1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Facilitate override of interface linkage and calling conventions.
47** Be aware that these macros may not be used within this particular
48** translation of the amalgamation and its associated header file.
49**
50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51** compiler that the target identifier should have external linkage.
52**
53** The SQLITE_CDECL macro is used to set the calling convention for
54** public functions that accept a variable number of arguments.
55**
56** The SQLITE_APICALL macro is used to set the calling convention for
57** public functions that accept a fixed number of arguments.
58**
59** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60**
61** The SQLITE_CALLBACK macro is used to set the calling convention for
62** function pointers.
63**
64** The SQLITE_SYSAPI macro is used to set the calling convention for
65** functions provided by the operating system.
66**
67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68** SQLITE_SYSAPI macros are used only when building for environments
69** that require non-default calling conventions.
70*/
71#ifndef SQLITE_EXTERN
72# define SQLITE_EXTERN extern
73#endif
74#ifndef SQLITE_API
75# define SQLITE_API
76#endif
77#ifndef SQLITE_CDECL
78# define SQLITE_CDECL
79#endif
80#ifndef SQLITE_APICALL
81# define SQLITE_APICALL
82#endif
83#ifndef SQLITE_STDCALL
84# define SQLITE_STDCALL SQLITE_APICALL
85#endif
86#ifndef SQLITE_CALLBACK
87# define SQLITE_CALLBACK
88#endif
89#ifndef SQLITE_SYSAPI
90# define SQLITE_SYSAPI
91#endif
92
93/*
94** These no-op macros are used in front of interfaces to mark those
95** interfaces as either deprecated or experimental. New applications
96** should not use deprecated interfaces - they are supported for backwards
97** compatibility only. Application writers should be aware that
98** experimental interfaces are subject to change in point releases.
99**
100** These macros used to resolve to various kinds of compiler magic that
101** would generate warning messages when they were used. But that
102** compiler magic ended up generating such a flurry of bug reports
103** that we have taken it all out and gone back to using simple
104** noop macros.
105*/
106#define SQLITE_DEPRECATED
107#define SQLITE_EXPERIMENTAL
108
109/*
110** Ensure these symbols were not defined by some previous header file.
111*/
112#ifdef SQLITE_VERSION
113# undef SQLITE_VERSION
114#endif
115#ifdef SQLITE_VERSION_NUMBER
116# undef SQLITE_VERSION_NUMBER
117#endif
118
119/*
120** CAPI3REF: Compile-Time Library Version Numbers
121**
122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123** evaluates to a string literal that is the SQLite version in the
124** format "X.Y.Z" where X is the major version number (always 3 for
125** SQLite3) and Y is the minor version number and Z is the release number.)^
126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128** numbers used in [SQLITE_VERSION].)^
129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130** be larger than the release from which it is derived. Either Y will
131** be held constant and Z will be incremented or else Y will be incremented
132** and Z will be reset to zero.
133**
134** Since [version 3.6.18] ([dateof:3.6.18]),
135** SQLite source code has been stored in the
136** <a href="http://www.fossil-scm.org/">Fossil configuration management
137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138** a string which identifies a particular check-in of SQLite
139** within its configuration management system. ^The SQLITE_SOURCE_ID
140** string contains the date and time of the check-in (UTC) and a SHA1
141** or SHA3-256 hash of the entire source tree. If the source code has
142** been edited in any way since it was last checked in, then the last
143** four hexadecimal digits of the hash may be modified.
144**
145** See also: [sqlite3_libversion()],
146** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147** [sqlite_version()] and [sqlite_source_id()].
148*/
149#define SQLITE_VERSION "3.46.0"
150#define SQLITE_VERSION_NUMBER 3046000
151#define SQLITE_SOURCE_ID "2024-05-23 13:25:27 96c92aba00c8375bc32fafcdf12429c58bd8aabfcadab6683e35bbb9cdebalt1"
152
153/*
154** CAPI3REF: Run-Time Library Version Numbers
155** KEYWORDS: sqlite3_version sqlite3_sourceid
156**
157** These interfaces provide the same information as the [SQLITE_VERSION],
158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159** but are associated with the library instead of the header file. ^(Cautious
160** programmers might include assert() statements in their application to
161** verify that values returned by these interfaces match the macros in
162** the header, and thus ensure that the application is
163** compiled with matching library and header files.
164**
165** <blockquote><pre>
166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169** </pre></blockquote>)^
170**
171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172** macro. ^The sqlite3_libversion() function returns a pointer to the
173** to the sqlite3_version[] string constant. The sqlite3_libversion()
174** function is provided for use in DLLs since DLL users usually do not have
175** direct access to string constants within the DLL. ^The
176** sqlite3_libversion_number() function returns an integer equal to
177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178** a pointer to a string constant whose value is the same as the
179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180** using an edited copy of [the amalgamation], then the last four characters
181** of the hash might be different from [SQLITE_SOURCE_ID].)^
182**
183** See also: [sqlite_version()] and [sqlite_source_id()].
