.
3181**
3182** ^If the filename is ":memory:", then a private, temporary in-memory database
3183** is created for the connection. ^This in-memory database will vanish when
3184** the database connection is closed. Future versions of SQLite might
3185** make use of additional special filenames that begin with the ":" character.
3186** It is recommended that when a database filename actually does begin with
3187** a ":" character you should prefix the filename with a pathname such as
3188** "./" to avoid ambiguity.
3189**
3190** ^If the filename is an empty string, then a private, temporary
3191** on-disk database will be created. ^This private database will be
3192** automatically deleted as soon as the database connection is closed.
3193**
3194** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3195**
3196** ^If [URI filename] interpretation is enabled, and the filename argument
3197** begins with "file:", then the filename is interpreted as a URI. ^URI
3198** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3199** set in the third argument to sqlite3_open_v2(), or if it has
3200** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3201** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3202** URI filename interpretation is turned off
3203** by default, but future releases of SQLite might enable URI filename
3204** interpretation by default. See "[URI filenames]" for additional
3205** information.
3206**
3207** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3208** authority, then it must be either an empty string or the string
3209** "localhost". ^If the authority is not an empty string or "localhost", an
3210** error is returned to the caller. ^The fragment component of a URI, if
3211** present, is ignored.
3212**
3213** ^SQLite uses the path component of the URI as the name of the disk file
3214** which contains the database. ^If the path begins with a '/' character,
3215** then it is interpreted as an absolute path. ^If the path does not begin
3216** with a '/' (meaning that the authority section is omitted from the URI)
3217** then the path is interpreted as a relative path.
3218** ^(On windows, the first component of an absolute path
3219** is a drive specification (e.g. "C:").)^
3220**
3221** [[core URI query parameters]]
3222** The query component of a URI may contain parameters that are interpreted
3223** either by SQLite itself, or by a [VFS | custom VFS implementation].
3224** SQLite and its built-in [VFSes] interpret the
3225** following query parameters:
3226**
3227** <ul>
3228** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3229** a VFS object that provides the operating system interface that should
3230** be used to access the database file on disk. ^If this option is set to
3231** an empty string the default VFS object is used. ^Specifying an unknown
3232** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3233** present, then the VFS specified by the option takes precedence over
3234** the value passed as the fourth parameter to sqlite3_open_v2().
3235**
3236** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3237** "rwc", or "memory". Attempting to set it to any other value is
3238** an error)^.
3239** ^If "ro" is specified, then the database is opened for read-only
3240** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3241** third argument to sqlite3_open_v2(). ^If the mode option is set to
3242** "rw", then the database is opened for read-write (but not create)
3243** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3244** been set. ^Value "rwc" is equivalent to setting both
3245** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3246** set to "memory" then a pure [in-memory database] that never reads
3247** or writes from disk is used. ^It is an error to specify a value for
3248** the mode parameter that is less restrictive than that specified by
3249** the flags passed in the third parameter to sqlite3_open_v2().
3250**
3251** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3252** "private". ^Setting it to "shared" is equivalent to setting the
3253** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3254** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3255** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3256** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3257** a URI filename, its value overrides any behavior requested by setting
3258** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3259**
3260** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3261** [powersafe overwrite] property does or does not apply to the
3262** storage media on which the database file resides.
3263**
3264** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3265** which if set disables file locking in rollback journal modes. This
3266** is useful for accessing a database on a filesystem that does not
3267** support locking. Caution: Database corruption might result if two
3268** or more processes write to the same database and any one of those
3269** processes uses nolock=1.
3270**
3271** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3272** parameter that indicates that the database file is stored on
3273** read-only media. ^When immutable is set, SQLite assumes that the
3274** database file cannot be changed, even by a process with higher
3275** privilege, and so the database is opened read-only and all locking
3276** and change detection is disabled. Caution: Setting the immutable
3277** property on a database file that does in fact change can result
3278** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3279** See also: [SQLITE_IOCAP_IMMUTABLE].
3280**
3281** </ul>
3282**
3283** ^Specifying an unknown parameter in the query component of a URI is not an
3284** error. Future versions of SQLite might understand additional query
3285** parameters. See "[query parameters with special meaning to SQLite]" for
3286** additional information.
3287**
3288** [[URI filename examples]] <h3>URI filename examples</h3>
3289**
3290** <table border="1" align=center cellpadding=5>
3291** <tr><th> URI filenames <th> Results
3292** <tr><td> file:data.db <td>
3293** Open the file "data.db" in the current directory.
3294** <tr><td> file:/home/fred/data.db<br>
3295** file:///home/fred/data.db <br>
3296** file://localhost/home/fred/data.db <br> <td>
3297** Open the database file "/home/fred/data.db".
3298** <tr><td> file://darkstar/home/fred/data.db <td>
3299** An error. "darkstar" is not a recognized authority.
3300** <tr><td style="white-space:nowrap">
3301** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3302** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3303** C:. Note that the %20 escaping in this example is not strictly
3304** necessary - space characters can be used literally
3305** in URI filenames.
3306** <tr><td> file:data.db?mode=ro&cache=private <td>
3307** Open file "data.db" in the current directory for read-only access.
3308** Regardless of whether or not shared-cache mode is enabled by
3309** default, use a private cache.
3310** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3311** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3312** that uses dot-files in place of posix advisory locking.
3313** <tr><td> file:data.db?mode=readonly <td>
3314** An error. "readonly" is not a valid option for the "mode" parameter.
3315** </table>
3316**
3317** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3318** query components of a URI. A hexadecimal escape sequence consists of a
3319** percent sign - "%" - followed by exactly two hexadecimal digits
3320** specifying an octet value. ^Before the path or query components of a
3321** URI filename are interpreted, they are encoded using UTF-8 and all
3322** hexadecimal escape sequences replaced by a single byte containing the
3323** corresponding octet. If this process generates an invalid UTF-8 encoding,
3324** the results are undefined.
3325**
3326** <b>Note to Windows users:</b> The encoding used for the filename argument
3327** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3328** codepage is currently defined. Filenames containing international
3329** characters must be converted to UTF-8 prior to passing them into
3330** sqlite3_open() or sqlite3_open_v2().
3331**
3332** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3333** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3334** features that require the use of temporary files may fail.
3335**
3336** See also: [sqlite3_temp_directory]
3337*/
3338SQLITE_API int sqlite3_open(
3339 const char *filename, /* Database filename (UTF-8) */
3340 sqlite3 **ppDb /* OUT: SQLite db handle */
3341);
3342SQLITE_API int sqlite3_open16(
3343 const void *filename, /* Database filename (UTF-16) */
3344 sqlite3 **ppDb /* OUT: SQLite db handle */
3345);
3346SQLITE_API int sqlite3_open_v2(
3347 const char *filename, /* Database filename (UTF-8) */
3348 sqlite3 **ppDb, /* OUT: SQLite db handle */
3349 int flags, /* Flags */
3350 const char *zVfs /* Name of VFS module to use */
3351);
3352
3353/*
3354** CAPI3REF: Obtain Values For URI Parameters
3355**
3356** These are utility routines, useful to VFS implementations, that check
3357** to see if a database file was a URI that contained a specific query
3358** parameter, and if so obtains the value of that query parameter.
3359**
3360** If F is the database filename pointer passed into the xOpen() method of
3361** a VFS implementation when the flags parameter to xOpen() has one or
3362** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3363** P is the name of the query parameter, then
3364** sqlite3_uri_parameter(F,P) returns the value of the P
3365** parameter if it exists or a NULL pointer if P does not appear as a
3366** query parameter on F. If P is a query parameter of F
3367** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3368** a pointer to an empty string.
3369**
3370** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3371** parameter and returns true (1) or false (0) according to the value
3372** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3373** value of query parameter P is one of "yes", "true", or "on" in any
3374** case or if the value begins with a non-zero number. The
3375** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3376** query parameter P is one of "no", "false", or "off" in any case or
3377** if the value begins with a numeric zero. If P is not a query
3378** parameter on F or if the value of P is does not match any of the
3379** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3380**
3381** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3382** 64-bit signed integer and returns that integer, or D if P does not
3383** exist. If the value of P is something other than an integer, then
3384** zero is returned.
3385**
3386** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3387** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3388** is not a database file pathname pointer that SQLite passed into the xOpen
3389** VFS method, then the behavior of this routine is undefined and probably
3390** undesirable.
3391*/
3392SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3393SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3394SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3395
3396
3397/*
3398** CAPI3REF: Error Codes And Messages
3399** METHOD: sqlite3
3400**
3401** ^If the most recent sqlite3_* API call associated with
3402** [database connection] D failed, then the sqlite3_errcode(D) interface
3403** returns the numeric [result code] or [extended result code] for that
3404** API call.
3405** ^The sqlite3_extended_errcode()
3406** interface is the same except that it always returns the
3407** [extended result code] even when extended result codes are
3408** disabled.
3409**
3410** The values returned by sqlite3_errcode() and/or
3411** sqlite3_extended_errcode() might change with each API call.
3412** Except, there are some interfaces that are guaranteed to never
3413** change the value of the error code. The error-code preserving
3414** interfaces are:
3415**
3416** <ul>
3417** <li> sqlite3_errcode()
3418** <li> sqlite3_extended_errcode()
3419** <li> sqlite3_errmsg()
3420** <li> sqlite3_errmsg16()
3421** </ul>
3422**
3423** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3424** text that describes the error, as either UTF-8 or UTF-16 respectively.
3425** ^(Memory to hold the error message string is managed internally.
3426** The application does not need to worry about freeing the result.
3427** However, the error string might be overwritten or deallocated by
3428** subsequent calls to other SQLite interface functions.)^
3429**
3430** ^The sqlite3_errstr() interface returns the English-language text
3431** that describes the [result code], as UTF-8.
3432** ^(Memory to hold the error message string is managed internally
3433** and must not be freed by the application)^.
3434**
3435** When the serialized [threading mode] is in use, it might be the
3436** case that a second error occurs on a separate thread in between
3437** the time of the first error and the call to these interfaces.
3438** When that happens, the second error will be reported since these
3439** interfaces always report the most recent result. To avoid
3440** this, each thread can obtain exclusive use of the [database connection] D
3441** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3442** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3443** all calls to the interfaces listed here are completed.
3444**
3445** If an interface fails with SQLITE_MISUSE, that means the interface
3446** was invoked incorrectly by the application. In that case, the
3447** error code and message may or may not be set.
3448*/
3449SQLITE_API int sqlite3_errcode(sqlite3 *db);
3450SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3451SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3452SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3453SQLITE_API const char *sqlite3_errstr(int);
3454
3455/*
3456** CAPI3REF: Prepared Statement Object
3457** KEYWORDS: {prepared statement} {prepared statements}
3458**
3459** An instance of this object represents a single SQL statement that
3460** has been compiled into binary form and is ready to be evaluated.
3461**
3462** Think of each SQL statement as a separate computer program. The
3463** original SQL text is source code. A prepared statement object
3464** is the compiled object code. All SQL must be converted into a
3465** prepared statement before it can be run.
3466**
3467** The life-cycle of a prepared statement object usually goes like this:
3468**
3469** <ol>
3470** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3471** <li> Bind values to [parameters] using the sqlite3_bind_*()
3472** interfaces.
3473** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3474** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3475** to step 2. Do this zero or more times.
3476** <li> Destroy the object using [sqlite3_finalize()].
3477** </ol>
3478*/
3479typedef struct sqlite3_stmt sqlite3_stmt;
3480
3481/*
3482** CAPI3REF: Run-time Limits
3483** METHOD: sqlite3
3484**
3485** ^(This interface allows the size of various constructs to be limited
3486** on a connection by connection basis. The first parameter is the
3487** [database connection] whose limit is to be set or queried. The
3488** second parameter is one of the [limit categories] that define a
3489** class of constructs to be size limited. The third parameter is the
3490** new limit for that construct.)^
3491**
3492** ^If the new limit is a negative number, the limit is unchanged.
3493** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3494** [limits | hard upper bound]
3495** set at compile-time by a C preprocessor macro called
3496** [limits | SQLITE_MAX_<i>NAME</i>].
3497** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3498** ^Attempts to increase a limit above its hard upper bound are
3499** silently truncated to the hard upper bound.
3500**
3501** ^Regardless of whether or not the limit was changed, the
3502** [sqlite3_limit()] interface returns the prior value of the limit.
3503** ^Hence, to find the current value of a limit without changing it,
3504** simply invoke this interface with the third parameter set to -1.
3505**
3506** Run-time limits are intended for use in applications that manage
3507** both their own internal database and also databases that are controlled
3508** by untrusted external sources. An example application might be a
3509** web browser that has its own databases for storing history and
3510** separate databases controlled by JavaScript applications downloaded
3511** off the Internet. The internal databases can be given the
3512** large, default limits. Databases managed by external sources can
3513** be given much smaller limits designed to prevent a denial of service
3514** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3515** interface to further control untrusted SQL. The size of the database
3516** created by an untrusted script can be contained using the
3517** [max_page_count] [PRAGMA].
3518**
3519** New run-time limit categories may be added in future releases.
3520*/
3521SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3522
3523/*
3524** CAPI3REF: Run-Time Limit Categories
3525** KEYWORDS: {limit category} {*limit categories}
3526**
3527** These constants define various performance limits
3528** that can be lowered at run-time using [sqlite3_limit()].
3529** The synopsis of the meanings of the various limits is shown below.
3530** Additional information is available at [limits | Limits in SQLite].
3531**
3532** <dl>
3533** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3534** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3535**
3536** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3537** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3538**
3539** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3540** <dd>The maximum number of columns in a table definition or in the
3541** result set of a [SELECT] or the maximum number of columns in an index
3542** or in an ORDER BY or GROUP BY clause.</dd>)^
3543**
3544** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3545** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3546**
3547** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3548** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3549**
3550** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3551** <dd>The maximum number of instructions in a virtual machine program
3552** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3553** the equivalent tries to allocate space for more than this many opcodes
3554** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3555**
3556** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3557** <dd>The maximum number of arguments on a function.</dd>)^
3558**
3559** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3560** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3561**
3562** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3563** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3564** <dd>The maximum length of the pattern argument to the [LIKE] or
3565** [GLOB] operators.</dd>)^
3566**
3567** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3568** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3569** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3570**
3571** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3572** <dd>The maximum depth of recursion for triggers.</dd>)^
3573**
3574** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3575** <dd>The maximum number of auxiliary worker threads that a single
3576** [prepared statement] may start.</dd>)^
3577** </dl>
3578*/
3579#define SQLITE_LIMIT_LENGTH 0
3580#define SQLITE_LIMIT_SQL_LENGTH 1
3581#define SQLITE_LIMIT_COLUMN 2
3582#define SQLITE_LIMIT_EXPR_DEPTH 3
3583#define SQLITE_LIMIT_COMPOUND_SELECT 4
3584#define SQLITE_LIMIT_VDBE_OP 5
3585#define SQLITE_LIMIT_FUNCTION_ARG 6
3586#define SQLITE_LIMIT_ATTACHED 7
3587#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3588#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3589#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3590#define SQLITE_LIMIT_WORKER_THREADS 11
3591
3592/*
3593** CAPI3REF: Prepare Flags
3594**
3595** These constants define various flags that can be passed into
3596** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3597** [sqlite3_prepare16_v3()] interfaces.
3598**
3599** New flags may be added in future releases of SQLite.
3600**
3601** <dl>
3602** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3603** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3604** that the prepared statement will be retained for a long time and
3605** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3606** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3607** be used just once or at most a few times and then destroyed using
3608** [sqlite3_finalize()] relatively soon. The current implementation acts
3609** on this hint by avoiding the use of [lookaside memory] so as not to
3610** deplete the limited store of lookaside memory. Future versions of
3611** SQLite may act on this hint differently.
3612** </dl>
3613*/
3614#define SQLITE_PREPARE_PERSISTENT 0x01
3615
3616/*
3617** CAPI3REF: Compiling An SQL Statement
3618** KEYWORDS: {SQL statement compiler}
3619** METHOD: sqlite3
3620** CONSTRUCTOR: sqlite3_stmt
3621**
3622** To execute an SQL statement, it must first be compiled into a byte-code
3623** program using one of these routines. Or, in other words, these routines
3624** are constructors for the [prepared statement] object.
3625**
3626** The preferred routine to use is [sqlite3_prepare_v2()]. The
3627** [sqlite3_prepare()] interface is legacy and should be avoided.
3628** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3629** for special purposes.
3630**
3631** The use of the UTF-8 interfaces is preferred, as SQLite currently
3632** does all parsing using UTF-8. The UTF-16 interfaces are provided
3633** as a convenience. The UTF-16 interfaces work by converting the
3634** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3635**
3636** The first argument, "db", is a [database connection] obtained from a
3637** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3638** [sqlite3_open16()]. The database connection must not have been closed.
3639**
3640** The second argument, "zSql", is the statement to be compiled, encoded
3641** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3642** and sqlite3_prepare_v3()
3643** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3644** and sqlite3_prepare16_v3() use UTF-16.
3645**
3646** ^If the nByte argument is negative, then zSql is read up to the
3647** first zero terminator. ^If nByte is positive, then it is the
3648** number of bytes read from zSql. ^If nByte is zero, then no prepared
3649** statement is generated.
3650** If the caller knows that the supplied string is nul-terminated, then
3651** there is a small performance advantage to passing an nByte parameter that
3652** is the number of bytes in the input string <i>including</i>
3653** the nul-terminator.
3654**
3655** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3656** past the end of the first SQL statement in zSql. These routines only
3657** compile the first statement in zSql, so *pzTail is left pointing to
3658** what remains uncompiled.
3659**
3660** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3661** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3662** to NULL. ^If the input text contains no SQL (if the input is an empty
3663** string or a comment) then *ppStmt is set to NULL.
3664** The calling procedure is responsible for deleting the compiled
3665** SQL statement using [sqlite3_finalize()] after it has finished with it.
3666** ppStmt may not be NULL.
3667**
3668** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3669** otherwise an [error code] is returned.
3670**
3671** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
3672** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
3673** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
3674** are retained for backwards compatibility, but their use is discouraged.
3675** ^In the "vX" interfaces, the prepared statement
3676** that is returned (the [sqlite3_stmt] object) contains a copy of the
3677** original SQL text. This causes the [sqlite3_step()] interface to
3678** behave differently in three ways:
3679**
3680** <ol>
3681** <li>
3682** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3683** always used to do, [sqlite3_step()] will automatically recompile the SQL
3684** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3685** retries will occur before sqlite3_step() gives up and returns an error.
3686** </li>
3687**
3688** <li>
3689** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3690** [error codes] or [extended error codes]. ^The legacy behavior was that
3691** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3692** and the application would have to make a second call to [sqlite3_reset()]
3693** in order to find the underlying cause of the problem. With the "v2" prepare
3694** interfaces, the underlying reason for the error is returned immediately.
3695** </li>
3696**
3697** <li>
3698** ^If the specific value bound to [parameter | host parameter] in the
3699** WHERE clause might influence the choice of query plan for a statement,
3700** then the statement will be automatically recompiled, as if there had been
3701** a schema change, on the first [sqlite3_step()] call following any change
3702** to the [sqlite3_bind_text | bindings] of that [parameter].
3703** ^The specific value of WHERE-clause [parameter] might influence the
3704** choice of query plan if the parameter is the left-hand side of a [LIKE]
3705** or [GLOB] operator or if the parameter is compared to an indexed column
3706** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3707** </li>
3708** </ol>
3709**
3710** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
3711** the extra prepFlags parameter, which is a bit array consisting of zero or
3712** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
3713** sqlite3_prepare_v2() interface works exactly the same as
3714** sqlite3_prepare_v3() with a zero prepFlags parameter.
3715*/
3716SQLITE_API int sqlite3_prepare(
3717 sqlite3 *db, /* Database handle */
3718 const char *zSql, /* SQL statement, UTF-8 encoded */
3719 int nByte, /* Maximum length of zSql in bytes. */
3720 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3721 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3722);
3723SQLITE_API int sqlite3_prepare_v2(
3724 sqlite3 *db, /* Database handle */
3725 const char *zSql, /* SQL statement, UTF-8 encoded */
3726 int nByte, /* Maximum length of zSql in bytes. */
3727 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3728 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3729);
3730SQLITE_API int sqlite3_prepare_v3(
3731 sqlite3 *db, /* Database handle */
3732 const char *zSql, /* SQL statement, UTF-8 encoded */
3733 int nByte, /* Maximum length of zSql in bytes. */
3734 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3735 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3736 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3737);
3738SQLITE_API int sqlite3_prepare16(
3739 sqlite3 *db, /* Database handle */
3740 const void *zSql, /* SQL statement, UTF-16 encoded */
3741 int nByte, /* Maximum length of zSql in bytes. */
3742 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3743 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3744);
3745SQLITE_API int sqlite3_prepare16_v2(
3746 sqlite3 *db, /* Database handle */
3747 const void *zSql, /* SQL statement, UTF-16 encoded */
3748 int nByte, /* Maximum length of zSql in bytes. */
3749 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3750 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3751);
3752SQLITE_API int sqlite3_prepare16_v3(
3753 sqlite3 *db, /* Database handle */
3754 const void *zSql, /* SQL statement, UTF-16 encoded */
3755 int nByte, /* Maximum length of zSql in bytes. */
3756 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3757 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3758 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3759);
3760
3761/*
3762** CAPI3REF: Retrieving Statement SQL
3763** METHOD: sqlite3_stmt
3764**
3765** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3766** SQL text used to create [prepared statement] P if P was
3767** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
3768** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
3769** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3770** string containing the SQL text of prepared statement P with
3771** [bound parameters] expanded.
3772**
3773** ^(For example, if a prepared statement is created using the SQL
3774** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3775** and parameter :xyz is unbound, then sqlite3_sql() will return
3776** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3777** will return "SELECT 2345,NULL".)^
3778**
3779** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3780** is available to hold the result, or if the result would exceed the
3781** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3782**
3783** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3784** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3785** option causes sqlite3_expanded_sql() to always return NULL.
3786**
3787** ^The string returned by sqlite3_sql(P) is managed by SQLite and is
3788** automatically freed when the prepared statement is finalized.
3789** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3790** is obtained from [sqlite3_malloc()] and must be free by the application
3791** by passing it to [sqlite3_free()].
3792*/
3793SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3794SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3795
3796/*
3797** CAPI3REF: Determine If An SQL Statement Writes The Database
3798** METHOD: sqlite3_stmt
3799**
3800** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3801** and only if the [prepared statement] X makes no direct changes to
3802** the content of the database file.
3803**
3804** Note that [application-defined SQL functions] or
3805** [virtual tables] might change the database indirectly as a side effect.
3806** ^(For example, if an application defines a function "eval()" that
3807** calls [sqlite3_exec()], then the following SQL statement would
3808** change the database file through side-effects:
3809**
3810** <blockquote><pre>
3811** SELECT eval('DELETE FROM t1') FROM t2;
3812** </pre></blockquote>
3813**
3814** But because the [SELECT] statement does not change the database file
3815** directly, sqlite3_stmt_readonly() would still return true.)^
3816**
3817** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3818** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3819** since the statements themselves do not actually modify the database but
3820** rather they control the timing of when other statements modify the
3821** database. ^The [ATTACH] and [DETACH] statements also cause
3822** sqlite3_stmt_readonly() to return true since, while those statements
3823** change the configuration of a database connection, they do not make
3824** changes to the content of the database files on disk.
3825** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3826** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3827** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3828** sqlite3_stmt_readonly() returns false for those commands.
3829*/
3830SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3831
3832/*
3833** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3834** METHOD: sqlite3_stmt
3835**
3836** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3837** [prepared statement] S has been stepped at least once using
3838** [sqlite3_step(S)] but has neither run to completion (returned
3839** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3840** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3841** interface returns false if S is a NULL pointer. If S is not a
3842** NULL pointer and is not a pointer to a valid [prepared statement]
3843** object, then the behavior is undefined and probably undesirable.
3844**
3845** This interface can be used in combination [sqlite3_next_stmt()]
3846** to locate all prepared statements associated with a database
3847** connection that are in need of being reset. This can be used,
3848** for example, in diagnostic routines to search for prepared
3849** statements that are holding a transaction open.
3850*/
3851SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3852
3853/*
3854** CAPI3REF: Dynamically Typed Value Object
3855** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3856**
3857** SQLite uses the sqlite3_value object to represent all values
3858** that can be stored in a database table. SQLite uses dynamic typing
3859** for the values it stores. ^Values stored in sqlite3_value objects
3860** can be integers, floating point values, strings, BLOBs, or NULL.
3861**
3862** An sqlite3_value object may be either "protected" or "unprotected".
3863** Some interfaces require a protected sqlite3_value. Other interfaces
3864** will accept either a protected or an unprotected sqlite3_value.
3865** Every interface that accepts sqlite3_value arguments specifies
3866** whether or not it requires a protected sqlite3_value. The
3867** [sqlite3_value_dup()] interface can be used to construct a new
3868** protected sqlite3_value from an unprotected sqlite3_value.
3869**
3870** The terms "protected" and "unprotected" refer to whether or not
3871** a mutex is held. An internal mutex is held for a protected
3872** sqlite3_value object but no mutex is held for an unprotected
3873** sqlite3_value object. If SQLite is compiled to be single-threaded
3874** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3875** or if SQLite is run in one of reduced mutex modes
3876** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3877** then there is no distinction between protected and unprotected
3878** sqlite3_value objects and they can be used interchangeably. However,
3879** for maximum code portability it is recommended that applications
3880** still make the distinction between protected and unprotected
3881** sqlite3_value objects even when not strictly required.
3882**
3883** ^The sqlite3_value objects that are passed as parameters into the
3884** implementation of [application-defined SQL functions] are protected.
3885** ^The sqlite3_value object returned by
3886** [sqlite3_column_value()] is unprotected.
3887** Unprotected sqlite3_value objects may only be used as arguments
3888** to [sqlite3_result_value()], [sqlite3_bind_value()], and
3889** [sqlite3_value_dup()].
3890** The [sqlite3_value_blob | sqlite3_value_type()] family of
3891** interfaces require protected sqlite3_value objects.
3892*/
3893typedef struct sqlite3_value sqlite3_value;
3894
3895/*
3896** CAPI3REF: SQL Function Context Object
3897**
3898** The context in which an SQL function executes is stored in an
3899** sqlite3_context object. ^A pointer to an sqlite3_context object
3900** is always first parameter to [application-defined SQL functions].
3901** The application-defined SQL function implementation will pass this
3902** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3903** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3904** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3905** and/or [sqlite3_set_auxdata()].
3906*/
3907typedef struct sqlite3_context sqlite3_context;
3908
3909/*
3910** CAPI3REF: Binding Values To Prepared Statements
3911** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3912** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3913** METHOD: sqlite3_stmt
3914**
3915** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3916** literals may be replaced by a [parameter] that matches one of following
3917** templates:
3918**
3919** <ul>
3920** <li> ?
3921** <li> ?NNN
3922** <li> :VVV
3923** <li> @VVV
3924** <li> $VVV
3925** </ul>
3926**
3927** In the templates above, NNN represents an integer literal,
3928** and VVV represents an alphanumeric identifier.)^ ^The values of these
3929** parameters (also called "host parameter names" or "SQL parameters")
3930** can be set using the sqlite3_bind_*() routines defined here.
3931**
3932** ^The first argument to the sqlite3_bind_*() routines is always
3933** a pointer to the [sqlite3_stmt] object returned from
3934** [sqlite3_prepare_v2()] or its variants.
3935**
3936** ^The second argument is the index of the SQL parameter to be set.
3937** ^The leftmost SQL parameter has an index of 1. ^When the same named
3938** SQL parameter is used more than once, second and subsequent
3939** occurrences have the same index as the first occurrence.
3940** ^The index for named parameters can be looked up using the
3941** [sqlite3_bind_parameter_index()] API if desired. ^The index
3942** for "?NNN" parameters is the value of NNN.
3943** ^The NNN value must be between 1 and the [sqlite3_limit()]
3944** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3945**
3946** ^The third argument is the value to bind to the parameter.
3947** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3948** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3949** is ignored and the end result is the same as sqlite3_bind_null().
3950**
3951** ^(In those routines that have a fourth argument, its value is the
3952** number of bytes in the parameter. To be clear: the value is the
3953** number of <u>bytes</u> in the value, not the number of characters.)^
3954** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3955** is negative, then the length of the string is
3956** the number of bytes up to the first zero terminator.
3957** If the fourth parameter to sqlite3_bind_blob() is negative, then
3958** the behavior is undefined.
3959** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3960** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3961** that parameter must be the byte offset
3962** where the NUL terminator would occur assuming the string were NUL
3963** terminated. If any NUL characters occur at byte offsets less than
3964** the value of the fourth parameter then the resulting string value will
3965** contain embedded NULs. The result of expressions involving strings
3966** with embedded NULs is undefined.
3967**
3968** ^The fifth argument to the BLOB and string binding interfaces
3969** is a destructor used to dispose of the BLOB or
3970** string after SQLite has finished with it. ^The destructor is called
3971** to dispose of the BLOB or string even if the call to bind API fails.
3972** ^If the fifth argument is
3973** the special value [SQLITE_STATIC], then SQLite assumes that the
3974** information is in static, unmanaged space and does not need to be freed.
3975** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3976** SQLite makes its own private copy of the data immediately, before
3977** the sqlite3_bind_*() routine returns.
3978**
3979** ^The sixth argument to sqlite3_bind_text64() must be one of
3980** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
3981** to specify the encoding of the text in the third parameter. If
3982** the sixth argument to sqlite3_bind_text64() is not one of the
3983** allowed values shown above, or if the text encoding is different
3984** from the encoding specified by the sixth parameter, then the behavior
3985** is undefined.
3986**
3987** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3988** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3989** (just an integer to hold its size) while it is being processed.
3990** Zeroblobs are intended to serve as placeholders for BLOBs whose
3991** content is later written using
3992** [sqlite3_blob_open | incremental BLOB I/O] routines.
3993** ^A negative value for the zeroblob results in a zero-length BLOB.
3994**
3995** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
3996** [prepared statement] S to have an SQL value of NULL, but to also be
3997** associated with the pointer P of type T. ^D is either a NULL pointer or
3998** a pointer to a destructor function for P. ^SQLite will invoke the
3999** destructor D with a single argument of P when it is finished using
4000** P. The T parameter should be a static string, preferably a string
4001** literal. The sqlite3_bind_pointer() routine is part of the
4002** [pointer passing interface] added for SQLite 3.20.0.
4003**
4004** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4005** for the [prepared statement] or with a prepared statement for which
4006** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4007** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4008** routine is passed a [prepared statement] that has been finalized, the
4009** result is undefined and probably harmful.
4010**
4011** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4012** ^Unbound parameters are interpreted as NULL.
4013**
4014** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4015** [error code] if anything goes wrong.
4016** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4017** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4018** [SQLITE_MAX_LENGTH].
4019** ^[SQLITE_RANGE] is returned if the parameter
4020** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4021**
4022** See also: [sqlite3_bind_parameter_count()],
4023** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4024*/
4025SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4026SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4027 void(*)(void*));
4028SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4029SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4030SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4031SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4032SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4033SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4034SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4035 void(*)(void*), unsigned char encoding);
4036SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4037SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4038SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4039SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4040
4041/*
4042** CAPI3REF: Number Of SQL Parameters
4043** METHOD: sqlite3_stmt
4044**
4045** ^This routine can be used to find the number of [SQL parameters]
4046** in a [prepared statement]. SQL parameters are tokens of the
4047** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4048** placeholders for values that are [sqlite3_bind_blob | bound]
4049** to the parameters at a later time.
4050**
4051** ^(This routine actually returns the index of the largest (rightmost)
4052** parameter. For all forms except ?NNN, this will correspond to the
4053** number of unique parameters. If parameters of the ?NNN form are used,
4054** there may be gaps in the list.)^
4055**
4056** See also: [sqlite3_bind_blob|sqlite3_bind()],
4057** [sqlite3_bind_parameter_name()], and
4058** [sqlite3_bind_parameter_index()].
4059*/
4060SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4061
4062/*
4063** CAPI3REF: Name Of A Host Parameter
4064** METHOD: sqlite3_stmt
4065**
4066** ^The sqlite3_bind_parameter_name(P,N) interface returns
4067** the name of the N-th [SQL parameter] in the [prepared statement] P.
4068** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4069** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4070** respectively.
4071** In other words, the initial ":" or "$" or "@" or "?"
4072** is included as part of the name.)^
4073** ^Parameters of the form "?" without a following integer have no name
4074** and are referred to as "nameless" or "anonymous parameters".
4075**
4076** ^The first host parameter has an index of 1, not 0.
4077**
4078** ^If the value N is out of range or if the N-th parameter is
4079** nameless, then NULL is returned. ^The returned string is
4080** always in UTF-8 encoding even if the named parameter was
4081** originally specified as UTF-16 in [sqlite3_prepare16()],
4082** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4083**
4084** See also: [sqlite3_bind_blob|sqlite3_bind()],
4085** [sqlite3_bind_parameter_count()], and
4086** [sqlite3_bind_parameter_index()].
4087*/
4088SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4089
4090/*
4091** CAPI3REF: Index Of A Parameter With A Given Name
4092** METHOD: sqlite3_stmt
4093**
4094** ^Return the index of an SQL parameter given its name. ^The
4095** index value returned is suitable for use as the second
4096** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4097** is returned if no matching parameter is found. ^The parameter
4098** name must be given in UTF-8 even if the original statement
4099** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4100** [sqlite3_prepare16_v3()].
4101**
4102** See also: [sqlite3_bind_blob|sqlite3_bind()],
4103** [sqlite3_bind_parameter_count()], and
4104** [sqlite3_bind_parameter_name()].
4105*/
4106SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4107
4108/*
4109** CAPI3REF: Reset All Bindings On A Prepared Statement
4110** METHOD: sqlite3_stmt
4111**
4112** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4113** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4114** ^Use this routine to reset all host parameters to NULL.
4115*/
4116SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4117
4118/*
4119** CAPI3REF: Number Of Columns In A Result Set
4120** METHOD: sqlite3_stmt
4121**
4122** ^Return the number of columns in the result set returned by the
4123** [prepared statement]. ^If this routine returns 0, that means the
4124** [prepared statement] returns no data (for example an [UPDATE]).
4125** ^However, just because this routine returns a positive number does not
4126** mean that one or more rows of data will be returned. ^A SELECT statement
4127** will always have a positive sqlite3_column_count() but depending on the
4128** WHERE clause constraints and the table content, it might return no rows.
4129**
4130** See also: [sqlite3_data_count()]
4131*/
4132SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4133
4134/*
4135** CAPI3REF: Column Names In A Result Set
4136** METHOD: sqlite3_stmt
4137**
4138** ^These routines return the name assigned to a particular column
4139** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4140** interface returns a pointer to a zero-terminated UTF-8 string
4141** and sqlite3_column_name16() returns a pointer to a zero-terminated
4142** UTF-16 string. ^The first parameter is the [prepared statement]
4143** that implements the [SELECT] statement. ^The second parameter is the
4144** column number. ^The leftmost column is number 0.
4145**
4146** ^The returned string pointer is valid until either the [prepared statement]
4147** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4148** reprepared by the first call to [sqlite3_step()] for a particular run
4149** or until the next call to
4150** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4151**
4152** ^If sqlite3_malloc() fails during the processing of either routine
4153** (for example during a conversion from UTF-8 to UTF-16) then a
4154** NULL pointer is returned.
4155**
4156** ^The name of a result column is the value of the "AS" clause for
4157** that column, if there is an AS clause. If there is no AS clause
4158** then the name of the column is unspecified and may change from
4159** one release of SQLite to the next.
4160*/
4161SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4162SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4163
4164/*
4165** CAPI3REF: Source Of Data In A Query Result
4166** METHOD: sqlite3_stmt
4167**
4168** ^These routines provide a means to determine the database, table, and
4169** table column that is the origin of a particular result column in
4170** [SELECT] statement.
4171** ^The name of the database or table or column can be returned as
4172** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4173** the database name, the _table_ routines return the table name, and
4174** the origin_ routines return the column name.
4175** ^The returned string is valid until the [prepared statement] is destroyed
4176** using [sqlite3_finalize()] or until the statement is automatically
4177** reprepared by the first call to [sqlite3_step()] for a particular run
4178** or until the same information is requested
4179** again in a different encoding.
4180**
4181** ^The names returned are the original un-aliased names of the
4182** database, table, and column.
4183**
4184** ^The first argument to these interfaces is a [prepared statement].
4185** ^These functions return information about the Nth result column returned by
4186** the statement, where N is the second function argument.
4187** ^The left-most column is column 0 for these routines.
4188**
4189** ^If the Nth column returned by the statement is an expression or
4190** subquery and is not a column value, then all of these functions return
4191** NULL. ^These routine might also return NULL if a memory allocation error
4192** occurs. ^Otherwise, they return the name of the attached database, table,
4193** or column that query result column was extracted from.
4194**
4195** ^As with all other SQLite APIs, those whose names end with "16" return
4196** UTF-16 encoded strings and the other functions return UTF-8.
4197**
4198** ^These APIs are only available if the library was compiled with the
4199** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4200**
4201** If two or more threads call one or more of these routines against the same
4202** prepared statement and column at the same time then the results are
4203** undefined.
4204**
4205** If two or more threads call one or more
4206** [sqlite3_column_database_name | column metadata interfaces]
4207** for the same [prepared statement] and result column
4208** at the same time then the results are undefined.
4209*/
4210SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4211SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4212SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4213SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4214SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4215SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4216
4217/*
4218** CAPI3REF: Declared Datatype Of A Query Result
4219** METHOD: sqlite3_stmt
4220**
4221** ^(The first parameter is a [prepared statement].
4222** If this statement is a [SELECT] statement and the Nth column of the
4223** returned result set of that [SELECT] is a table column (not an
4224** expression or subquery) then the declared type of the table
4225** column is returned.)^ ^If the Nth column of the result set is an
4226** expression or subquery, then a NULL pointer is returned.