184*/
185SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186SQLITE_API const char *sqlite3_libversion(void);
187SQLITE_API const char *sqlite3_sourceid(void);
188SQLITE_API int sqlite3_libversion_number(void);
189
190/*
191** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192**
193** ^The sqlite3_compileoption_used() function returns 0 or 1
194** indicating whether the specified option was defined at
195** compile time. ^The SQLITE_ prefix may be omitted from the
196** option name passed to sqlite3_compileoption_used().
197**
198** ^The sqlite3_compileoption_get() function allows iterating
199** over the list of options that were defined at compile time by
200** returning the N-th compile time option string. ^If N is out of range,
201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202** prefix is omitted from any strings returned by
203** sqlite3_compileoption_get().
204**
205** ^Support for the diagnostic functions sqlite3_compileoption_used()
206** and sqlite3_compileoption_get() may be omitted by specifying the
207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208**
209** See also: SQL functions [sqlite_compileoption_used()] and
210** [sqlite_compileoption_get()] and the [compile_options pragma].
211*/
212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214SQLITE_API const char *sqlite3_compileoption_get(int N);
215#else
216# define sqlite3_compileoption_used(X) 0
217# define sqlite3_compileoption_get(X) ((void*)0)
218#endif
219
220/*
221** CAPI3REF: Test To See If The Library Is Threadsafe
222**
223** ^The sqlite3_threadsafe() function returns zero if and only if
224** SQLite was compiled with mutexing code omitted due to the
225** [SQLITE_THREADSAFE] compile-time option being set to 0.
226**
227** SQLite can be compiled with or without mutexes. When
228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229** are enabled and SQLite is threadsafe. When the
230** [SQLITE_THREADSAFE] macro is 0,
231** the mutexes are omitted. Without the mutexes, it is not safe
232** to use SQLite concurrently from more than one thread.
233**
234** Enabling mutexes incurs a measurable performance penalty.
235** So if speed is of utmost importance, it makes sense to disable
236** the mutexes. But for maximum safety, mutexes should be enabled.
237** ^The default behavior is for mutexes to be enabled.
238**
239** This interface can be used by an application to make sure that the
240** version of SQLite that it is linking against was compiled with
241** the desired setting of the [SQLITE_THREADSAFE] macro.
242**
243** This interface only reports on the compile-time mutex setting
244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246** can be fully or partially disabled using a call to [sqlite3_config()]
247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249** sqlite3_threadsafe() function shows only the compile-time setting of
250** thread safety, not any run-time changes to that setting made by
251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252** is unchanged by calls to sqlite3_config().)^
253**
254** See the [threading mode] documentation for additional information.
255*/
256SQLITE_API int sqlite3_threadsafe(void);
257
258/*
259** CAPI3REF: Database Connection Handle
260** KEYWORDS: {database connection} {database connections}
261**
262** Each open SQLite database is represented by a pointer to an instance of
263** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266** and [sqlite3_close_v2()] are its destructors. There are many other
267** interfaces (such as
268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269** [sqlite3_busy_timeout()] to name but three) that are methods on an
270** sqlite3 object.
271*/
272typedef struct sqlite3 sqlite3;
273
274/*
275** CAPI3REF: 64-Bit Integer Types
276** KEYWORDS: sqlite_int64 sqlite_uint64
277**
278** Because there is no cross-platform way to specify 64-bit integer types
279** SQLite includes typedefs for 64-bit signed and unsigned integers.
280**
281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283** compatibility only.
284**
285** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287** sqlite3_uint64 and sqlite_uint64 types can store integer values
288** between 0 and +18446744073709551615 inclusive.
289*/
290#ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292# ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294# else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296# endif
297#elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300#else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303#endif
304typedef sqlite_int64 sqlite3_int64;
305typedef sqlite_uint64 sqlite3_uint64;
306
307/*
308** If compiling for a processor that lacks floating point support,
309** substitute integer for floating-point.
310*/
311#ifdef SQLITE_OMIT_FLOATING_POINT
312# define double sqlite3_int64
313#endif
314
315/*
316** CAPI3REF: Closing A Database Connection
317** DESTRUCTOR: sqlite3
318**
319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320** for the [sqlite3] object.
321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322** the [sqlite3] object is successfully destroyed and all associated
323** resources are deallocated.
324**
325** Ideally, applications should [sqlite3_finalize | finalize] all
326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328** with the [sqlite3] object prior to attempting to close the object.