4227** ^The returned string is always UTF-8 encoded.
4228**
4229** ^(For example, given the database schema:
4230**
4231** CREATE TABLE t1(c1 VARIANT);
4232**
4233** and the following statement to be compiled:
4234**
4235** SELECT c1 + 1, c1 FROM t1;
4236**
4237** this routine would return the string "VARIANT" for the second result
4238** column (i==1), and a NULL pointer for the first result column (i==0).)^
4239**
4240** ^SQLite uses dynamic run-time typing. ^So just because a column
4241** is declared to contain a particular type does not mean that the
4242** data stored in that column is of the declared type. SQLite is
4243** strongly typed, but the typing is dynamic not static. ^Type
4244** is associated with individual values, not with the containers
4245** used to hold those values.
4246*/
4247SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4248SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4249
4250/*
4251** CAPI3REF: Evaluate An SQL Statement
4252** METHOD: sqlite3_stmt
4253**
4254** After a [prepared statement] has been prepared using any of
4255** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4256** or [sqlite3_prepare16_v3()] or one of the legacy
4257** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4258** must be called one or more times to evaluate the statement.
4259**
4260** The details of the behavior of the sqlite3_step() interface depend
4261** on whether the statement was prepared using the newer "vX" interfaces
4262** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4263** [sqlite3_prepare16_v2()] or the older legacy
4264** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4265** new "vX" interface is recommended for new applications but the legacy
4266** interface will continue to be supported.
4267**
4268** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4269** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4270** ^With the "v2" interface, any of the other [result codes] or
4271** [extended result codes] might be returned as well.
4272**
4273** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4274** database locks it needs to do its job. ^If the statement is a [COMMIT]
4275** or occurs outside of an explicit transaction, then you can retry the
4276** statement. If the statement is not a [COMMIT] and occurs within an
4277** explicit transaction then you should rollback the transaction before
4278** continuing.
4279**
4280** ^[SQLITE_DONE] means that the statement has finished executing
4281** successfully. sqlite3_step() should not be called again on this virtual
4282** machine without first calling [sqlite3_reset()] to reset the virtual
4283** machine back to its initial state.
4284**
4285** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4286** is returned each time a new row of data is ready for processing by the
4287** caller. The values may be accessed using the [column access functions].
4288** sqlite3_step() is called again to retrieve the next row of data.
4289**
4290** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4291** violation) has occurred. sqlite3_step() should not be called again on
4292** the VM. More information may be found by calling [sqlite3_errmsg()].
4293** ^With the legacy interface, a more specific error code (for example,
4294** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4295** can be obtained by calling [sqlite3_reset()] on the
4296** [prepared statement]. ^In the "v2" interface,
4297** the more specific error code is returned directly by sqlite3_step().
4298**
4299** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4300** Perhaps it was called on a [prepared statement] that has
4301** already been [sqlite3_finalize | finalized] or on one that had
4302** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4303** be the case that the same database connection is being used by two or
4304** more threads at the same moment in time.
4305**
4306** For all versions of SQLite up to and including 3.6.23.1, a call to
4307** [sqlite3_reset()] was required after sqlite3_step() returned anything
4308** other than [SQLITE_ROW] before any subsequent invocation of
4309** sqlite3_step(). Failure to reset the prepared statement using
4310** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4311** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4312** sqlite3_step() began
4313** calling [sqlite3_reset()] automatically in this circumstance rather
4314** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4315** break because any application that ever receives an SQLITE_MISUSE error
4316** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4317** can be used to restore the legacy behavior.
4318**
4319** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4320** API always returns a generic error code, [SQLITE_ERROR], following any
4321** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4322** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4323** specific [error codes] that better describes the error.
4324** We admit that this is a goofy design. The problem has been fixed
4325** with the "v2" interface. If you prepare all of your SQL statements
4326** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4327** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4328** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4329** then the more specific [error codes] are returned directly
4330** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4331*/
4332SQLITE_API int sqlite3_step(sqlite3_stmt*);
4333
4334/*
4335** CAPI3REF: Number of columns in a result set
4336** METHOD: sqlite3_stmt
4337**
4338** ^The sqlite3_data_count(P) interface returns the number of columns in the
4339** current row of the result set of [prepared statement] P.
4340** ^If prepared statement P does not have results ready to return
4341** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4342** interfaces) then sqlite3_data_count(P) returns 0.
4343** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4344** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4345** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4346** will return non-zero if previous call to [sqlite3_step](P) returned
4347** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4348** where it always returns zero since each step of that multi-step
4349** pragma returns 0 columns of data.
4350**
4351** See also: [sqlite3_column_count()]
4352*/
4353SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4354
4355/*
4356** CAPI3REF: Fundamental Datatypes
4357** KEYWORDS: SQLITE_TEXT
4358**
4359** ^(Every value in SQLite has one of five fundamental datatypes:
4360**
4361** <ul>
4362** <li> 64-bit signed integer
4363** <li> 64-bit IEEE floating point number
4364** <li> string
4365** <li> BLOB
4366** <li> NULL
4367** </ul>)^
4368**
4369** These constants are codes for each of those types.
4370**
4371** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4372** for a completely different meaning. Software that links against both
4373** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4374** SQLITE_TEXT.
4375*/
4376#define SQLITE_INTEGER 1
4377#define SQLITE_FLOAT 2
4378#define SQLITE_BLOB 4
4379#define SQLITE_NULL 5
4380#ifdef SQLITE_TEXT
4381# undef SQLITE_TEXT
4382#else
4383# define SQLITE_TEXT 3
4384#endif
4385#define SQLITE3_TEXT 3
4386
4387/*
4388** CAPI3REF: Result Values From A Query
4389** KEYWORDS: {column access functions}
4390** METHOD: sqlite3_stmt
4391**
4392** <b>Summary:</b>
4393** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4394** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4395** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4396** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4397** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4398** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4399** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4400** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4401** [sqlite3_value|unprotected sqlite3_value] object.
4402** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4403** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4404** or a UTF-8 TEXT result in bytes
4405** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4406** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4407** TEXT in bytes
4408** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4409** datatype of the result
4410** </table></blockquote>
4411**
4412** <b>Details:</b>
4413**
4414** ^These routines return information about a single column of the current
4415** result row of a query. ^In every case the first argument is a pointer
4416** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4417** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4418** and the second argument is the index of the column for which information
4419** should be returned. ^The leftmost column of the result set has the index 0.
4420** ^The number of columns in the result can be determined using
4421** [sqlite3_column_count()].
4422**
4423** If the SQL statement does not currently point to a valid row, or if the
4424** column index is out of range, the result is undefined.
4425** These routines may only be called when the most recent call to
4426** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4427** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4428** If any of these routines are called after [sqlite3_reset()] or
4429** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4430** something other than [SQLITE_ROW], the results are undefined.
4431** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4432** are called from a different thread while any of these routines
4433** are pending, then the results are undefined.
4434**
4435** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4436** each return the value of a result column in a specific data format. If
4437** the result column is not initially in the requested format (for example,
4438** if the query returns an integer but the sqlite3_column_text() interface
4439** is used to extract the value) then an automatic type conversion is performed.
4440**
4441** ^The sqlite3_column_type() routine returns the
4442** [SQLITE_INTEGER | datatype code] for the initial data type
4443** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4444** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4445** The return value of sqlite3_column_type() can be used to decide which
4446** of the first six interface should be used to extract the column value.
4447** The value returned by sqlite3_column_type() is only meaningful if no
4448** automatic type conversions have occurred for the value in question.
4449** After a type conversion, the result of calling sqlite3_column_type()
4450** is undefined, though harmless. Future
4451** versions of SQLite may change the behavior of sqlite3_column_type()
4452** following a type conversion.
4453**
4454** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4455** or sqlite3_column_bytes16() interfaces can be used to determine the size
4456** of that BLOB or string.
4457**
4458** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4459** routine returns the number of bytes in that BLOB or string.
4460** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4461** the string to UTF-8 and then returns the number of bytes.
4462** ^If the result is a numeric value then sqlite3_column_bytes() uses
4463** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4464** the number of bytes in that string.
4465** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4466**
4467** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4468** routine returns the number of bytes in that BLOB or string.
4469** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4470** the string to UTF-16 and then returns the number of bytes.
4471** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4472** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4473** the number of bytes in that string.
4474** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4475**
4476** ^The values returned by [sqlite3_column_bytes()] and
4477** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4478** of the string. ^For clarity: the values returned by
4479** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4480** bytes in the string, not the number of characters.
4481**
4482** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4483** even empty strings, are always zero-terminated. ^The return
4484** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4485**
4486** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4487** [unprotected sqlite3_value] object. In a multithreaded environment,
4488** an unprotected sqlite3_value object may only be used safely with
4489** [sqlite3_bind_value()] and [sqlite3_result_value()].
4490** If the [unprotected sqlite3_value] object returned by
4491** [sqlite3_column_value()] is used in any other way, including calls
4492** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4493** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4494** Hence, the sqlite3_column_value() interface
4495** is normally only useful within the implementation of
4496** [application-defined SQL functions] or [virtual tables], not within
4497** top-level application code.
4498**
4499** The these routines may attempt to convert the datatype of the result.
4500** ^For example, if the internal representation is FLOAT and a text result
4501** is requested, [sqlite3_snprintf()] is used internally to perform the
4502** conversion automatically. ^(The following table details the conversions
4503** that are applied:
4504**
4505** <blockquote>
4506** <table border="1">
4507** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4508**
4509** <tr><td> NULL <td> INTEGER <td> Result is 0
4510** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4511** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4512** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4513** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4514** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4515** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4516** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4517** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4518** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4519** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4520** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4521** <tr><td> TEXT <td> BLOB <td> No change
4522** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4523** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4524** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4525** </table>
4526** </blockquote>)^
4527**
4528** Note that when type conversions occur, pointers returned by prior
4529** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4530** sqlite3_column_text16() may be invalidated.
4531** Type conversions and pointer invalidations might occur
4532** in the following cases:
4533**
4534** <ul>
4535** <li> The initial content is a BLOB and sqlite3_column_text() or
4536** sqlite3_column_text16() is called. A zero-terminator might
4537** need to be added to the string.</li>
4538** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4539** sqlite3_column_text16() is called. The content must be converted
4540** to UTF-16.</li>
4541** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4542** sqlite3_column_text() is called. The content must be converted
4543** to UTF-8.</li>
4544** </ul>
4545**
4546** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4547** not invalidate a prior pointer, though of course the content of the buffer
4548** that the prior pointer references will have been modified. Other kinds
4549** of conversion are done in place when it is possible, but sometimes they
4550** are not possible and in those cases prior pointers are invalidated.
4551**
4552** The safest policy is to invoke these routines
4553** in one of the following ways:
4554**
4555** <ul>
4556** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4557** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4558** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4559** </ul>
4560**
4561** In other words, you should call sqlite3_column_text(),
4562** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4563** into the desired format, then invoke sqlite3_column_bytes() or
4564** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4565** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4566** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4567** with calls to sqlite3_column_bytes().
4568**
4569** ^The pointers returned are valid until a type conversion occurs as
4570** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4571** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4572** and BLOBs is freed automatically. Do not pass the pointers returned
4573** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4574** [sqlite3_free()].
4575**
4576** As long as the input parameters are correct, these routines will only
4577** fail if an out-of-memory error occurs during a format conversion.
4578** Only the following subset of interfaces are subject to out-of-memory
4579** errors:
4580**
4581** <ul>
4582** <li> sqlite3_column_blob()
4583** <li> sqlite3_column_text()
4584** <li> sqlite3_column_text16()
4585** <li> sqlite3_column_bytes()
4586** <li> sqlite3_column_bytes16()
4587** </ul>
4588**
4589** If an out-of-memory error occurs, then the return value from these
4590** routines is the same as if the column had contained an SQL NULL value.
4591** Valid SQL NULL returns can be distinguished from out-of-memory errors
4592** by invoking the [sqlite3_errcode()] immediately after the suspect
4593** return value is obtained and before any
4594** other SQLite interface is called on the same [database connection].
4595*/
4596SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4597SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4598SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4599SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4600SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4601SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4602SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4603SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4604SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4605SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4606
4607/*
4608** CAPI3REF: Destroy A Prepared Statement Object
4609** DESTRUCTOR: sqlite3_stmt
4610**
4611** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4612** ^If the most recent evaluation of the statement encountered no errors
4613** or if the statement is never been evaluated, then sqlite3_finalize() returns
4614** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4615** sqlite3_finalize(S) returns the appropriate [error code] or
4616** [extended error code].
4617**
4618** ^The sqlite3_finalize(S) routine can be called at any point during
4619** the life cycle of [prepared statement] S:
4620** before statement S is ever evaluated, after
4621** one or more calls to [sqlite3_reset()], or after any call
4622** to [sqlite3_step()] regardless of whether or not the statement has
4623** completed execution.
4624**
4625** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4626**
4627** The application must finalize every [prepared statement] in order to avoid
4628** resource leaks. It is a grievous error for the application to try to use
4629** a prepared statement after it has been finalized. Any use of a prepared
4630** statement after it has been finalized can result in undefined and
4631** undesirable behavior such as segfaults and heap corruption.
4632*/
4633SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4634
4635/*
4636** CAPI3REF: Reset A Prepared Statement Object
4637** METHOD: sqlite3_stmt
4638**
4639** The sqlite3_reset() function is called to reset a [prepared statement]
4640** object back to its initial state, ready to be re-executed.
4641** ^Any SQL statement variables that had values bound to them using
4642** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4643** Use [sqlite3_clear_bindings()] to reset the bindings.
4644**
4645** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4646** back to the beginning of its program.
4647**
4648** ^If the most recent call to [sqlite3_step(S)] for the
4649** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4650** or if [sqlite3_step(S)] has never before been called on S,
4651** then [sqlite3_reset(S)] returns [SQLITE_OK].
4652**
4653** ^If the most recent call to [sqlite3_step(S)] for the
4654** [prepared statement] S indicated an error, then
4655** [sqlite3_reset(S)] returns an appropriate [error code].
4656**
4657** ^The [sqlite3_reset(S)] interface does not change the values
4658** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4659*/
4660SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4661
4662/*
4663** CAPI3REF: Create Or Redefine SQL Functions
4664** KEYWORDS: {function creation routines}
4665** KEYWORDS: {application-defined SQL function}
4666** KEYWORDS: {application-defined SQL functions}
4667** METHOD: sqlite3
4668**
4669** ^These functions (collectively known as "function creation routines")
4670** are used to add SQL functions or aggregates or to redefine the behavior
4671** of existing SQL functions or aggregates. The only differences between
4672** the three "sqlite3_create_function*" routines are the text encoding
4673** expected for the second parameter (the name of the function being
4674** created) and the presence or absence of a destructor callback for
4675** the application data pointer. Function sqlite3_create_window_function()
4676** is similar, but allows the user to supply the extra callback functions
4677** needed by [aggregate window functions].
4678**
4679** ^The first parameter is the [database connection] to which the SQL
4680** function is to be added. ^If an application uses more than one database
4681** connection then application-defined SQL functions must be added
4682** to each database connection separately.
4683**
4684** ^The second parameter is the name of the SQL function to be created or
4685** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4686** representation, exclusive of the zero-terminator. ^Note that the name
4687** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4688** ^Any attempt to create a function with a longer name
4689** will result in [SQLITE_MISUSE] being returned.
4690**
4691** ^The third parameter (nArg)
4692** is the number of arguments that the SQL function or
4693** aggregate takes. ^If this parameter is -1, then the SQL function or
4694** aggregate may take any number of arguments between 0 and the limit
4695** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4696** parameter is less than -1 or greater than 127 then the behavior is
4697** undefined.
4698**
4699** ^The fourth parameter, eTextRep, specifies what
4700** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4701** its parameters. The application should set this parameter to
4702** [SQLITE_UTF16LE] if the function implementation invokes
4703** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4704** implementation invokes [sqlite3_value_text16be()] on an input, or
4705** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4706** otherwise. ^The same SQL function may be registered multiple times using
4707** different preferred text encodings, with different implementations for
4708** each encoding.
4709** ^When multiple implementations of the same function are available, SQLite
4710** will pick the one that involves the least amount of data conversion.
4711**
4712** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4713** to signal that the function will always return the same result given
4714** the same inputs within a single SQL statement. Most SQL functions are
4715** deterministic. The built-in [random()] SQL function is an example of a
4716** function that is not deterministic. The SQLite query planner is able to
4717** perform additional optimizations on deterministic functions, so use
4718** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4719**
4720** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4721** function can gain access to this pointer using [sqlite3_user_data()].)^
4722**
4723** ^The sixth, seventh and eighth parameters passed to the three
4724** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
4725** pointers to C-language functions that implement the SQL function or
4726** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4727** callback only; NULL pointers must be passed as the xStep and xFinal
4728** parameters. ^An aggregate SQL function requires an implementation of xStep
4729** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4730** SQL function or aggregate, pass NULL pointers for all three function
4731** callbacks.
4732**
4733** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
4734** and xInverse) passed to sqlite3_create_window_function are pointers to
4735** C-language callbacks that implement the new function. xStep and xFinal
4736** must both be non-NULL. xValue and xInverse may either both be NULL, in
4737** which case a regular aggregate function is created, or must both be
4738** non-NULL, in which case the new function may be used as either an aggregate
4739** or aggregate window function. More details regarding the implementation
4740** of aggregate window functions are
4741** [user-defined window functions|available here].
4742**
4743** ^(If the final parameter to sqlite3_create_function_v2() or
4744** sqlite3_create_window_function() is not NULL, then it is destructor for
4745** the application data pointer. The destructor is invoked when the function
4746** is deleted, either by being overloaded or when the database connection
4747** closes.)^ ^The destructor is also invoked if the call to
4748** sqlite3_create_function_v2() fails. ^When the destructor callback is
4749** invoked, it is passed a single argument which is a copy of the application
4750** data pointer which was the fifth parameter to sqlite3_create_function_v2().
4751**
4752** ^It is permitted to register multiple implementations of the same
4753** functions with the same name but with either differing numbers of
4754** arguments or differing preferred text encodings. ^SQLite will use
4755** the implementation that most closely matches the way in which the
4756** SQL function is used. ^A function implementation with a non-negative
4757** nArg parameter is a better match than a function implementation with
4758** a negative nArg. ^A function where the preferred text encoding
4759** matches the database encoding is a better
4760** match than a function where the encoding is different.
4761** ^A function where the encoding difference is between UTF16le and UTF16be
4762** is a closer match than a function where the encoding difference is
4763** between UTF8 and UTF16.
4764**
4765** ^Built-in functions may be overloaded by new application-defined functions.
4766**
4767** ^An application-defined function is permitted to call other
4768** SQLite interfaces. However, such calls must not
4769** close the database connection nor finalize or reset the prepared
4770** statement in which the function is running.
4771*/
4772SQLITE_API int sqlite3_create_function(
4773 sqlite3 *db,
4774 const char *zFunctionName,
4775 int nArg,
4776 int eTextRep,
4777 void *pApp,
4778 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4779 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4780 void (*xFinal)(sqlite3_context*)
4781);
4782SQLITE_API int sqlite3_create_function16(
4783 sqlite3 *db,
4784 const void *zFunctionName,
4785 int nArg,
4786 int eTextRep,
4787 void *pApp,
4788 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4789 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4790 void (*xFinal)(sqlite3_context*)
4791);
4792SQLITE_API int sqlite3_create_function_v2(
4793 sqlite3 *db,
4794 const char *zFunctionName,
4795 int nArg,
4796 int eTextRep,
4797 void *pApp,
4798 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4799 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4800 void (*xFinal)(sqlite3_context*),
4801 void(*xDestroy)(void*)
4802);
4803SQLITE_API int sqlite3_create_window_function(
4804 sqlite3 *db,
4805 const char *zFunctionName,
4806 int nArg,
4807 int eTextRep,
4808 void *pApp,
4809 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4810 void (*xFinal)(sqlite3_context*),
4811 void (*xValue)(sqlite3_context*),
4812 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
4813 void(*xDestroy)(void*)
4814);
4815
4816/*
4817** CAPI3REF: Text Encodings
4818**
4819** These constant define integer codes that represent the various
4820** text encodings supported by SQLite.
4821*/
4822#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4823#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4824#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4825#define SQLITE_UTF16 4 /* Use native byte order */
4826#define SQLITE_ANY 5 /* Deprecated */
4827#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4828
4829/*
4830** CAPI3REF: Function Flags
4831**
4832** These constants may be ORed together with the
4833** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4834** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4835** [sqlite3_create_function_v2()].
4836*/
4837#define SQLITE_DETERMINISTIC 0x800
4838
4839/*
4840** CAPI3REF: Deprecated Functions
4841** DEPRECATED
4842**
4843** These functions are [deprecated]. In order to maintain
4844** backwards compatibility with older code, these functions continue
4845** to be supported. However, new applications should avoid
4846** the use of these functions. To encourage programmers to avoid
4847** these functions, we will not explain what they do.
4848*/
4849#ifndef SQLITE_OMIT_DEPRECATED
4850SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4851SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4852SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4853SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4854SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4855SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4856 void*,sqlite3_int64);
4857#endif
4858
4859/*
4860** CAPI3REF: Obtaining SQL Values
4861** METHOD: sqlite3_value
4862**
4863** <b>Summary:</b>
4864** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4865** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
4866** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
4867** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
4868** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
4869** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
4870** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
4871** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
4872** the native byteorder
4873** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
4874** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
4875** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4876** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
4877** or a UTF-8 TEXT in bytes
4878** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
4879** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4880** TEXT in bytes
4881** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
4882** datatype of the value
4883** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
4884** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
4885** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
4886** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
4887** against a virtual table.
4888** </table></blockquote>
4889**
4890** <b>Details:</b>
4891**
4892** These routines extract type, size, and content information from
4893** [protected sqlite3_value] objects. Protected sqlite3_value objects
4894** are used to pass parameter information into implementation of
4895** [application-defined SQL functions] and [virtual tables].
4896**
4897** These routines work only with [protected sqlite3_value] objects.
4898** Any attempt to use these routines on an [unprotected sqlite3_value]
4899** is not threadsafe.
4900**
4901** ^These routines work just like the corresponding [column access functions]
4902** except that these routines take a single [protected sqlite3_value] object
4903** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4904**
4905** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4906** in the native byte-order of the host machine. ^The
4907** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4908** extract UTF-16 strings as big-endian and little-endian respectively.
4909**
4910** ^If [sqlite3_value] object V was initialized
4911** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
4912** and if X and Y are strings that compare equal according to strcmp(X,Y),
4913** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
4914** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
4915** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
4916**
4917** ^(The sqlite3_value_type(V) interface returns the
4918** [SQLITE_INTEGER | datatype code] for the initial datatype of the
4919** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
4920** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
4921** Other interfaces might change the datatype for an sqlite3_value object.
4922** For example, if the datatype is initially SQLITE_INTEGER and
4923** sqlite3_value_text(V) is called to extract a text value for that
4924** integer, then subsequent calls to sqlite3_value_type(V) might return
4925** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
4926** occurs is undefined and may change from one release of SQLite to the next.
4927**
4928** ^(The sqlite3_value_numeric_type() interface attempts to apply
4929** numeric affinity to the value. This means that an attempt is
4930** made to convert the value to an integer or floating point. If
4931** such a conversion is possible without loss of information (in other
4932** words, if the value is a string that looks like a number)
4933** then the conversion is performed. Otherwise no conversion occurs.
4934** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4935**
4936** ^Within the [xUpdate] method of a [virtual table], the
4937** sqlite3_value_nochange(X) interface returns true if and only if
4938** the column corresponding to X is unchanged by the UPDATE operation
4939** that the xUpdate method call was invoked to implement and if
4940** and the prior [xColumn] method call that was invoked to extracted
4941** the value for that column returned without setting a result (probably
4942** because it queried [sqlite3_vtab_nochange()] and found that the column
4943** was unchanging). ^Within an [xUpdate] method, any value for which
4944** sqlite3_value_nochange(X) is true will in all other respects appear
4945** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
4946** than within an [xUpdate] method call for an UPDATE statement, then
4947** the return value is arbitrary and meaningless.
4948**
4949** Please pay particular attention to the fact that the pointer returned
4950** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4951** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4952** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4953** or [sqlite3_value_text16()].
4954**
4955** These routines must be called from the same thread as
4956** the SQL function that supplied the [sqlite3_value*] parameters.
4957**
4958** As long as the input parameter is correct, these routines can only
4959** fail if an out-of-memory error occurs during a format conversion.
4960** Only the following subset of interfaces are subject to out-of-memory
4961** errors:
4962**
4963** <ul>
4964** <li> sqlite3_value_blob()
4965** <li> sqlite3_value_text()
4966** <li> sqlite3_value_text16()
4967** <li> sqlite3_value_text16le()
4968** <li> sqlite3_value_text16be()
4969** <li> sqlite3_value_bytes()
4970** <li> sqlite3_value_bytes16()
4971** </ul>
4972**
4973** If an out-of-memory error occurs, then the return value from these
4974** routines is the same as if the column had contained an SQL NULL value.
4975** Valid SQL NULL returns can be distinguished from out-of-memory errors
4976** by invoking the [sqlite3_errcode()] immediately after the suspect
4977** return value is obtained and before any
4978** other SQLite interface is called on the same [database connection].
4979*/
4980SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
4981SQLITE_API double sqlite3_value_double(sqlite3_value*);
4982SQLITE_API int sqlite3_value_int(sqlite3_value*);
4983SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
4984SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
4985SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
4986SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
4987SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
4988SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
4989SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
4990SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
4991SQLITE_API int sqlite3_value_type(sqlite3_value*);
4992SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
4993SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
4994
4995/*
4996** CAPI3REF: Finding The Subtype Of SQL Values
4997** METHOD: sqlite3_value
4998**
4999** The sqlite3_value_subtype(V) function returns the subtype for
5000** an [application-defined SQL function] argument V. The subtype
5001** information can be used to pass a limited amount of context from
5002** one SQL function to another. Use the [sqlite3_result_subtype()]
5003** routine to set the subtype for the return value of an SQL function.
5004*/
5005SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5006
5007/*
5008** CAPI3REF: Copy And Free SQL Values
5009** METHOD: sqlite3_value
5010**
5011** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5012** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5013** is a [protected sqlite3_value] object even if the input is not.
5014** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5015** memory allocation fails.
5016**
5017** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5018** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5019** then sqlite3_value_free(V) is a harmless no-op.
5020*/
5021SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5022SQLITE_API void sqlite3_value_free(sqlite3_value*);
5023
5024/*
5025** CAPI3REF: Obtain Aggregate Function Context
5026** METHOD: sqlite3_context
5027**
5028** Implementations of aggregate SQL functions use this
5029** routine to allocate memory for storing their state.
5030**
5031** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5032** for a particular aggregate function, SQLite
5033** allocates N of memory, zeroes out that memory, and returns a pointer
5034** to the new memory. ^On second and subsequent calls to
5035** sqlite3_aggregate_context() for the same aggregate function instance,
5036** the same buffer is returned. Sqlite3_aggregate_context() is normally
5037** called once for each invocation of the xStep callback and then one
5038** last time when the xFinal callback is invoked. ^(When no rows match
5039** an aggregate query, the xStep() callback of the aggregate function
5040** implementation is never called and xFinal() is called exactly once.
5041** In those cases, sqlite3_aggregate_context() might be called for the
5042** first time from within xFinal().)^
5043**
5044** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5045** when first called if N is less than or equal to zero or if a memory
5046** allocate error occurs.
5047**
5048** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5049** determined by the N parameter on first successful call. Changing the
5050** value of N in subsequent call to sqlite3_aggregate_context() within
5051** the same aggregate function instance will not resize the memory
5052** allocation.)^ Within the xFinal callback, it is customary to set
5053** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5054** pointless memory allocations occur.
5055**
5056** ^SQLite automatically frees the memory allocated by
5057** sqlite3_aggregate_context() when the aggregate query concludes.
5058**
5059** The first parameter must be a copy of the
5060** [sqlite3_context | SQL function context] that is the first parameter
5061** to the xStep or xFinal callback routine that implements the aggregate
5062** function.
5063**
5064** This routine must be called from the same thread in which
5065** the aggregate SQL function is running.
5066*/
5067SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5068
5069/*
5070** CAPI3REF: User Data For Functions
5071** METHOD: sqlite3_context
5072**
5073** ^The sqlite3_user_data() interface returns a copy of
5074** the pointer that was the pUserData parameter (the 5th parameter)
5075** of the [sqlite3_create_function()]
5076** and [sqlite3_create_function16()] routines that originally
5077** registered the application defined function.
5078**
5079** This routine must be called from the same thread in which
5080** the application-defined function is running.
5081*/
5082SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5083
5084/*
5085** CAPI3REF: Database Connection For Functions
5086** METHOD: sqlite3_context
5087**
5088** ^The sqlite3_context_db_handle() interface returns a copy of
5089** the pointer to the [database connection] (the 1st parameter)
5090** of the [sqlite3_create_function()]
5091** and [sqlite3_create_function16()] routines that originally
5092** registered the application defined function.
5093*/
5094SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5095
5096/*
5097** CAPI3REF: Function Auxiliary Data
5098** METHOD: sqlite3_context
5099**
5100** These functions may be used by (non-aggregate) SQL functions to
5101** associate metadata with argument values. If the same value is passed to
5102** multiple invocations of the same SQL function during query execution, under
5103** some circumstances the associated metadata may be preserved. An example
5104** of where this might be useful is in a regular-expression matching
5105** function. The compiled version of the regular expression can be stored as
5106** metadata associated with the pattern string.
5107** Then as long as the pattern string remains the same,
5108** the compiled regular expression can be reused on multiple
5109** invocations of the same function.
5110**
5111** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5112** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5113** value to the application-defined function. ^N is zero for the left-most
5114** function argument. ^If there is no metadata
5115** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5116** returns a NULL pointer.
5117**
5118** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5119** argument of the application-defined function. ^Subsequent
5120** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5121** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5122** NULL if the metadata has been discarded.
5123** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5124** SQLite will invoke the destructor function X with parameter P exactly
5125** once, when the metadata is discarded.
5126** SQLite is free to discard the metadata at any time, including: <ul>
5127** <li> ^(when the corresponding function parameter changes)^, or
5128** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5129** SQL statement)^, or
5130** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5131** parameter)^, or
5132** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5133** allocation error occurs.)^ </ul>
5134**
5135** Note the last bullet in particular. The destructor X in
5136** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5137** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5138** should be called near the end of the function implementation and the
5139** function implementation should not make any use of P after
5140** sqlite3_set_auxdata() has been called.
5141**
5142** ^(In practice, metadata is preserved between function calls for
5143** function parameters that are compile-time constants, including literal
5144** values and [parameters] and expressions composed from the same.)^
5145**
5146** The value of the N parameter to these interfaces should be non-negative.
5147** Future enhancements may make use of negative N values to define new
5148** kinds of function caching behavior.
5149**
5150** These routines must be called from the same thread in which
5151** the SQL function is running.
5152*/
5153SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5154SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5155
5156
5157/*
5158** CAPI3REF: Constants Defining Special Destructor Behavior
5159**
5160** These are special values for the destructor that is passed in as the
5161** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5162** argument is SQLITE_STATIC, it means that the content pointer is constant
5163** and will never change. It does not need to be destroyed. ^The
5164** SQLITE_TRANSIENT value means that the content will likely change in
5165** the near future and that SQLite should make its own private copy of
5166** the content before returning.
5167**
5168** The typedef is necessary to work around problems in certain
5169** C++ compilers.
5170*/
5171typedef void (*sqlite3_destructor_type)(void*);
5172#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5173#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5174
5175/*
5176** CAPI3REF: Setting The Result Of An SQL Function
5177** METHOD: sqlite3_context
5178**
5179** These routines are used by the xFunc or xFinal callbacks that
5180** implement SQL functions and aggregates. See
5181** [sqlite3_create_function()] and [sqlite3_create_function16()]
5182** for additional information.
5183**
5184** These functions work very much like the [parameter binding] family of
5185** functions used to bind values to host parameters in prepared statements.
5186** Refer to the [SQL parameter] documentation for additional information.
5187**
5188** ^The sqlite3_result_blob() interface sets the result from
5189** an application-defined function to be the BLOB whose content is pointed
5190** to by the second parameter and which is N bytes long where N is the
5191** third parameter.
5192**
5193** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5194** interfaces set the result of the application-defined function to be
5195** a BLOB containing all zero bytes and N bytes in size.
5196**
5197** ^The sqlite3_result_double() interface sets the result from
5198** an application-defined function to be a floating point value specified
5199** by its 2nd argument.
5200**
5201** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5202** cause the implemented SQL function to throw an exception.
5203** ^SQLite uses the string pointed to by the
5204** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5205** as the text of an error message. ^SQLite interprets the error
5206** message string from sqlite3_result_error() as UTF-8. ^SQLite
5207** interprets the string from sqlite3_result_error16() as UTF-16 in native
5208** byte order. ^If the third parameter to sqlite3_result_error()
5209** or sqlite3_result_error16() is negative then SQLite takes as the error
5210** message all text up through the first zero character.
5211** ^If the third parameter to sqlite3_result_error() or
5212** sqlite3_result_error16() is non-negative then SQLite takes that many
5213** bytes (not characters) from the 2nd parameter as the error message.
5214** ^The sqlite3_result_error() and sqlite3_result_error16()
5215** routines make a private copy of the error message text before
5216** they return. Hence, the calling function can deallocate or
5217** modify the text after they return without harm.
5218** ^The sqlite3_result_error_code() function changes the error code
5219** returned by SQLite as a result of an error in a function. ^By default,
5220** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5221** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5222**
5223** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5224** error indicating that a string or BLOB is too long to represent.
5225**
5226** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5227** error indicating that a memory allocation failed.
5228**
5229** ^The sqlite3_result_int() interface sets the return value
5230** of the application-defined function to be the 32-bit signed integer
5231** value given in the 2nd argument.
5232** ^The sqlite3_result_int64() interface sets the return value
5233** of the application-defined function to be the 64-bit signed integer
5234** value given in the 2nd argument.
5235**
5236** ^The sqlite3_result_null() interface sets the return value
5237** of the application-defined function to be NULL.
5238**
5239** ^The sqlite3_result_text(), sqlite3_result_text16(),
5240** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5241** set the return value of the application-defined function to be
5242** a text string which is represented as UTF-8, UTF-16 native byte order,
5243** UTF-16 little endian, or UTF-16 big endian, respectively.
5244** ^The sqlite3_result_text64() interface sets the return value of an
5245** application-defined function to be a text string in an encoding
5246** specified by the fifth (and last) parameter, which must be one
5247** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5248** ^SQLite takes the text result from the application from
5249** the 2nd parameter of the sqlite3_result_text* interfaces.
5250** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5251** is negative, then SQLite takes result text from the 2nd parameter
5252** through the first zero character.
5253** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5254** is non-negative, then as many bytes (not characters) of the text
5255** pointed to by the 2nd parameter are taken as the application-defined
5256** function result. If the 3rd parameter is non-negative, then it
5257** must be the byte offset into the string where the NUL terminator would
5258** appear if the string where NUL terminated. If any NUL characters occur
5259** in the string at a byte offset that is less than the value of the 3rd
5260** parameter, then the resulting string will contain embedded NULs and the
5261** result of expressions operating on strings with embedded NULs is undefined.
5262** ^If the 4th parameter to the sqlite3_result_text* interfaces
5263** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5264** function as the destructor on the text or BLOB result when it has
5265** finished using that result.
5266** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5267** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5268** assumes that the text or BLOB result is in constant space and does not
5269** copy the content of the parameter nor call a destructor on the content
5270** when it has finished using that result.
5271** ^If the 4th parameter to the sqlite3_result_text* interfaces
5272** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5273** then SQLite makes a copy of the result into space obtained
5274** from [sqlite3_malloc()] before it returns.
5275**
5276** ^The sqlite3_result_value() interface sets the result of
5277** the application-defined function to be a copy of the
5278** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5279** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5280** so that the [sqlite3_value] specified in the parameter may change or
5281** be deallocated after sqlite3_result_value() returns without harm.
5282** ^A [protected sqlite3_value] object may always be used where an
5283** [unprotected sqlite3_value] object is required, so either
5284** kind of [sqlite3_value] object can be used with this interface.
5285**
5286** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5287** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5288** also associates the host-language pointer P or type T with that
5289** NULL value such that the pointer can be retrieved within an
5290** [application-defined SQL function] using [sqlite3_value_pointer()].
5291** ^If the D parameter is not NULL, then it is a pointer to a destructor
5292** for the P parameter. ^SQLite invokes D with P as its only argument
5293** when SQLite is finished with P. The T parameter should be a static
5294** string and preferably a string literal. The sqlite3_result_pointer()
5295** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5296**
5297** If these routines are called from within the different thread
5298** than the one containing the application-defined function that received
5299** the [sqlite3_context] pointer, the results are undefined.
5300*/
5301SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5302SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5303 sqlite3_uint64,void(*)(void*));
5304SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5305SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5306SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5307SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5308SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5309SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5310SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5311SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5312SQLITE_API void sqlite3_result_null(sqlite3_context*);
5313SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5314SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5315 void(*)(void*), unsigned char encoding);
5316SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5317SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5318SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5319SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5320SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5321SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5322SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5323
5324
5325/*
5326** CAPI3REF: Setting The Subtype Of An SQL Function
5327** METHOD: sqlite3_context
5328**
5329** The sqlite3_result_subtype(C,T) function causes the subtype of
5330** the result from the [application-defined SQL function] with
5331** [sqlite3_context] C to be the value T. Only the lower 8 bits
5332** of the subtype T are preserved in current versions of SQLite;
5333** higher order bits are discarded.
5334** The number of subtype bytes preserved by SQLite might increase
5335** in future releases of SQLite.