329** ^If the database connection is associated with unfinalized prepared
330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331** sqlite3_close() will leave the database connection open and return
332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335** connection immediately, it marks the database connection as an unusable
336** "zombie" and makes arrangements to automatically deallocate the database
337** connection after all prepared statements are finalized, all BLOB handles
338** are closed, and all backups have finished. The sqlite3_close_v2() interface
339** is intended for use with host languages that are garbage collected, and
340** where the order in which destructors are called is arbitrary.
341**
342** ^If an [sqlite3] object is destroyed while a transaction is open,
343** the transaction is automatically rolled back.
344**
345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346** must be either a NULL
347** pointer or an [sqlite3] object pointer obtained
348** from [sqlite3_open()], [sqlite3_open16()], or
349** [sqlite3_open_v2()], and not previously closed.
350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351** argument is a harmless no-op.
352*/
353SQLITE_API int sqlite3_close(sqlite3*);
354SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356/*
357** The type for a callback function.
358** This is legacy and deprecated. It is included for historical
359** compatibility and is not documented.
360*/
361typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363/*
364** CAPI3REF: One-Step Query Execution Interface
365** METHOD: sqlite3
366**
367** The sqlite3_exec() interface is a convenience wrapper around
368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369** that allows an application to run multiple statements of SQL
370** without having to use a lot of C code.
371**
372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373** semicolon-separate SQL statements passed into its 2nd argument,
374** in the context of the [database connection] passed in as its 1st
375** argument. ^If the callback function of the 3rd argument to
376** sqlite3_exec() is not NULL, then it is invoked for each result row
377** coming out of the evaluated SQL statements. ^The 4th argument to
378** sqlite3_exec() is relayed through to the 1st argument of each
379** callback invocation. ^If the callback pointer to sqlite3_exec()
380** is NULL, then no callback is ever invoked and result rows are
381** ignored.
382**
383** ^If an error occurs while evaluating the SQL statements passed into
384** sqlite3_exec(), then execution of the current statement stops and
385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386** is not NULL then any error message is written into memory obtained
387** from [sqlite3_malloc()] and passed back through the 5th parameter.
388** To avoid memory leaks, the application should invoke [sqlite3_free()]
389** on error message strings returned through the 5th parameter of
390** sqlite3_exec() after the error message string is no longer needed.
391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393** NULL before returning.
394**
395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396** routine returns SQLITE_ABORT without invoking the callback again and
397** without running any subsequent SQL statements.
398**
399** ^The 2nd argument to the sqlite3_exec() callback function is the
400** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401** callback is an array of pointers to strings obtained as if from
402** [sqlite3_column_text()], one for each column. ^If an element of a
403** result row is NULL then the corresponding string pointer for the
404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405** sqlite3_exec() callback is an array of pointers to strings where each
406** entry represents the name of corresponding result column as obtained
407** from [sqlite3_column_name()].
408**
409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410** to an empty string, or a pointer that contains only whitespace and/or
411** SQL comments, then no SQL statements are evaluated and the database
412** is not changed.
413**
414** Restrictions:
415**
416** <ul>
417** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418** is a valid and open [database connection].
419** <li> The application must not close the [database connection] specified by
420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421** <li> The application must not modify the SQL statement text passed into
422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423** <li> The application must not dereference the arrays or string pointers
424** passed as the 3rd and 4th callback parameters after it returns.
425** </ul>
426*/
427SQLITE_API int sqlite3_exec(
428 sqlite3*, /* An open database */
429 const char *sql, /* SQL to be evaluated */
430 int (*callback)(void*,int,char**,char**), /* Callback function */
431 void *, /* 1st argument to callback */
432 char **errmsg /* Error msg written here */
433);
434
435/*
436** CAPI3REF: Result Codes
437** KEYWORDS: {result code definitions}
438**
439** Many SQLite functions return an integer result code from the set shown
440** here in order to indicate success or failure.
441**
442** New error codes may be added in future versions of SQLite.