5336*/
5337SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5338
5339/*
5340** CAPI3REF: Define New Collating Sequences
5341** METHOD: sqlite3
5342**
5343** ^These functions add, remove, or modify a [collation] associated
5344** with the [database connection] specified as the first argument.
5345**
5346** ^The name of the collation is a UTF-8 string
5347** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5348** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5349** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5350** considered to be the same name.
5351**
5352** ^(The third argument (eTextRep) must be one of the constants:
5353** <ul>
5354** <li> [SQLITE_UTF8],
5355** <li> [SQLITE_UTF16LE],
5356** <li> [SQLITE_UTF16BE],
5357** <li> [SQLITE_UTF16], or
5358** <li> [SQLITE_UTF16_ALIGNED].
5359** </ul>)^
5360** ^The eTextRep argument determines the encoding of strings passed
5361** to the collating function callback, xCallback.
5362** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5363** force strings to be UTF16 with native byte order.
5364** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5365** on an even byte address.
5366**
5367** ^The fourth argument, pArg, is an application data pointer that is passed
5368** through as the first argument to the collating function callback.
5369**
5370** ^The fifth argument, xCallback, is a pointer to the collating function.
5371** ^Multiple collating functions can be registered using the same name but
5372** with different eTextRep parameters and SQLite will use whichever
5373** function requires the least amount of data transformation.
5374** ^If the xCallback argument is NULL then the collating function is
5375** deleted. ^When all collating functions having the same name are deleted,
5376** that collation is no longer usable.
5377**
5378** ^The collating function callback is invoked with a copy of the pArg
5379** application data pointer and with two strings in the encoding specified
5380** by the eTextRep argument. The collating function must return an
5381** integer that is negative, zero, or positive
5382** if the first string is less than, equal to, or greater than the second,
5383** respectively. A collating function must always return the same answer
5384** given the same inputs. If two or more collating functions are registered
5385** to the same collation name (using different eTextRep values) then all
5386** must give an equivalent answer when invoked with equivalent strings.
5387** The collating function must obey the following properties for all
5388** strings A, B, and C:
5389**
5390** <ol>
5391** <li> If A==B then B==A.
5392** <li> If A==B and B==C then A==C.
5393** <li> If A&lt;B THEN B&gt;A.
5394** <li> If A&lt;B and B&lt;C then A&lt;C.
5395** </ol>
5396**
5397** If a collating function fails any of the above constraints and that
5398** collating function is registered and used, then the behavior of SQLite
5399** is undefined.
5400**
5401** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5402** with the addition that the xDestroy callback is invoked on pArg when
5403** the collating function is deleted.
5404** ^Collating functions are deleted when they are overridden by later
5405** calls to the collation creation functions or when the
5406** [database connection] is closed using [sqlite3_close()].
5407**
5408** ^The xDestroy callback is <u>not</u> called if the
5409** sqlite3_create_collation_v2() function fails. Applications that invoke
5410** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5411** check the return code and dispose of the application data pointer
5412** themselves rather than expecting SQLite to deal with it for them.
5413** This is different from every other SQLite interface. The inconsistency
5414** is unfortunate but cannot be changed without breaking backwards
5415** compatibility.
5416**
5417** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5418*/
5419SQLITE_API int sqlite3_create_collation(
5420 sqlite3*,
5421 const char *zName,
5422 int eTextRep,
5423 void *pArg,
5424 int(*xCompare)(void*,int,const void*,int,const void*)
5425);
5426SQLITE_API int sqlite3_create_collation_v2(
5427 sqlite3*,
5428 const char *zName,
5429 int eTextRep,
5430 void *pArg,
5431 int(*xCompare)(void*,int,const void*,int,const void*),
5432 void(*xDestroy)(void*)
5433);
5434SQLITE_API int sqlite3_create_collation16(
5435 sqlite3*,
5436 const void *zName,
5437 int eTextRep,
5438 void *pArg,
5439 int(*xCompare)(void*,int,const void*,int,const void*)
5440);
5441
5442/*
5443** CAPI3REF: Collation Needed Callbacks
5444** METHOD: sqlite3
5445**
5446** ^To avoid having to register all collation sequences before a database
5447** can be used, a single callback function may be registered with the
5448** [database connection] to be invoked whenever an undefined collation
5449** sequence is required.
5450**
5451** ^If the function is registered using the sqlite3_collation_needed() API,
5452** then it is passed the names of undefined collation sequences as strings
5453** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5454** the names are passed as UTF-16 in machine native byte order.
5455** ^A call to either function replaces the existing collation-needed callback.
5456**
5457** ^(When the callback is invoked, the first argument passed is a copy
5458** of the second argument to sqlite3_collation_needed() or
5459** sqlite3_collation_needed16(). The second argument is the database
5460** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5461** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5462** sequence function required. The fourth parameter is the name of the
5463** required collation sequence.)^
5464**
5465** The callback function should register the desired collation using
5466** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5467** [sqlite3_create_collation_v2()].
5468*/
5469SQLITE_API int sqlite3_collation_needed(
5470 sqlite3*,
5471 void*,
5472 void(*)(void*,sqlite3*,int eTextRep,const char*)
5473);
5474SQLITE_API int sqlite3_collation_needed16(
5475 sqlite3*,
5476 void*,
5477 void(*)(void*,sqlite3*,int eTextRep,const void*)
5478);
5479
5480#ifdef SQLITE_HAS_CODEC
5481/*
5482** Specify the key for an encrypted database. This routine should be
5483** called right after sqlite3_open().
5484**
5485** The code to implement this API is not available in the public release
5486** of SQLite.
5487*/
5488SQLITE_API int sqlite3_key(
5489 sqlite3 *db, /* Database to be rekeyed */
5490 const void *pKey, int nKey /* The key */
5491);
5492SQLITE_API int sqlite3_key_v2(
5493 sqlite3 *db, /* Database to be rekeyed */
5494 const char *zDbName, /* Name of the database */
5495 const void *pKey, int nKey /* The key */
5496);
5497
5498/*
5499** Change the key on an open database. If the current database is not
5500** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5501** database is decrypted.
5502**
5503** The code to implement this API is not available in the public release
5504** of SQLite.
5505*/
5506SQLITE_API int sqlite3_rekey(
5507 sqlite3 *db, /* Database to be rekeyed */
5508 const void *pKey, int nKey /* The new key */
5509);
5510SQLITE_API int sqlite3_rekey_v2(
5511 sqlite3 *db, /* Database to be rekeyed */
5512 const char *zDbName, /* Name of the database */
5513 const void *pKey, int nKey /* The new key */
5514);
5515
5516/*
5517** Specify the activation key for a SEE database. Unless
5518** activated, none of the SEE routines will work.
5519*/
5520SQLITE_API void sqlite3_activate_see(
5521 const char *zPassPhrase /* Activation phrase */
5522);
5523#endif
5524
5525#ifdef SQLITE_ENABLE_CEROD
5526/*
5527** Specify the activation key for a CEROD database. Unless
5528** activated, none of the CEROD routines will work.
5529*/
5530SQLITE_API void sqlite3_activate_cerod(
5531 const char *zPassPhrase /* Activation phrase */
5532);
5533#endif
5534
5535/*
5536** CAPI3REF: Suspend Execution For A Short Time
5537**
5538** The sqlite3_sleep() function causes the current thread to suspend execution
5539** for at least a number of milliseconds specified in its parameter.
5540**
5541** If the operating system does not support sleep requests with
5542** millisecond time resolution, then the time will be rounded up to
5543** the nearest second. The number of milliseconds of sleep actually
5544** requested from the operating system is returned.
5545**
5546** ^SQLite implements this interface by calling the xSleep()
5547** method of the default [sqlite3_vfs] object. If the xSleep() method
5548** of the default VFS is not implemented correctly, or not implemented at
5549** all, then the behavior of sqlite3_sleep() may deviate from the description
5550** in the previous paragraphs.
5551*/
5552SQLITE_API int sqlite3_sleep(int);
5553
5554/*
5555** CAPI3REF: Name Of The Folder Holding Temporary Files
5556**
5557** ^(If this global variable is made to point to a string which is
5558** the name of a folder (a.k.a. directory), then all temporary files
5559** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5560** will be placed in that directory.)^ ^If this variable
5561** is a NULL pointer, then SQLite performs a search for an appropriate
5562** temporary file directory.
5563**
5564** Applications are strongly discouraged from using this global variable.
5565** It is required to set a temporary folder on Windows Runtime (WinRT).
5566** But for all other platforms, it is highly recommended that applications
5567** neither read nor write this variable. This global variable is a relic
5568** that exists for backwards compatibility of legacy applications and should
5569** be avoided in new projects.
5570**
5571** It is not safe to read or modify this variable in more than one
5572** thread at a time. It is not safe to read or modify this variable
5573** if a [database connection] is being used at the same time in a separate
5574** thread.
5575** It is intended that this variable be set once
5576** as part of process initialization and before any SQLite interface
5577** routines have been called and that this variable remain unchanged
5578** thereafter.
5579**
5580** ^The [temp_store_directory pragma] may modify this variable and cause
5581** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5582** the [temp_store_directory pragma] always assumes that any string
5583** that this variable points to is held in memory obtained from
5584** [sqlite3_malloc] and the pragma may attempt to free that memory
5585** using [sqlite3_free].
5586** Hence, if this variable is modified directly, either it should be
5587** made NULL or made to point to memory obtained from [sqlite3_malloc]
5588** or else the use of the [temp_store_directory pragma] should be avoided.
5589** Except when requested by the [temp_store_directory pragma], SQLite
5590** does not free the memory that sqlite3_temp_directory points to. If
5591** the application wants that memory to be freed, it must do
5592** so itself, taking care to only do so after all [database connection]
5593** objects have been destroyed.
5594**
5595** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5596** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5597** features that require the use of temporary files may fail. Here is an
5598** example of how to do this using C++ with the Windows Runtime:
5599**
5600** <blockquote><pre>
5601** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5602** &nbsp; TemporaryFolder->Path->Data();
5603** char zPathBuf&#91;MAX_PATH + 1&#93;;
5604** memset(zPathBuf, 0, sizeof(zPathBuf));
5605** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5606** &nbsp; NULL, NULL);
5607** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5608** </pre></blockquote>
5609*/
5610SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5611
5612/*
5613** CAPI3REF: Name Of The Folder Holding Database Files
5614**
5615** ^(If this global variable is made to point to a string which is
5616** the name of a folder (a.k.a. directory), then all database files
5617** specified with a relative pathname and created or accessed by
5618** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5619** to be relative to that directory.)^ ^If this variable is a NULL
5620** pointer, then SQLite assumes that all database files specified
5621** with a relative pathname are relative to the current directory
5622** for the process. Only the windows VFS makes use of this global
5623** variable; it is ignored by the unix VFS.
5624**
5625** Changing the value of this variable while a database connection is
5626** open can result in a corrupt database.
5627**
5628** It is not safe to read or modify this variable in more than one
5629** thread at a time. It is not safe to read or modify this variable
5630** if a [database connection] is being used at the same time in a separate
5631** thread.
5632** It is intended that this variable be set once
5633** as part of process initialization and before any SQLite interface
5634** routines have been called and that this variable remain unchanged
5635** thereafter.
5636**
5637** ^The [data_store_directory pragma] may modify this variable and cause
5638** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5639** the [data_store_directory pragma] always assumes that any string
5640** that this variable points to is held in memory obtained from
5641** [sqlite3_malloc] and the pragma may attempt to free that memory
5642** using [sqlite3_free].
5643** Hence, if this variable is modified directly, either it should be
5644** made NULL or made to point to memory obtained from [sqlite3_malloc]
5645** or else the use of the [data_store_directory pragma] should be avoided.
5646*/
5647SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5648
5649/*
5650** CAPI3REF: Win32 Specific Interface
5651**
5652** These interfaces are available only on Windows. The
5653** [sqlite3_win32_set_directory] interface is used to set the value associated
5654** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
5655** zValue, depending on the value of the type parameter. The zValue parameter
5656** should be NULL to cause the previous value to be freed via [sqlite3_free];
5657** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
5658** prior to being used. The [sqlite3_win32_set_directory] interface returns
5659** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
5660** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
5661** [sqlite3_data_directory] variable is intended to act as a replacement for
5662** the current directory on the sub-platforms of Win32 where that concept is
5663** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
5664** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
5665** sqlite3_win32_set_directory interface except the string parameter must be
5666** UTF-8 or UTF-16, respectively.
5667*/
5668SQLITE_API int sqlite3_win32_set_directory(
5669 unsigned long type, /* Identifier for directory being set or reset */
5670 void *zValue /* New value for directory being set or reset */
5671);
5672SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
5673SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
5674
5675/*
5676** CAPI3REF: Win32 Directory Types
5677**
5678** These macros are only available on Windows. They define the allowed values
5679** for the type argument to the [sqlite3_win32_set_directory] interface.
5680*/
5681#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
5682#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
5683
5684/*
5685** CAPI3REF: Test For Auto-Commit Mode
5686** KEYWORDS: {autocommit mode}
5687** METHOD: sqlite3
5688**
5689** ^The sqlite3_get_autocommit() interface returns non-zero or
5690** zero if the given database connection is or is not in autocommit mode,
5691** respectively. ^Autocommit mode is on by default.
5692** ^Autocommit mode is disabled by a [BEGIN] statement.
5693** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5694**
5695** If certain kinds of errors occur on a statement within a multi-statement
5696** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5697** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5698** transaction might be rolled back automatically. The only way to
5699** find out whether SQLite automatically rolled back the transaction after
5700** an error is to use this function.
5701**
5702** If another thread changes the autocommit status of the database
5703** connection while this routine is running, then the return value
5704** is undefined.
5705*/
5706SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5707
5708/*
5709** CAPI3REF: Find The Database Handle Of A Prepared Statement
5710** METHOD: sqlite3_stmt
5711**
5712** ^The sqlite3_db_handle interface returns the [database connection] handle
5713** to which a [prepared statement] belongs. ^The [database connection]
5714** returned by sqlite3_db_handle is the same [database connection]
5715** that was the first argument
5716** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5717** create the statement in the first place.
5718*/
5719SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5720
5721/*
5722** CAPI3REF: Return The Filename For A Database Connection
5723** METHOD: sqlite3
5724**
5725** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5726** associated with database N of connection D. ^The main database file
5727** has the name "main". If there is no attached database N on the database
5728** connection D, or if database N is a temporary or in-memory database, then
5729** a NULL pointer is returned.
5730**
5731** ^The filename returned by this function is the output of the
5732** xFullPathname method of the [VFS]. ^In other words, the filename
5733** will be an absolute pathname, even if the filename used
5734** to open the database originally was a URI or relative pathname.
5735*/
5736SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5737
5738/*
5739** CAPI3REF: Determine if a database is read-only
5740** METHOD: sqlite3
5741**
5742** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5743** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5744** the name of a database on connection D.
5745*/
5746SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5747
5748/*
5749** CAPI3REF: Find the next prepared statement
5750** METHOD: sqlite3
5751**
5752** ^This interface returns a pointer to the next [prepared statement] after
5753** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5754** then this interface returns a pointer to the first prepared statement
5755** associated with the database connection pDb. ^If no prepared statement
5756** satisfies the conditions of this routine, it returns NULL.
5757**
5758** The [database connection] pointer D in a call to
5759** [sqlite3_next_stmt(D,S)] must refer to an open database
5760** connection and in particular must not be a NULL pointer.
5761*/
5762SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5763
5764/*
5765** CAPI3REF: Commit And Rollback Notification Callbacks
5766** METHOD: sqlite3
5767**
5768** ^The sqlite3_commit_hook() interface registers a callback
5769** function to be invoked whenever a transaction is [COMMIT | committed].
5770** ^Any callback set by a previous call to sqlite3_commit_hook()
5771** for the same database connection is overridden.
5772** ^The sqlite3_rollback_hook() interface registers a callback
5773** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5774** ^Any callback set by a previous call to sqlite3_rollback_hook()
5775** for the same database connection is overridden.
5776** ^The pArg argument is passed through to the callback.
5777** ^If the callback on a commit hook function returns non-zero,
5778** then the commit is converted into a rollback.
5779**
5780** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5781** return the P argument from the previous call of the same function
5782** on the same [database connection] D, or NULL for
5783** the first call for each function on D.
5784**
5785** The commit and rollback hook callbacks are not reentrant.
5786** The callback implementation must not do anything that will modify
5787** the database connection that invoked the callback. Any actions
5788** to modify the database connection must be deferred until after the
5789** completion of the [sqlite3_step()] call that triggered the commit
5790** or rollback hook in the first place.
5791** Note that running any other SQL statements, including SELECT statements,
5792** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5793** the database connections for the meaning of "modify" in this paragraph.
5794**
5795** ^Registering a NULL function disables the callback.
5796**
5797** ^When the commit hook callback routine returns zero, the [COMMIT]
5798** operation is allowed to continue normally. ^If the commit hook
5799** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5800** ^The rollback hook is invoked on a rollback that results from a commit
5801** hook returning non-zero, just as it would be with any other rollback.
5802**
5803** ^For the purposes of this API, a transaction is said to have been
5804** rolled back if an explicit "ROLLBACK" statement is executed, or
5805** an error or constraint causes an implicit rollback to occur.
5806** ^The rollback callback is not invoked if a transaction is
5807** automatically rolled back because the database connection is closed.
5808**
5809** See also the [sqlite3_update_hook()] interface.
5810*/
5811SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5812SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5813
5814/*
5815** CAPI3REF: Data Change Notification Callbacks
5816** METHOD: sqlite3
5817**
5818** ^The sqlite3_update_hook() interface registers a callback function
5819** with the [database connection] identified by the first argument
5820** to be invoked whenever a row is updated, inserted or deleted in
5821** a [rowid table].
5822** ^Any callback set by a previous call to this function
5823** for the same database connection is overridden.
5824**
5825** ^The second argument is a pointer to the function to invoke when a
5826** row is updated, inserted or deleted in a rowid table.
5827** ^The first argument to the callback is a copy of the third argument
5828** to sqlite3_update_hook().
5829** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5830** or [SQLITE_UPDATE], depending on the operation that caused the callback
5831** to be invoked.
5832** ^The third and fourth arguments to the callback contain pointers to the
5833** database and table name containing the affected row.
5834** ^The final callback parameter is the [rowid] of the row.
5835** ^In the case of an update, this is the [rowid] after the update takes place.
5836**
5837** ^(The update hook is not invoked when internal system tables are
5838** modified (i.e. sqlite_master and sqlite_sequence).)^
5839** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5840**
5841** ^In the current implementation, the update hook
5842** is not invoked when conflicting rows are deleted because of an
5843** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5844** invoked when rows are deleted using the [truncate optimization].
5845** The exceptions defined in this paragraph might change in a future
5846** release of SQLite.
5847**
5848** The update hook implementation must not do anything that will modify
5849** the database connection that invoked the update hook. Any actions
5850** to modify the database connection must be deferred until after the
5851** completion of the [sqlite3_step()] call that triggered the update hook.
5852** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5853** database connections for the meaning of "modify" in this paragraph.
5854**
5855** ^The sqlite3_update_hook(D,C,P) function
5856** returns the P argument from the previous call
5857** on the same [database connection] D, or NULL for
5858** the first call on D.
5859**
5860** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5861** and [sqlite3_preupdate_hook()] interfaces.
5862*/
5863SQLITE_API void *sqlite3_update_hook(
5864 sqlite3*,
5865 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5866 void*
5867);
5868
5869/*
5870** CAPI3REF: Enable Or Disable Shared Pager Cache
5871**
5872** ^(This routine enables or disables the sharing of the database cache
5873** and schema data structures between [database connection | connections]
5874** to the same database. Sharing is enabled if the argument is true
5875** and disabled if the argument is false.)^
5876**
5877** ^Cache sharing is enabled and disabled for an entire process.
5878** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5879** In prior versions of SQLite,
5880** sharing was enabled or disabled for each thread separately.
5881**
5882** ^(The cache sharing mode set by this interface effects all subsequent
5883** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5884** Existing database connections continue use the sharing mode
5885** that was in effect at the time they were opened.)^
5886**
5887** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5888** successfully. An [error code] is returned otherwise.)^
5889**
5890** ^Shared cache is disabled by default. But this might change in
5891** future releases of SQLite. Applications that care about shared
5892** cache setting should set it explicitly.
5893**
5894** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5895** and will always return SQLITE_MISUSE. On those systems,
5896** shared cache mode should be enabled per-database connection via
5897** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5898**
5899** This interface is threadsafe on processors where writing a
5900** 32-bit integer is atomic.
5901**
5902** See Also: [SQLite Shared-Cache Mode]
5903*/
5904SQLITE_API int sqlite3_enable_shared_cache(int);
5905
5906/*
5907** CAPI3REF: Attempt To Free Heap Memory
5908**
5909** ^The sqlite3_release_memory() interface attempts to free N bytes
5910** of heap memory by deallocating non-essential memory allocations
5911** held by the database library. Memory used to cache database
5912** pages to improve performance is an example of non-essential memory.
5913** ^sqlite3_release_memory() returns the number of bytes actually freed,
5914** which might be more or less than the amount requested.
5915** ^The sqlite3_release_memory() routine is a no-op returning zero
5916** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5917**
5918** See also: [sqlite3_db_release_memory()]
5919*/
5920SQLITE_API int sqlite3_release_memory(int);
5921
5922/*
5923** CAPI3REF: Free Memory Used By A Database Connection
5924** METHOD: sqlite3
5925**
5926** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5927** memory as possible from database connection D. Unlike the
5928** [sqlite3_release_memory()] interface, this interface is in effect even
5929** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5930** omitted.
5931**
5932** See also: [sqlite3_release_memory()]
5933*/
5934SQLITE_API int sqlite3_db_release_memory(sqlite3*);
5935
5936/*
5937** CAPI3REF: Impose A Limit On Heap Size
5938**
5939** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5940** soft limit on the amount of heap memory that may be allocated by SQLite.
5941** ^SQLite strives to keep heap memory utilization below the soft heap
5942** limit by reducing the number of pages held in the page cache
5943** as heap memory usages approaches the limit.
5944** ^The soft heap limit is "soft" because even though SQLite strives to stay
5945** below the limit, it will exceed the limit rather than generate
5946** an [SQLITE_NOMEM] error. In other words, the soft heap limit
5947** is advisory only.
5948**
5949** ^The return value from sqlite3_soft_heap_limit64() is the size of
5950** the soft heap limit prior to the call, or negative in the case of an
5951** error. ^If the argument N is negative
5952** then no change is made to the soft heap limit. Hence, the current
5953** size of the soft heap limit can be determined by invoking
5954** sqlite3_soft_heap_limit64() with a negative argument.
5955**
5956** ^If the argument N is zero then the soft heap limit is disabled.
5957**
5958** ^(The soft heap limit is not enforced in the current implementation
5959** if one or more of following conditions are true:
5960**
5961** <ul>
5962** <li> The soft heap limit is set to zero.
5963** <li> Memory accounting is disabled using a combination of the
5964** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5965** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5966** <li> An alternative page cache implementation is specified using
5967** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5968** <li> The page cache allocates from its own memory pool supplied
5969** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5970** from the heap.
5971** </ul>)^
5972**
5973** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
5974** the soft heap limit is enforced
5975** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5976** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5977** the soft heap limit is enforced on every memory allocation. Without
5978** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5979** when memory is allocated by the page cache. Testing suggests that because
5980** the page cache is the predominate memory user in SQLite, most
5981** applications will achieve adequate soft heap limit enforcement without
5982** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5983**
5984** The circumstances under which SQLite will enforce the soft heap limit may
5985** changes in future releases of SQLite.
5986*/
5987SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
5988
5989/*
5990** CAPI3REF: Deprecated Soft Heap Limit Interface
5991** DEPRECATED
5992**
5993** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5994** interface. This routine is provided for historical compatibility
5995** only. All new applications should use the
5996** [sqlite3_soft_heap_limit64()] interface rather than this one.
5997*/
5998SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
5999
6000
6001/*
6002** CAPI3REF: Extract Metadata About A Column Of A Table
6003** METHOD: sqlite3
6004**
6005** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6006** information about column C of table T in database D
6007** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6008** interface returns SQLITE_OK and fills in the non-NULL pointers in
6009** the final five arguments with appropriate values if the specified
6010** column exists. ^The sqlite3_table_column_metadata() interface returns
6011** SQLITE_ERROR and if the specified column does not exist.
6012** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6013** NULL pointer, then this routine simply checks for the existence of the
6014** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6015** does not. If the table name parameter T in a call to
6016** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6017** undefined behavior.
6018**
6019** ^The column is identified by the second, third and fourth parameters to
6020** this function. ^(The second parameter is either the name of the database
6021** (i.e. "main", "temp", or an attached database) containing the specified
6022** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6023** for the table using the same algorithm used by the database engine to
6024** resolve unqualified table references.
6025**
6026** ^The third and fourth parameters to this function are the table and column
6027** name of the desired column, respectively.
6028**
6029** ^Metadata is returned by writing to the memory locations passed as the 5th
6030** and subsequent parameters to this function. ^Any of these arguments may be
6031** NULL, in which case the corresponding element of metadata is omitted.
6032**
6033** ^(<blockquote>
6034** <table border="1">
6035** <tr><th> Parameter <th> Output<br>Type <th> Description
6036**
6037** <tr><td> 5th <td> const char* <td> Data type
6038** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6039** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6040** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6041** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6042** </table>
6043** </blockquote>)^
6044**
6045** ^The memory pointed to by the character pointers returned for the
6046** declaration type and collation sequence is valid until the next
6047** call to any SQLite API function.
6048**
6049** ^If the specified table is actually a view, an [error code] is returned.
6050**
6051** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6052** is not a [WITHOUT ROWID] table and an
6053** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6054** parameters are set for the explicitly declared column. ^(If there is no
6055** [INTEGER PRIMARY KEY] column, then the outputs
6056** for the [rowid] are set as follows:
6057**
6058** <pre>
6059** data type: "INTEGER"
6060** collation sequence: "BINARY"
6061** not null: 0
6062** primary key: 1
6063** auto increment: 0
6064** </pre>)^
6065**
6066** ^This function causes all database schemas to be read from disk and
6067** parsed, if that has not already been done, and returns an error if
6068** any errors are encountered while loading the schema.
6069*/
6070SQLITE_API int sqlite3_table_column_metadata(
6071 sqlite3 *db, /* Connection handle */
6072 const char *zDbName, /* Database name or NULL */
6073 const char *zTableName, /* Table name */
6074 const char *zColumnName, /* Column name */
6075 char const **pzDataType, /* OUTPUT: Declared data type */
6076 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6077 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6078 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6079 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6080);
6081
6082/*
6083** CAPI3REF: Load An Extension
6084** METHOD: sqlite3
6085**
6086** ^This interface loads an SQLite extension library from the named file.
6087**
6088** ^The sqlite3_load_extension() interface attempts to load an
6089** [SQLite extension] library contained in the file zFile. If
6090** the file cannot be loaded directly, attempts are made to load
6091** with various operating-system specific extensions added.
6092** So for example, if "samplelib" cannot be loaded, then names like
6093** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6094** be tried also.
6095**
6096** ^The entry point is zProc.
6097** ^(zProc may be 0, in which case SQLite will try to come up with an
6098** entry point name on its own. It first tries "sqlite3_extension_init".
6099** If that does not work, it constructs a name "sqlite3_X_init" where the
6100** X is consists of the lower-case equivalent of all ASCII alphabetic
6101** characters in the filename from the last "/" to the first following
6102** "." and omitting any initial "lib".)^
6103** ^The sqlite3_load_extension() interface returns
6104** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6105** ^If an error occurs and pzErrMsg is not 0, then the
6106** [sqlite3_load_extension()] interface shall attempt to
6107** fill *pzErrMsg with error message text stored in memory
6108** obtained from [sqlite3_malloc()]. The calling function
6109** should free this memory by calling [sqlite3_free()].
6110**
6111** ^Extension loading must be enabled using
6112** [sqlite3_enable_load_extension()] or
6113** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6114** prior to calling this API,
6115** otherwise an error will be returned.
6116**
6117** <b>Security warning:</b> It is recommended that the
6118** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6119** interface. The use of the [sqlite3_enable_load_extension()] interface
6120** should be avoided. This will keep the SQL function [load_extension()]
6121** disabled and prevent SQL injections from giving attackers
6122** access to extension loading capabilities.
6123**
6124** See also the [load_extension() SQL function].
6125*/
6126SQLITE_API int sqlite3_load_extension(
6127 sqlite3 *db, /* Load the extension into this database connection */
6128 const char *zFile, /* Name of the shared library containing extension */
6129 const char *zProc, /* Entry point. Derived from zFile if 0 */
6130 char **pzErrMsg /* Put error message here if not 0 */
6131);
6132
6133/*
6134** CAPI3REF: Enable Or Disable Extension Loading
6135** METHOD: sqlite3
6136**
6137** ^So as not to open security holes in older applications that are
6138** unprepared to deal with [extension loading], and as a means of disabling
6139** [extension loading] while evaluating user-entered SQL, the following API
6140** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6141**
6142** ^Extension loading is off by default.
6143** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6144** to turn extension loading on and call it with onoff==0 to turn
6145** it back off again.
6146**
6147** ^This interface enables or disables both the C-API
6148** [sqlite3_load_extension()] and the SQL function [load_extension()].
6149** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6150** to enable or disable only the C-API.)^
6151**
6152** <b>Security warning:</b> It is recommended that extension loading
6153** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6154** rather than this interface, so the [load_extension()] SQL function
6155** remains disabled. This will prevent SQL injections from giving attackers
6156** access to extension loading capabilities.
6157*/
6158SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6159
6160/*
6161** CAPI3REF: Automatically Load Statically Linked Extensions
6162**
6163** ^This interface causes the xEntryPoint() function to be invoked for
6164** each new [database connection] that is created. The idea here is that
6165** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6166** that is to be automatically loaded into all new database connections.
6167**
6168** ^(Even though the function prototype shows that xEntryPoint() takes
6169** no arguments and returns void, SQLite invokes xEntryPoint() with three
6170** arguments and expects an integer result as if the signature of the
6171** entry point where as follows:
6172**
6173** <blockquote><pre>
6174** &nbsp; int xEntryPoint(
6175** &nbsp; sqlite3 *db,
6176** &nbsp; const char **pzErrMsg,
6177** &nbsp; const struct sqlite3_api_routines *pThunk
6178** &nbsp; );
6179** </pre></blockquote>)^
6180**
6181** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6182** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6183** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6184** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6185** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6186** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6187** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6188**
6189** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6190** on the list of automatic extensions is a harmless no-op. ^No entry point
6191** will be called more than once for each database connection that is opened.
6192**
6193** See also: [sqlite3_reset_auto_extension()]
6194** and [sqlite3_cancel_auto_extension()]
6195*/
6196SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6197
6198/*
6199** CAPI3REF: Cancel Automatic Extension Loading
6200**
6201** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6202** initialization routine X that was registered using a prior call to
6203** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6204** routine returns 1 if initialization routine X was successfully
6205** unregistered and it returns 0 if X was not on the list of initialization
6206** routines.
6207*/
6208SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6209
6210/*
6211** CAPI3REF: Reset Automatic Extension Loading
6212**
6213** ^This interface disables all automatic extensions previously
6214** registered using [sqlite3_auto_extension()].
6215*/
6216SQLITE_API void sqlite3_reset_auto_extension(void);
6217
6218/*
6219** The interface to the virtual-table mechanism is currently considered
6220** to be experimental. The interface might change in incompatible ways.
6221** If this is a problem for you, do not use the interface at this time.
6222**
6223** When the virtual-table mechanism stabilizes, we will declare the
6224** interface fixed, support it indefinitely, and remove this comment.
6225*/
6226
6227/*
6228** Structures used by the virtual table interface
6229*/
6230typedef struct sqlite3_vtab sqlite3_vtab;
6231typedef struct sqlite3_index_info sqlite3_index_info;
6232typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6233typedef struct sqlite3_module sqlite3_module;
6234
6235/*
6236** CAPI3REF: Virtual Table Object
6237** KEYWORDS: sqlite3_module {virtual table module}
6238**
6239** This structure, sometimes called a "virtual table module",
6240** defines the implementation of a [virtual tables].
6241** This structure consists mostly of methods for the module.
6242**
6243** ^A virtual table module is created by filling in a persistent
6244** instance of this structure and passing a pointer to that instance
6245** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6246** ^The registration remains valid until it is replaced by a different
6247** module or until the [database connection] closes. The content
6248** of this structure must not change while it is registered with
6249** any database connection.
6250*/
6251struct sqlite3_module {
6252 int iVersion;
6253 int (*xCreate)(sqlite3*, void *pAux,
6254 int argc, const char *const*argv,
6255 sqlite3_vtab **ppVTab, char**);
6256 int (*xConnect)(sqlite3*, void *pAux,
6257 int argc, const char *const*argv,
6258 sqlite3_vtab **ppVTab, char**);
6259 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6260 int (*xDisconnect)(sqlite3_vtab *pVTab);
6261 int (*xDestroy)(sqlite3_vtab *pVTab);
6262 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6263 int (*xClose)(sqlite3_vtab_cursor*);
6264 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6265 int argc, sqlite3_value **argv);
6266 int (*xNext)(sqlite3_vtab_cursor*);
6267 int (*xEof)(sqlite3_vtab_cursor*);
6268 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6269 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6270 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6271 int (*xBegin)(sqlite3_vtab *pVTab);
6272 int (*xSync)(sqlite3_vtab *pVTab);
6273 int (*xCommit)(sqlite3_vtab *pVTab);
6274 int (*xRollback)(sqlite3_vtab *pVTab);
6275 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6276 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6277 void **ppArg);
6278 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6279 /* The methods above are in version 1 of the sqlite_module object. Those
6280 ** below are for version 2 and greater. */
6281 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6282 int (*xRelease)(sqlite3_vtab *pVTab, int);
6283 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6284};
6285
6286/*
6287** CAPI3REF: Virtual Table Indexing Information
6288** KEYWORDS: sqlite3_index_info
6289**
6290** The sqlite3_index_info structure and its substructures is used as part
6291** of the [virtual table] interface to
6292** pass information into and receive the reply from the [xBestIndex]
6293** method of a [virtual table module]. The fields under **Inputs** are the
6294** inputs to xBestIndex and are read-only. xBestIndex inserts its
6295** results into the **Outputs** fields.
6296**
6297** ^(The aConstraint[] array records WHERE clause constraints of the form:
6298**
6299** <blockquote>column OP expr</blockquote>
6300**
6301** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6302** stored in aConstraint[].op using one of the
6303** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6304** ^(The index of the column is stored in
6305** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6306** expr on the right-hand side can be evaluated (and thus the constraint
6307** is usable) and false if it cannot.)^
6308**
6309** ^The optimizer automatically inverts terms of the form "expr OP column"
6310** and makes other simplifications to the WHERE clause in an attempt to
6311** get as many WHERE clause terms into the form shown above as possible.
6312** ^The aConstraint[] array only reports WHERE clause terms that are
6313** relevant to the particular virtual table being queried.
6314**
6315** ^Information about the ORDER BY clause is stored in aOrderBy[].
6316** ^Each term of aOrderBy records a column of the ORDER BY clause.
6317**
6318** The colUsed field indicates which columns of the virtual table may be
6319** required by the current scan. Virtual table columns are numbered from
6320** zero in the order in which they appear within the CREATE TABLE statement
6321** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6322** the corresponding bit is set within the colUsed mask if the column may be
6323** required by SQLite. If the table has at least 64 columns and any column
6324** to the right of the first 63 is required, then bit 63 of colUsed is also
6325** set. In other words, column iCol may be required if the expression
6326** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6327** non-zero.
6328**
6329** The [xBestIndex] method must fill aConstraintUsage[] with information
6330** about what parameters to pass to xFilter. ^If argvIndex>0 then
6331** the right-hand side of the corresponding aConstraint[] is evaluated
6332** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6333** is true, then the constraint is assumed to be fully handled by the
6334** virtual table and is not checked again by SQLite.)^
6335**
6336** ^The idxNum and idxPtr values are recorded and passed into the
6337** [xFilter] method.
6338** ^[sqlite3_free()] is used to free idxPtr if and only if
6339** needToFreeIdxPtr is true.
6340**
6341** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6342** the correct order to satisfy the ORDER BY clause so that no separate
6343** sorting step is required.
6344**
6345** ^The estimatedCost value is an estimate of the cost of a particular
6346** strategy. A cost of N indicates that the cost of the strategy is similar
6347** to a linear scan of an SQLite table with N rows. A cost of log(N)
6348** indicates that the expense of the operation is similar to that of a
6349** binary search on a unique indexed field of an SQLite table with N rows.
6350**
6351** ^The estimatedRows value is an estimate of the number of rows that
6352** will be returned by the strategy.
6353**
6354** The xBestIndex method may optionally populate the idxFlags field with a
6355** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6356** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6357** assumes that the strategy may visit at most one row.
6358**
6359** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6360** SQLite also assumes that if a call to the xUpdate() method is made as
6361** part of the same statement to delete or update a virtual table row and the
6362** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6363** any database changes. In other words, if the xUpdate() returns
6364** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6365** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6366** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6367** the xUpdate method are automatically rolled back by SQLite.
6368**
6369** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6370** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6371** If a virtual table extension is
6372** used with an SQLite version earlier than 3.8.2, the results of attempting
6373** to read or write the estimatedRows field are undefined (but are likely
6374** to included crashing the application). The estimatedRows field should
6375** therefore only be used if [sqlite3_libversion_number()] returns a
6376** value greater than or equal to 3008002. Similarly, the idxFlags field
6377** was added for [version 3.9.0] ([dateof:3.9.0]).
6378** It may therefore only be used if
6379** sqlite3_libversion_number() returns a value greater than or equal to
6380** 3009000.