443**
444** See also: [extended result code definitions]
445*/
446#define SQLITE_OK 0 /* Successful result */
447/* beginning-of-error-codes */
448#define SQLITE_ERROR 1 /* Generic error */
449#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
450#define SQLITE_PERM 3 /* Access permission denied */
451#define SQLITE_ABORT 4 /* Callback routine requested an abort */
452#define SQLITE_BUSY 5 /* The database file is locked */
453#define SQLITE_LOCKED 6 /* A table in the database is locked */
454#define SQLITE_NOMEM 7 /* A malloc() failed */
455#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
456#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
457#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
458#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
459#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
460#define SQLITE_FULL 13 /* Insertion failed because database is full */
461#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
462#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
463#define SQLITE_EMPTY 16 /* Internal use only */
464#define SQLITE_SCHEMA 17 /* The database schema changed */
465#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
466#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
467#define SQLITE_MISMATCH 20 /* Data type mismatch */
468#define SQLITE_MISUSE 21 /* Library used incorrectly */
469#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
470#define SQLITE_AUTH 23 /* Authorization denied */
471#define SQLITE_FORMAT 24 /* Not used */
472#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
473#define SQLITE_NOTADB 26 /* File opened that is not a database file */
474#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
475#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
476#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
477#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
478/* end-of-error-codes */
479
480/*
481** CAPI3REF: Extended Result Codes
482** KEYWORDS: {extended result code definitions}
483**
484** In its default configuration, SQLite API routines return one of 30 integer
485** [result codes]. However, experience has shown that many of
486** these result codes are too coarse-grained. They do not provide as
487** much information about problems as programmers might like. In an effort to
488** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
489** and later) include
490** support for additional result codes that provide more detailed information
491** about errors. These [extended result codes] are enabled or disabled
492** on a per database connection basis using the
493** [sqlite3_extended_result_codes()] API. Or, the extended code for
494** the most recent error can be obtained using
495** [sqlite3_extended_errcode()].
496*/
497#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
498#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
499#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
500#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
501#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
502#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
503#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
504#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
505#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
506#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
507#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
508#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
509#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
510#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
511#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
512#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
513#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
514#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
515#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
516#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
517#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
518#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
519#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
520#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
521#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
522#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
523#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
524#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
525#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
526#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
527#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
528#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
529#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
530#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
531#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
532#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
533#define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
534#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
535#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
536#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
537#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
538#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
539#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
540#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
541#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
542#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
543#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
544#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
545#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
546#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
547#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
548#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
549#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
550#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
551#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
552#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
553#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
554#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
555#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
556#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
557#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
558#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
559#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
560#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
561#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
562#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
563#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
564#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
565#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
566#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
567#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
568#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
569#define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
570#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
571#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
572#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
573#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
574
575/*
576** CAPI3REF: Flags For File Open Operations
577**
578** These bit values are intended for use in the
579** 3rd parameter to the [sqlite3_open_v2()] interface and
580** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
581**
582** Only those flags marked as "Ok for sqlite3_open_v2()" may be
583** used as the third argument to the [sqlite3_open_v2()] interface.
584** The other flags have historically been ignored by sqlite3_open_v2(),
585** though future versions of SQLite might change so that an error is
586** raised if any of the disallowed bits are passed into sqlite3_open_v2().
587** Applications should not depend on the historical behavior.
588**
589** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
590** [sqlite3_open_v2()] does *not* cause the underlying database file
591** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
592** [sqlite3_open_v2()] has historically be a no-op and might become an
593** error in future versions of SQLite.
594*/
595#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
596#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
597#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
598#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
599#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
600#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
601#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
602#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
603#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
604#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
605#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
606#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
607#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
608#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
609#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
610#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
611#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
613#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
614#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
615#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
616#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
617
618/* Reserved: 0x00F00000 */
619/* Legacy compatibility: */
620#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
621
622
623/*
624** CAPI3REF: Device Characteristics
625**
626** The xDeviceCharacteristics method of the [sqlite3_io_methods]
627** object returns an integer which is a vector of these
628** bit values expressing I/O characteristics of the mass storage
629** device that holds the file that the [sqlite3_io_methods]
630** refers to.
631**
632** The SQLITE_IOCAP_ATOMIC property means that all writes of
633** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
634** mean that writes of blocks that are nnn bytes in size and
635** are aligned to an address which is an integer multiple of
636** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
637** that when data is appended to a file, the data is appended
638** first then the size of the file is extended, never the other
639** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
640** information is written to disk in the same order as calls
641** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
642** after reboot following a crash or power loss, the only bytes in a
643** file that were written at the application level might have changed
644** and that adjacent bytes, even bytes within the same sector are
645** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
646** flag indicates that a file cannot be deleted when open. The
647** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
648** read-only media and cannot be changed even by processes with
649** elevated privileges.
650**
651** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
652** filesystem supports doing multiple write operations atomically when those
653** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
654** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
655*/
656#define SQLITE_IOCAP_ATOMIC 0x00000001
657#define SQLITE_IOCAP_ATOMIC512 0x00000002
658#define SQLITE_IOCAP_ATOMIC1K 0x00000004
659#define SQLITE_IOCAP_ATOMIC2K 0x00000008
660#define SQLITE_IOCAP_ATOMIC4K 0x00000010
661#define SQLITE_IOCAP_ATOMIC8K 0x00000020
662#define SQLITE_IOCAP_ATOMIC16K 0x00000040
663#define SQLITE_IOCAP_ATOMIC32K 0x00000080
664#define SQLITE_IOCAP_ATOMIC64K 0x00000100
665#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
666#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
667#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
668#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
669#define SQLITE_IOCAP_IMMUTABLE 0x00002000
670#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
671
672/*
673** CAPI3REF: File Locking Levels
674**
675** SQLite uses one of these integer values as the second
676** argument to calls it makes to the xLock() and xUnlock() methods
677** of an [sqlite3_io_methods] object. These values are ordered from
678** lest restrictive to most restrictive.
679**
680** The argument to xLock() is always SHARED or higher. The argument to
681** xUnlock is either SHARED or NONE.
682*/
683#define SQLITE_LOCK_NONE 0 /* xUnlock() only */
684#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
685#define SQLITE_LOCK_RESERVED 2 /* xLock() only */
686#define SQLITE_LOCK_PENDING 3 /* xLock() only */
687#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
688
689/*
690** CAPI3REF: Synchronization Type Flags
691**
692** When SQLite invokes the xSync() method of an
693** [sqlite3_io_methods] object it uses a combination of
694** these integer values as the second argument.
695**
696** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
697** sync operation only needs to flush data to mass storage. Inode
698** information need not be flushed. If the lower four bits of the flag
699** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
700** If the lower four bits equal SQLITE_SYNC_FULL, that means
701** to use Mac OS X style fullsync instead of fsync().
702**
703** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
704** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
705** settings. The [synchronous pragma] determines when calls to the
706** xSync VFS method occur and applies uniformly across all platforms.
707** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
708** energetic or rigorous or forceful the sync operations are and
709** only make a difference on Mac OSX for the default SQLite code.
710** (Third-party VFS implementations might also make the distinction
711** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
712** operating systems natively supported by SQLite, only Mac OSX
713** cares about the difference.)
714*/
715#define SQLITE_SYNC_NORMAL 0x00002
716#define SQLITE_SYNC_FULL 0x00003
717#define SQLITE_SYNC_DATAONLY 0x00010
718
719/*
720** CAPI3REF: OS Interface Open File Handle
721**
722** An [sqlite3_file] object represents an open file in the
723** [sqlite3_vfs | OS interface layer]. Individual OS interface
724** implementations will
725** want to subclass this object by appending additional fields
726** for their own use. The pMethods entry is a pointer to an
727** [sqlite3_io_methods] object that defines methods for performing
728** I/O operations on the open file.
729*/
730typedef struct sqlite3_file sqlite3_file;
731struct sqlite3_file {
732 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
733};
734
735/*
736** CAPI3REF: OS Interface File Virtual Methods Object
737**
738** Every file opened by the [sqlite3_vfs.xOpen] method populates an
739** [sqlite3_file] object (or, more commonly, a subclass of the
740** [sqlite3_file] object) with a pointer to an instance of this object.
741** This object defines the methods used to perform various operations
742** against the open file represented by the [sqlite3_file] object.
743**
744** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
745** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
746** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
747** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
748** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
749** to NULL.
750**
751** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
752** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
753** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
754** flag may be ORed in to indicate that only the data of the file
755** and not its inode needs to be synced.
756**
757** The integer values to xLock() and xUnlock() are one of
758** <ul>
759** <li> [SQLITE_LOCK_NONE],
760** <li> [SQLITE_LOCK_SHARED],
761** <li> [SQLITE_LOCK_RESERVED],
762** <li> [SQLITE_LOCK_PENDING], or
763** <li> [SQLITE_LOCK_EXCLUSIVE].
764** </ul>
765** xLock() upgrades the database file lock. In other words, xLock() moves the
766** database file lock in the direction NONE toward EXCLUSIVE. The argument to
767** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
768** SQLITE_LOCK_NONE. If the database file lock is already at or above the
769** requested lock, then the call to xLock() is a no-op.
770** xUnlock() downgrades the database file lock to either SHARED or NONE.
771** If the lock is already at or below the requested lock state, then the call
772** to xUnlock() is a no-op.
773** The xCheckReservedLock() method checks whether any database connection,
774** either in this process or in some other process, is holding a RESERVED,
775** PENDING, or EXCLUSIVE lock on the file. It returns true
776** if such a lock exists and false otherwise.
777**
778** The xFileControl() method is a generic interface that allows custom
779** VFS implementations to directly control an open file using the
780** [sqlite3_file_control()] interface. The second "op" argument is an
781** integer opcode. The third argument is a generic pointer intended to
782** point to a structure that may contain arguments or space in which to
783** write return values. Potential uses for xFileControl() might be
784** functions to enable blocking locks with timeouts, to change the
785** locking strategy (for example to use dot-file locks), to inquire
786** about the status of a lock, or to break stale locks. The SQLite
787** core reserves all opcodes less than 100 for its own use.