6381*/
6382struct sqlite3_index_info {
6383 /* Inputs */
6384 int nConstraint; /* Number of entries in aConstraint */
6385 struct sqlite3_index_constraint {
6386 int iColumn; /* Column constrained. -1 for ROWID */
6387 unsigned char op; /* Constraint operator */
6388 unsigned char usable; /* True if this constraint is usable */
6389 int iTermOffset; /* Used internally - xBestIndex should ignore */
6390 } *aConstraint; /* Table of WHERE clause constraints */
6391 int nOrderBy; /* Number of terms in the ORDER BY clause */
6392 struct sqlite3_index_orderby {
6393 int iColumn; /* Column number */
6394 unsigned char desc; /* True for DESC. False for ASC. */
6395 } *aOrderBy; /* The ORDER BY clause */
6396 /* Outputs */
6397 struct sqlite3_index_constraint_usage {
6398 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6399 unsigned char omit; /* Do not code a test for this constraint */
6400 } *aConstraintUsage;
6401 int idxNum; /* Number used to identify the index */
6402 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6403 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6404 int orderByConsumed; /* True if output is already ordered */
6405 double estimatedCost; /* Estimated cost of using this index */
6406 /* Fields below are only available in SQLite 3.8.2 and later */
6407 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6408 /* Fields below are only available in SQLite 3.9.0 and later */
6409 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6410 /* Fields below are only available in SQLite 3.10.0 and later */
6411 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6412};
6413
6414/*
6415** CAPI3REF: Virtual Table Scan Flags
6416**
6417** Virtual table implementations are allowed to set the
6418** [sqlite3_index_info].idxFlags field to some combination of
6419** these bits.
6420*/
6421#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6422
6423/*
6424** CAPI3REF: Virtual Table Constraint Operator Codes
6425**
6426** These macros defined the allowed values for the
6427** [sqlite3_index_info].aConstraint[].op field. Each value represents
6428** an operator that is part of a constraint term in the wHERE clause of
6429** a query that uses a [virtual table].
6430*/
6431#define SQLITE_INDEX_CONSTRAINT_EQ 2
6432#define SQLITE_INDEX_CONSTRAINT_GT 4
6433#define SQLITE_INDEX_CONSTRAINT_LE 8
6434#define SQLITE_INDEX_CONSTRAINT_LT 16
6435#define SQLITE_INDEX_CONSTRAINT_GE 32
6436#define SQLITE_INDEX_CONSTRAINT_MATCH 64
6437#define SQLITE_INDEX_CONSTRAINT_LIKE 65
6438#define SQLITE_INDEX_CONSTRAINT_GLOB 66
6439#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6440#define SQLITE_INDEX_CONSTRAINT_NE 68
6441#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6442#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6443#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6444#define SQLITE_INDEX_CONSTRAINT_IS 72
6445#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
6446
6447/*
6448** CAPI3REF: Register A Virtual Table Implementation
6449** METHOD: sqlite3
6450**
6451** ^These routines are used to register a new [virtual table module] name.
6452** ^Module names must be registered before
6453** creating a new [virtual table] using the module and before using a
6454** preexisting [virtual table] for the module.
6455**
6456** ^The module name is registered on the [database connection] specified
6457** by the first parameter. ^The name of the module is given by the
6458** second parameter. ^The third parameter is a pointer to
6459** the implementation of the [virtual table module]. ^The fourth
6460** parameter is an arbitrary client data pointer that is passed through
6461** into the [xCreate] and [xConnect] methods of the virtual table module
6462** when a new virtual table is be being created or reinitialized.
6463**
6464** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6465** is a pointer to a destructor for the pClientData. ^SQLite will
6466** invoke the destructor function (if it is not NULL) when SQLite
6467** no longer needs the pClientData pointer. ^The destructor will also
6468** be invoked if the call to sqlite3_create_module_v2() fails.
6469** ^The sqlite3_create_module()
6470** interface is equivalent to sqlite3_create_module_v2() with a NULL
6471** destructor.
6472*/
6473SQLITE_API int sqlite3_create_module(
6474 sqlite3 *db, /* SQLite connection to register module with */
6475 const char *zName, /* Name of the module */
6476 const sqlite3_module *p, /* Methods for the module */
6477 void *pClientData /* Client data for xCreate/xConnect */
6478);
6479SQLITE_API int sqlite3_create_module_v2(
6480 sqlite3 *db, /* SQLite connection to register module with */
6481 const char *zName, /* Name of the module */
6482 const sqlite3_module *p, /* Methods for the module */
6483 void *pClientData, /* Client data for xCreate/xConnect */
6484 void(*xDestroy)(void*) /* Module destructor function */
6485);
6486
6487/*
6488** CAPI3REF: Virtual Table Instance Object
6489** KEYWORDS: sqlite3_vtab
6490**
6491** Every [virtual table module] implementation uses a subclass
6492** of this object to describe a particular instance
6493** of the [virtual table]. Each subclass will
6494** be tailored to the specific needs of the module implementation.
6495** The purpose of this superclass is to define certain fields that are
6496** common to all module implementations.
6497**
6498** ^Virtual tables methods can set an error message by assigning a
6499** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6500** take care that any prior string is freed by a call to [sqlite3_free()]
6501** prior to assigning a new string to zErrMsg. ^After the error message
6502** is delivered up to the client application, the string will be automatically
6503** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6504*/
6505struct sqlite3_vtab {
6506 const sqlite3_module *pModule; /* The module for this virtual table */
6507 int nRef; /* Number of open cursors */
6508 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6509 /* Virtual table implementations will typically add additional fields */
6510};
6511
6512/*
6513** CAPI3REF: Virtual Table Cursor Object
6514** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6515**
6516** Every [virtual table module] implementation uses a subclass of the
6517** following structure to describe cursors that point into the
6518** [virtual table] and are used
6519** to loop through the virtual table. Cursors are created using the
6520** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6521** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6522** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6523** of the module. Each module implementation will define
6524** the content of a cursor structure to suit its own needs.
6525**
6526** This superclass exists in order to define fields of the cursor that
6527** are common to all implementations.
6528*/
6529struct sqlite3_vtab_cursor {
6530 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6531 /* Virtual table implementations will typically add additional fields */
6532};
6533
6534/*
6535** CAPI3REF: Declare The Schema Of A Virtual Table
6536**
6537** ^The [xCreate] and [xConnect] methods of a
6538** [virtual table module] call this interface
6539** to declare the format (the names and datatypes of the columns) of
6540** the virtual tables they implement.
6541*/
6542SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6543
6544/*
6545** CAPI3REF: Overload A Function For A Virtual Table
6546** METHOD: sqlite3
6547**
6548** ^(Virtual tables can provide alternative implementations of functions
6549** using the [xFindFunction] method of the [virtual table module].
6550** But global versions of those functions
6551** must exist in order to be overloaded.)^
6552**
6553** ^(This API makes sure a global version of a function with a particular
6554** name and number of parameters exists. If no such function exists
6555** before this API is called, a new function is created.)^ ^The implementation
6556** of the new function always causes an exception to be thrown. So
6557** the new function is not good for anything by itself. Its only
6558** purpose is to be a placeholder function that can be overloaded
6559** by a [virtual table].
6560*/
6561SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6562
6563/*
6564** The interface to the virtual-table mechanism defined above (back up
6565** to a comment remarkably similar to this one) is currently considered
6566** to be experimental. The interface might change in incompatible ways.
6567** If this is a problem for you, do not use the interface at this time.
6568**
6569** When the virtual-table mechanism stabilizes, we will declare the
6570** interface fixed, support it indefinitely, and remove this comment.
6571*/
6572
6573/*
6574** CAPI3REF: A Handle To An Open BLOB
6575** KEYWORDS: {BLOB handle} {BLOB handles}
6576**
6577** An instance of this object represents an open BLOB on which
6578** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6579** ^Objects of this type are created by [sqlite3_blob_open()]
6580** and destroyed by [sqlite3_blob_close()].
6581** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6582** can be used to read or write small subsections of the BLOB.
6583** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6584*/
6585typedef struct sqlite3_blob sqlite3_blob;
6586
6587/*
6588** CAPI3REF: Open A BLOB For Incremental I/O
6589** METHOD: sqlite3
6590** CONSTRUCTOR: sqlite3_blob
6591**
6592** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6593** in row iRow, column zColumn, table zTable in database zDb;
6594** in other words, the same BLOB that would be selected by:
6595**
6596** <pre>
6597** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6598** </pre>)^
6599**
6600** ^(Parameter zDb is not the filename that contains the database, but
6601** rather the symbolic name of the database. For attached databases, this is
6602** the name that appears after the AS keyword in the [ATTACH] statement.
6603** For the main database file, the database name is "main". For TEMP
6604** tables, the database name is "temp".)^
6605**
6606** ^If the flags parameter is non-zero, then the BLOB is opened for read
6607** and write access. ^If the flags parameter is zero, the BLOB is opened for
6608** read-only access.
6609**
6610** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6611** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6612** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6613** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6614** on *ppBlob after this function it returns.
6615**
6616** This function fails with SQLITE_ERROR if any of the following are true:
6617** <ul>
6618** <li> ^(Database zDb does not exist)^,
6619** <li> ^(Table zTable does not exist within database zDb)^,
6620** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6621** <li> ^(Column zColumn does not exist)^,
6622** <li> ^(Row iRow is not present in the table)^,
6623** <li> ^(The specified column of row iRow contains a value that is not
6624** a TEXT or BLOB value)^,
6625** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6626** constraint and the blob is being opened for read/write access)^,
6627** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6628** column zColumn is part of a [child key] definition and the blob is
6629** being opened for read/write access)^.
6630** </ul>
6631**
6632** ^Unless it returns SQLITE_MISUSE, this function sets the
6633** [database connection] error code and message accessible via
6634** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6635**
6636** A BLOB referenced by sqlite3_blob_open() may be read using the
6637** [sqlite3_blob_read()] interface and modified by using
6638** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6639** different row of the same table using the [sqlite3_blob_reopen()]
6640** interface. However, the column, table, or database of a [BLOB handle]
6641** cannot be changed after the [BLOB handle] is opened.
6642**
6643** ^(If the row that a BLOB handle points to is modified by an
6644** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6645** then the BLOB handle is marked as "expired".
6646** This is true if any column of the row is changed, even a column
6647** other than the one the BLOB handle is open on.)^
6648** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6649** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6650** ^(Changes written into a BLOB prior to the BLOB expiring are not
6651** rolled back by the expiration of the BLOB. Such changes will eventually
6652** commit if the transaction continues to completion.)^
6653**
6654** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6655** the opened blob. ^The size of a blob may not be changed by this
6656** interface. Use the [UPDATE] SQL command to change the size of a
6657** blob.
6658**
6659** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6660** and the built-in [zeroblob] SQL function may be used to create a
6661** zero-filled blob to read or write using the incremental-blob interface.
6662**
6663** To avoid a resource leak, every open [BLOB handle] should eventually
6664** be released by a call to [sqlite3_blob_close()].
6665**
6666** See also: [sqlite3_blob_close()],
6667** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6668** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6669*/
6670SQLITE_API int sqlite3_blob_open(
6671 sqlite3*,
6672 const char *zDb,
6673 const char *zTable,
6674 const char *zColumn,
6675 sqlite3_int64 iRow,
6676 int flags,
6677 sqlite3_blob **ppBlob
6678);
6679
6680/*
6681** CAPI3REF: Move a BLOB Handle to a New Row
6682** METHOD: sqlite3_blob
6683**
6684** ^This function is used to move an existing [BLOB handle] so that it points
6685** to a different row of the same database table. ^The new row is identified
6686** by the rowid value passed as the second argument. Only the row can be
6687** changed. ^The database, table and column on which the blob handle is open
6688** remain the same. Moving an existing [BLOB handle] to a new row is
6689** faster than closing the existing handle and opening a new one.
6690**
6691** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6692** it must exist and there must be either a blob or text value stored in
6693** the nominated column.)^ ^If the new row is not present in the table, or if
6694** it does not contain a blob or text value, or if another error occurs, an
6695** SQLite error code is returned and the blob handle is considered aborted.
6696** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6697** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6698** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6699** always returns zero.
6700**
6701** ^This function sets the database handle error code and message.
6702*/
6703SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6704
6705/*
6706** CAPI3REF: Close A BLOB Handle
6707** DESTRUCTOR: sqlite3_blob
6708**
6709** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6710** unconditionally. Even if this routine returns an error code, the
6711** handle is still closed.)^
6712**
6713** ^If the blob handle being closed was opened for read-write access, and if
6714** the database is in auto-commit mode and there are no other open read-write
6715** blob handles or active write statements, the current transaction is
6716** committed. ^If an error occurs while committing the transaction, an error
6717** code is returned and the transaction rolled back.
6718**
6719** Calling this function with an argument that is not a NULL pointer or an
6720** open blob handle results in undefined behaviour. ^Calling this routine
6721** with a null pointer (such as would be returned by a failed call to
6722** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6723** is passed a valid open blob handle, the values returned by the
6724** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6725*/
6726SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6727
6728/*
6729** CAPI3REF: Return The Size Of An Open BLOB
6730** METHOD: sqlite3_blob
6731**
6732** ^Returns the size in bytes of the BLOB accessible via the
6733** successfully opened [BLOB handle] in its only argument. ^The
6734** incremental blob I/O routines can only read or overwriting existing
6735** blob content; they cannot change the size of a blob.
6736**
6737** This routine only works on a [BLOB handle] which has been created
6738** by a prior successful call to [sqlite3_blob_open()] and which has not
6739** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6740** to this routine results in undefined and probably undesirable behavior.
6741*/
6742SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6743
6744/*
6745** CAPI3REF: Read Data From A BLOB Incrementally
6746** METHOD: sqlite3_blob
6747**
6748** ^(This function is used to read data from an open [BLOB handle] into a
6749** caller-supplied buffer. N bytes of data are copied into buffer Z
6750** from the open BLOB, starting at offset iOffset.)^
6751**
6752** ^If offset iOffset is less than N bytes from the end of the BLOB,
6753** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6754** less than zero, [SQLITE_ERROR] is returned and no data is read.
6755** ^The size of the blob (and hence the maximum value of N+iOffset)
6756** can be determined using the [sqlite3_blob_bytes()] interface.
6757**
6758** ^An attempt to read from an expired [BLOB handle] fails with an
6759** error code of [SQLITE_ABORT].
6760**
6761** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6762** Otherwise, an [error code] or an [extended error code] is returned.)^
6763**
6764** This routine only works on a [BLOB handle] which has been created
6765** by a prior successful call to [sqlite3_blob_open()] and which has not
6766** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6767** to this routine results in undefined and probably undesirable behavior.
6768**
6769** See also: [sqlite3_blob_write()].
6770*/
6771SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6772
6773/*
6774** CAPI3REF: Write Data Into A BLOB Incrementally
6775** METHOD: sqlite3_blob
6776**
6777** ^(This function is used to write data into an open [BLOB handle] from a
6778** caller-supplied buffer. N bytes of data are copied from the buffer Z
6779** into the open BLOB, starting at offset iOffset.)^
6780**
6781** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6782** Otherwise, an [error code] or an [extended error code] is returned.)^
6783** ^Unless SQLITE_MISUSE is returned, this function sets the
6784** [database connection] error code and message accessible via
6785** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6786**
6787** ^If the [BLOB handle] passed as the first argument was not opened for
6788** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6789** this function returns [SQLITE_READONLY].
6790**
6791** This function may only modify the contents of the BLOB; it is
6792** not possible to increase the size of a BLOB using this API.
6793** ^If offset iOffset is less than N bytes from the end of the BLOB,
6794** [SQLITE_ERROR] is returned and no data is written. The size of the
6795** BLOB (and hence the maximum value of N+iOffset) can be determined
6796** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6797** than zero [SQLITE_ERROR] is returned and no data is written.
6798**
6799** ^An attempt to write to an expired [BLOB handle] fails with an
6800** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6801** before the [BLOB handle] expired are not rolled back by the
6802** expiration of the handle, though of course those changes might
6803** have been overwritten by the statement that expired the BLOB handle
6804** or by other independent statements.
6805**
6806** This routine only works on a [BLOB handle] which has been created
6807** by a prior successful call to [sqlite3_blob_open()] and which has not
6808** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6809** to this routine results in undefined and probably undesirable behavior.
6810**
6811** See also: [sqlite3_blob_read()].
6812*/
6813SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6814
6815/*
6816** CAPI3REF: Virtual File System Objects
6817**
6818** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6819** that SQLite uses to interact
6820** with the underlying operating system. Most SQLite builds come with a
6821** single default VFS that is appropriate for the host computer.
6822** New VFSes can be registered and existing VFSes can be unregistered.
6823** The following interfaces are provided.
6824**
6825** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6826** ^Names are case sensitive.
6827** ^Names are zero-terminated UTF-8 strings.
6828** ^If there is no match, a NULL pointer is returned.
6829** ^If zVfsName is NULL then the default VFS is returned.
6830**
6831** ^New VFSes are registered with sqlite3_vfs_register().
6832** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6833** ^The same VFS can be registered multiple times without injury.
6834** ^To make an existing VFS into the default VFS, register it again
6835** with the makeDflt flag set. If two different VFSes with the
6836** same name are registered, the behavior is undefined. If a
6837** VFS is registered with a name that is NULL or an empty string,
6838** then the behavior is undefined.
6839**
6840** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6841** ^(If the default VFS is unregistered, another VFS is chosen as
6842** the default. The choice for the new VFS is arbitrary.)^
6843*/
6844SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6845SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6846SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6847
6848/*
6849** CAPI3REF: Mutexes
6850**
6851** The SQLite core uses these routines for thread
6852** synchronization. Though they are intended for internal
6853** use by SQLite, code that links against SQLite is
6854** permitted to use any of these routines.
6855**
6856** The SQLite source code contains multiple implementations
6857** of these mutex routines. An appropriate implementation
6858** is selected automatically at compile-time. The following
6859** implementations are available in the SQLite core:
6860**
6861** <ul>
6862** <li> SQLITE_MUTEX_PTHREADS
6863** <li> SQLITE_MUTEX_W32
6864** <li> SQLITE_MUTEX_NOOP
6865** </ul>
6866**
6867** The SQLITE_MUTEX_NOOP implementation is a set of routines
6868** that does no real locking and is appropriate for use in
6869** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6870** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6871** and Windows.
6872**
6873** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6874** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6875** implementation is included with the library. In this case the
6876** application must supply a custom mutex implementation using the
6877** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6878** before calling sqlite3_initialize() or any other public sqlite3_
6879** function that calls sqlite3_initialize().
6880**
6881** ^The sqlite3_mutex_alloc() routine allocates a new
6882** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6883** routine returns NULL if it is unable to allocate the requested
6884** mutex. The argument to sqlite3_mutex_alloc() must one of these
6885** integer constants:
6886**
6887** <ul>
6888** <li> SQLITE_MUTEX_FAST
6889** <li> SQLITE_MUTEX_RECURSIVE
6890** <li> SQLITE_MUTEX_STATIC_MASTER
6891** <li> SQLITE_MUTEX_STATIC_MEM
6892** <li> SQLITE_MUTEX_STATIC_OPEN
6893** <li> SQLITE_MUTEX_STATIC_PRNG
6894** <li> SQLITE_MUTEX_STATIC_LRU
6895** <li> SQLITE_MUTEX_STATIC_PMEM
6896** <li> SQLITE_MUTEX_STATIC_APP1
6897** <li> SQLITE_MUTEX_STATIC_APP2
6898** <li> SQLITE_MUTEX_STATIC_APP3
6899** <li> SQLITE_MUTEX_STATIC_VFS1
6900** <li> SQLITE_MUTEX_STATIC_VFS2
6901** <li> SQLITE_MUTEX_STATIC_VFS3
6902** </ul>
6903**
6904** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6905** cause sqlite3_mutex_alloc() to create
6906** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6907** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6908** The mutex implementation does not need to make a distinction
6909** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6910** not want to. SQLite will only request a recursive mutex in
6911** cases where it really needs one. If a faster non-recursive mutex
6912** implementation is available on the host platform, the mutex subsystem
6913** might return such a mutex in response to SQLITE_MUTEX_FAST.
6914**
6915** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6916** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6917** a pointer to a static preexisting mutex. ^Nine static mutexes are
6918** used by the current version of SQLite. Future versions of SQLite
6919** may add additional static mutexes. Static mutexes are for internal
6920** use by SQLite only. Applications that use SQLite mutexes should
6921** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6922** SQLITE_MUTEX_RECURSIVE.
6923**
6924** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6925** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6926** returns a different mutex on every call. ^For the static
6927** mutex types, the same mutex is returned on every call that has
6928** the same type number.
6929**
6930** ^The sqlite3_mutex_free() routine deallocates a previously
6931** allocated dynamic mutex. Attempting to deallocate a static
6932** mutex results in undefined behavior.
6933**
6934** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6935** to enter a mutex. ^If another thread is already within the mutex,
6936** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6937** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6938** upon successful entry. ^(Mutexes created using
6939** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6940** In such cases, the
6941** mutex must be exited an equal number of times before another thread
6942** can enter.)^ If the same thread tries to enter any mutex other
6943** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6944**
6945** ^(Some systems (for example, Windows 95) do not support the operation
6946** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
6947** will always return SQLITE_BUSY. The SQLite core only ever uses
6948** sqlite3_mutex_try() as an optimization so this is acceptable
6949** behavior.)^
6950**
6951** ^The sqlite3_mutex_leave() routine exits a mutex that was
6952** previously entered by the same thread. The behavior
6953** is undefined if the mutex is not currently entered by the
6954** calling thread or is not currently allocated.
6955**
6956** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6957** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6958** behave as no-ops.
6959**
6960** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6961*/
6962SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
6963SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
6964SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
6965SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
6966SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
6967
6968/*
6969** CAPI3REF: Mutex Methods Object
6970**
6971** An instance of this structure defines the low-level routines
6972** used to allocate and use mutexes.
6973**
6974** Usually, the default mutex implementations provided by SQLite are
6975** sufficient, however the application has the option of substituting a custom
6976** implementation for specialized deployments or systems for which SQLite
6977** does not provide a suitable implementation. In this case, the application
6978** creates and populates an instance of this structure to pass
6979** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6980** Additionally, an instance of this structure can be used as an
6981** output variable when querying the system for the current mutex
6982** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6983**
6984** ^The xMutexInit method defined by this structure is invoked as
6985** part of system initialization by the sqlite3_initialize() function.
6986** ^The xMutexInit routine is called by SQLite exactly once for each
6987** effective call to [sqlite3_initialize()].
6988**
6989** ^The xMutexEnd method defined by this structure is invoked as
6990** part of system shutdown by the sqlite3_shutdown() function. The
6991** implementation of this method is expected to release all outstanding
6992** resources obtained by the mutex methods implementation, especially
6993** those obtained by the xMutexInit method. ^The xMutexEnd()
6994** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6995**
6996** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6997** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6998** xMutexNotheld) implement the following interfaces (respectively):
6999**
7000** <ul>
7001** <li> [sqlite3_mutex_alloc()] </li>
7002** <li> [sqlite3_mutex_free()] </li>
7003** <li> [sqlite3_mutex_enter()] </li>
7004** <li> [sqlite3_mutex_try()] </li>
7005** <li> [sqlite3_mutex_leave()] </li>
7006** <li> [sqlite3_mutex_held()] </li>
7007** <li> [sqlite3_mutex_notheld()] </li>
7008** </ul>)^
7009**
7010** The only difference is that the public sqlite3_XXX functions enumerated
7011** above silently ignore any invocations that pass a NULL pointer instead
7012** of a valid mutex handle. The implementations of the methods defined
7013** by this structure are not required to handle this case, the results
7014** of passing a NULL pointer instead of a valid mutex handle are undefined
7015** (i.e. it is acceptable to provide an implementation that segfaults if
7016** it is passed a NULL pointer).
7017**
7018** The xMutexInit() method must be threadsafe. It must be harmless to
7019** invoke xMutexInit() multiple times within the same process and without
7020** intervening calls to xMutexEnd(). Second and subsequent calls to
7021** xMutexInit() must be no-ops.
7022**
7023** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7024** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7025** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7026** memory allocation for a fast or recursive mutex.
7027**
7028** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7029** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7030** If xMutexInit fails in any way, it is expected to clean up after itself
7031** prior to returning.
7032*/
7033typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7034struct sqlite3_mutex_methods {
7035 int (*xMutexInit)(void);
7036 int (*xMutexEnd)(void);
7037 sqlite3_mutex *(*xMutexAlloc)(int);
7038 void (*xMutexFree)(sqlite3_mutex *);
7039 void (*xMutexEnter)(sqlite3_mutex *);
7040 int (*xMutexTry)(sqlite3_mutex *);
7041 void (*xMutexLeave)(sqlite3_mutex *);
7042 int (*xMutexHeld)(sqlite3_mutex *);
7043 int (*xMutexNotheld)(sqlite3_mutex *);
7044};
7045
7046/*
7047** CAPI3REF: Mutex Verification Routines
7048**
7049** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7050** are intended for use inside assert() statements. The SQLite core
7051** never uses these routines except inside an assert() and applications
7052** are advised to follow the lead of the core. The SQLite core only
7053** provides implementations for these routines when it is compiled
7054** with the SQLITE_DEBUG flag. External mutex implementations
7055** are only required to provide these routines if SQLITE_DEBUG is
7056** defined and if NDEBUG is not defined.
7057**
7058** These routines should return true if the mutex in their argument
7059** is held or not held, respectively, by the calling thread.
7060**
7061** The implementation is not required to provide versions of these
7062** routines that actually work. If the implementation does not provide working
7063** versions of these routines, it should at least provide stubs that always
7064** return true so that one does not get spurious assertion failures.
7065**
7066** If the argument to sqlite3_mutex_held() is a NULL pointer then
7067** the routine should return 1. This seems counter-intuitive since
7068** clearly the mutex cannot be held if it does not exist. But
7069** the reason the mutex does not exist is because the build is not
7070** using mutexes. And we do not want the assert() containing the
7071** call to sqlite3_mutex_held() to fail, so a non-zero return is
7072** the appropriate thing to do. The sqlite3_mutex_notheld()
7073** interface should also return 1 when given a NULL pointer.
7074*/
7075#ifndef NDEBUG
7076SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7077SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7078#endif
7079
7080/*
7081** CAPI3REF: Mutex Types
7082**
7083** The [sqlite3_mutex_alloc()] interface takes a single argument
7084** which is one of these integer constants.
7085**
7086** The set of static mutexes may change from one SQLite release to the
7087** next. Applications that override the built-in mutex logic must be
7088** prepared to accommodate additional static mutexes.
7089*/
7090#define SQLITE_MUTEX_FAST 0
7091#define SQLITE_MUTEX_RECURSIVE 1
7092#define SQLITE_MUTEX_STATIC_MASTER 2
7093#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7094#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7095#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7096#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7097#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7098#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7099#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7100#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7101#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7102#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7103#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7104#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7105#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7106
7107/*
7108** CAPI3REF: Retrieve the mutex for a database connection
7109** METHOD: sqlite3
7110**
7111** ^This interface returns a pointer the [sqlite3_mutex] object that
7112** serializes access to the [database connection] given in the argument
7113** when the [threading mode] is Serialized.
7114** ^If the [threading mode] is Single-thread or Multi-thread then this
7115** routine returns a NULL pointer.
7116*/
7117SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7118
7119/*
7120** CAPI3REF: Low-Level Control Of Database Files
7121** METHOD: sqlite3
7122** KEYWORDS: {file control}
7123**
7124** ^The [sqlite3_file_control()] interface makes a direct call to the
7125** xFileControl method for the [sqlite3_io_methods] object associated
7126** with a particular database identified by the second argument. ^The
7127** name of the database is "main" for the main database or "temp" for the
7128** TEMP database, or the name that appears after the AS keyword for
7129** databases that are added using the [ATTACH] SQL command.
7130** ^A NULL pointer can be used in place of "main" to refer to the
7131** main database file.
7132** ^The third and fourth parameters to this routine
7133** are passed directly through to the second and third parameters of
7134** the xFileControl method. ^The return value of the xFileControl
7135** method becomes the return value of this routine.
7136**
7137** A few opcodes for [sqlite3_file_control()] are handled directly
7138** by the SQLite core and never invoke the
7139** sqlite3_io_methods.xFileControl method.
7140** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7141** a pointer to the underlying [sqlite3_file] object to be written into
7142** the space pointed to by the 4th parameter. The
7143** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7144** the [sqlite3_file] object associated with the journal file instead of
7145** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7146** a pointer to the underlying [sqlite3_vfs] object for the file.
7147** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7148** from the pager.
7149**
7150** ^If the second parameter (zDbName) does not match the name of any
7151** open database file, then SQLITE_ERROR is returned. ^This error
7152** code is not remembered and will not be recalled by [sqlite3_errcode()]
7153** or [sqlite3_errmsg()]. The underlying xFileControl method might
7154** also return SQLITE_ERROR. There is no way to distinguish between
7155** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7156** xFileControl method.
7157**
7158** See also: [file control opcodes]
7159*/
7160SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7161
7162/*
7163** CAPI3REF: Testing Interface
7164**
7165** ^The sqlite3_test_control() interface is used to read out internal
7166** state of SQLite and to inject faults into SQLite for testing
7167** purposes. ^The first parameter is an operation code that determines
7168** the number, meaning, and operation of all subsequent parameters.
7169**
7170** This interface is not for use by applications. It exists solely
7171** for verifying the correct operation of the SQLite library. Depending
7172** on how the SQLite library is compiled, this interface might not exist.
7173**
7174** The details of the operation codes, their meanings, the parameters
7175** they take, and what they do are all subject to change without notice.
7176** Unlike most of the SQLite API, this function is not guaranteed to
7177** operate consistently from one release to the next.
7178*/
7179SQLITE_API int sqlite3_test_control(int op, ...);
7180
7181/*
7182** CAPI3REF: Testing Interface Operation Codes
7183**
7184** These constants are the valid operation code parameters used
7185** as the first argument to [sqlite3_test_control()].
7186**
7187** These parameters and their meanings are subject to change
7188** without notice. These values are for testing purposes only.
7189** Applications should not use any of these parameters or the
7190** [sqlite3_test_control()] interface.
7191*/
7192#define SQLITE_TESTCTRL_FIRST 5
7193#define SQLITE_TESTCTRL_PRNG_SAVE 5
7194#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7195#define SQLITE_TESTCTRL_PRNG_RESET 7
7196#define SQLITE_TESTCTRL_BITVEC_TEST 8
7197#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7198#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7199#define SQLITE_TESTCTRL_PENDING_BYTE 11
7200#define SQLITE_TESTCTRL_ASSERT 12
7201#define SQLITE_TESTCTRL_ALWAYS 13
7202#define SQLITE_TESTCTRL_RESERVE 14
7203#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7204#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7205#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7206#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7207#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7208#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7209#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7210#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7211#define SQLITE_TESTCTRL_BYTEORDER 22
7212#define SQLITE_TESTCTRL_ISINIT 23
7213#define SQLITE_TESTCTRL_SORTER_MMAP 24
7214#define SQLITE_TESTCTRL_IMPOSTER 25
7215#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7216#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */
7217
7218/*
7219** CAPI3REF: SQL Keyword Checking
7220**
7221** These routines provide access to the set of SQL language keywords
7222** recognized by SQLite. Applications can uses these routines to determine
7223** whether or not a specific identifier needs to be escaped (for example,
7224** by enclosing in double-quotes) so as not to confuse the parser.
7225**
7226** The sqlite3_keyword_count() interface returns the number of distinct
7227** keywords understood by SQLite.
7228**
7229** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7230** makes *Z point to that keyword expressed as UTF8 and writes the number
7231** of bytes in the keyword into *L. The string that *Z points to is not
7232** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7233** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7234** or L are NULL or invalid pointers then calls to
7235** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7236**
7237** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7238** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7239** if it is and zero if not.
7240**
7241** The parser used by SQLite is forgiving. It is often possible to use
7242** a keyword as an identifier as long as such use does not result in a
7243** parsing ambiguity. For example, the statement
7244** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7245** creates a new table named "BEGIN" with three columns named
7246** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7247** using keywords as identifiers. Common techniques used to avoid keyword
7248** name collisions include:
7249** <ul>
7250** <li> Put all identifier names inside double-quotes. This is the official
7251** SQL way to escape identifier names.
7252** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
7253** but it is what SQL Server does and so lots of programmers use this
7254** technique.
7255** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7256** with "Z".
7257** <li> Include a digit somewhere in every identifier name.
7258** </ul>
7259**
7260** Note that the number of keywords understood by SQLite can depend on
7261** compile-time options. For example, "VACUUM" is not a keyword if
7262** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7263** new keywords may be added to future releases of SQLite.
7264*/
7265SQLITE_API int sqlite3_keyword_count(void);
7266SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7267SQLITE_API int sqlite3_keyword_check(const char*,int);
7268
7269/*
7270** CAPI3REF: Dynamic String Object
7271** KEYWORDS: {dynamic string}
7272**
7273** An instance of the sqlite3_str object contains a dynamically-sized
7274** string under construction.
7275**
7276** The lifecycle of an sqlite3_str object is as follows:
7277** <ol>
7278** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7279** <li> ^Text is appended to the sqlite3_str object using various
7280** methods, such as [sqlite3_str_appendf()].
7281** <li> ^The sqlite3_str object is destroyed and the string it created
7282** is returned using the [sqlite3_str_finish()] interface.
7283** </ol>
7284*/
7285typedef struct sqlite3_str sqlite3_str;
7286
7287/*
7288** CAPI3REF: Create A New Dynamic String Object
7289** CONSTRUCTOR: sqlite3_str
7290**
7291** ^The [sqlite3_str_new(D)] interface allocates and initializes
7292** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7293** [sqlite3_str_new()] must be freed by a subsequent call to
7294** [sqlite3_str_finish(X)].
7295**
7296** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7297** valid [sqlite3_str] object, though in the event of an out-of-memory
7298** error the returned object might be a special singleton that will
7299** silently reject new text, always return SQLITE_NOMEM from
7300** [sqlite3_str_errcode()], always return 0 for
7301** [sqlite3_str_length()], and always return NULL from
7302** [sqlite3_str_finish(X)]. It is always safe to use the value
7303** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7304** to any of the other [sqlite3_str] methods.
7305**
7306** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7307** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7308** length of the string contained in the [sqlite3_str] object will be
7309** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7310** of [SQLITE_MAX_LENGTH].
7311*/
7312SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7313
7314/*
7315** CAPI3REF: Finalize A Dynamic String
7316** DESTRUCTOR: sqlite3_str
7317**
7318** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7319** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7320** that contains the constructed string. The calling application should
7321** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7322** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7323** errors were encountered during construction of the string. ^The
7324** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7325** string in [sqlite3_str] object X is zero bytes long.
7326*/
7327SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7328
7329/*
7330** CAPI3REF: Add Content To A Dynamic String
7331** METHOD: sqlite3_str
7332**
7333** These interfaces add content to an sqlite3_str object previously obtained
7334** from [sqlite3_str_new()].
7335**
7336** ^The [sqlite3_str_appendf(X,F,...)] and
7337** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7338** functionality of SQLite to append formatted text onto the end of
7339** [sqlite3_str] object X.
7340**
7341** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7342** onto the end of the [sqlite3_str] object X. N must be non-negative.
7343** S must contain at least N non-zero bytes of content. To append a
7344** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7345** method instead.
7346**
7347** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7348** zero-terminated string S onto the end of [sqlite3_str] object X.
7349**
7350** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7351** single-byte character C onto the end of [sqlite3_str] object X.
7352** ^This method can be used, for example, to add whitespace indentation.
7353**
7354** ^The [sqlite3_str_reset(X)] method resets the string under construction
7355** inside [sqlite3_str] object X back to zero bytes in length.
7356**
7357** These methods do not return a result code. ^If an error occurs, that fact
7358** is recorded in the [sqlite3_str] object and can be recovered by a
7359** subsequent call to [sqlite3_str_errcode(X)].
7360*/
7361SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7362SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7363SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7364SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7365SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7366SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7367
7368/*
7369** CAPI3REF: Status Of A Dynamic String
7370** METHOD: sqlite3_str
7371**
7372** These interfaces return the current status of an [sqlite3_str] object.
7373**
7374** ^If any prior errors have occurred while constructing the dynamic string
7375** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7376** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7377** [SQLITE_NOMEM] following any out-of-memory error, or
7378** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7379** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7380**
7381** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7382** of the dynamic string under construction in [sqlite3_str] object X.
7383** ^The length returned by [sqlite3_str_length(X)] does not include the
7384** zero-termination byte.
7385**
7386** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7387** content of the dynamic string under construction in X. The value
7388** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7389** and might be freed or altered by any subsequent method on the same
7390** [sqlite3_str] object. Applications must not used the pointer returned
7391** [sqlite3_str_value(X)] after any subsequent method call on the same
7392** object. ^Applications may change the content of the string returned
7393** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7394** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7395** write any byte after any subsequent sqlite3_str method call.
7396*/
7397SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7398SQLITE_API int sqlite3_str_length(sqlite3_str*);
7399SQLITE_API char *sqlite3_str_value(sqlite3_str*);
7400
7401/*
7402** CAPI3REF: SQLite Runtime Status
7403**
7404** ^These interfaces are used to retrieve runtime status information
7405** about the performance of SQLite, and optionally to reset various
7406** highwater marks. ^The first argument is an integer code for
7407** the specific parameter to measure. ^(Recognized integer codes
7408** are of the form [status parameters | SQLITE_STATUS_...].)^
7409** ^The current value of the parameter is returned into *pCurrent.
7410** ^The highest recorded value is returned in *pHighwater. ^If the
7411** resetFlag is true, then the highest record value is reset after
7412** *pHighwater is written. ^(Some parameters do not record the highest
7413** value. For those parameters
7414** nothing is written into *pHighwater and the resetFlag is ignored.)^
7415** ^(Other parameters record only the highwater mark and not the current
7416** value. For these latter parameters nothing is written into *pCurrent.)^
7417**
7418** ^The sqlite3_status() and sqlite3_status64() routines return
7419** SQLITE_OK on success and a non-zero [error code] on failure.
7420**
7421** If either the current value or the highwater mark is too large to
7422** be represented by a 32-bit integer, then the values returned by
7423** sqlite3_status() are undefined.
7424**
7425** See also: [sqlite3_db_status()]
7426*/
7427SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7428SQLITE_API int sqlite3_status64(
7429 int op,
7430 sqlite3_int64 *pCurrent,
7431 sqlite3_int64 *pHighwater,
7432 int resetFlag
7433);
7434
7435
7436/*
7437** CAPI3REF: Status Parameters
7438** KEYWORDS: {status parameters}
7439**
7440** These integer constants designate various run-time status parameters
7441** that can be returned by [sqlite3_status()].
7442**
7443** <dl>
7444** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7445** <dd>This parameter is the current amount of memory checked out
7446** using [sqlite3_malloc()], either directly or indirectly. The
7447** figure includes calls made to [sqlite3_malloc()] by the application
7448** and internal memory usage by the SQLite library. Auxiliary page-cache
7449** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
7450** this parameter. The amount returned is the sum of the allocation
7451** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
7452**
7453** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
7454** <dd>This parameter records the largest memory allocation request
7455** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
7456** internal equivalents). Only the value returned in the
7457** *pHighwater parameter to [sqlite3_status()] is of interest.
7458** The value written into the *pCurrent parameter is undefined.</dd>)^
7459**
7460** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
7461** <dd>This parameter records the number of separate memory allocations
7462** currently checked out.</dd>)^
7463**
7464** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
7465** <dd>This parameter returns the number of pages used out of the
7466** [pagecache memory allocator] that was configured using
7467** [SQLITE_CONFIG_PAGECACHE]. The
7468** value returned is in pages, not in bytes.</dd>)^
7469**
7470** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
7471** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
7472** <dd>This parameter returns the number of bytes of page cache
7473** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
7474** buffer and where forced to overflow to [sqlite3_malloc()]. The
7475** returned value includes allocations that overflowed because they
7476** where too large (they were larger than the "sz" parameter to
7477** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
7478** no space was left in the page cache.</dd>)^
7479**
7480** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
7481** <dd>This parameter records the largest memory allocation request
7482** handed to [pagecache memory allocator]. Only the value returned in the
7483** *pHighwater parameter to [sqlite3_status()] is of interest.
7484** The value written into the *pCurrent parameter is undefined.</dd>)^
7485**
7486** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
7487** <dd>No longer used.</dd>
7488**
7489** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
7490** <dd>No longer used.</dd>
7491**
7492** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
7493** <dd>No longer used.</dd>
7494**
7495** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
7496** <dd>The *pHighwater parameter records the deepest parser stack.
7497** The *pCurrent value is undefined. The *pHighwater value is only
7498** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
7499** </dl>
7500**
7501** New status parameters may be added from time to time.
7502*/
7503#define SQLITE_STATUS_MEMORY_USED 0
7504#define SQLITE_STATUS_PAGECACHE_USED 1
7505#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
7506#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
7507#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
7508#define SQLITE_STATUS_MALLOC_SIZE 5
7509#define SQLITE_STATUS_PARSER_STACK 6
7510#define SQLITE_STATUS_PAGECACHE_SIZE 7
7511#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
7512#define SQLITE_STATUS_MALLOC_COUNT 9
7513
7514/*
7515** CAPI3REF: Database Connection Status
7516** METHOD: sqlite3
7517**
7518** ^This interface is used to retrieve runtime status information
7519** about a single [database connection]. ^The first argument is the
7520** database connection object to be interrogated. ^The second argument
7521** is an integer constant, taken from the set of
7522** [SQLITE_DBSTATUS options], that
7523** determines the parameter to interrogate. The set of
7524** [SQLITE_DBSTATUS options] is likely
7525** to grow in future releases of SQLite.
7526**
7527** ^The current value of the requested parameter is written into *pCur
7528** and the highest instantaneous value is written into *pHiwtr. ^If
7529** the resetFlg is true, then the highest instantaneous value is
7530** reset back down to the current value.
7531**
7532** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
7533** non-zero [error code] on failure.
7534**
7535** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
7536*/
7537SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
7538
7539/*
7540** CAPI3REF: Status Parameters for database connections
7541** KEYWORDS: {SQLITE_DBSTATUS options}
7542**
7543** These constants are the available integer "verbs" that can be passed as
7544** the second argument to the [sqlite3_db_status()] interface.
7545**
7546** New verbs may be added in future releases of SQLite. Existing verbs
7547** might be discontinued. Applications should check the return code from
7548** [sqlite3_db_status()] to make sure that the call worked.
7549** The [sqlite3_db_status()] interface will return a non-zero error code
7550** if a discontinued or unsupported verb is invoked.
7551**
7552** <dl>
7553** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
7554** <dd>This parameter returns the number of lookaside memory slots currently
7555** checked out.</dd>)^
7556**
7557** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
7558** <dd>This parameter returns the number malloc attempts that were
7559** satisfied using lookaside memory. Only the high-water value is meaningful;
7560** the current value is always zero.)^
7561**
7562** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
7563** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
7564** <dd>This parameter returns the number malloc attempts that might have
7565** been satisfied using lookaside memory but failed due to the amount of
7566** memory requested being larger than the lookaside slot size.
7567** Only the high-water value is meaningful;
7568** the current value is always zero.)^
7569**
7570** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
7571** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
7572** <dd>This parameter returns the number malloc attempts that might have
7573** been satisfied using lookaside memory but failed due to all lookaside
7574** memory already being in use.
7575** Only the high-water value is meaningful;
7576** the current value is always zero.)^
7577**
7578** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
7579** <dd>This parameter returns the approximate number of bytes of heap
7580** memory used by all pager caches associated with the database connection.)^
7581** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
7582**
7583** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
7584** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
7585** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
7586** pager cache is shared between two or more connections the bytes of heap
7587** memory used by that pager cache is divided evenly between the attached
7588** connections.)^ In other words, if none of the pager caches associated
7589** with the database connection are shared, this request returns the same
7590** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
7591** shared, the value returned by this call will be smaller than that returned
7592** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
7593** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
7594**
7595** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
7596** <dd>This parameter returns the approximate number of bytes of heap
7597** memory used to store the schema for all databases associated
7598** with the connection - main, temp, and any [ATTACH]-ed databases.)^
7599** ^The full amount of memory used by the schemas is reported, even if the
7600** schema memory is shared with other database connections due to
7601** [shared cache mode] being enabled.
7602** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
7603**
7604** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
7605** <dd>This parameter returns the approximate number of bytes of heap
7606** and lookaside memory used by all prepared statements associated with
7607** the database connection.)^
7608** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7609** </dd>
7610**
7611** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7612** <dd>This parameter returns the number of pager cache hits that have
7613** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7614** is always 0.
7615** </dd>
7616**
7617** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7618** <dd>This parameter returns the number of pager cache misses that have
7619** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7620** is always 0.
7621** </dd>
7622**
7623** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7624** <dd>This parameter returns the number of dirty cache entries that have
7625** been written to disk. Specifically, the number of pages written to the
7626** wal file in wal mode databases, or the number of pages written to the
7627** database file in rollback mode databases. Any pages written as part of
7628** transaction rollback or database recovery operations are not included.
7629** If an IO or other error occurs while writing a page to disk, the effect
7630** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7631** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7632** </dd>
7633**
7634** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
7635** <dd>This parameter returns the number of dirty cache entries that have
7636** been written to disk in the middle of a transaction due to the page
7637** cache overflowing. Transactions are more efficient if they are written
7638** to disk all at once. When pages spill mid-transaction, that introduces
7639** additional overhead. This parameter can be used help identify
7640** inefficiencies that can be resolve by increasing the cache size.
7641** </dd>
7642**
7643** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7644** <dd>This parameter returns zero for the current value if and only if
7645** all foreign key constraints (deferred or immediate) have been
7646** resolved.)^ ^The highwater mark is always 0.
7647** </dd>
7648** </dl>
7649*/
7650#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7651#define SQLITE_DBSTATUS_CACHE_USED 1
7652#define SQLITE_DBSTATUS_SCHEMA_USED 2
7653#define SQLITE_DBSTATUS_STMT_USED 3
7654#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7655#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7656#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7657#define SQLITE_DBSTATUS_CACHE_HIT 7
7658#define SQLITE_DBSTATUS_CACHE_MISS 8
7659#define SQLITE_DBSTATUS_CACHE_WRITE 9
7660#define SQLITE_DBSTATUS_DEFERRED_FKS 10
7661#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7662#define SQLITE_DBSTATUS_CACHE_SPILL 12
7663#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
7664
7665
7666/*
7667** CAPI3REF: Prepared Statement Status
7668** METHOD: sqlite3_stmt
7669**
7670** ^(Each prepared statement maintains various
7671** [SQLITE_STMTSTATUS counters] that measure the number
7672** of times it has performed specific operations.)^ These counters can
7673** be used to monitor the performance characteristics of the prepared
7674** statements. For example, if the number of table steps greatly exceeds
7675** the number of table searches or result rows, that would tend to indicate
7676** that the prepared statement is using a full table scan rather than
7677** an index.
7678**
7679** ^(This interface is used to retrieve and reset counter values from
7680** a [prepared statement]. The first argument is the prepared statement
7681** object to be interrogated. The second argument
7682** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7683** to be interrogated.)^
7684** ^The current value of the requested counter is returned.
7685** ^If the resetFlg is true, then the counter is reset to zero after this
7686** interface call returns.
7687**
7688** See also: [sqlite3_status()] and [sqlite3_db_status()].
7689*/
7690SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7691
7692/*
7693** CAPI3REF: Status Parameters for prepared statements
7694** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7695**
7696** These preprocessor macros define integer codes that name counter
7697** values associated with the [sqlite3_stmt_status()] interface.
7698** The meanings of the various counters are as follows:
7699**
7700** <dl>
7701** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7702** <dd>^This is the number of times that SQLite has stepped forward in
7703** a table as part of a full table scan. Large numbers for this counter
7704** may indicate opportunities for performance improvement through
7705** careful use of indices.</dd>
7706**
7707** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7708** <dd>^This is the number of sort operations that have occurred.
7709** A non-zero value in this counter may indicate an opportunity to
7710** improvement performance through careful use of indices.</dd>
7711**
7712** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7713** <dd>^This is the number of rows inserted into transient indices that
7714** were created automatically in order to help joins run faster.
7715** A non-zero value in this counter may indicate an opportunity to
7716** improvement performance by adding permanent indices that do not
7717** need to be reinitialized each time the statement is run.</dd>
7718**
7719** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7720** <dd>^This is the number of virtual machine operations executed
7721** by the prepared statement if that number is less than or equal
7722** to 2147483647. The number of virtual machine operations can be
7723** used as a proxy for the total work done by the prepared statement.
7724** If the number of virtual machine operations exceeds 2147483647
7725** then the value returned by this statement status code is undefined.
7726**
7727** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
7728** <dd>^This is the number of times that the prepare statement has been
7729** automatically regenerated due to schema changes or change to
7730** [bound parameters] that might affect the query plan.
7731**
7732** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
7733** <dd>^This is the number of times that the prepared statement has
7734** been run. A single "run" for the purposes of this counter is one
7735** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
7736** The counter is incremented on the first [sqlite3_step()] call of each
7737** cycle.
7738**
7739** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
7740** <dd>^This is the approximate number of bytes of heap memory
7741** used to store the prepared statement. ^This value is not actually
7742** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
7743** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
7744** </dd>
7745** </dl>
7746*/
7747#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7748#define SQLITE_STMTSTATUS_SORT 2
7749#define SQLITE_STMTSTATUS_AUTOINDEX 3
7750#define SQLITE_STMTSTATUS_VM_STEP 4
7751#define SQLITE_STMTSTATUS_REPREPARE 5
7752#define SQLITE_STMTSTATUS_RUN 6
7753#define SQLITE_STMTSTATUS_MEMUSED 99
7754
7755/*
7756** CAPI3REF: Custom Page Cache Object
7757**
7758** The sqlite3_pcache type is opaque. It is implemented by
7759** the pluggable module. The SQLite core has no knowledge of
7760** its size or internal structure and never deals with the
7761** sqlite3_pcache object except by holding and passing pointers
7762** to the object.
7763**
7764** See [sqlite3_pcache_methods2] for additional information.
7765*/
7766typedef struct sqlite3_pcache sqlite3_pcache;
7767
7768/*
7769** CAPI3REF: Custom Page Cache Object
7770**
7771** The sqlite3_pcache_page object represents a single page in the
7772** page cache. The page cache will allocate instances of this
7773** object. Various methods of the page cache use pointers to instances
7774** of this object as parameters or as their return value.
7775**
7776** See [sqlite3_pcache_methods2] for additional information.
7777*/
7778typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7779struct sqlite3_pcache_page {
7780 void *pBuf; /* The content of the page */
7781 void *pExtra; /* Extra information associated with the page */
7782};
7783
7784/*
7785** CAPI3REF: Application Defined Page Cache.
7786** KEYWORDS: {page cache}
7787**
7788** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7789** register an alternative page cache implementation by passing in an
7790** instance of the sqlite3_pcache_methods2 structure.)^
7791** In many applications, most of the heap memory allocated by
7792** SQLite is used for the page cache.
7793** By implementing a
7794** custom page cache using this API, an application can better control
7795** the amount of memory consumed by SQLite, the way in which
7796** that memory is allocated and released, and the policies used to
7797** determine exactly which parts of a database file are cached and for
7798** how long.
7799**
7800** The alternative page cache mechanism is an
7801** extreme measure that is only needed by the most demanding applications.
7802** The built-in page cache is recommended for most uses.
7803**
7804** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7805** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7806** the application may discard the parameter after the call to
7807** [sqlite3_config()] returns.)^
7808**
7809** [[the xInit() page cache method]]
7810** ^(The xInit() method is called once for each effective
7811** call to [sqlite3_initialize()])^
7812** (usually only once during the lifetime of the process). ^(The xInit()
7813** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7814** The intent of the xInit() method is to set up global data structures
7815** required by the custom page cache implementation.
7816** ^(If the xInit() method is NULL, then the
7817** built-in default page cache is used instead of the application defined
7818** page cache.)^
7819**
7820** [[the xShutdown() page cache method]]
7821** ^The xShutdown() method is called by [sqlite3_shutdown()].
7822** It can be used to clean up
7823** any outstanding resources before process shutdown, if required.
7824** ^The xShutdown() method may be NULL.
7825**
7826** ^SQLite automatically serializes calls to the xInit method,
7827** so the xInit method need not be threadsafe. ^The
7828** xShutdown method is only called from [sqlite3_shutdown()] so it does
7829** not need to be threadsafe either. All other methods must be threadsafe
7830** in multithreaded applications.
7831**
7832** ^SQLite will never invoke xInit() more than once without an intervening
7833** call to xShutdown().
7834**
7835** [[the xCreate() page cache methods]]
7836** ^SQLite invokes the xCreate() method to construct a new cache instance.
7837** SQLite will typically create one cache instance for each open database file,
7838** though this is not guaranteed. ^The
7839** first parameter, szPage, is the size in bytes of the pages that must
7840** be allocated by the cache. ^szPage will always a power of two. ^The
7841** second parameter szExtra is a number of bytes of extra storage
7842** associated with each page cache entry. ^The szExtra parameter will
7843** a number less than 250. SQLite will use the
7844** extra szExtra bytes on each page to store metadata about the underlying
7845** database page on disk. The value passed into szExtra depends
7846** on the SQLite version, the target platform, and how SQLite was compiled.
7847** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7848** created will be used to cache database pages of a file stored on disk, or
7849** false if it is used for an in-memory database. The cache implementation
7850** does not have to do anything special based with the value of bPurgeable;
7851** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7852** never invoke xUnpin() except to deliberately delete a page.
7853** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7854** false will always have the "discard" flag set to true.
7855** ^Hence, a cache created with bPurgeable false will
7856** never contain any unpinned pages.
7857**
7858** [[the xCachesize() page cache method]]
7859** ^(The xCachesize() method may be called at any time by SQLite to set the
7860** suggested maximum cache-size (number of pages stored by) the cache
7861** instance passed as the first argument. This is the value configured using
7862** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7863** parameter, the implementation is not required to do anything with this
7864** value; it is advisory only.
7865**
7866** [[the xPagecount() page cache methods]]
7867** The xPagecount() method must return the number of pages currently
7868** stored in the cache, both pinned and unpinned.
7869**
7870** [[the xFetch() page cache methods]]
7871** The xFetch() method locates a page in the cache and returns a pointer to
7872** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7873** The pBuf element of the returned sqlite3_pcache_page object will be a
7874** pointer to a buffer of szPage bytes used to store the content of a
7875** single database page. The pExtra element of sqlite3_pcache_page will be
7876** a pointer to the szExtra bytes of extra storage that SQLite has requested
7877** for each entry in the page cache.
7878**
7879** The page to be fetched is determined by the key. ^The minimum key value
7880** is 1. After it has been retrieved using xFetch, the page is considered
7881** to be "pinned".
7882**
7883** If the requested page is already in the page cache, then the page cache
7884** implementation must return a pointer to the page buffer with its content
7885** intact. If the requested page is not already in the cache, then the
7886** cache implementation should use the value of the createFlag
7887** parameter to help it determined what action to take:
7888**
7889** <table border=1 width=85% align=center>
7890** <tr><th> createFlag <th> Behavior when page is not already in cache
7891** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7892** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7893** Otherwise return NULL.
7894** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7895** NULL if allocating a new page is effectively impossible.
7896** </table>
7897**
7898** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7899** will only use a createFlag of 2 after a prior call with a createFlag of 1
7900** failed.)^ In between the to xFetch() calls, SQLite may
7901** attempt to unpin one or more cache pages by spilling the content of
7902** pinned pages to disk and synching the operating system disk cache.
7903**
7904** [[the xUnpin() page cache method]]
7905** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7906** as its second argument. If the third parameter, discard, is non-zero,
7907** then the page must be evicted from the cache.
7908** ^If the discard parameter is
7909** zero, then the page may be discarded or retained at the discretion of
7910** page cache implementation. ^The page cache implementation
7911** may choose to evict unpinned pages at any time.
7912**
7913** The cache must not perform any reference counting. A single
7914** call to xUnpin() unpins the page regardless of the number of prior calls
7915** to xFetch().
7916**
7917** [[the xRekey() page cache methods]]
7918** The xRekey() method is used to change the key value associated with the
7919** page passed as the second argument. If the cache
7920** previously contains an entry associated with newKey, it must be
7921** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7922** to be pinned.
7923**
7924** When SQLite calls the xTruncate() method, the cache must discard all
7925** existing cache entries with page numbers (keys) greater than or equal
7926** to the value of the iLimit parameter passed to xTruncate(). If any
7927** of these pages are pinned, they are implicitly unpinned, meaning that
7928** they can be safely discarded.
7929**
7930** [[the xDestroy() page cache method]]
7931** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7932** All resources associated with the specified cache should be freed. ^After
7933** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7934** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7935** functions.
7936**
7937** [[the xShrink() page cache method]]
7938** ^SQLite invokes the xShrink() method when it wants the page cache to
7939** free up as much of heap memory as possible. The page cache implementation
7940** is not obligated to free any memory, but well-behaved implementations should
7941** do their best.
7942*/
7943typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7944struct sqlite3_pcache_methods2 {
7945 int iVersion;
7946 void *pArg;
7947 int (*xInit)(void*);
7948 void (*xShutdown)(void*);
7949 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7950 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7951 int (*xPagecount)(sqlite3_pcache*);
7952 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7953 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7954 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7955 unsigned oldKey, unsigned newKey);
7956 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7957 void (*xDestroy)(sqlite3_pcache*);
7958 void (*xShrink)(sqlite3_pcache*);
7959};
7960
7961/*
7962** This is the obsolete pcache_methods object that has now been replaced
7963** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
7964** retained in the header file for backwards compatibility only.
7965*/
7966typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
7967struct sqlite3_pcache_methods {
7968 void *pArg;
7969 int (*xInit)(void*);
7970 void (*xShutdown)(void*);
7971 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
7972 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7973 int (*xPagecount)(sqlite3_pcache*);
7974 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7975 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
7976 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
7977 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7978 void (*xDestroy)(sqlite3_pcache*);
7979};
7980
7981
7982/*
7983** CAPI3REF: Online Backup Object
7984**
7985** The sqlite3_backup object records state information about an ongoing
7986** online backup operation. ^The sqlite3_backup object is created by
7987** a call to [sqlite3_backup_init()] and is destroyed by a call to
7988** [sqlite3_backup_finish()].
7989**
7990** See Also: [Using the SQLite Online Backup API]
7991*/
7992typedef struct sqlite3_backup sqlite3_backup;
7993
7994/*
7995** CAPI3REF: Online Backup API.
7996**
7997** The backup API copies the content of one database into another.
7998** It is useful either for creating backups of databases or
7999** for copying in-memory databases to or from persistent files.
8000**
8001** See Also: [Using the SQLite Online Backup API]
8002**
8003** ^SQLite holds a write transaction open on the destination database file
8004** for the duration of the backup operation.
8005** ^The source database is read-locked only while it is being read;
8006** it is not locked continuously for the entire backup operation.
8007** ^Thus, the backup may be performed on a live source database without
8008** preventing other database connections from
8009** reading or writing to the source database while the backup is underway.
8010**
8011** ^(To perform a backup operation:
8012** <ol>
8013** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8014** backup,
8015** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8016** the data between the two databases, and finally
8017** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8018** associated with the backup operation.
8019** </ol>)^
8020** There should be exactly one call to sqlite3_backup_finish() for each
8021** successful call to sqlite3_backup_init().
8022**
8023** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8024**
8025** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8026** [database connection] associated with the destination database
8027** and the database name, respectively.
8028** ^The database name is "main" for the main database, "temp" for the
8029** temporary database, or the name specified after the AS keyword in
8030** an [ATTACH] statement for an attached database.
8031** ^The S and M arguments passed to
8032** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8033** and database name of the source database, respectively.
8034** ^The source and destination [database connections] (parameters S and D)
8035** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8036** an error.
8037**
8038** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8039** there is already a read or read-write transaction open on the
8040** destination database.
8041**
8042** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8043** returned and an error code and error message are stored in the
8044** destination [database connection] D.
8045** ^The error code and message for the failed call to sqlite3_backup_init()
8046** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8047** [sqlite3_errmsg16()] functions.
8048** ^A successful call to sqlite3_backup_init() returns a pointer to an
8049** [sqlite3_backup] object.
8050** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8051** sqlite3_backup_finish() functions to perform the specified backup
8052** operation.
8053**
8054** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8055**
8056** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8057** the source and destination databases specified by [sqlite3_backup] object B.
8058** ^If N is negative, all remaining source pages are copied.
8059** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8060** are still more pages to be copied, then the function returns [SQLITE_OK].
8061** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8062** from source to destination, then it returns [SQLITE_DONE].
8063** ^If an error occurs while running sqlite3_backup_step(B,N),
8064** then an [error code] is returned. ^As well as [SQLITE_OK] and
8065** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8066** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8067** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8068**
8069** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8070** <ol>
8071** <li> the destination database was opened read-only, or
8072** <li> the destination database is using write-ahead-log journaling
8073** and the destination and source page sizes differ, or
8074** <li> the destination database is an in-memory database and the
8075** destination and source page sizes differ.
8076** </ol>)^
8077**
8078** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8079** the [sqlite3_busy_handler | busy-handler function]
8080** is invoked (if one is specified). ^If the
8081** busy-handler returns non-zero before the lock is available, then
8082** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8083** sqlite3_backup_step() can be retried later. ^If the source
8084** [database connection]
8085** is being used to write to the source database when sqlite3_backup_step()
8086** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8087** case the call to sqlite3_backup_step() can be retried later on. ^(If
8088** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8089** [SQLITE_READONLY] is returned, then
8090** there is no point in retrying the call to sqlite3_backup_step(). These
8091** errors are considered fatal.)^ The application must accept
8092** that the backup operation has failed and pass the backup operation handle
8093** to the sqlite3_backup_finish() to release associated resources.
8094**
8095** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8096** on the destination file. ^The exclusive lock is not released until either
8097** sqlite3_backup_finish() is called or the backup operation is complete
8098** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8099** sqlite3_backup_step() obtains a [shared lock] on the source database that
8100** lasts for the duration of the sqlite3_backup_step() call.
8101** ^Because the source database is not locked between calls to
8102** sqlite3_backup_step(), the source database may be modified mid-way
8103** through the backup process. ^If the source database is modified by an
8104** external process or via a database connection other than the one being
8105** used by the backup operation, then the backup will be automatically
8106** restarted by the next call to sqlite3_backup_step(). ^If the source
8107** database is modified by the using the same database connection as is used
8108** by the backup operation, then the backup database is automatically
8109** updated at the same time.
8110**
8111** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8112**
8113** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8114** application wishes to abandon the backup operation, the application
8115** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8116** ^The sqlite3_backup_finish() interfaces releases all
8117** resources associated with the [sqlite3_backup] object.
8118** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8119** active write-transaction on the destination database is rolled back.
8120** The [sqlite3_backup] object is invalid
8121** and may not be used following a call to sqlite3_backup_finish().
8122**
8123** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8124** sqlite3_backup_step() errors occurred, regardless or whether or not
8125** sqlite3_backup_step() completed.
8126** ^If an out-of-memory condition or IO error occurred during any prior
8127** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8128** sqlite3_backup_finish() returns the corresponding [error code].
8129**
8130** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8131** is not a permanent error and does not affect the return value of
8132** sqlite3_backup_finish().
8133**
8134** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8135** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8136**
8137** ^The sqlite3_backup_remaining() routine returns the number of pages still
8138** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8139** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8140** in the source database at the conclusion of the most recent
8141** sqlite3_backup_step().
8142** ^(The values returned by these functions are only updated by
8143** sqlite3_backup_step(). If the source database is modified in a way that
8144** changes the size of the source database or the number of pages remaining,
8145** those changes are not reflected in the output of sqlite3_backup_pagecount()
8146** and sqlite3_backup_remaining() until after the next
8147** sqlite3_backup_step().)^
8148**
8149** <b>Concurrent Usage of Database Handles</b>
8150**
8151** ^The source [database connection] may be used by the application for other
8152** purposes while a backup operation is underway or being initialized.
8153** ^If SQLite is compiled and configured to support threadsafe database
8154** connections, then the source database connection may be used concurrently
8155** from within other threads.
8156**
8157** However, the application must guarantee that the destination
8158** [database connection] is not passed to any other API (by any thread) after
8159** sqlite3_backup_init() is called and before the corresponding call to
8160** sqlite3_backup_finish(). SQLite does not currently check to see
8161** if the application incorrectly accesses the destination [database connection]
8162** and so no error code is reported, but the operations may malfunction
8163** nevertheless. Use of the destination database connection while a
8164** backup is in progress might also also cause a mutex deadlock.
8165**
8166** If running in [shared cache mode], the application must
8167** guarantee that the shared cache used by the destination database
8168** is not accessed while the backup is running. In practice this means
8169** that the application must guarantee that the disk file being
8170** backed up to is not accessed by any connection within the process,
8171** not just the specific connection that was passed to sqlite3_backup_init().
8172**
8173** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8174** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8175** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8176** APIs are not strictly speaking threadsafe. If they are invoked at the
8177** same time as another thread is invoking sqlite3_backup_step() it is
8178** possible that they return invalid values.
8179*/
8180SQLITE_API sqlite3_backup *sqlite3_backup_init(
8181 sqlite3 *pDest, /* Destination database handle */
8182 const char *zDestName, /* Destination database name */
8183 sqlite3 *pSource, /* Source database handle */
8184 const char *zSourceName /* Source database name */
8185);
8186SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8187SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8188SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8189SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8190
8191/*
8192** CAPI3REF: Unlock Notification
8193** METHOD: sqlite3
8194**
8195** ^When running in shared-cache mode, a database operation may fail with
8196** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8197** individual tables within the shared-cache cannot be obtained. See
8198** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8199** ^This API may be used to register a callback that SQLite will invoke
8200** when the connection currently holding the required lock relinquishes it.
8201** ^This API is only available if the library was compiled with the
8202** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8203**
8204** See Also: [Using the SQLite Unlock Notification Feature].
8205**
8206** ^Shared-cache locks are released when a database connection concludes
8207** its current transaction, either by committing it or rolling it back.
8208**
8209** ^When a connection (known as the blocked connection) fails to obtain a
8210** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8211** identity of the database connection (the blocking connection) that
8212** has locked the required resource is stored internally. ^After an
8213** application receives an SQLITE_LOCKED error, it may call the
8214** sqlite3_unlock_notify() method with the blocked connection handle as
8215** the first argument to register for a callback that will be invoked
8216** when the blocking connections current transaction is concluded. ^The
8217** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8218** call that concludes the blocking connections transaction.
8219**
8220** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8221** there is a chance that the blocking connection will have already
8222** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8223** If this happens, then the specified callback is invoked immediately,
8224** from within the call to sqlite3_unlock_notify().)^
8225**
8226** ^If the blocked connection is attempting to obtain a write-lock on a
8227** shared-cache table, and more than one other connection currently holds
8228** a read-lock on the same table, then SQLite arbitrarily selects one of
8229** the other connections to use as the blocking connection.
8230**
8231** ^(There may be at most one unlock-notify callback registered by a
8232** blocked connection. If sqlite3_unlock_notify() is called when the
8233** blocked connection already has a registered unlock-notify callback,
8234** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8235** called with a NULL pointer as its second argument, then any existing
8236** unlock-notify callback is canceled. ^The blocked connections
8237** unlock-notify callback may also be canceled by closing the blocked
8238** connection using [sqlite3_close()].
8239**
8240** The unlock-notify callback is not reentrant. If an application invokes
8241** any sqlite3_xxx API functions from within an unlock-notify callback, a
8242** crash or deadlock may be the result.
8243**
8244** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8245** returns SQLITE_OK.
8246**
8247** <b>Callback Invocation Details</b>
8248**
8249** When an unlock-notify callback is registered, the application provides a
8250** single void* pointer that is passed to the callback when it is invoked.
8251** However, the signature of the callback function allows SQLite to pass
8252** it an array of void* context pointers. The first argument passed to
8253** an unlock-notify callback is a pointer to an array of void* pointers,
8254** and the second is the number of entries in the array.
8255**
8256** When a blocking connections transaction is concluded, there may be
8257** more than one blocked connection that has registered for an unlock-notify
8258** callback. ^If two or more such blocked connections have specified the
8259** same callback function, then instead of invoking the callback function
8260** multiple times, it is invoked once with the set of void* context pointers
8261** specified by the blocked connections bundled together into an array.
8262** This gives the application an opportunity to prioritize any actions
8263** related to the set of unblocked database connections.
8264**
8265** <b>Deadlock Detection</b>
8266**
8267** Assuming that after registering for an unlock-notify callback a
8268** database waits for the callback to be issued before taking any further
8269** action (a reasonable assumption), then using this API may cause the
8270** application to deadlock. For example, if connection X is waiting for
8271** connection Y's transaction to be concluded, and similarly connection
8272** Y is waiting on connection X's transaction, then neither connection
8273** will proceed and the system may remain deadlocked indefinitely.
8274**
8275** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8276** detection. ^If a given call to sqlite3_unlock_notify() would put the
8277** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8278** unlock-notify callback is registered. The system is said to be in
8279** a deadlocked state if connection A has registered for an unlock-notify
8280** callback on the conclusion of connection B's transaction, and connection
8281** B has itself registered for an unlock-notify callback when connection
8282** A's transaction is concluded. ^Indirect deadlock is also detected, so
8283** the system is also considered to be deadlocked if connection B has
8284** registered for an unlock-notify callback on the conclusion of connection
8285** C's transaction, where connection C is waiting on connection A. ^Any
8286** number of levels of indirection are allowed.
8287**
8288** <b>The "DROP TABLE" Exception</b>
8289**
8290** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
8291** always appropriate to call sqlite3_unlock_notify(). There is however,
8292** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8293** SQLite checks if there are any currently executing SELECT statements
8294** that belong to the same connection. If there are, SQLITE_LOCKED is
8295** returned. In this case there is no "blocking connection", so invoking
8296** sqlite3_unlock_notify() results in the unlock-notify callback being
8297** invoked immediately. If the application then re-attempts the "DROP TABLE"
8298** or "DROP INDEX" query, an infinite loop might be the result.
8299**
8300** One way around this problem is to check the extended error code returned
8301** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8302** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
8303** the special "DROP TABLE/INDEX" case, the extended error code is just
8304** SQLITE_LOCKED.)^
8305*/
8306SQLITE_API int sqlite3_unlock_notify(
8307 sqlite3 *pBlocked, /* Waiting connection */
8308 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8309 void *pNotifyArg /* Argument to pass to xNotify */
8310);
8311
8312
8313/*
8314** CAPI3REF: String Comparison
8315**
8316** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8317** and extensions to compare the contents of two buffers containing UTF-8
8318** strings in a case-independent fashion, using the same definition of "case
8319** independence" that SQLite uses internally when comparing identifiers.
8320*/
8321SQLITE_API int sqlite3_stricmp(const char *, const char *);
8322SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8323
8324/*
8325** CAPI3REF: String Globbing
8326*
8327** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8328** string X matches the [GLOB] pattern P.
8329** ^The definition of [GLOB] pattern matching used in
8330** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8331** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8332** is case sensitive.
8333**
8334** Note that this routine returns zero on a match and non-zero if the strings
8335** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8336**
8337** See also: [sqlite3_strlike()].
8338*/
8339SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8340
8341/*
8342** CAPI3REF: String LIKE Matching
8343*
8344** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8345** string X matches the [LIKE] pattern P with escape character E.
8346** ^The definition of [LIKE] pattern matching used in
8347** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8348** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8349** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8350** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8351** insensitive - equivalent upper and lower case ASCII characters match
8352** one another.
8353**
8354** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8355** only ASCII characters are case folded.
8356**
8357** Note that this routine returns zero on a match and non-zero if the strings
8358** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8359**
8360** See also: [sqlite3_strglob()].
8361*/
8362SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8363
8364/*
8365** CAPI3REF: Error Logging Interface
8366**
8367** ^The [sqlite3_log()] interface writes a message into the [error log]
8368** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8369** ^If logging is enabled, the zFormat string and subsequent arguments are
8370** used with [sqlite3_snprintf()] to generate the final output string.
8371**
8372** The sqlite3_log() interface is intended for use by extensions such as
8373** virtual tables, collating functions, and SQL functions. While there is
8374** nothing to prevent an application from calling sqlite3_log(), doing so
8375** is considered bad form.
8376**
8377** The zFormat string must not be NULL.
8378**
8379** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8380** will not use dynamically allocated memory. The log message is stored in
8381** a fixed-length buffer on the stack. If the log message is longer than
8382** a few hundred characters, it will be truncated to the length of the
8383** buffer.
8384*/
8385SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8386
8387/*
8388** CAPI3REF: Write-Ahead Log Commit Hook
8389** METHOD: sqlite3
8390**
8391** ^The [sqlite3_wal_hook()] function is used to register a callback that
8392** is invoked each time data is committed to a database in wal mode.
8393**
8394** ^(The callback is invoked by SQLite after the commit has taken place and
8395** the associated write-lock on the database released)^, so the implementation
8396** may read, write or [checkpoint] the database as required.
8397**
8398** ^The first parameter passed to the callback function when it is invoked
8399** is a copy of the third parameter passed to sqlite3_wal_hook() when
8400** registering the callback. ^The second is a copy of the database handle.
8401** ^The third parameter is the name of the database that was written to -
8402** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8403** is the number of pages currently in the write-ahead log file,
8404** including those that were just committed.
8405**
8406** The callback function should normally return [SQLITE_OK]. ^If an error
8407** code is returned, that error will propagate back up through the
8408** SQLite code base to cause the statement that provoked the callback
8409** to report an error, though the commit will have still occurred. If the
8410** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8411** that does not correspond to any valid SQLite error code, the results
8412** are undefined.
8413**
8414** A single database handle may have at most a single write-ahead log callback
8415** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8416** previously registered write-ahead log callback. ^Note that the
8417** [sqlite3_wal_autocheckpoint()] interface and the
8418** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8419** overwrite any prior [sqlite3_wal_hook()] settings.
8420*/
8421SQLITE_API void *sqlite3_wal_hook(
8422 sqlite3*,
8423 int(*)(void *,sqlite3*,const char*,int),
8424 void*
8425);
8426
8427/*
8428** CAPI3REF: Configure an auto-checkpoint
8429** METHOD: sqlite3
8430**
8431** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8432** [sqlite3_wal_hook()] that causes any database on [database connection] D
8433** to automatically [checkpoint]
8434** after committing a transaction if there are N or
8435** more frames in the [write-ahead log] file. ^Passing zero or
8436** a negative value as the nFrame parameter disables automatic
8437** checkpoints entirely.
8438**
8439** ^The callback registered by this function replaces any existing callback
8440** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8441** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8442** configured by this function.
8443**
8444** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8445** from SQL.
8446**
8447** ^Checkpoints initiated by this mechanism are
8448** [sqlite3_wal_checkpoint_v2|PASSIVE].
8449**
8450** ^Every new [database connection] defaults to having the auto-checkpoint
8451** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
8452** pages. The use of this interface
8453** is only necessary if the default setting is found to be suboptimal
8454** for a particular application.
8455*/
8456SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
8457
8458/*
8459** CAPI3REF: Checkpoint a database
8460** METHOD: sqlite3
8461**
8462** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
8463** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
8464**
8465** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
8466** [write-ahead log] for database X on [database connection] D to be
8467** transferred into the database file and for the write-ahead log to
8468** be reset. See the [checkpointing] documentation for addition
8469** information.