788** A [file control opcodes | list of opcodes] less than 100 is available.
789** Applications that define a custom xFileControl method should use opcodes
790** greater than 100 to avoid conflicts. VFS implementations should
791** return [SQLITE_NOTFOUND] for file control opcodes that they do not
792** recognize.
793**
794** The xSectorSize() method returns the sector size of the
795** device that underlies the file. The sector size is the
796** minimum write that can be performed without disturbing
797** other bytes in the file. The xDeviceCharacteristics()
798** method returns a bit vector describing behaviors of the
799** underlying device:
800**
801** <ul>
802** <li> [SQLITE_IOCAP_ATOMIC]
803** <li> [SQLITE_IOCAP_ATOMIC512]
804** <li> [SQLITE_IOCAP_ATOMIC1K]
805** <li> [SQLITE_IOCAP_ATOMIC2K]
806** <li> [SQLITE_IOCAP_ATOMIC4K]
807** <li> [SQLITE_IOCAP_ATOMIC8K]
808** <li> [SQLITE_IOCAP_ATOMIC16K]
809** <li> [SQLITE_IOCAP_ATOMIC32K]
810** <li> [SQLITE_IOCAP_ATOMIC64K]
811** <li> [SQLITE_IOCAP_SAFE_APPEND]
812** <li> [SQLITE_IOCAP_SEQUENTIAL]
813** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
814** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
815** <li> [SQLITE_IOCAP_IMMUTABLE]
816** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
817** </ul>
818**
819** The SQLITE_IOCAP_ATOMIC property means that all writes of
820** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
821** mean that writes of blocks that are nnn bytes in size and
822** are aligned to an address which is an integer multiple of
823** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
824** that when data is appended to a file, the data is appended
825** first then the size of the file is extended, never the other
826** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
827** information is written to disk in the same order as calls
828** to xWrite().
829**
830** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
831** in the unread portions of the buffer with zeros. A VFS that
832** fails to zero-fill short reads might seem to work. However,
833** failure to zero-fill short reads will eventually lead to
834** database corruption.
835*/
836typedef struct sqlite3_io_methods sqlite3_io_methods;
837struct sqlite3_io_methods {
838 int iVersion;
839 int (*xClose)(sqlite3_file*);
840 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
841 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
842 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
843 int (*xSync)(sqlite3_file*, int flags);
844 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
845 int (*xLock)(sqlite3_file*, int);
846 int (*xUnlock)(sqlite3_file*, int);
847 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
848 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
849 int (*xSectorSize)(sqlite3_file*);
850 int (*xDeviceCharacteristics)(sqlite3_file*);
851 /* Methods above are valid for version 1 */
852 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
853 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
854 void (*xShmBarrier)(sqlite3_file*);
855 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
856 /* Methods above are valid for version 2 */
857 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
858 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
859 /* Methods above are valid for version 3 */
860 /* Additional methods may be added in future releases */
861};
862
863/*
864** CAPI3REF: Standard File Control Opcodes
865** KEYWORDS: {file control opcodes} {file control opcode}
866**
867** These integer constants are opcodes for the xFileControl method
868** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
869** interface.
870**
871** <ul>
872** <li>[[SQLITE_FCNTL_LOCKSTATE]]
873** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
874** opcode causes the xFileControl method to write the current state of
875** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
876** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
877** into an integer that the pArg argument points to.
878** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
879**
880** <li>[[SQLITE_FCNTL_SIZE_HINT]]
881** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
882** layer a hint of how large the database file will grow to be during the
883** current transaction. This hint is not guaranteed to be accurate but it
884** is often close. The underlying VFS might choose to preallocate database
885** file space based on this hint in order to help writes to the database
886** file run faster.
887**
888** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
889** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
890** implements [sqlite3_deserialize()] to set an upper bound on the size
891** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
892** If the integer pointed to is negative, then it is filled in with the
893** current limit. Otherwise the limit is set to the larger of the value
894** of the integer pointed to and the current database size. The integer
895** pointed to is set to the new limit.
896**
897** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
898** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
899** extends and truncates the database file in chunks of a size specified
900** by the user. The fourth argument to [sqlite3_file_control()] should
901** point to an integer (type int) containing the new chunk-size to use
902** for the nominated database. Allocating database file space in large
903** chunks (say 1MB at a time), may reduce file-system fragmentation and
904** improve performance on some systems.