8470**
8471** This interface used to be the only way to cause a checkpoint to
8472** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
8473** interface was added. This interface is retained for backwards
8474** compatibility and as a convenience for applications that need to manually
8475** start a callback but which do not need the full power (and corresponding
8476** complication) of [sqlite3_wal_checkpoint_v2()].
8477*/
8478SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
8479
8480/*
8481** CAPI3REF: Checkpoint a database
8482** METHOD: sqlite3
8483**
8484** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
8485** operation on database X of [database connection] D in mode M. Status
8486** information is written back into integers pointed to by L and C.)^
8487** ^(The M parameter must be a valid [checkpoint mode]:)^
8488**
8489** <dl>
8490** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
8491** ^Checkpoint as many frames as possible without waiting for any database
8492** readers or writers to finish, then sync the database file if all frames
8493** in the log were checkpointed. ^The [busy-handler callback]
8494** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
8495** ^On the other hand, passive mode might leave the checkpoint unfinished
8496** if there are concurrent readers or writers.
8497**
8498** <dt>SQLITE_CHECKPOINT_FULL<dd>
8499** ^This mode blocks (it invokes the
8500** [sqlite3_busy_handler|busy-handler callback]) until there is no
8501** database writer and all readers are reading from the most recent database
8502** snapshot. ^It then checkpoints all frames in the log file and syncs the
8503** database file. ^This mode blocks new database writers while it is pending,
8504** but new database readers are allowed to continue unimpeded.
8505**
8506** <dt>SQLITE_CHECKPOINT_RESTART<dd>
8507** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
8508** that after checkpointing the log file it blocks (calls the
8509** [busy-handler callback])
8510** until all readers are reading from the database file only. ^This ensures
8511** that the next writer will restart the log file from the beginning.
8512** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
8513** database writer attempts while it is pending, but does not impede readers.
8514**
8515** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
8516** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
8517** addition that it also truncates the log file to zero bytes just prior
8518** to a successful return.
8519** </dl>
8520**
8521** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
8522** the log file or to -1 if the checkpoint could not run because
8523** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
8524** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
8525** log file (including any that were already checkpointed before the function
8526** was called) or to -1 if the checkpoint could not run due to an error or
8527** because the database is not in WAL mode. ^Note that upon successful
8528** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
8529** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
8530**
8531** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
8532** any other process is running a checkpoint operation at the same time, the
8533** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
8534** busy-handler configured, it will not be invoked in this case.
8535**
8536** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
8537** exclusive "writer" lock on the database file. ^If the writer lock cannot be
8538** obtained immediately, and a busy-handler is configured, it is invoked and
8539** the writer lock retried until either the busy-handler returns 0 or the lock
8540** is successfully obtained. ^The busy-handler is also invoked while waiting for
8541** database readers as described above. ^If the busy-handler returns 0 before
8542** the writer lock is obtained or while waiting for database readers, the
8543** checkpoint operation proceeds from that point in the same way as
8544** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
8545** without blocking any further. ^SQLITE_BUSY is returned in this case.
8546**
8547** ^If parameter zDb is NULL or points to a zero length string, then the
8548** specified operation is attempted on all WAL databases [attached] to
8549** [database connection] db. In this case the
8550** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
8551** an SQLITE_BUSY error is encountered when processing one or more of the
8552** attached WAL databases, the operation is still attempted on any remaining
8553** attached databases and SQLITE_BUSY is returned at the end. ^If any other
8554** error occurs while processing an attached database, processing is abandoned
8555** and the error code is returned to the caller immediately. ^If no error
8556** (SQLITE_BUSY or otherwise) is encountered while processing the attached
8557** databases, SQLITE_OK is returned.
8558**
8559** ^If database zDb is the name of an attached database that is not in WAL
8560** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
8561** zDb is not NULL (or a zero length string) and is not the name of any
8562** attached database, SQLITE_ERROR is returned to the caller.
8563**
8564** ^Unless it returns SQLITE_MISUSE,
8565** the sqlite3_wal_checkpoint_v2() interface
8566** sets the error information that is queried by
8567** [sqlite3_errcode()] and [sqlite3_errmsg()].
8568**
8569** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
8570** from SQL.
8571*/
8572SQLITE_API int sqlite3_wal_checkpoint_v2(
8573 sqlite3 *db, /* Database handle */
8574 const char *zDb, /* Name of attached database (or NULL) */
8575 int eMode, /* SQLITE_CHECKPOINT_* value */
8576 int *pnLog, /* OUT: Size of WAL log in frames */
8577 int *pnCkpt /* OUT: Total number of frames checkpointed */
8578);
8579
8580/*
8581** CAPI3REF: Checkpoint Mode Values
8582** KEYWORDS: {checkpoint mode}
8583**
8584** These constants define all valid values for the "checkpoint mode" passed
8585** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
8586** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
8587** meaning of each of these checkpoint modes.
8588*/
8589#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
8590#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
8591#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
8592#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
8593
8594/*
8595** CAPI3REF: Virtual Table Interface Configuration
8596**
8597** This function may be called by either the [xConnect] or [xCreate] method
8598** of a [virtual table] implementation to configure
8599** various facets of the virtual table interface.
8600**
8601** If this interface is invoked outside the context of an xConnect or
8602** xCreate virtual table method then the behavior is undefined.
8603**
8604** At present, there is only one option that may be configured using
8605** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
8606** may be added in the future.
8607*/
8608SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
8609
8610/*
8611** CAPI3REF: Virtual Table Configuration Options
8612**
8613** These macros define the various options to the
8614** [sqlite3_vtab_config()] interface that [virtual table] implementations
8615** can use to customize and optimize their behavior.
8616**
8617** <dl>
8618** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
8619** <dd>Calls of the form
8620** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
8621** where X is an integer. If X is zero, then the [virtual table] whose
8622** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
8623** support constraints. In this configuration (which is the default) if
8624** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
8625** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
8626** specified as part of the users SQL statement, regardless of the actual
8627** ON CONFLICT mode specified.
8628**
8629** If X is non-zero, then the virtual table implementation guarantees
8630** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
8631** any modifications to internal or persistent data structures have been made.
8632** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
8633** is able to roll back a statement or database transaction, and abandon
8634** or continue processing the current SQL statement as appropriate.
8635** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
8636** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
8637** had been ABORT.
8638**
8639** Virtual table implementations that are required to handle OR REPLACE
8640** must do so within the [xUpdate] method. If a call to the
8641** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8642** CONFLICT policy is REPLACE, the virtual table implementation should
8643** silently replace the appropriate rows within the xUpdate callback and
8644** return SQLITE_OK. Or, if this is not possible, it may return
8645** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8646** constraint handling.
8647** </dl>
8648*/
8649#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8650
8651/*
8652** CAPI3REF: Determine The Virtual Table Conflict Policy
8653**
8654** This function may only be called from within a call to the [xUpdate] method
8655** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8656** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8657** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8658** of the SQL statement that triggered the call to the [xUpdate] method of the
8659** [virtual table].
8660*/
8661SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8662
8663/*
8664** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
8665**
8666** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
8667** method of a [virtual table], then it returns true if and only if the
8668** column is being fetched as part of an UPDATE operation during which the
8669** column value will not change. Applications might use this to substitute
8670** a return value that is less expensive to compute and that the corresponding
8671** [xUpdate] method understands as a "no-change" value.
8672**
8673** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
8674** the column is not changed by the UPDATE statement, then the xColumn
8675** method can optionally return without setting a result, without calling
8676** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
8677** In that case, [sqlite3_value_nochange(X)] will return true for the
8678** same column in the [xUpdate] method.
8679*/
8680SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
8681
8682/*
8683** CAPI3REF: Determine The Collation For a Virtual Table Constraint
8684**
8685** This function may only be called from within a call to the [xBestIndex]
8686** method of a [virtual table].
8687**
8688** The first argument must be the sqlite3_index_info object that is the
8689** first parameter to the xBestIndex() method. The second argument must be
8690** an index into the aConstraint[] array belonging to the sqlite3_index_info
8691** structure passed to xBestIndex. This function returns a pointer to a buffer
8692** containing the name of the collation sequence for the corresponding
8693** constraint.
8694*/
8695SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
8696
8697/*
8698** CAPI3REF: Conflict resolution modes
8699** KEYWORDS: {conflict resolution mode}
8700**
8701** These constants are returned by [sqlite3_vtab_on_conflict()] to
8702** inform a [virtual table] implementation what the [ON CONFLICT] mode
8703** is for the SQL statement being evaluated.
8704**
8705** Note that the [SQLITE_IGNORE] constant is also used as a potential
8706** return value from the [sqlite3_set_authorizer()] callback and that
8707** [SQLITE_ABORT] is also a [result code].
8708*/
8709#define SQLITE_ROLLBACK 1
8710/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8711#define SQLITE_FAIL 3
8712/* #define SQLITE_ABORT 4 // Also an error code */
8713#define SQLITE_REPLACE 5
8714
8715/*
8716** CAPI3REF: Prepared Statement Scan Status Opcodes
8717** KEYWORDS: {scanstatus options}
8718**
8719** The following constants can be used for the T parameter to the
8720** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8721** different metric for sqlite3_stmt_scanstatus() to return.
8722**
8723** When the value returned to V is a string, space to hold that string is
8724** managed by the prepared statement S and will be automatically freed when
8725** S is finalized.
8726**
8727** <dl>
8728** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8729** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8730** set to the total number of times that the X-th loop has run.</dd>
8731**
8732** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8733** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8734** to the total number of rows examined by all iterations of the X-th loop.</dd>
8735**
8736** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8737** <dd>^The "double" variable pointed to by the T parameter will be set to the
8738** query planner's estimate for the average number of rows output from each
8739** iteration of the X-th loop. If the query planner's estimates was accurate,
8740** then this value will approximate the quotient NVISIT/NLOOP and the
8741** product of this value for all prior loops with the same SELECTID will
8742** be the NLOOP value for the current loop.
8743**
8744** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8745** <dd>^The "const char *" variable pointed to by the T parameter will be set
8746** to a zero-terminated UTF-8 string containing the name of the index or table
8747** used for the X-th loop.
8748**
8749** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8750** <dd>^The "const char *" variable pointed to by the T parameter will be set
8751** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8752** description for the X-th loop.
8753**
8754** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8755** <dd>^The "int" variable pointed to by the T parameter will be set to the
8756** "select-id" for the X-th loop. The select-id identifies which query or
8757** subquery the loop is part of. The main query has a select-id of zero.
8758** The select-id is the same value as is output in the first column
8759** of an [EXPLAIN QUERY PLAN] query.
8760** </dl>
8761*/
8762#define SQLITE_SCANSTAT_NLOOP 0
8763#define SQLITE_SCANSTAT_NVISIT 1
8764#define SQLITE_SCANSTAT_EST 2
8765#define SQLITE_SCANSTAT_NAME 3
8766#define SQLITE_SCANSTAT_EXPLAIN 4
8767#define SQLITE_SCANSTAT_SELECTID 5
8768
8769/*
8770** CAPI3REF: Prepared Statement Scan Status
8771** METHOD: sqlite3_stmt
8772**
8773** This interface returns information about the predicted and measured
8774** performance for pStmt. Advanced applications can use this
8775** interface to compare the predicted and the measured performance and
8776** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8777**
8778** Since this interface is expected to be rarely used, it is only
8779** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8780** compile-time option.
8781**
8782** The "iScanStatusOp" parameter determines which status information to return.
8783** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8784** of this interface is undefined.
8785** ^The requested measurement is written into a variable pointed to by
8786** the "pOut" parameter.
8787** Parameter "idx" identifies the specific loop to retrieve statistics for.
8788** Loops are numbered starting from zero. ^If idx is out of range - less than
8789** zero or greater than or equal to the total number of loops used to implement
8790** the statement - a non-zero value is returned and the variable that pOut
8791** points to is unchanged.
8792**
8793** ^Statistics might not be available for all loops in all statements. ^In cases
8794** where there exist loops with no available statistics, this function behaves
8795** as if the loop did not exist - it returns non-zero and leave the variable
8796** that pOut points to unchanged.
8797**
8798** See also: [sqlite3_stmt_scanstatus_reset()]
8799*/
8800SQLITE_API int sqlite3_stmt_scanstatus(
8801 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8802 int idx, /* Index of loop to report on */
8803 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8804 void *pOut /* Result written here */
8805);
8806
8807/*
8808** CAPI3REF: Zero Scan-Status Counters
8809** METHOD: sqlite3_stmt
8810**
8811** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8812**
8813** This API is only available if the library is built with pre-processor
8814** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8815*/
8816SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8817
8818/*
8819** CAPI3REF: Flush caches to disk mid-transaction
8820**
8821** ^If a write-transaction is open on [database connection] D when the
8822** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8823** pages in the pager-cache that are not currently in use are written out
8824** to disk. A dirty page may be in use if a database cursor created by an
8825** active SQL statement is reading from it, or if it is page 1 of a database
8826** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8827** interface flushes caches for all schemas - "main", "temp", and
8828** any [attached] databases.
8829**
8830** ^If this function needs to obtain extra database locks before dirty pages
8831** can be flushed to disk, it does so. ^If those locks cannot be obtained
8832** immediately and there is a busy-handler callback configured, it is invoked
8833** in the usual manner. ^If the required lock still cannot be obtained, then
8834** the database is skipped and an attempt made to flush any dirty pages
8835** belonging to the next (if any) database. ^If any databases are skipped
8836** because locks cannot be obtained, but no other error occurs, this
8837** function returns SQLITE_BUSY.
8838**
8839** ^If any other error occurs while flushing dirty pages to disk (for
8840** example an IO error or out-of-memory condition), then processing is
8841** abandoned and an SQLite [error code] is returned to the caller immediately.
8842**
8843** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8844**
8845** ^This function does not set the database handle error code or message
8846** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8847*/
8848SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8849
8850/*
8851** CAPI3REF: The pre-update hook.
8852**
8853** ^These interfaces are only available if SQLite is compiled using the
8854** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8855**
8856** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8857** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8858** on a database table.
8859** ^At most one preupdate hook may be registered at a time on a single
8860** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8861** the previous setting.
8862** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8863** with a NULL pointer as the second parameter.
8864** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8865** the first parameter to callbacks.
8866**
8867** ^The preupdate hook only fires for changes to real database tables; the
8868** preupdate hook is not invoked for changes to [virtual tables] or to
8869** system tables like sqlite_master or sqlite_stat1.
8870**
8871** ^The second parameter to the preupdate callback is a pointer to
8872** the [database connection] that registered the preupdate hook.
8873** ^The third parameter to the preupdate callback is one of the constants
8874** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8875** kind of update operation that is about to occur.
8876** ^(The fourth parameter to the preupdate callback is the name of the
8877** database within the database connection that is being modified. This
8878** will be "main" for the main database or "temp" for TEMP tables or
8879** the name given after the AS keyword in the [ATTACH] statement for attached
8880** databases.)^
8881** ^The fifth parameter to the preupdate callback is the name of the
8882** table that is being modified.
8883**
8884** For an UPDATE or DELETE operation on a [rowid table], the sixth
8885** parameter passed to the preupdate callback is the initial [rowid] of the
8886** row being modified or deleted. For an INSERT operation on a rowid table,
8887** or any operation on a WITHOUT ROWID table, the value of the sixth
8888** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8889** seventh parameter is the final rowid value of the row being inserted
8890** or updated. The value of the seventh parameter passed to the callback
8891** function is not defined for operations on WITHOUT ROWID tables, or for
8892** INSERT operations on rowid tables.
8893**
8894** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
8895** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
8896** provide additional information about a preupdate event. These routines
8897** may only be called from within a preupdate callback. Invoking any of
8898** these routines from outside of a preupdate callback or with a
8899** [database connection] pointer that is different from the one supplied
8900** to the preupdate callback results in undefined and probably undesirable
8901** behavior.
8902**
8903** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8904** in the row that is being inserted, updated, or deleted.
8905**
8906** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8907** a [protected sqlite3_value] that contains the value of the Nth column of
8908** the table row before it is updated. The N parameter must be between 0
8909** and one less than the number of columns or the behavior will be
8910** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8911** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8912** behavior is undefined. The [sqlite3_value] that P points to
8913** will be destroyed when the preupdate callback returns.
8914**
8915** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8916** a [protected sqlite3_value] that contains the value of the Nth column of
8917** the table row after it is updated. The N parameter must be between 0
8918** and one less than the number of columns or the behavior will be
8919** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8920** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8921** behavior is undefined. The [sqlite3_value] that P points to
8922** will be destroyed when the preupdate callback returns.
8923**
8924** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8925** callback was invoked as a result of a direct insert, update, or delete
8926** operation; or 1 for inserts, updates, or deletes invoked by top-level
8927** triggers; or 2 for changes resulting from triggers called by top-level
8928** triggers; and so forth.
8929**
8930** See also: [sqlite3_update_hook()]
8931*/
8932#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
8933SQLITE_API void *sqlite3_preupdate_hook(
8934 sqlite3 *db,
8935 void(*xPreUpdate)(
8936 void *pCtx, /* Copy of third arg to preupdate_hook() */
8937 sqlite3 *db, /* Database handle */
8938 int op, /* SQLITE_UPDATE, DELETE or INSERT */
8939 char const *zDb, /* Database name */
8940 char const *zName, /* Table name */
8941 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
8942 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
8943 ),
8944 void*
8945);
8946SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
8947SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
8948SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
8949SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
8950#endif
8951
8952/*
8953** CAPI3REF: Low-level system error code
8954**
8955** ^Attempt to return the underlying operating system error code or error
8956** number that caused the most recent I/O error or failure to open a file.
8957** The return value is OS-dependent. For example, on unix systems, after
8958** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
8959** called to get back the underlying "errno" that caused the problem, such
8960** as ENOSPC, EAUTH, EISDIR, and so forth.
8961*/
8962SQLITE_API int sqlite3_system_errno(sqlite3*);
8963
8964/*
8965** CAPI3REF: Database Snapshot
8966** KEYWORDS: {snapshot} {sqlite3_snapshot}
8967**
8968** An instance of the snapshot object records the state of a [WAL mode]
8969** database for some specific point in history.
8970**
8971** In [WAL mode], multiple [database connections] that are open on the
8972** same database file can each be reading a different historical version
8973** of the database file. When a [database connection] begins a read
8974** transaction, that connection sees an unchanging copy of the database
8975** as it existed for the point in time when the transaction first started.
8976** Subsequent changes to the database from other connections are not seen
8977** by the reader until a new read transaction is started.
8978**
8979** The sqlite3_snapshot object records state information about an historical
8980** version of the database file so that it is possible to later open a new read
8981** transaction that sees that historical version of the database rather than
8982** the most recent version.
8983*/
8984typedef struct sqlite3_snapshot {
8985 unsigned char hidden[48];
8986} sqlite3_snapshot;
8987
8988/*
8989** CAPI3REF: Record A Database Snapshot
8990** CONSTRUCTOR: sqlite3_snapshot
8991**
8992** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
8993** new [sqlite3_snapshot] object that records the current state of
8994** schema S in database connection D. ^On success, the
8995** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
8996** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
8997** If there is not already a read-transaction open on schema S when
8998** this function is called, one is opened automatically.
8999**
9000** The following must be true for this function to succeed. If any of
9001** the following statements are false when sqlite3_snapshot_get() is
9002** called, SQLITE_ERROR is returned. The final value of *P is undefined
9003** in this case.
9004**
9005** <ul>
9006** <li> The database handle must not be in [autocommit mode].
9007**
9008** <li> Schema S of [database connection] D must be a [WAL mode] database.
9009**
9010** <li> There must not be a write transaction open on schema S of database
9011** connection D.
9012**
9013** <li> One or more transactions must have been written to the current wal
9014** file since it was created on disk (by any connection). This means
9015** that a snapshot cannot be taken on a wal mode database with no wal
9016** file immediately after it is first opened. At least one transaction
9017** must be written to it first.
9018** </ul>
9019**
9020** This function may also return SQLITE_NOMEM. If it is called with the
9021** database handle in autocommit mode but fails for some other reason,
9022** whether or not a read transaction is opened on schema S is undefined.
9023**
9024** The [sqlite3_snapshot] object returned from a successful call to
9025** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9026** to avoid a memory leak.
9027**
9028** The [sqlite3_snapshot_get()] interface is only available when the
9029** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9030*/
9031SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9032 sqlite3 *db,
9033 const char *zSchema,
9034 sqlite3_snapshot **ppSnapshot
9035);
9036
9037/*
9038** CAPI3REF: Start a read transaction on an historical snapshot
9039** METHOD: sqlite3_snapshot
9040**
9041** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9042** transaction or upgrades an existing one for schema S of
9043** [database connection] D such that the read transaction refers to
9044** historical [snapshot] P, rather than the most recent change to the
9045** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9046** on success or an appropriate [error code] if it fails.
9047**
9048** ^In order to succeed, the database connection must not be in
9049** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9050** is already a read transaction open on schema S, then the database handle
9051** must have no active statements (SELECT statements that have been passed
9052** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9053** SQLITE_ERROR is returned if either of these conditions is violated, or
9054** if schema S does not exist, or if the snapshot object is invalid.
9055**
9056** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9057** snapshot has been overwritten by a [checkpoint]. In this case
9058** SQLITE_ERROR_SNAPSHOT is returned.
9059**
9060** If there is already a read transaction open when this function is
9061** invoked, then the same read transaction remains open (on the same
9062** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9063** is returned. If another error code - for example SQLITE_PROTOCOL or an
9064** SQLITE_IOERR error code - is returned, then the final state of the
9065** read transaction is undefined. If SQLITE_OK is returned, then the
9066** read transaction is now open on database snapshot P.
9067**
9068** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9069** database connection D does not know that the database file for
9070** schema S is in [WAL mode]. A database connection might not know
9071** that the database file is in [WAL mode] if there has been no prior
9072** I/O on that database connection, or if the database entered [WAL mode]
9073** after the most recent I/O on the database connection.)^
9074** (Hint: Run "[PRAGMA application_id]" against a newly opened
9075** database connection in order to make it ready to use snapshots.)
9076**
9077** The [sqlite3_snapshot_open()] interface is only available when the
9078** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9079*/
9080SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9081 sqlite3 *db,
9082 const char *zSchema,
9083 sqlite3_snapshot *pSnapshot
9084);
9085
9086/*
9087** CAPI3REF: Destroy a snapshot
9088** DESTRUCTOR: sqlite3_snapshot
9089**
9090** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9091** The application must eventually free every [sqlite3_snapshot] object
9092** using this routine to avoid a memory leak.
9093**
9094** The [sqlite3_snapshot_free()] interface is only available when the
9095** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9096*/
9097SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9098
9099/*
9100** CAPI3REF: Compare the ages of two snapshot handles.
9101** METHOD: sqlite3_snapshot
9102**
9103** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9104** of two valid snapshot handles.
9105**
9106** If the two snapshot handles are not associated with the same database
9107** file, the result of the comparison is undefined.
9108**
9109** Additionally, the result of the comparison is only valid if both of the
9110** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9111** last time the wal file was deleted. The wal file is deleted when the
9112** database is changed back to rollback mode or when the number of database
9113** clients drops to zero. If either snapshot handle was obtained before the
9114** wal file was last deleted, the value returned by this function
9115** is undefined.
9116**
9117** Otherwise, this API returns a negative value if P1 refers to an older
9118** snapshot than P2, zero if the two handles refer to the same database
9119** snapshot, and a positive value if P1 is a newer snapshot than P2.
9120**
9121** This interface is only available if SQLite is compiled with the
9122** [SQLITE_ENABLE_SNAPSHOT] option.
9123*/
9124SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9125 sqlite3_snapshot *p1,
9126 sqlite3_snapshot *p2
9127);
9128
9129/*
9130** CAPI3REF: Recover snapshots from a wal file
9131** METHOD: sqlite3_snapshot
9132**
9133** If a [WAL file] remains on disk after all database connections close
9134** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9135** or because the last process to have the database opened exited without
9136** calling [sqlite3_close()]) and a new connection is subsequently opened
9137** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9138** will only be able to open the last transaction added to the WAL file
9139** even though the WAL file contains other valid transactions.
9140**
9141** This function attempts to scan the WAL file associated with database zDb
9142** of database handle db and make all valid snapshots available to
9143** sqlite3_snapshot_open(). It is an error if there is already a read
9144** transaction open on the database, or if the database is not a WAL mode
9145** database.
9146**
9147** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9148**
9149** This interface is only available if SQLite is compiled with the
9150** [SQLITE_ENABLE_SNAPSHOT] option.
9151*/
9152SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9153
9154/*
9155** CAPI3REF: Serialize a database
9156**
9157** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9158** that is a serialization of the S database on [database connection] D.
9159** If P is not a NULL pointer, then the size of the database in bytes
9160** is written into *P.
9161**
9162** For an ordinary on-disk database file, the serialization is just a
9163** copy of the disk file. For an in-memory database or a "TEMP" database,
9164** the serialization is the same sequence of bytes which would be written
9165** to disk if that database where backed up to disk.
9166**
9167** The usual case is that sqlite3_serialize() copies the serialization of
9168** the database into memory obtained from [sqlite3_malloc64()] and returns
9169** a pointer to that memory. The caller is responsible for freeing the
9170** returned value to avoid a memory leak. However, if the F argument
9171** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9172** are made, and the sqlite3_serialize() function will return a pointer
9173** to the contiguous memory representation of the database that SQLite
9174** is currently using for that database, or NULL if the no such contiguous
9175** memory representation of the database exists. A contiguous memory
9176** representation of the database will usually only exist if there has
9177** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9178** values of D and S.
9179** The size of the database is written into *P even if the
9180** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9181** of the database exists.
9182**
9183** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9184** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9185** allocation error occurs.
9186**
9187** This interface is only available if SQLite is compiled with the
9188** [SQLITE_ENABLE_DESERIALIZE] option.
9189*/
9190SQLITE_API unsigned char *sqlite3_serialize(
9191 sqlite3 *db, /* The database connection */
9192 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9193 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9194 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9195);
9196
9197/*
9198** CAPI3REF: Flags for sqlite3_serialize
9199**
9200** Zero or more of the following constants can be OR-ed together for
9201** the F argument to [sqlite3_serialize(D,S,P,F)].
9202**
9203** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9204** a pointer to contiguous in-memory database that it is currently using,
9205** without making a copy of the database. If SQLite is not currently using
9206** a contiguous in-memory database, then this option causes
9207** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9208** using a contiguous in-memory database if it has been initialized by a
9209** prior call to [sqlite3_deserialize()].
9210*/
9211#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9212
9213/*
9214** CAPI3REF: Deserialize a database
9215**
9216** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9217** [database connection] D to disconnect from database S and then
9218** reopen S as an in-memory database based on the serialization contained
9219** in P. The serialized database P is N bytes in size. M is the size of
9220** the buffer P, which might be larger than N. If M is larger than N, and
9221** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9222** permitted to add content to the in-memory database as long as the total
9223** size does not exceed M bytes.
9224**
9225** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9226** invoke sqlite3_free() on the serialization buffer when the database
9227** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9228** SQLite will try to increase the buffer size using sqlite3_realloc64()
9229** if writes on the database cause it to grow larger than M bytes.
9230**
9231** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9232** database is currently in a read transaction or is involved in a backup
9233** operation.
9234**
9235** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9236** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9237** [sqlite3_free()] is invoked on argument P prior to returning.
9238**
9239** This interface is only available if SQLite is compiled with the
9240** [SQLITE_ENABLE_DESERIALIZE] option.
9241*/
9242SQLITE_API int sqlite3_deserialize(
9243 sqlite3 *db, /* The database connection */
9244 const char *zSchema, /* Which DB to reopen with the deserialization */
9245 unsigned char *pData, /* The serialized database content */
9246 sqlite3_int64 szDb, /* Number bytes in the deserialization */
9247 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9248 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9249);
9250
9251/*
9252** CAPI3REF: Flags for sqlite3_deserialize()
9253**
9254** The following are allowed values for 6th argument (the F argument) to
9255** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9256**
9257** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9258** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9259** and that SQLite should take ownership of this memory and automatically
9260** free it when it has finished using it. Without this flag, the caller
9261** is responsible for freeing any dynamically allocated memory.
9262**
9263** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9264** grow the size of the database using calls to [sqlite3_realloc64()]. This
9265** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9266** Without this flag, the deserialized database cannot increase in size beyond
9267** the number of bytes specified by the M parameter.
9268**
9269** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9270** should be treated as read-only.
9271*/
9272#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9273#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9274#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9275
9276/*
9277** Undo the hack that converts floating point types to integer for
9278** builds on processors without floating point support.
9279*/
9280#ifdef SQLITE_OMIT_FLOATING_POINT
9281# undef double
9282#endif
9283
9284#ifdef __cplusplus
9285} /* End of the 'extern "C"' block */
9286#endif
9287#endif /* SQLITE3_H */
9288
9289/******** Begin file sqlite3rtree.h *********/
9290/*
9291** 2010 August 30
9292**
9293** The author disclaims copyright to this source code. In place of
9294** a legal notice, here is a blessing:
9295**
9296** May you do good and not evil.
9297** May you find forgiveness for yourself and forgive others.
9298** May you share freely, never taking more than you give.
9299**
9300*************************************************************************
9301*/
9302
9303#ifndef _SQLITE3RTREE_H_
9304#define _SQLITE3RTREE_H_
9305
9306
9307#ifdef __cplusplus
9308extern "C" {
9309#endif
9310
9311typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
9312typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9313
9314/* The double-precision datatype used by RTree depends on the
9315** SQLITE_RTREE_INT_ONLY compile-time option.
9316*/
9317#ifdef SQLITE_RTREE_INT_ONLY
9318 typedef sqlite3_int64 sqlite3_rtree_dbl;
9319#else
9320 typedef double sqlite3_rtree_dbl;
9321#endif
9322
9323/*
9324** Register a geometry callback named zGeom that can be used as part of an
9325** R-Tree geometry query as follows:
9326**
9327** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9328*/
9329SQLITE_API int sqlite3_rtree_geometry_callback(
9330 sqlite3 *db,
9331 const char *zGeom,
9332 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
9333 void *pContext
9334);
9335
9336
9337/*
9338** A pointer to a structure of the following type is passed as the first
9339** argument to callbacks registered using rtree_geometry_callback().
9340*/
9341struct sqlite3_rtree_geometry {
9342 void *pContext; /* Copy of pContext passed to s_r_g_c() */
9343 int nParam; /* Size of array aParam[] */
9344 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
9345 void *pUser; /* Callback implementation user data */
9346 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9347};
9348
9349/*
9350** Register a 2nd-generation geometry callback named zScore that can be
9351** used as part of an R-Tree geometry query as follows:
9352**
9353** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9354*/
9355SQLITE_API int sqlite3_rtree_query_callback(
9356 sqlite3 *db,
9357 const char *zQueryFunc,
9358 int (*xQueryFunc)(sqlite3_rtree_query_info*),
9359 void *pContext,
9360 void (*xDestructor)(void*)
9361);
9362
9363
9364/*
9365** A pointer to a structure of the following type is passed as the
9366** argument to scored geometry callback registered using
9367** sqlite3_rtree_query_callback().
9368**
9369** Note that the first 5 fields of this structure are identical to
9370** sqlite3_rtree_geometry. This structure is a subclass of
9371** sqlite3_rtree_geometry.
9372*/
9373struct sqlite3_rtree_query_info {
9374 void *pContext; /* pContext from when function registered */
9375 int nParam; /* Number of function parameters */
9376 sqlite3_rtree_dbl *aParam; /* value of function parameters */
9377 void *pUser; /* callback can use this, if desired */
9378 void (*xDelUser)(void*); /* function to free pUser */
9379 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9380 unsigned int *anQueue; /* Number of pending entries in the queue */
9381 int nCoord; /* Number of coordinates */
9382 int iLevel; /* Level of current node or entry */
9383 int mxLevel; /* The largest iLevel value in the tree */
9384 sqlite3_int64 iRowid; /* Rowid for current entry */
9385 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9386 int eParentWithin; /* Visibility of parent node */
9387 int eWithin; /* OUT: Visiblity */
9388 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9389 /* The following fields are only available in 3.8.11 and later */
9390 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9391};
9392
9393/*
9394** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9395*/
9396#define NOT_WITHIN 0 /* Object completely outside of query region */
9397#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9398#define FULLY_WITHIN 2 /* Object fully contained within query region */
9399
9400
9401#ifdef __cplusplus
9402} /* end of the 'extern "C"' block */
9403#endif
9404
9405#endif /* ifndef _SQLITE3RTREE_H_ */
9406
9407/******** End of sqlite3rtree.h *********/
9408/******** Begin file sqlite3session.h *********/
9409
9410#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
9411#define __SQLITESESSION_H_ 1
9412
9413/*
9414** Make sure we can call this stuff from C++.
9415*/
9416#ifdef __cplusplus
9417extern "C" {
9418#endif
9419
9420
9421/*
9422** CAPI3REF: Session Object Handle
9423**
9424** An instance of this object is a [session] that can be used to
9425** record changes to a database.
9426*/
9427typedef struct sqlite3_session sqlite3_session;
9428
9429/*
9430** CAPI3REF: Changeset Iterator Handle
9431**
9432** An instance of this object acts as a cursor for iterating
9433** over the elements of a [changeset] or [patchset].
9434*/
9435typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
9436
9437/*
9438** CAPI3REF: Create A New Session Object
9439** CONSTRUCTOR: sqlite3_session
9440**
9441** Create a new session object attached to database handle db. If successful,
9442** a pointer to the new object is written to *ppSession and SQLITE_OK is
9443** returned. If an error occurs, *ppSession is set to NULL and an SQLite
9444** error code (e.g. SQLITE_NOMEM) is returned.
9445**
9446** It is possible to create multiple session objects attached to a single
9447** database handle.
9448**
9449** Session objects created using this function should be deleted using the
9450** [sqlite3session_delete()] function before the database handle that they
9451** are attached to is itself closed. If the database handle is closed before
9452** the session object is deleted, then the results of calling any session
9453** module function, including [sqlite3session_delete()] on the session object
9454** are undefined.
9455**
9456** Because the session module uses the [sqlite3_preupdate_hook()] API, it
9457** is not possible for an application to register a pre-update hook on a
9458** database handle that has one or more session objects attached. Nor is
9459** it possible to create a session object attached to a database handle for
9460** which a pre-update hook is already defined. The results of attempting
9461** either of these things are undefined.
9462**
9463** The session object will be used to create changesets for tables in
9464** database zDb, where zDb is either "main", or "temp", or the name of an
9465** attached database. It is not an error if database zDb is not attached
9466** to the database when the session object is created.
9467*/
9468SQLITE_API int sqlite3session_create(
9469 sqlite3 *db, /* Database handle */
9470 const char *zDb, /* Name of db (e.g. "main") */
9471 sqlite3_session **ppSession /* OUT: New session object */
9472);
9473
9474/*
9475** CAPI3REF: Delete A Session Object
9476** DESTRUCTOR: sqlite3_session
9477**
9478** Delete a session object previously allocated using
9479** [sqlite3session_create()]. Once a session object has been deleted, the
9480** results of attempting to use pSession with any other session module
9481** function are undefined.
9482**
9483** Session objects must be deleted before the database handle to which they
9484** are attached is closed. Refer to the documentation for
9485** [sqlite3session_create()] for details.
9486*/
9487SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
9488
9489
9490/*
9491** CAPI3REF: Enable Or Disable A Session Object
9492** METHOD: sqlite3_session
9493**
9494** Enable or disable the recording of changes by a session object. When
9495** enabled, a session object records changes made to the database. When
9496** disabled - it does not. A newly created session object is enabled.
9497** Refer to the documentation for [sqlite3session_changeset()] for further
9498** details regarding how enabling and disabling a session object affects
9499** the eventual changesets.
9500**
9501** Passing zero to this function disables the session. Passing a value
9502** greater than zero enables it. Passing a value less than zero is a
9503** no-op, and may be used to query the current state of the session.
9504**
9505** The return value indicates the final state of the session object: 0 if
9506** the session is disabled, or 1 if it is enabled.
9507*/
9508SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
9509
9510/*
9511** CAPI3REF: Set Or Clear the Indirect Change Flag
9512** METHOD: sqlite3_session
9513**
9514** Each change recorded by a session object is marked as either direct or
9515** indirect. A change is marked as indirect if either:
9516**
9517** <ul>
9518** <li> The session object "indirect" flag is set when the change is
9519** made, or
9520** <li> The change is made by an SQL trigger or foreign key action
9521** instead of directly as a result of a users SQL statement.
9522** </ul>
9523**
9524** If a single row is affected by more than one operation within a session,
9525** then the change is considered indirect if all operations meet the criteria
9526** for an indirect change above, or direct otherwise.
9527**
9528** This function is used to set, clear or query the session object indirect
9529** flag. If the second argument passed to this function is zero, then the
9530** indirect flag is cleared. If it is greater than zero, the indirect flag
9531** is set. Passing a value less than zero does not modify the current value
9532** of the indirect flag, and may be used to query the current state of the
9533** indirect flag for the specified session object.
9534**
9535** The return value indicates the final state of the indirect flag: 0 if
9536** it is clear, or 1 if it is set.
9537*/
9538SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
9539
9540/*
9541** CAPI3REF: Attach A Table To A Session Object
9542** METHOD: sqlite3_session
9543**
9544** If argument zTab is not NULL, then it is the name of a table to attach
9545** to the session object passed as the first argument. All subsequent changes
9546** made to the table while the session object is enabled will be recorded. See
9547** documentation for [sqlite3session_changeset()] for further details.
9548**
9549** Or, if argument zTab is NULL, then changes are recorded for all tables
9550** in the database. If additional tables are added to the database (by
9551** executing "CREATE TABLE" statements) after this call is made, changes for
9552** the new tables are also recorded.
9553**
9554** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
9555** defined as part of their CREATE TABLE statement. It does not matter if the
9556** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
9557** KEY may consist of a single column, or may be a composite key.
9558**
9559** It is not an error if the named table does not exist in the database. Nor
9560** is it an error if the named table does not have a PRIMARY KEY. However,
9561** no changes will be recorded in either of these scenarios.
9562**
9563** Changes are not recorded for individual rows that have NULL values stored
9564** in one or more of their PRIMARY KEY columns.
9565**
9566** SQLITE_OK is returned if the call completes without error. Or, if an error
9567** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
9568**
9569** <h3>Special sqlite_stat1 Handling</h3>
9570**
9571** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
9572** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
9573** <pre>
9574** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
9575** </pre>
9576**
9577** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
9578** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
9579** are recorded for rows for which (idx IS NULL) is true. However, for such
9580** rows a zero-length blob (SQL value X'') is stored in the changeset or
9581** patchset instead of a NULL value. This allows such changesets to be
9582** manipulated by legacy implementations of sqlite3changeset_invert(),
9583** concat() and similar.
9584**
9585** The sqlite3changeset_apply() function automatically converts the
9586** zero-length blob back to a NULL value when updating the sqlite_stat1
9587** table. However, if the application calls sqlite3changeset_new(),
9588** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
9589** iterator directly (including on a changeset iterator passed to a
9590** conflict-handler callback) then the X'' value is returned. The application
9591** must translate X'' to NULL itself if required.
9592**
9593** Legacy (older than 3.22.0) versions of the sessions module cannot capture
9594** changes made to the sqlite_stat1 table. Legacy versions of the
9595** sqlite3changeset_apply() function silently ignore any modifications to the
9596** sqlite_stat1 table that are part of a changeset or patchset.
9597*/
9598SQLITE_API int sqlite3session_attach(
9599 sqlite3_session *pSession, /* Session object */
9600 const char *zTab /* Table name */
9601);
9602
9603/*
9604** CAPI3REF: Set a table filter on a Session Object.
9605** METHOD: sqlite3_session
9606**
9607** The second argument (xFilter) is the "filter callback". For changes to rows
9608** in tables that are not attached to the Session object, the filter is called
9609** to determine whether changes to the table's rows should be tracked or not.
9610** If xFilter returns 0, changes is not tracked. Note that once a table is
9611** attached, xFilter will not be called again.
9612*/
9613SQLITE_API void sqlite3session_table_filter(
9614 sqlite3_session *pSession, /* Session object */
9615 int(*xFilter)(
9616 void *pCtx, /* Copy of third arg to _filter_table() */
9617 const char *zTab /* Table name */
9618 ),
9619 void *pCtx /* First argument passed to xFilter */
9620);
9621
9622/*
9623** CAPI3REF: Generate A Changeset From A Session Object
9624** METHOD: sqlite3_session
9625**
9626** Obtain a changeset containing changes to the tables attached to the
9627** session object passed as the first argument. If successful,
9628** set *ppChangeset to point to a buffer containing the changeset
9629** and *pnChangeset to the size of the changeset in bytes before returning
9630** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
9631** zero and return an SQLite error code.
9632**
9633** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
9634** each representing a change to a single row of an attached table. An INSERT
9635** change contains the values of each field of a new database row. A DELETE
9636** contains the original values of each field of a deleted database row. An
9637** UPDATE change contains the original values of each field of an updated
9638** database row along with the updated values for each updated non-primary-key
9639** column. It is not possible for an UPDATE change to represent a change that
9640** modifies the values of primary key columns. If such a change is made, it
9641** is represented in a changeset as a DELETE followed by an INSERT.
9642**
9643** Changes are not recorded for rows that have NULL values stored in one or
9644** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
9645** no corresponding change is present in the changesets returned by this
9646** function. If an existing row with one or more NULL values stored in
9647** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
9648** only an INSERT is appears in the changeset. Similarly, if an existing row
9649** with non-NULL PRIMARY KEY values is updated so that one or more of its
9650** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
9651** DELETE change only.
9652**
9653** The contents of a changeset may be traversed using an iterator created
9654** using the [sqlite3changeset_start()] API. A changeset may be applied to
9655** a database with a compatible schema using the [sqlite3changeset_apply()]
9656** API.
9657**
9658** Within a changeset generated by this function, all changes related to a
9659** single table are grouped together. In other words, when iterating through
9660** a changeset or when applying a changeset to a database, all changes related
9661** to a single table are processed before moving on to the next table. Tables
9662** are sorted in the same order in which they were attached (or auto-attached)
9663** to the sqlite3_session object. The order in which the changes related to
9664** a single table are stored is undefined.
9665**
9666** Following a successful call to this function, it is the responsibility of
9667** the caller to eventually free the buffer that *ppChangeset points to using
9668** [sqlite3_free()].
9669**
9670** <h3>Changeset Generation</h3>
9671**
9672** Once a table has been attached to a session object, the session object
9673** records the primary key values of all new rows inserted into the table.
9674** It also records the original primary key and other column values of any
9675** deleted or updated rows. For each unique primary key value, data is only
9676** recorded once - the first time a row with said primary key is inserted,
9677** updated or deleted in the lifetime of the session.
9678**
9679** There is one exception to the previous paragraph: when a row is inserted,
9680** updated or deleted, if one or more of its primary key columns contain a
9681** NULL value, no record of the change is made.
9682**
9683** The session object therefore accumulates two types of records - those
9684** that consist of primary key values only (created when the user inserts
9685** a new record) and those that consist of the primary key values and the
9686** original values of other table columns (created when the users deletes
9687** or updates a record).
9688**
9689** When this function is called, the requested changeset is created using
9690** both the accumulated records and the current contents of the database
9691** file. Specifically:
9692**
9693** <ul>
9694** <li> For each record generated by an insert, the database is queried
9695** for a row with a matching primary key. If one is found, an INSERT
9696** change is added to the changeset. If no such row is found, no change
9697** is added to the changeset.
9698**
9699** <li> For each record generated by an update or delete, the database is
9700** queried for a row with a matching primary key. If such a row is
9701** found and one or more of the non-primary key fields have been
9702** modified from their original values, an UPDATE change is added to
9703** the changeset. Or, if no such row is found in the table, a DELETE
9704** change is added to the changeset. If there is a row with a matching
9705** primary key in the database, but all fields contain their original
9706** values, no change is added to the changeset.
9707** </ul>
9708**
9709** This means, amongst other things, that if a row is inserted and then later
9710** deleted while a session object is active, neither the insert nor the delete
9711** will be present in the changeset. Or if a row is deleted and then later a
9712** row with the same primary key values inserted while a session object is
9713** active, the resulting changeset will contain an UPDATE change instead of
9714** a DELETE and an INSERT.
9715**
9716** When a session object is disabled (see the [sqlite3session_enable()] API),
9717** it does not accumulate records when rows are inserted, updated or deleted.
9718** This may appear to have some counter-intuitive effects if a single row
9719** is written to more than once during a session. For example, if a row
9720** is inserted while a session object is enabled, then later deleted while
9721** the same session object is disabled, no INSERT record will appear in the
9722** changeset, even though the delete took place while the session was disabled.
9723** Or, if one field of a row is updated while a session is disabled, and
9724** another field of the same row is updated while the session is enabled, the
9725** resulting changeset will contain an UPDATE change that updates both fields.
9726*/
9727SQLITE_API int sqlite3session_changeset(
9728 sqlite3_session *pSession, /* Session object */
9729 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
9730 void **ppChangeset /* OUT: Buffer containing changeset */
9731);
9732
9733/*
9734** CAPI3REF: Load The Difference Between Tables Into A Session
9735** METHOD: sqlite3_session
9736**
9737** If it is not already attached to the session object passed as the first
9738** argument, this function attaches table zTbl in the same manner as the
9739** [sqlite3session_attach()] function. If zTbl does not exist, or if it
9740** does not have a primary key, this function is a no-op (but does not return
9741** an error).
9742**
9743** Argument zFromDb must be the name of a database ("main", "temp" etc.)
9744** attached to the same database handle as the session object that contains
9745** a table compatible with the table attached to the session by this function.
9746** A table is considered compatible if it:
9747**
9748** <ul>
9749** <li> Has the same name,
9750** <li> Has the same set of columns declared in the same order, and
9751** <li> Has the same PRIMARY KEY definition.
9752** </ul>
9753**
9754** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
9755** are compatible but do not have any PRIMARY KEY columns, it is not an error
9756** but no changes are added to the session object. As with other session
9757** APIs, tables without PRIMARY KEYs are simply ignored.
9758**
9759** This function adds a set of changes to the session object that could be
9760** used to update the table in database zFrom (call this the "from-table")
9761** so that its content is the same as the table attached to the session
9762** object (call this the "to-table"). Specifically:
9763**
9764** <ul>
9765** <li> For each row (primary key) that exists in the to-table but not in
9766** the from-table, an INSERT record is added to the session object.
9767**
9768** <li> For each row (primary key) that exists in the to-table but not in
9769** the from-table, a DELETE record is added to the session object.
9770**
9771** <li> For each row (primary key) that exists in both tables, but features
9772** different non-PK values in each, an UPDATE record is added to the
9773** session.
9774** </ul>
9775**
9776** To clarify, if this function is called and then a changeset constructed
9777** using [sqlite3session_changeset()], then after applying that changeset to
9778** database zFrom the contents of the two compatible tables would be
9779** identical.
9780**
9781** It an error if database zFrom does not exist or does not contain the
9782** required compatible table.
9783**
9784** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
9785** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
9786** may be set to point to a buffer containing an English language error
9787** message. It is the responsibility of the caller to free this buffer using
9788** sqlite3_free().
9789*/
9790SQLITE_API int sqlite3session_diff(
9791 sqlite3_session *pSession,
9792 const char *zFromDb,
9793 const char *zTbl,
9794 char **pzErrMsg
9795);
9796
9797
9798/*
9799** CAPI3REF: Generate A Patchset From A Session Object
9800** METHOD: sqlite3_session
9801**
9802** The differences between a patchset and a changeset are that:
9803**
9804** <ul>
9805** <li> DELETE records consist of the primary key fields only. The
9806** original values of other fields are omitted.
9807** <li> The original values of any modified fields are omitted from
9808** UPDATE records.
9809** </ul>
9810**
9811** A patchset blob may be used with up to date versions of all
9812** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
9813** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
9814** attempting to use a patchset blob with old versions of the
9815** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
9816**
9817** Because the non-primary key "old.*" fields are omitted, no
9818** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
9819** is passed to the sqlite3changeset_apply() API. Other conflict types work
9820** in the same way as for changesets.
9821**
9822** Changes within a patchset are ordered in the same way as for changesets
9823** generated by the sqlite3session_changeset() function (i.e. all changes for
9824** a single table are grouped together, tables appear in the order in which
9825** they were attached to the session object).
9826*/
9827SQLITE_API int sqlite3session_patchset(
9828 sqlite3_session *pSession, /* Session object */
9829 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
9830 void **ppPatchset /* OUT: Buffer containing patchset */
9831);
9832
9833/*
9834** CAPI3REF: Test if a changeset has recorded any changes.
9835**
9836** Return non-zero if no changes to attached tables have been recorded by
9837** the session object passed as the first argument. Otherwise, if one or
9838** more changes have been recorded, return zero.
9839**
9840** Even if this function returns zero, it is possible that calling
9841** [sqlite3session_changeset()] on the session handle may still return a
9842** changeset that contains no changes. This can happen when a row in
9843** an attached table is modified and then later on the original values
9844** are restored. However, if this function returns non-zero, then it is
9845** guaranteed that a call to sqlite3session_changeset() will return a
9846** changeset containing zero changes.
9847*/
9848SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
9849
9850/*
9851** CAPI3REF: Create An Iterator To Traverse A Changeset
9852** CONSTRUCTOR: sqlite3_changeset_iter
9853**
9854** Create an iterator used to iterate through the contents of a changeset.
9855** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9856** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9857** SQLite error code is returned.
9858**
9859** The following functions can be used to advance and query a changeset
9860** iterator created by this function:
9861**
9862** <ul>
9863** <li> [sqlite3changeset_next()]
9864** <li> [sqlite3changeset_op()]
9865** <li> [sqlite3changeset_new()]
9866** <li> [sqlite3changeset_old()]
9867** </ul>
9868**
9869** It is the responsibility of the caller to eventually destroy the iterator
9870** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9871** changeset (pChangeset) must remain valid until after the iterator is
9872** destroyed.
9873**
9874** Assuming the changeset blob was created by one of the
9875** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9876** [sqlite3changeset_invert()] functions, all changes within the changeset
9877** that apply to a single table are grouped together. This means that when
9878** an application iterates through a changeset using an iterator created by
9879** this function, all changes that relate to a single table are visited
9880** consecutively. There is no chance that the iterator will visit a change
9881** the applies to table X, then one for table Y, and then later on visit
9882** another change for table X.
9883*/
9884SQLITE_API int sqlite3changeset_start(
9885 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9886 int nChangeset, /* Size of changeset blob in bytes */
9887 void *pChangeset /* Pointer to blob containing changeset */
9888);
9889
9890
9891/*
9892** CAPI3REF: Advance A Changeset Iterator
9893** METHOD: sqlite3_changeset_iter
9894**
9895** This function may only be used with iterators created by function
9896** [sqlite3changeset_start()]. If it is called on an iterator passed to
9897** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
9898** is returned and the call has no effect.
9899**
9900** Immediately after an iterator is created by sqlite3changeset_start(), it
9901** does not point to any change in the changeset. Assuming the changeset
9902** is not empty, the first call to this function advances the iterator to
9903** point to the first change in the changeset. Each subsequent call advances
9904** the iterator to point to the next change in the changeset (if any). If
9905** no error occurs and the iterator points to a valid change after a call
9906** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
9907** Otherwise, if all changes in the changeset have already been visited,
9908** SQLITE_DONE is returned.
9909**
9910** If an error occurs, an SQLite error code is returned. Possible error
9911** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
9912** SQLITE_NOMEM.
9913*/
9914SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
9915
9916/*
9917** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
9918** METHOD: sqlite3_changeset_iter
9919**
9920** The pIter argument passed to this function may either be an iterator
9921** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9922** created by [sqlite3changeset_start()]. In the latter case, the most recent
9923** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
9924** is not the case, this function returns [SQLITE_MISUSE].
9925**
9926** If argument pzTab is not NULL, then *pzTab is set to point to a
9927** nul-terminated utf-8 encoded string containing the name of the table
9928** affected by the current change. The buffer remains valid until either
9929** sqlite3changeset_next() is called on the iterator or until the
9930** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
9931** set to the number of columns in the table affected by the change. If
9932** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
9933** is an indirect change, or false (0) otherwise. See the documentation for
9934** [sqlite3session_indirect()] for a description of direct and indirect
9935** changes. Finally, if pOp is not NULL, then *pOp is set to one of
9936** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
9937** type of change that the iterator currently points to.
9938**
9939** If no error occurs, SQLITE_OK is returned. If an error does occur, an
9940** SQLite error code is returned. The values of the output variables may not
9941** be trusted in this case.
9942*/
9943SQLITE_API int sqlite3changeset_op(
9944 sqlite3_changeset_iter *pIter, /* Iterator object */
9945 const char **pzTab, /* OUT: Pointer to table name */
9946 int *pnCol, /* OUT: Number of columns in table */
9947 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
9948 int *pbIndirect /* OUT: True for an 'indirect' change */
9949);
9950
9951/*
9952** CAPI3REF: Obtain The Primary Key Definition Of A Table
9953** METHOD: sqlite3_changeset_iter
9954**
9955** For each modified table, a changeset includes the following:
9956**
9957** <ul>
9958** <li> The number of columns in the table, and
9959** <li> Which of those columns make up the tables PRIMARY KEY.
9960** </ul>
9961**
9962** This function is used to find which columns comprise the PRIMARY KEY of
9963** the table modified by the change that iterator pIter currently points to.
9964** If successful, *pabPK is set to point to an array of nCol entries, where
9965** nCol is the number of columns in the table. Elements of *pabPK are set to
9966** 0x01 if the corresponding column is part of the tables primary key, or
9967** 0x00 if it is not.
9968**
9969** If argument pnCol is not NULL, then *pnCol is set to the number of columns
9970** in the table.
9971**
9972** If this function is called when the iterator does not point to a valid
9973** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
9974** SQLITE_OK is returned and the output variables populated as described
9975** above.
9976*/
9977SQLITE_API int sqlite3changeset_pk(
9978 sqlite3_changeset_iter *pIter, /* Iterator object */
9979 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
9980 int *pnCol /* OUT: Number of entries in output array */
9981);
9982
9983/*
9984** CAPI3REF: Obtain old.* Values From A Changeset Iterator
9985** METHOD: sqlite3_changeset_iter
9986**
9987** The pIter argument passed to this function may either be an iterator
9988** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9989** created by [sqlite3changeset_start()]. In the latter case, the most recent
9990** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
9991** Furthermore, it may only be called if the type of change that the iterator
9992** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
9993** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
9994**
9995** Argument iVal must be greater than or equal to 0, and less than the number
9996** of columns in the table affected by the current change. Otherwise,
9997** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
9998**
9999** If successful, this function sets *ppValue to point to a protected
10000** sqlite3_value object containing the iVal'th value from the vector of
10001** original row values stored as part of the UPDATE or DELETE change and
10002** returns SQLITE_OK. The name of the function comes from the fact that this
10003** is similar to the "old.*" columns available to update or delete triggers.
10004**
10005** If some other error occurs (e.g. an OOM condition), an SQLite error code
10006** is returned and *ppValue is set to NULL.
10007*/
10008SQLITE_API int sqlite3changeset_old(
10009 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10010 int iVal, /* Column number */
10011 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10012);
10013
10014/*
10015** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10016** METHOD: sqlite3_changeset_iter
10017**
10018** The pIter argument passed to this function may either be an iterator
10019** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10020** created by [sqlite3changeset_start()]. In the latter case, the most recent
10021** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10022** Furthermore, it may only be called if the type of change that the iterator
10023** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10024** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10025**
10026** Argument iVal must be greater than or equal to 0, and less than the number
10027** of columns in the table affected by the current change. Otherwise,
10028** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10029**
10030** If successful, this function sets *ppValue to point to a protected
10031** sqlite3_value object containing the iVal'th value from the vector of
10032** new row values stored as part of the UPDATE or INSERT change and
10033** returns SQLITE_OK. If the change is an UPDATE and does not include
10034** a new value for the requested column, *ppValue is set to NULL and
10035** SQLITE_OK returned. The name of the function comes from the fact that
10036** this is similar to the "new.*" columns available to update or delete
10037** triggers.
10038**
10039** If some other error occurs (e.g. an OOM condition), an SQLite error code
10040** is returned and *ppValue is set to NULL.
10041*/
10042SQLITE_API int sqlite3changeset_new(
10043 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10044 int iVal, /* Column number */
10045 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10046);
10047
10048/*
10049** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10050** METHOD: sqlite3_changeset_iter
10051**
10052** This function should only be used with iterator objects passed to a
10053** conflict-handler callback by [sqlite3changeset_apply()] with either
10054** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10055** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10056** is set to NULL.
10057**
10058** Argument iVal must be greater than or equal to 0, and less than the number
10059** of columns in the table affected by the current change. Otherwise,
10060** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10061**
10062** If successful, this function sets *ppValue to point to a protected
10063** sqlite3_value object containing the iVal'th value from the
10064** "conflicting row" associated with the current conflict-handler callback
10065** and returns SQLITE_OK.
10066**
10067** If some other error occurs (e.g. an OOM condition), an SQLite error code
10068** is returned and *ppValue is set to NULL.
10069*/
10070SQLITE_API int sqlite3changeset_conflict(
10071 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10072 int iVal, /* Column number */
10073 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10074);
10075
10076/*
10077** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10078** METHOD: sqlite3_changeset_iter
10079**
10080** This function may only be called with an iterator passed to an
10081** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10082** it sets the output variable to the total number of known foreign key
10083** violations in the destination database and returns SQLITE_OK.
10084**
10085** In all other cases this function returns SQLITE_MISUSE.
10086*/
10087SQLITE_API int sqlite3changeset_fk_conflicts(
10088 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10089 int *pnOut /* OUT: Number of FK violations */
10090);
10091
10092
10093/*
10094** CAPI3REF: Finalize A Changeset Iterator
10095** METHOD: sqlite3_changeset_iter
10096**
10097** This function is used to finalize an iterator allocated with
10098** [sqlite3changeset_start()].
10099**
10100** This function should only be called on iterators created using the
10101** [sqlite3changeset_start()] function. If an application calls this
10102** function with an iterator passed to a conflict-handler by
10103** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10104** call has no effect.
10105**
10106** If an error was encountered within a call to an sqlite3changeset_xxx()
10107** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10108** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10109** to that error is returned by this function. Otherwise, SQLITE_OK is
10110** returned. This is to allow the following pattern (pseudo-code):
10111**
10112** <pre>
10113** sqlite3changeset_start();
10114** while( SQLITE_ROW==sqlite3changeset_next() ){
10115** // Do something with change.
10116** }
10117** rc = sqlite3changeset_finalize();
10118** if( rc!=SQLITE_OK ){
10119** // An error has occurred
10120** }
10121** </pre>
10122*/
10123SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10124
10125/*
10126** CAPI3REF: Invert A Changeset
10127**
10128** This function is used to "invert" a changeset object. Applying an inverted
10129** changeset to a database reverses the effects of applying the uninverted
10130** changeset. Specifically:
10131**
10132** <ul>
10133** <li> Each DELETE change is changed to an INSERT, and
10134** <li> Each INSERT change is changed to a DELETE, and
10135** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10136** </ul>
10137**
10138** This function does not change the order in which changes appear within
10139** the changeset. It merely reverses the sense of each individual change.
10140**
10141** If successful, a pointer to a buffer containing the inverted changeset
10142** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10143** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10144** zeroed and an SQLite error code returned.
10145**
10146** It is the responsibility of the caller to eventually call sqlite3_free()
10147** on the *ppOut pointer to free the buffer allocation following a successful
10148** call to this function.
10149**
10150** WARNING/TODO: This function currently assumes that the input is a valid
10151** changeset. If it is not, the results are undefined.
10152*/
10153SQLITE_API int sqlite3changeset_invert(
10154 int nIn, const void *pIn, /* Input changeset */
10155 int *pnOut, void **ppOut /* OUT: Inverse of input */
10156);
10157
10158/*
10159** CAPI3REF: Concatenate Two Changeset Objects
10160**
10161** This function is used to concatenate two changesets, A and B, into a
10162** single changeset. The result is a changeset equivalent to applying
10163** changeset A followed by changeset B.
10164**
10165** This function combines the two input changesets using an
10166** sqlite3_changegroup object. Calling it produces similar results as the
10167** following code fragment:
10168**
10169** <pre>
10170** sqlite3_changegroup *pGrp;
10171** rc = sqlite3_changegroup_new(&pGrp);
10172** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10173** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10174** if( rc==SQLITE_OK ){
10175** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10176** }else{
10177** *ppOut = 0;
10178** *pnOut = 0;
10179** }
10180** </pre>
10181**
10182** Refer to the sqlite3_changegroup documentation below for details.
10183*/
10184SQLITE_API int sqlite3changeset_concat(
10185 int nA, /* Number of bytes in buffer pA */
10186 void *pA, /* Pointer to buffer containing changeset A */
10187 int nB, /* Number of bytes in buffer pB */
10188 void *pB, /* Pointer to buffer containing changeset B */
10189 int *pnOut, /* OUT: Number of bytes in output changeset */
10190 void **ppOut /* OUT: Buffer containing output changeset */
10191);
10192
10193
10194/*
10195** CAPI3REF: Changegroup Handle
10196**
10197** A changegroup is an object used to combine two or more
10198** [changesets] or [patchsets]
10199*/
10200typedef struct sqlite3_changegroup sqlite3_changegroup;
10201
10202/*
10203** CAPI3REF: Create A New Changegroup Object
10204** CONSTRUCTOR: sqlite3_changegroup
10205**
10206** An sqlite3_changegroup object is used to combine two or more changesets
10207** (or patchsets) into a single changeset (or patchset). A single changegroup
10208** object may combine changesets or patchsets, but not both. The output is
10209** always in the same format as the input.
10210**
10211** If successful, this function returns SQLITE_OK and populates (*pp) with
10212** a pointer to a new sqlite3_changegroup object before returning. The caller
10213** should eventually free the returned object using a call to
10214** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10215** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10216**
10217** The usual usage pattern for an sqlite3_changegroup object is as follows:
10218**
10219** <ul>
10220** <li> It is created using a call to sqlite3changegroup_new().
10221**
10222** <li> Zero or more changesets (or patchsets) are added to the object
10223** by calling sqlite3changegroup_add().
10224**
10225** <li> The result of combining all input changesets together is obtained
10226** by the application via a call to sqlite3changegroup_output().
10227**
10228** <li> The object is deleted using a call to sqlite3changegroup_delete().
10229** </ul>
10230**
10231** Any number of calls to add() and output() may be made between the calls to
10232** new() and delete(), and in any order.
10233**
10234** As well as the regular sqlite3changegroup_add() and
10235** sqlite3changegroup_output() functions, also available are the streaming
10236** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10237*/
10238SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
10239
10240/*
10241** CAPI3REF: Add A Changeset To A Changegroup
10242** METHOD: sqlite3_changegroup
10243**
10244** Add all changes within the changeset (or patchset) in buffer pData (size
10245** nData bytes) to the changegroup.
10246**
10247** If the buffer contains a patchset, then all prior calls to this function
10248** on the same changegroup object must also have specified patchsets. Or, if
10249** the buffer contains a changeset, so must have the earlier calls to this
10250** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10251** to the changegroup.
10252**
10253** Rows within the changeset and changegroup are identified by the values in
10254** their PRIMARY KEY columns. A change in the changeset is considered to
10255** apply to the same row as a change already present in the changegroup if
10256** the two rows have the same primary key.
10257**
10258** Changes to rows that do not already appear in the changegroup are
10259** simply copied into it. Or, if both the new changeset and the changegroup
10260** contain changes that apply to a single row, the final contents of the
10261** changegroup depends on the type of each change, as follows:
10262**
10263** <table border=1 style="margin-left:8ex;margin-right:8ex">
10264** <tr><th style="white-space:pre">Existing Change </th>
10265** <th style="white-space:pre">New Change </th>
10266** <th>Output Change
10267** <tr><td>INSERT <td>INSERT <td>
10268** The new change is ignored. This case does not occur if the new
10269** changeset was recorded immediately after the changesets already
10270** added to the changegroup.
10271** <tr><td>INSERT <td>UPDATE <td>
10272** The INSERT change remains in the changegroup. The values in the
10273** INSERT change are modified as if the row was inserted by the
10274** existing change and then updated according to the new change.
10275** <tr><td>INSERT <td>DELETE <td>
10276** The existing INSERT is removed from the changegroup. The DELETE is
10277** not added.
10278** <tr><td>UPDATE <td>INSERT <td>
10279** The new change is ignored. This case does not occur if the new
10280** changeset was recorded immediately after the changesets already
10281** added to the changegroup.
10282** <tr><td>UPDATE <td>UPDATE <td>
10283** The existing UPDATE remains within the changegroup. It is amended
10284** so that the accompanying values are as if the row was updated once
10285** by the existing change and then again by the new change.
10286** <tr><td>UPDATE <td>DELETE <td>
10287** The existing UPDATE is replaced by the new DELETE within the
10288** changegroup.
10289** <tr><td>DELETE <td>INSERT <td>
10290** If one or more of the column values in the row inserted by the
10291** new change differ from those in the row deleted by the existing
10292** change, the existing DELETE is replaced by an UPDATE within the
10293** changegroup. Otherwise, if the inserted row is exactly the same
10294** as the deleted row, the existing DELETE is simply discarded.
10295** <tr><td>DELETE <td>UPDATE <td>
10296** The new change is ignored. This case does not occur if the new
10297** changeset was recorded immediately after the changesets already
10298** added to the changegroup.
10299** <tr><td>DELETE <td>DELETE <td>
10300** The new change is ignored. This case does not occur if the new
10301** changeset was recorded immediately after the changesets already
10302** added to the changegroup.
10303** </table>
10304**
10305** If the new changeset contains changes to a table that is already present
10306** in the changegroup, then the number of columns and the position of the
10307** primary key columns for the table must be consistent. If this is not the
10308** case, this function fails with SQLITE_SCHEMA. If the input changeset
10309** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10310** returned. Or, if an out-of-memory condition occurs during processing, this
10311** function returns SQLITE_NOMEM. In all cases, if an error occurs the
10312** final contents of the changegroup is undefined.
10313**
10314** If no error occurs, SQLITE_OK is returned.
10315*/
10316SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
10317
10318/*
10319** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10320** METHOD: sqlite3_changegroup
10321**
10322** Obtain a buffer containing a changeset (or patchset) representing the
10323** current contents of the changegroup. If the inputs to the changegroup
10324** were themselves changesets, the output is a changeset. Or, if the
10325** inputs were patchsets, the output is also a patchset.
10326**
10327** As with the output of the sqlite3session_changeset() and
10328** sqlite3session_patchset() functions, all changes related to a single
10329** table are grouped together in the output of this function. Tables appear
10330** in the same order as for the very first changeset added to the changegroup.
10331** If the second or subsequent changesets added to the changegroup contain
10332** changes for tables that do not appear in the first changeset, they are
10333** appended onto the end of the output changeset, again in the order in
10334** which they are first encountered.
10335**
10336** If an error occurs, an SQLite error code is returned and the output
10337** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
10338** is returned and the output variables are set to the size of and a
10339** pointer to the output buffer, respectively. In this case it is the
10340** responsibility of the caller to eventually free the buffer using a
10341** call to sqlite3_free().
10342*/
10343SQLITE_API int sqlite3changegroup_output(
10344 sqlite3_changegroup*,
10345 int *pnData, /* OUT: Size of output buffer in bytes */
10346 void **ppData /* OUT: Pointer to output buffer */
10347);
10348
10349/*
10350** CAPI3REF: Delete A Changegroup Object
10351** DESTRUCTOR: sqlite3_changegroup
10352*/
10353SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
10354
10355/*
10356** CAPI3REF: Apply A Changeset To A Database
10357**
10358** Apply a changeset or patchset to a database. These functions attempt to
10359** update the "main" database attached to handle db with the changes found in
10360** the changeset passed via the second and third arguments.
10361**
10362** The fourth argument (xFilter) passed to these functions is the "filter
10363** callback". If it is not NULL, then for each table affected by at least one
10364** change in the changeset, the filter callback is invoked with
10365** the table name as the second argument, and a copy of the context pointer
10366** passed as the sixth argument as the first. If the "filter callback"
10367** returns zero, then no attempt is made to apply any changes to the table.
10368** Otherwise, if the return value is non-zero or the xFilter argument to
10369** is NULL, all changes related to the table are attempted.
10370**
10371** For each table that is not excluded by the filter callback, this function
10372** tests that the target database contains a compatible table. A table is
10373** considered compatible if all of the following are true:
10374**
10375** <ul>
10376** <li> The table has the same name as the name recorded in the
10377** changeset, and
10378** <li> The table has at least as many columns as recorded in the
10379** changeset, and
10380** <li> The table has primary key columns in the same position as
10381** recorded in the changeset.
10382** </ul>
10383**
10384** If there is no compatible table, it is not an error, but none of the
10385** changes associated with the table are applied. A warning message is issued
10386** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
10387** one such warning is issued for each table in the changeset.
10388**
10389** For each change for which there is a compatible table, an attempt is made
10390** to modify the table contents according to the UPDATE, INSERT or DELETE
10391** change. If a change cannot be applied cleanly, the conflict handler
10392** function passed as the fifth argument to sqlite3changeset_apply() may be
10393** invoked. A description of exactly when the conflict handler is invoked for
10394** each type of change is below.
10395**
10396** Unlike the xFilter argument, xConflict may not be passed NULL. The results
10397** of passing anything other than a valid function pointer as the xConflict
10398** argument are undefined.
10399**
10400** Each time the conflict handler function is invoked, it must return one
10401** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
10402** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
10403** if the second argument passed to the conflict handler is either
10404** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
10405** returns an illegal value, any changes already made are rolled back and
10406** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
10407** actions are taken by sqlite3changeset_apply() depending on the value
10408** returned by each invocation of the conflict-handler function. Refer to
10409** the documentation for the three
10410** [SQLITE_CHANGESET_OMIT|available return values] for details.
10411**
10412** <dl>
10413** <dt>DELETE Changes<dd>
10414** For each DELETE change, the function checks if the target database
10415** contains a row with the same primary key value (or values) as the
10416** original row values stored in the changeset. If it does, and the values
10417** stored in all non-primary key columns also match the values stored in
10418** the changeset the row is deleted from the target database.
10419**
10420** If a row with matching primary key values is found, but one or more of
10421** the non-primary key fields contains a value different from the original
10422** row value stored in the changeset, the conflict-handler function is
10423** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
10424** database table has more columns than are recorded in the changeset,
10425** only the values of those non-primary key fields are compared against
10426** the current database contents - any trailing database table columns
10427** are ignored.
10428**
10429** If no row with matching primary key values is found in the database,
10430** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10431** passed as the second argument.
10432**
10433** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
10434** (which can only happen if a foreign key constraint is violated), the
10435** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
10436** passed as the second argument. This includes the case where the DELETE
10437** operation is attempted because an earlier call to the conflict handler
10438** function returned [SQLITE_CHANGESET_REPLACE].
10439**
10440** <dt>INSERT Changes<dd>
10441** For each INSERT change, an attempt is made to insert the new row into
10442** the database. If the changeset row contains fewer fields than the
10443** database table, the trailing fields are populated with their default
10444** values.
10445**
10446** If the attempt to insert the row fails because the database already
10447** contains a row with the same primary key values, the conflict handler
10448** function is invoked with the second argument set to
10449** [SQLITE_CHANGESET_CONFLICT].
10450**
10451** If the attempt to insert the row fails because of some other constraint
10452** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
10453** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
10454** This includes the case where the INSERT operation is re-attempted because
10455** an earlier call to the conflict handler function returned
10456** [SQLITE_CHANGESET_REPLACE].
10457**
10458** <dt>UPDATE Changes<dd>
10459** For each UPDATE change, the function checks if the target database
10460** contains a row with the same primary key value (or values) as the
10461** original row values stored in the changeset. If it does, and the values
10462** stored in all modified non-primary key columns also match the values
10463** stored in the changeset the row is updated within the target database.
10464**
10465** If a row with matching primary key values is found, but one or more of
10466** the modified non-primary key fields contains a value different from an
10467** original row value stored in the changeset, the conflict-handler function
10468** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
10469** UPDATE changes only contain values for non-primary key fields that are
10470** to be modified, only those fields need to match the original values to
10471** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
10472**
10473** If no row with matching primary key values is found in the database,
10474** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10475** passed as the second argument.
10476**
10477** If the UPDATE operation is attempted, but SQLite returns
10478** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
10479** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
10480** This includes the case where the UPDATE operation is attempted after
10481** an earlier call to the conflict handler function returned
10482** [SQLITE_CHANGESET_REPLACE].
10483** </dl>
10484**
10485** It is safe to execute SQL statements, including those that write to the
10486** table that the callback related to, from within the xConflict callback.
10487** This can be used to further customize the applications conflict
10488** resolution strategy.
10489**
10490** All changes made by these functions are enclosed in a savepoint transaction.
10491** If any other error (aside from a constraint failure when attempting to
10492** write to the target database) occurs, then the savepoint transaction is
10493** rolled back, restoring the target database to its original state, and an
10494** SQLite error code returned.
10495**
10496** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
10497** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
10498** may set (*ppRebase) to point to a "rebase" that may be used with the
10499** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
10500** is set to the size of the buffer in bytes. It is the responsibility of the
10501** caller to eventually free any such buffer using sqlite3_free(). The buffer
10502** is only allocated and populated if one or more conflicts were encountered
10503** while applying the patchset. See comments surrounding the sqlite3_rebaser
10504** APIs for further details.
10505**
10506** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
10507** may be modified by passing a combination of
10508** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
10509**
10510** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
10511** and therefore subject to change.
10512*/
10513SQLITE_API int sqlite3changeset_apply(
10514 sqlite3 *db, /* Apply change to "main" db of this handle */
10515 int nChangeset, /* Size of changeset in bytes */
10516 void *pChangeset, /* Changeset blob */
10517 int(*xFilter)(
10518 void *pCtx, /* Copy of sixth arg to _apply() */
10519 const char *zTab /* Table name */
10520 ),
10521 int(*xConflict)(
10522 void *pCtx, /* Copy of sixth arg to _apply() */
10523 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10524 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10525 ),
10526 void *pCtx /* First argument passed to xConflict */
10527);
10528SQLITE_API int sqlite3changeset_apply_v2(
10529 sqlite3 *db, /* Apply change to "main" db of this handle */
10530 int nChangeset, /* Size of changeset in bytes */
10531 void *pChangeset, /* Changeset blob */
10532 int(*xFilter)(
10533 void *pCtx, /* Copy of sixth arg to _apply() */
10534 const char *zTab /* Table name */
10535 ),
10536 int(*xConflict)(
10537 void *pCtx, /* Copy of sixth arg to _apply() */
10538 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10539 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10540 ),
10541 void *pCtx, /* First argument passed to xConflict */
10542 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
10543 int flags /* Combination of SESSION_APPLY_* flags */
10544);
10545
10546/*
10547** CAPI3REF: Flags for sqlite3changeset_apply_v2
10548**
10549** The following flags may passed via the 9th parameter to
10550** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
10551**
10552** <dl>
10553** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
10554** Usually, the sessions module encloses all operations performed by
10555** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
10556** SAVEPOINT is committed if the changeset or patchset is successfully
10557** applied, or rolled back if an error occurs. Specifying this flag
10558** causes the sessions module to omit this savepoint. In this case, if the
10559** caller has an open transaction or savepoint when apply_v2() is called,
10560** it may revert the partially applied changeset by rolling it back.