905**
906** <li>[[SQLITE_FCNTL_FILE_POINTER]]
907** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
908** to the [sqlite3_file] object associated with a particular database
909** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
910**
911** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
912** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
913** to the [sqlite3_file] object associated with the journal file (either
914** the [rollback journal] or the [write-ahead log]) for a particular database
915** connection. See also [SQLITE_FCNTL_FILE_POINTER].
916**
917** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
918** No longer in use.
919**
920** <li>[[SQLITE_FCNTL_SYNC]]
921** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
922** sent to the VFS immediately before the xSync method is invoked on a
923** database file descriptor. Or, if the xSync method is not invoked
924** because the user has configured SQLite with
925** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
926** of the xSync method. In most cases, the pointer argument passed with
927** this file-control is NULL. However, if the database file is being synced
928** as part of a multi-database commit, the argument points to a nul-terminated
929** string containing the transactions super-journal file name. VFSes that
930** do not need this signal should silently ignore this opcode. Applications
931** should not call [sqlite3_file_control()] with this opcode as doing so may
932** disrupt the operation of the specialized VFSes that do require it.
933**
934** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
935** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
936** and sent to the VFS after a transaction has been committed immediately
937** but before the database is unlocked. VFSes that do not need this signal
938** should silently ignore this opcode. Applications should not call
939** [sqlite3_file_control()] with this opcode as doing so may disrupt the
940** operation of the specialized VFSes that do require it.
941**
942** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
943** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
944** retry counts and intervals for certain disk I/O operations for the
945** windows [VFS] in order to provide robustness in the presence of
946** anti-virus programs. By default, the windows VFS will retry file read,
947** file write, and file delete operations up to 10 times, with a delay
948** of 25 milliseconds before the first retry and with the delay increasing
949** by an additional 25 milliseconds with each subsequent retry. This
950** opcode allows these two values (10 retries and 25 milliseconds of delay)
951** to be adjusted. The values are changed for all database connections
952** within the same process. The argument is a pointer to an array of two
953** integers where the first integer is the new retry count and the second
954** integer is the delay. If either integer is negative, then the setting
955** is not changed but instead the prior value of that setting is written
956** into the array entry, allowing the current retry settings to be
957** interrogated. The zDbName parameter is ignored.
958**
959** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
960** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
961** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
962** write ahead log ([WAL file]) and shared memory
963** files used for transaction control
964** are automatically deleted when the latest connection to the database
965** closes. Setting persistent WAL mode causes those files to persist after
966** close. Persisting the files is useful when other processes that do not
967** have write permission on the directory containing the database file want
968** to read the database file, as the WAL and shared memory files must exist
969** in order for the database to be readable. The fourth parameter to
970** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
971** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
972** WAL mode. If the integer is -1, then it is overwritten with the current
973** WAL persistence setting.
974**
975** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
976** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
977** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
978** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
979** xDeviceCharacteristics methods. The fourth parameter to
980** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
981** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
982** mode. If the integer is -1, then it is overwritten with the current
983** zero-damage mode setting.
984**
985** <li>[[SQLITE_FCNTL_OVERWRITE]]
986** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
987** a write transaction to indicate that, unless it is rolled back for some
988** reason, the entire database file will be overwritten by the current
989** transaction. This is used by VACUUM operations.
990**
991** <li>[[SQLITE_FCNTL_VFSNAME]]
992** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
993** all [VFSes] in the VFS stack. The names are of all VFS shims and the
994** final bottom-level VFS are written into memory obtained from
995** [sqlite3_malloc()] and the result is stored in the char* variable
996** that the fourth parameter of [sqlite3_file_control()] points to.
997** The caller is responsible for freeing the memory when done. As with
998** all file-control actions, there is no guarantee that this will actually
999** do anything. Callers should initialize the char* variable to a NULL
1000** pointer in case this file-control is not implemented. This file-control
1001** is intended for diagnostic use only.
1002**
1003** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1004** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1005** [VFSes] currently in use. ^(The argument X in
1006** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1007** of type "[sqlite3_vfs] **". This opcodes will set *X
1008** to a pointer to the top-level VFS.)^
1009** ^When there are multiple VFS shims in the stack, this opcode finds the
1010** upper-most shim only.
1011**
1012** <li>[[SQLITE_FCNTL_PRAGMA]]
1013** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1014** file control is sent to the open [sqlite3_file] object corresponding
1015** to the database file to which the pragma statement refers. ^The argument
1016** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1017** pointers to strings (char**) in which the second element of the array
1018** is the name of the pragma and the third element is the argument to the
1019** pragma or NULL if the pragma has no argument. ^The handler for an
1020** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1021** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1022** or the equivalent and that string will become the result of the pragma or
1023** the error message if the pragma fails. ^If the
1024** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1025** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1026** file control returns [SQLITE_OK], then the parser assumes that the
1027** VFS has handled the PRAGMA itself and the parser generates a no-op
1028** prepared statement if result string is NULL, or that returns a copy
1029** of the result string if the string is non-NULL.