10561*/
10562#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
10563
10564/*
10565** CAPI3REF: Constants Passed To The Conflict Handler
10566**
10567** Values that may be passed as the second argument to a conflict-handler.
10568**
10569** <dl>
10570** <dt>SQLITE_CHANGESET_DATA<dd>
10571** The conflict handler is invoked with CHANGESET_DATA as the second argument
10572** when processing a DELETE or UPDATE change if a row with the required
10573** PRIMARY KEY fields is present in the database, but one or more other
10574** (non primary-key) fields modified by the update do not contain the
10575** expected "before" values.
10576**
10577** The conflicting row, in this case, is the database row with the matching
10578** primary key.
10579**
10580** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
10581** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
10582** argument when processing a DELETE or UPDATE change if a row with the
10583** required PRIMARY KEY fields is not present in the database.
10584**
10585** There is no conflicting row in this case. The results of invoking the
10586** sqlite3changeset_conflict() API are undefined.
10587**
10588** <dt>SQLITE_CHANGESET_CONFLICT<dd>
10589** CHANGESET_CONFLICT is passed as the second argument to the conflict
10590** handler while processing an INSERT change if the operation would result
10591** in duplicate primary key values.
10592**
10593** The conflicting row in this case is the database row with the matching
10594** primary key.
10595**
10596** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
10597** If foreign key handling is enabled, and applying a changeset leaves the
10598** database in a state containing foreign key violations, the conflict
10599** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
10600** exactly once before the changeset is committed. If the conflict handler
10601** returns CHANGESET_OMIT, the changes, including those that caused the
10602** foreign key constraint violation, are committed. Or, if it returns
10603** CHANGESET_ABORT, the changeset is rolled back.
10604**
10605** No current or conflicting row information is provided. The only function
10606** it is possible to call on the supplied sqlite3_changeset_iter handle
10607** is sqlite3changeset_fk_conflicts().
10608**
10609** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
10610** If any other constraint violation occurs while applying a change (i.e.
10611** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
10612** invoked with CHANGESET_CONSTRAINT as the second argument.
10613**
10614** There is no conflicting row in this case. The results of invoking the
10615** sqlite3changeset_conflict() API are undefined.
10616**
10617** </dl>
10618*/
10619#define SQLITE_CHANGESET_DATA 1
10620#define SQLITE_CHANGESET_NOTFOUND 2
10621#define SQLITE_CHANGESET_CONFLICT 3
10622#define SQLITE_CHANGESET_CONSTRAINT 4
10623#define SQLITE_CHANGESET_FOREIGN_KEY 5
10624
10625/*
10626** CAPI3REF: Constants Returned By The Conflict Handler
10627**
10628** A conflict handler callback must return one of the following three values.
10629**
10630** <dl>
10631** <dt>SQLITE_CHANGESET_OMIT<dd>
10632** If a conflict handler returns this value no special action is taken. The
10633** change that caused the conflict is not applied. The session module
10634** continues to the next change in the changeset.
10635**
10636** <dt>SQLITE_CHANGESET_REPLACE<dd>
10637** This value may only be returned if the second argument to the conflict
10638** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
10639** is not the case, any changes applied so far are rolled back and the
10640** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
10641**
10642** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
10643** handler, then the conflicting row is either updated or deleted, depending
10644** on the type of change.
10645**
10646** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
10647** handler, then the conflicting row is removed from the database and a
10648** second attempt to apply the change is made. If this second attempt fails,
10649** the original row is restored to the database before continuing.
10650**
10651** <dt>SQLITE_CHANGESET_ABORT<dd>
10652** If this value is returned, any changes applied so far are rolled back
10653** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
10654** </dl>
10655*/
10656#define SQLITE_CHANGESET_OMIT 0
10657#define SQLITE_CHANGESET_REPLACE 1
10658#define SQLITE_CHANGESET_ABORT 2
10659
10660/*
10661** CAPI3REF: Rebasing changesets
10662** EXPERIMENTAL
10663**
10664** Suppose there is a site hosting a database in state S0. And that
10665** modifications are made that move that database to state S1 and a
10666** changeset recorded (the "local" changeset). Then, a changeset based
10667** on S0 is received from another site (the "remote" changeset) and
10668** applied to the database. The database is then in state
10669** (S1+"remote"), where the exact state depends on any conflict
10670** resolution decisions (OMIT or REPLACE) made while applying "remote".
10671** Rebasing a changeset is to update it to take those conflict
10672** resolution decisions into account, so that the same conflicts
10673** do not have to be resolved elsewhere in the network.
10674**
10675** For example, if both the local and remote changesets contain an
10676** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
10677**
10678** local: INSERT INTO t1 VALUES(1, 'v1');
10679** remote: INSERT INTO t1 VALUES(1, 'v2');
10680**
10681** and the conflict resolution is REPLACE, then the INSERT change is
10682** removed from the local changeset (it was overridden). Or, if the
10683** conflict resolution was "OMIT", then the local changeset is modified
10684** to instead contain:
10685**
10686** UPDATE t1 SET b = 'v2' WHERE a=1;
10687**
10688** Changes within the local changeset are rebased as follows:
10689**
10690** <dl>
10691** <dt>Local INSERT<dd>
10692** This may only conflict with a remote INSERT. If the conflict
10693** resolution was OMIT, then add an UPDATE change to the rebased
10694** changeset. Or, if the conflict resolution was REPLACE, add
10695** nothing to the rebased changeset.
10696**
10697** <dt>Local DELETE<dd>
10698** This may conflict with a remote UPDATE or DELETE. In both cases the
10699** only possible resolution is OMIT. If the remote operation was a
10700** DELETE, then add no change to the rebased changeset. If the remote
10701** operation was an UPDATE, then the old.* fields of change are updated
10702** to reflect the new.* values in the UPDATE.
10703**
10704** <dt>Local UPDATE<dd>
10705** This may conflict with a remote UPDATE or DELETE. If it conflicts
10706** with a DELETE, and the conflict resolution was OMIT, then the update
10707** is changed into an INSERT. Any undefined values in the new.* record
10708** from the update change are filled in using the old.* values from
10709** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
10710** the UPDATE change is simply omitted from the rebased changeset.
10711**
10712** If conflict is with a remote UPDATE and the resolution is OMIT, then
10713** the old.* values are rebased using the new.* values in the remote
10714** change. Or, if the resolution is REPLACE, then the change is copied
10715** into the rebased changeset with updates to columns also updated by
10716** the conflicting remote UPDATE removed. If this means no columns would
10717** be updated, the change is omitted.
10718** </dl>
10719**
10720** A local change may be rebased against multiple remote changes
10721** simultaneously. If a single key is modified by multiple remote
10722** changesets, they are combined as follows before the local changeset
10723** is rebased:
10724**
10725** <ul>
10726** <li> If there has been one or more REPLACE resolutions on a
10727** key, it is rebased according to a REPLACE.
10728**
10729** <li> If there have been no REPLACE resolutions on a key, then
10730** the local changeset is rebased according to the most recent
10731** of the OMIT resolutions.
10732** </ul>
10733**
10734** Note that conflict resolutions from multiple remote changesets are
10735** combined on a per-field basis, not per-row. This means that in the
10736** case of multiple remote UPDATE operations, some fields of a single
10737** local change may be rebased for REPLACE while others are rebased for
10738** OMIT.
10739**
10740** In order to rebase a local changeset, the remote changeset must first
10741** be applied to the local database using sqlite3changeset_apply_v2() and
10742** the buffer of rebase information captured. Then:
10743**
10744** <ol>
10745** <li> An sqlite3_rebaser object is created by calling
10746** sqlite3rebaser_create().
10747** <li> The new object is configured with the rebase buffer obtained from
10748** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
10749** If the local changeset is to be rebased against multiple remote
10750** changesets, then sqlite3rebaser_configure() should be called
10751** multiple times, in the same order that the multiple
10752** sqlite3changeset_apply_v2() calls were made.
10753** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
10754** <li> The sqlite3_rebaser object is deleted by calling
10755** sqlite3rebaser_delete().
10756** </ol>
10757*/
10758typedef struct sqlite3_rebaser sqlite3_rebaser;
10759
10760/*
10761** CAPI3REF: Create a changeset rebaser object.
10762** EXPERIMENTAL
10763**
10764** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
10765** point to the new object and return SQLITE_OK. Otherwise, if an error
10766** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
10767** to NULL.
10768*/
10769SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
10770
10771/*
10772** CAPI3REF: Configure a changeset rebaser object.
10773** EXPERIMENTAL
10774**
10775** Configure the changeset rebaser object to rebase changesets according
10776** to the conflict resolutions described by buffer pRebase (size nRebase
10777** bytes), which must have been obtained from a previous call to
10778** sqlite3changeset_apply_v2().
10779*/
10780SQLITE_API int sqlite3rebaser_configure(
10781 sqlite3_rebaser*,
10782 int nRebase, const void *pRebase
10783);
10784
10785/*
10786** CAPI3REF: Rebase a changeset
10787** EXPERIMENTAL
10788**
10789** Argument pIn must point to a buffer containing a changeset nIn bytes
10790** in size. This function allocates and populates a buffer with a copy
10791** of the changeset rebased rebased according to the configuration of the
10792** rebaser object passed as the first argument. If successful, (*ppOut)
10793** is set to point to the new buffer containing the rebased changset and
10794** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
10795** responsibility of the caller to eventually free the new buffer using
10796** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
10797** are set to zero and an SQLite error code returned.
10798*/
10799SQLITE_API int sqlite3rebaser_rebase(
10800 sqlite3_rebaser*,
10801 int nIn, const void *pIn,
10802 int *pnOut, void **ppOut
10803);
10804
10805/*
10806** CAPI3REF: Delete a changeset rebaser object.
10807** EXPERIMENTAL
10808**
10809** Delete the changeset rebaser object and all associated resources. There
10810** should be one call to this function for each successful invocation
10811** of sqlite3rebaser_create().
10812*/
10813SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
10814
10815/*
10816** CAPI3REF: Streaming Versions of API functions.
10817**
10818** The six streaming API xxx_strm() functions serve similar purposes to the
10819** corresponding non-streaming API functions:
10820**
10821** <table border=1 style="margin-left:8ex;margin-right:8ex">
10822** <tr><th>Streaming function<th>Non-streaming equivalent</th>
10823** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
10824** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
10825** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
10826** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
10827** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
10828** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
10829** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
10830** </table>
10831**
10832** Non-streaming functions that accept changesets (or patchsets) as input
10833** require that the entire changeset be stored in a single buffer in memory.
10834** Similarly, those that return a changeset or patchset do so by returning
10835** a pointer to a single large buffer allocated using sqlite3_malloc().
10836** Normally this is convenient. However, if an application running in a
10837** low-memory environment is required to handle very large changesets, the
10838** large contiguous memory allocations required can become onerous.
10839**
10840** In order to avoid this problem, instead of a single large buffer, input
10841** is passed to a streaming API functions by way of a callback function that
10842** the sessions module invokes to incrementally request input data as it is
10843** required. In all cases, a pair of API function parameters such as
10844**
10845** <pre>
10846** &nbsp; int nChangeset,
10847** &nbsp; void *pChangeset,
10848** </pre>
10849**
10850** Is replaced by:
10851**
10852** <pre>
10853** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
10854** &nbsp; void *pIn,
10855** </pre>
10856**
10857** Each time the xInput callback is invoked by the sessions module, the first
10858** argument passed is a copy of the supplied pIn context pointer. The second
10859** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
10860** error occurs the xInput method should copy up to (*pnData) bytes of data
10861** into the buffer and set (*pnData) to the actual number of bytes copied
10862** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
10863** should be set to zero to indicate this. Or, if an error occurs, an SQLite
10864** error code should be returned. In all cases, if an xInput callback returns
10865** an error, all processing is abandoned and the streaming API function
10866** returns a copy of the error code to the caller.
10867**
10868** In the case of sqlite3changeset_start_strm(), the xInput callback may be
10869** invoked by the sessions module at any point during the lifetime of the
10870** iterator. If such an xInput callback returns an error, the iterator enters
10871** an error state, whereby all subsequent calls to iterator functions
10872** immediately fail with the same error code as returned by xInput.
10873**
10874** Similarly, streaming API functions that return changesets (or patchsets)
10875** return them in chunks by way of a callback function instead of via a
10876** pointer to a single large buffer. In this case, a pair of parameters such
10877** as:
10878**
10879** <pre>
10880** &nbsp; int *pnChangeset,
10881** &nbsp; void **ppChangeset,
10882** </pre>
10883**
10884** Is replaced by:
10885**
10886** <pre>
10887** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
10888** &nbsp; void *pOut
10889** </pre>
10890**
10891** The xOutput callback is invoked zero or more times to return data to
10892** the application. The first parameter passed to each call is a copy of the
10893** pOut pointer supplied by the application. The second parameter, pData,
10894** points to a buffer nData bytes in size containing the chunk of output
10895** data being returned. If the xOutput callback successfully processes the
10896** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
10897** it should return some other SQLite error code. In this case processing
10898** is immediately abandoned and the streaming API function returns a copy
10899** of the xOutput error code to the application.
10900**
10901** The sessions module never invokes an xOutput callback with the third
10902** parameter set to a value less than or equal to zero. Other than this,
10903** no guarantees are made as to the size of the chunks of data returned.
10904*/
10905SQLITE_API int sqlite3changeset_apply_strm(
10906 sqlite3 *db, /* Apply change to "main" db of this handle */
10907 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
10908 void *pIn, /* First arg for xInput */
10909 int(*xFilter)(
10910 void *pCtx, /* Copy of sixth arg to _apply() */
10911 const char *zTab /* Table name */
10912 ),
10913 int(*xConflict)(
10914 void *pCtx, /* Copy of sixth arg to _apply() */
10915 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10916 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10917 ),
10918 void *pCtx /* First argument passed to xConflict */
10919);
10920SQLITE_API int sqlite3changeset_apply_v2_strm(
10921 sqlite3 *db, /* Apply change to "main" db of this handle */
10922 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
10923 void *pIn, /* First arg for xInput */
10924 int(*xFilter)(
10925 void *pCtx, /* Copy of sixth arg to _apply() */
10926 const char *zTab /* Table name */
10927 ),
10928 int(*xConflict)(
10929 void *pCtx, /* Copy of sixth arg to _apply() */
10930 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10931 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10932 ),
10933 void *pCtx, /* First argument passed to xConflict */
10934 void **ppRebase, int *pnRebase,
10935 int flags
10936);
10937SQLITE_API int sqlite3changeset_concat_strm(
10938 int (*xInputA)(void *pIn, void *pData, int *pnData),
10939 void *pInA,
10940 int (*xInputB)(void *pIn, void *pData, int *pnData),
10941 void *pInB,
10942 int (*xOutput)(void *pOut, const void *pData, int nData),
10943 void *pOut
10944);
10945SQLITE_API int sqlite3changeset_invert_strm(
10946 int (*xInput)(void *pIn, void *pData, int *pnData),
10947 void *pIn,
10948 int (*xOutput)(void *pOut, const void *pData, int nData),
10949 void *pOut
10950);
10951SQLITE_API int sqlite3changeset_start_strm(
10952 sqlite3_changeset_iter **pp,
10953 int (*xInput)(void *pIn, void *pData, int *pnData),
10954 void *pIn
10955);
10956SQLITE_API int sqlite3session_changeset_strm(
10957 sqlite3_session *pSession,
10958 int (*xOutput)(void *pOut, const void *pData, int nData),
10959 void *pOut
10960);
10961SQLITE_API int sqlite3session_patchset_strm(
10962 sqlite3_session *pSession,
10963 int (*xOutput)(void *pOut, const void *pData, int nData),
10964 void *pOut
10965);
10966SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
10967 int (*xInput)(void *pIn, void *pData, int *pnData),
10968 void *pIn
10969);
10970SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
10971 int (*xOutput)(void *pOut, const void *pData, int nData),
10972 void *pOut
10973);
10974SQLITE_API int sqlite3rebaser_rebase_strm(
10975 sqlite3_rebaser *pRebaser,
10976 int (*xInput)(void *pIn, void *pData, int *pnData),
10977 void *pIn,
10978 int (*xOutput)(void *pOut, const void *pData, int nData),
10979 void *pOut
10980);
10981
10982
10983/*
10984** Make sure we can call this stuff from C++.
10985*/
10986#ifdef __cplusplus
10987}
10988#endif
10989
10990#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
10991
10992/******** End of sqlite3session.h *********/
10993/******** Begin file fts5.h *********/
10994/*
10995** 2014 May 31
10996**
10997** The author disclaims copyright to this source code. In place of
10998** a legal notice, here is a blessing:
10999**
11000** May you do good and not evil.
11001** May you find forgiveness for yourself and forgive others.
11002** May you share freely, never taking more than you give.
11003**
11004******************************************************************************
11005**
11006** Interfaces to extend FTS5. Using the interfaces defined in this file,
11007** FTS5 may be extended with:
11008**
11009** * custom tokenizers, and
11010** * custom auxiliary functions.
11011*/
11012
11013
11014#ifndef _FTS5_H
11015#define _FTS5_H
11016
11017
11018#ifdef __cplusplus
11019extern "C" {
11020#endif
11021
11022/*************************************************************************
11023** CUSTOM AUXILIARY FUNCTIONS
11024**
11025** Virtual table implementations may overload SQL functions by implementing
11026** the sqlite3_module.xFindFunction() method.
11027*/
11028
11029typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11030typedef struct Fts5Context Fts5Context;
11031typedef struct Fts5PhraseIter Fts5PhraseIter;
11032
11033typedef void (*fts5_extension_function)(
11034 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11035 Fts5Context *pFts, /* First arg to pass to pApi functions */
11036 sqlite3_context *pCtx, /* Context for returning result/error */
11037 int nVal, /* Number of values in apVal[] array */
11038 sqlite3_value **apVal /* Array of trailing arguments */
11039);
11040
11041struct Fts5PhraseIter {
11042 const unsigned char *a;
11043 const unsigned char *b;
11044};
11045
11046/*
11047** EXTENSION API FUNCTIONS
11048**
11049** xUserData(pFts):
11050** Return a copy of the context pointer the extension function was
11051** registered with.
11052**
11053** xColumnTotalSize(pFts, iCol, pnToken):
11054** If parameter iCol is less than zero, set output variable *pnToken
11055** to the total number of tokens in the FTS5 table. Or, if iCol is
11056** non-negative but less than the number of columns in the table, return
11057** the total number of tokens in column iCol, considering all rows in
11058** the FTS5 table.
11059**
11060** If parameter iCol is greater than or equal to the number of columns
11061** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11062** an OOM condition or IO error), an appropriate SQLite error code is
11063** returned.
11064**
11065** xColumnCount(pFts):
11066** Return the number of columns in the table.
11067**
11068** xColumnSize(pFts, iCol, pnToken):
11069** If parameter iCol is less than zero, set output variable *pnToken
11070** to the total number of tokens in the current row. Or, if iCol is
11071** non-negative but less than the number of columns in the table, set
11072** *pnToken to the number of tokens in column iCol of the current row.
11073**
11074** If parameter iCol is greater than or equal to the number of columns
11075** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11076** an OOM condition or IO error), an appropriate SQLite error code is
11077** returned.
11078**
11079** This function may be quite inefficient if used with an FTS5 table
11080** created with the "columnsize=0" option.
11081**
11082** xColumnText:
11083** This function attempts to retrieve the text of column iCol of the
11084** current document. If successful, (*pz) is set to point to a buffer
11085** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11086** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11087** if an error occurs, an SQLite error code is returned and the final values
11088** of (*pz) and (*pn) are undefined.
11089**
11090** xPhraseCount:
11091** Returns the number of phrases in the current query expression.
11092**
11093** xPhraseSize:
11094** Returns the number of tokens in phrase iPhrase of the query. Phrases
11095** are numbered starting from zero.
11096**
11097** xInstCount:
11098** Set *pnInst to the total number of occurrences of all phrases within
11099** the query within the current row. Return SQLITE_OK if successful, or
11100** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11101**
11102** This API can be quite slow if used with an FTS5 table created with the
11103** "detail=none" or "detail=column" option. If the FTS5 table is created
11104** with either "detail=none" or "detail=column" and "content=" option
11105** (i.e. if it is a contentless table), then this API always returns 0.
11106**
11107** xInst:
11108** Query for the details of phrase match iIdx within the current row.
11109** Phrase matches are numbered starting from zero, so the iIdx argument
11110** should be greater than or equal to zero and smaller than the value
11111** output by xInstCount().
11112**
11113** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11114** to the column in which it occurs and *piOff the token offset of the
11115** first token of the phrase. The exception is if the table was created
11116** with the offsets=0 option specified. In this case *piOff is always
11117** set to -1.
11118**
11119** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
11120** if an error occurs.
11121**
11122** This API can be quite slow if used with an FTS5 table created with the
11123** "detail=none" or "detail=column" option.
11124**
11125** xRowid:
11126** Returns the rowid of the current row.
11127**
11128** xTokenize:
11129** Tokenize text using the tokenizer belonging to the FTS5 table.
11130**
11131** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11132** This API function is used to query the FTS table for phrase iPhrase
11133** of the current query. Specifically, a query equivalent to:
11134**
11135** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11136**
11137** with $p set to a phrase equivalent to the phrase iPhrase of the
11138** current query is executed. Any column filter that applies to
11139** phrase iPhrase of the current query is included in $p. For each
11140** row visited, the callback function passed as the fourth argument
11141** is invoked. The context and API objects passed to the callback
11142** function may be used to access the properties of each matched row.
11143** Invoking Api.xUserData() returns a copy of the pointer passed as
11144** the third argument to pUserData.
11145**
11146** If the callback function returns any value other than SQLITE_OK, the
11147** query is abandoned and the xQueryPhrase function returns immediately.
11148** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11149** Otherwise, the error code is propagated upwards.
11150**
11151** If the query runs to completion without incident, SQLITE_OK is returned.
11152** Or, if some error occurs before the query completes or is aborted by
11153** the callback, an SQLite error code is returned.
11154**
11155**
11156** xSetAuxdata(pFts5, pAux, xDelete)
11157**
11158** Save the pointer passed as the second argument as the extension functions
11159** "auxiliary data". The pointer may then be retrieved by the current or any
11160** future invocation of the same fts5 extension function made as part of
11161** of the same MATCH query using the xGetAuxdata() API.
11162**
11163** Each extension function is allocated a single auxiliary data slot for
11164** each FTS query (MATCH expression). If the extension function is invoked
11165** more than once for a single FTS query, then all invocations share a
11166** single auxiliary data context.
11167**
11168** If there is already an auxiliary data pointer when this function is
11169** invoked, then it is replaced by the new pointer. If an xDelete callback
11170** was specified along with the original pointer, it is invoked at this
11171** point.
11172**
11173** The xDelete callback, if one is specified, is also invoked on the
11174** auxiliary data pointer after the FTS5 query has finished.
11175**
11176** If an error (e.g. an OOM condition) occurs within this function, an
11177** the auxiliary data is set to NULL and an error code returned. If the
11178** xDelete parameter was not NULL, it is invoked on the auxiliary data
11179** pointer before returning.
11180**
11181**
11182** xGetAuxdata(pFts5, bClear)
11183**
11184** Returns the current auxiliary data pointer for the fts5 extension
11185** function. See the xSetAuxdata() method for details.
11186**
11187** If the bClear argument is non-zero, then the auxiliary data is cleared
11188** (set to NULL) before this function returns. In this case the xDelete,
11189** if any, is not invoked.
11190**
11191**
11192** xRowCount(pFts5, pnRow)
11193**
11194** This function is used to retrieve the total number of rows in the table.
11195** In other words, the same value that would be returned by:
11196**
11197** SELECT count(*) FROM ftstable;
11198**
11199** xPhraseFirst()
11200** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11201** method, to iterate through all instances of a single query phrase within
11202** the current row. This is the same information as is accessible via the
11203** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
11204** to use, this API may be faster under some circumstances. To iterate
11205** through instances of phrase iPhrase, use the following code:
11206**
11207** Fts5PhraseIter iter;
11208** int iCol, iOff;
11209** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11210** iCol>=0;
11211** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11212** ){
11213** // An instance of phrase iPhrase at offset iOff of column iCol
11214** }
11215**
11216** The Fts5PhraseIter structure is defined above. Applications should not
11217** modify this structure directly - it should only be used as shown above
11218** with the xPhraseFirst() and xPhraseNext() API methods (and by
11219** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11220**
11221** This API can be quite slow if used with an FTS5 table created with the
11222** "detail=none" or "detail=column" option. If the FTS5 table is created
11223** with either "detail=none" or "detail=column" and "content=" option
11224** (i.e. if it is a contentless table), then this API always iterates
11225** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11226**
11227** xPhraseNext()
11228** See xPhraseFirst above.
11229**
11230** xPhraseFirstColumn()
11231** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11232** and xPhraseNext() APIs described above. The difference is that instead
11233** of iterating through all instances of a phrase in the current row, these
11234** APIs are used to iterate through the set of columns in the current row
11235** that contain one or more instances of a specified phrase. For example:
11236**
11237** Fts5PhraseIter iter;
11238** int iCol;
11239** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11240** iCol>=0;
11241** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11242** ){
11243** // Column iCol contains at least one instance of phrase iPhrase
11244** }
11245**
11246** This API can be quite slow if used with an FTS5 table created with the
11247** "detail=none" option. If the FTS5 table is created with either
11248** "detail=none" "content=" option (i.e. if it is a contentless table),
11249** then this API always iterates through an empty set (all calls to
11250** xPhraseFirstColumn() set iCol to -1).
11251**
11252** The information accessed using this API and its companion
11253** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11254** (or xInst/xInstCount). The chief advantage of this API is that it is
11255** significantly more efficient than those alternatives when used with
11256** "detail=column" tables.
11257**
11258** xPhraseNextColumn()
11259** See xPhraseFirstColumn above.
11260*/
11261struct Fts5ExtensionApi {
11262 int iVersion; /* Currently always set to 3 */
11263
11264 void *(*xUserData)(Fts5Context*);
11265
11266 int (*xColumnCount)(Fts5Context*);
11267 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11268 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11269
11270 int (*xTokenize)(Fts5Context*,
11271 const char *pText, int nText, /* Text to tokenize */
11272 void *pCtx, /* Context passed to xToken() */
11273 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11274 );
11275
11276 int (*xPhraseCount)(Fts5Context*);
11277 int (*xPhraseSize)(Fts5Context*, int iPhrase);
11278
11279 int (*xInstCount)(Fts5Context*, int *pnInst);
11280 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11281
11282 sqlite3_int64 (*xRowid)(Fts5Context*);
11283 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11284 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11285
11286 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11287 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11288 );
11289 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11290 void *(*xGetAuxdata)(Fts5Context*, int bClear);
11291
11292 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11293 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11294
11295 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11296 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11297};
11298
11299/*
11300** CUSTOM AUXILIARY FUNCTIONS
11301*************************************************************************/
11302
11303/*************************************************************************
11304** CUSTOM TOKENIZERS
11305**
11306** Applications may also register custom tokenizer types. A tokenizer
11307** is registered by providing fts5 with a populated instance of the
11308** following structure. All structure methods must be defined, setting
11309** any member of the fts5_tokenizer struct to NULL leads to undefined
11310** behaviour. The structure methods are expected to function as follows:
11311**
11312** xCreate:
11313** This function is used to allocate and initialize a tokenizer instance.
11314** A tokenizer instance is required to actually tokenize text.
11315**
11316** The first argument passed to this function is a copy of the (void*)
11317** pointer provided by the application when the fts5_tokenizer object
11318** was registered with FTS5 (the third argument to xCreateTokenizer()).
11319** The second and third arguments are an array of nul-terminated strings
11320** containing the tokenizer arguments, if any, specified following the
11321** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
11322** to create the FTS5 table.
11323**
11324** The final argument is an output variable. If successful, (*ppOut)
11325** should be set to point to the new tokenizer handle and SQLITE_OK
11326** returned. If an error occurs, some value other than SQLITE_OK should
11327** be returned. In this case, fts5 assumes that the final value of *ppOut
11328** is undefined.
11329**
11330** xDelete:
11331** This function is invoked to delete a tokenizer handle previously
11332** allocated using xCreate(). Fts5 guarantees that this function will
11333** be invoked exactly once for each successful call to xCreate().
11334**
11335** xTokenize:
11336** This function is expected to tokenize the nText byte string indicated
11337** by argument pText. pText may or may not be nul-terminated. The first
11338** argument passed to this function is a pointer to an Fts5Tokenizer object
11339** returned by an earlier call to xCreate().
11340**
11341** The second argument indicates the reason that FTS5 is requesting
11342** tokenization of the supplied text. This is always one of the following
11343** four values:
11344**
11345** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
11346** or removed from the FTS table. The tokenizer is being invoked to
11347** determine the set of tokens to add to (or delete from) the
11348** FTS index.
11349**
11350** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
11351** against the FTS index. The tokenizer is being called to tokenize
11352** a bareword or quoted string specified as part of the query.
11353**
11354** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
11355** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
11356** followed by a "*" character, indicating that the last token
11357** returned by the tokenizer will be treated as a token prefix.
11358**
11359** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
11360** satisfy an fts5_api.xTokenize() request made by an auxiliary
11361** function. Or an fts5_api.xColumnSize() request made by the same
11362** on a columnsize=0 database.
11363** </ul>
11364**
11365** For each token in the input string, the supplied callback xToken() must
11366** be invoked. The first argument to it should be a copy of the pointer
11367** passed as the second argument to xTokenize(). The third and fourth
11368** arguments are a pointer to a buffer containing the token text, and the
11369** size of the token in bytes. The 4th and 5th arguments are the byte offsets
11370** of the first byte of and first byte immediately following the text from
11371** which the token is derived within the input.
11372**
11373** The second argument passed to the xToken() callback ("tflags") should
11374** normally be set to 0. The exception is if the tokenizer supports
11375** synonyms. In this case see the discussion below for details.
11376**
11377** FTS5 assumes the xToken() callback is invoked for each token in the
11378** order that they occur within the input text.
11379**
11380** If an xToken() callback returns any value other than SQLITE_OK, then
11381** the tokenization should be abandoned and the xTokenize() method should
11382** immediately return a copy of the xToken() return value. Or, if the
11383** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
11384** if an error occurs with the xTokenize() implementation itself, it
11385** may abandon the tokenization and return any error code other than
11386** SQLITE_OK or SQLITE_DONE.
11387**
11388** SYNONYM SUPPORT
11389**
11390** Custom tokenizers may also support synonyms. Consider a case in which a
11391** user wishes to query for a phrase such as "first place". Using the
11392** built-in tokenizers, the FTS5 query 'first + place' will match instances
11393** of "first place" within the document set, but not alternative forms
11394** such as "1st place". In some applications, it would be better to match
11395** all instances of "first place" or "1st place" regardless of which form
11396** the user specified in the MATCH query text.
11397**
11398** There are several ways to approach this in FTS5:
11399**
11400** <ol><li> By mapping all synonyms to a single token. In this case, the
11401** In the above example, this means that the tokenizer returns the
11402** same token for inputs "first" and "1st". Say that token is in
11403** fact "first", so that when the user inserts the document "I won
11404** 1st place" entries are added to the index for tokens "i", "won",
11405** "first" and "place". If the user then queries for '1st + place',
11406** the tokenizer substitutes "first" for "1st" and the query works
11407** as expected.
11408**
11409** <li> By adding multiple synonyms for a single term to the FTS index.
11410** In this case, when tokenizing query text, the tokenizer may
11411** provide multiple synonyms for a single term within the document.
11412** FTS5 then queries the index for each synonym individually. For
11413** example, faced with the query:
11414**
11415** <codeblock>
11416** ... MATCH 'first place'</codeblock>
11417**
11418** the tokenizer offers both "1st" and "first" as synonyms for the
11419** first token in the MATCH query and FTS5 effectively runs a query
11420** similar to:
11421**
11422** <codeblock>
11423** ... MATCH '(first OR 1st) place'</codeblock>
11424**
11425** except that, for the purposes of auxiliary functions, the query
11426** still appears to contain just two phrases - "(first OR 1st)"
11427** being treated as a single phrase.
11428**
11429** <li> By adding multiple synonyms for a single term to the FTS index.
11430** Using this method, when tokenizing document text, the tokenizer
11431** provides multiple synonyms for each token. So that when a
11432** document such as "I won first place" is tokenized, entries are
11433** added to the FTS index for "i", "won", "first", "1st" and
11434** "place".
11435**
11436** This way, even if the tokenizer does not provide synonyms
11437** when tokenizing query text (it should not - to do would be
11438** inefficient), it doesn't matter if the user queries for
11439** 'first + place' or '1st + place', as there are entries in the
11440** FTS index corresponding to both forms of the first token.
11441** </ol>
11442**
11443** Whether it is parsing document or query text, any call to xToken that
11444** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
11445** is considered to supply a synonym for the previous token. For example,
11446** when parsing the document "I won first place", a tokenizer that supports
11447** synonyms would call xToken() 5 times, as follows:
11448**
11449** <codeblock>
11450** xToken(pCtx, 0, "i", 1, 0, 1);
11451** xToken(pCtx, 0, "won", 3, 2, 5);
11452** xToken(pCtx, 0, "first", 5, 6, 11);
11453** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
11454** xToken(pCtx, 0, "place", 5, 12, 17);
11455**</codeblock>
11456**
11457** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
11458** xToken() is called. Multiple synonyms may be specified for a single token
11459** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
11460** There is no limit to the number of synonyms that may be provided for a
11461** single token.
11462**
11463** In many cases, method (1) above is the best approach. It does not add
11464** extra data to the FTS index or require FTS5 to query for multiple terms,
11465** so it is efficient in terms of disk space and query speed. However, it
11466** does not support prefix queries very well. If, as suggested above, the
11467** token "first" is substituted for "1st" by the tokenizer, then the query:
11468**
11469** <codeblock>
11470** ... MATCH '1s*'</codeblock>
11471**
11472** will not match documents that contain the token "1st" (as the tokenizer
11473** will probably not map "1s" to any prefix of "first").
11474**
11475** For full prefix support, method (3) may be preferred. In this case,
11476** because the index contains entries for both "first" and "1st", prefix
11477** queries such as 'fi*' or '1s*' will match correctly. However, because
11478** extra entries are added to the FTS index, this method uses more space
11479** within the database.
11480**
11481** Method (2) offers a midpoint between (1) and (3). Using this method,
11482** a query such as '1s*' will match documents that contain the literal
11483** token "1st", but not "first" (assuming the tokenizer is not able to
11484** provide synonyms for prefixes). However, a non-prefix query like '1st'
11485** will match against "1st" and "first". This method does not require
11486** extra disk space, as no extra entries are added to the FTS index.
11487** On the other hand, it may require more CPU cycles to run MATCH queries,
11488** as separate queries of the FTS index are required for each synonym.
11489**
11490** When using methods (2) or (3), it is important that the tokenizer only
11491** provide synonyms when tokenizing document text (method (2)) or query
11492** text (method (3)), not both. Doing so will not cause any errors, but is
11493** inefficient.
11494*/
11495typedef struct Fts5Tokenizer Fts5Tokenizer;
11496typedef struct fts5_tokenizer fts5_tokenizer;
11497struct fts5_tokenizer {
11498 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
11499 void (*xDelete)(Fts5Tokenizer*);
11500 int (*xTokenize)(Fts5Tokenizer*,
11501 void *pCtx,
11502 int flags, /* Mask of FTS5_TOKENIZE_* flags */
11503 const char *pText, int nText,
11504 int (*xToken)(
11505 void *pCtx, /* Copy of 2nd argument to xTokenize() */
11506 int tflags, /* Mask of FTS5_TOKEN_* flags */
11507 const char *pToken, /* Pointer to buffer containing token */
11508 int nToken, /* Size of token in bytes */
11509 int iStart, /* Byte offset of token within input text */
11510 int iEnd /* Byte offset of end of token within input text */
11511 )
11512 );
11513};
11514
11515/* Flags that may be passed as the third argument to xTokenize() */
11516#define FTS5_TOKENIZE_QUERY 0x0001
11517#define FTS5_TOKENIZE_PREFIX 0x0002
11518#define FTS5_TOKENIZE_DOCUMENT 0x0004
11519#define FTS5_TOKENIZE_AUX 0x0008
11520
11521/* Flags that may be passed by the tokenizer implementation back to FTS5
11522** as the third argument to the supplied xToken callback. */
11523#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
11524
11525/*
11526** END OF CUSTOM TOKENIZERS
11527*************************************************************************/
11528
11529/*************************************************************************
11530** FTS5 EXTENSION REGISTRATION API
11531*/
11532typedef struct fts5_api fts5_api;
11533struct fts5_api {
11534 int iVersion; /* Currently always set to 2 */
11535
11536 /* Create a new tokenizer */
11537 int (*xCreateTokenizer)(
11538 fts5_api *pApi,
11539 const char *zName,
11540 void *pContext,
11541 fts5_tokenizer *pTokenizer,
11542 void (*xDestroy)(void*)
11543 );
11544
11545 /* Find an existing tokenizer */
11546 int (*xFindTokenizer)(
11547 fts5_api *pApi,
11548 const char *zName,
11549 void **ppContext,
11550 fts5_tokenizer *pTokenizer
11551 );
11552
11553 /* Create a new auxiliary function */
11554 int (*xCreateFunction)(
11555 fts5_api *pApi,
11556 const char *zName,
11557 void *pContext,
11558 fts5_extension_function xFunction,
11559 void (*xDestroy)(void*)
11560 );
11561};
11562
11563/*
11564** END OF REGISTRATION API
11565*************************************************************************/
11566
11567#ifdef __cplusplus
11568} /* end of the 'extern "C"' block */
11569#endif
11570
11571#endif /* _FTS5_H */
11572
11573/******** End of fts5.h *********/
11574