1030** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1031** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1032** that the VFS encountered an error while handling the [PRAGMA] and the
1033** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1034** file control occurs at the beginning of pragma statement analysis and so
1035** it is able to override built-in [PRAGMA] statements.
1036**
1037** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1038** ^The [SQLITE_FCNTL_BUSYHANDLER]
1039** file-control may be invoked by SQLite on the database file handle
1040** shortly after it is opened in order to provide a custom VFS with access
1041** to the connection's busy-handler callback. The argument is of type (void**)
1042** - an array of two (void *) values. The first (void *) actually points
1043** to a function of type (int (*)(void *)). In order to invoke the connection's
1044** busy-handler, this function should be invoked with the second (void *) in
1045** the array as the only argument. If it returns non-zero, then the operation
1046** should be retried. If it returns zero, the custom VFS should abandon the
1047** current operation.
1048**
1049** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1050** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1051** to have SQLite generate a
1052** temporary filename using the same algorithm that is followed to generate
1053** temporary filenames for TEMP tables and other internal uses. The
1054** argument should be a char** which will be filled with the filename
1055** written into memory obtained from [sqlite3_malloc()]. The caller should
1056** invoke [sqlite3_free()] on the result to avoid a memory leak.
1057**
1058** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1059** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1060** maximum number of bytes that will be used for memory-mapped I/O.
1061** The argument is a pointer to a value of type sqlite3_int64 that
1062** is an advisory maximum number of bytes in the file to memory map. The
1063** pointer is overwritten with the old value. The limit is not changed if
1064** the value originally pointed to is negative, and so the current limit
1065** can be queried by passing in a pointer to a negative number. This
1066** file-control is used internally to implement [PRAGMA mmap_size].
1067**
1068** <li>[[SQLITE_FCNTL_TRACE]]
1069** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1070** to the VFS about what the higher layers of the SQLite stack are doing.
1071** This file control is used by some VFS activity tracing [shims].
1072** The argument is a zero-terminated string. Higher layers in the
1073** SQLite stack may generate instances of this file control if
1074** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1075**
1076** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1077** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1078** pointer to an integer and it writes a boolean into that integer depending
1079** on whether or not the file has been renamed, moved, or deleted since it
1080** was first opened.
1081**
1082** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1083** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1084** underlying native file handle associated with a file handle. This file
1085** control interprets its argument as a pointer to a native file handle and
1086** writes the resulting value there.
1087**
1088** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1089** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1090** opcode causes the xFileControl method to swap the file handle with the one
1091** pointed to by the pArg argument. This capability is used during testing
1092** and only needs to be supported when SQLITE_TEST is defined.
1093**
1094** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1095** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1096** be advantageous to block on the next WAL lock if the lock is not immediately
1097** available. The WAL subsystem issues this signal during rare
1098** circumstances in order to fix a problem with priority inversion.
1099** Applications should <em>not</em> use this file-control.
1100**
1101** <li>[[SQLITE_FCNTL_ZIPVFS]]
1102** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1103** VFS should return SQLITE_NOTFOUND for this opcode.
1104**
1105** <li>[[SQLITE_FCNTL_RBU]]
1106** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1107** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1108** this opcode.
1109**
1110** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1111** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1112** the file descriptor is placed in "batch write mode", which
1113** means all subsequent write operations will be deferred and done
1114** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1115** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1116** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1117** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1118** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1119** no VFS interface calls on the same [sqlite3_file] file descriptor
1120** except for calls to the xWrite method and the xFileControl method
1121** with [SQLITE_FCNTL_SIZE_HINT].
1122**
1123** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1124** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1125** operations since the previous successful call to
1126** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1127** This file control returns [SQLITE_OK] if and only if the writes were
1128** all performed successfully and have been committed to persistent storage.
1129** ^Regardless of whether or not it is successful, this file control takes
1130** the file descriptor out of batch write mode so that all subsequent
1131** write operations are independent.
1132** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1133** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1134**
1135** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1136** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1137** operations since the previous successful call to
1138** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1139** ^This file control takes the file descriptor out of batch write mode
1140** so that all subsequent write operations are independent.
1141** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1142** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1143**
1144** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1145** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1146** to block for up to M milliseconds before failing when attempting to
1147** obtain a file lock using the xLock or xShmLock methods of the VFS.
1148** The parameter is a pointer to a 32-bit signed integer that contains
1149** the value that M is to be set to. Before returning, the 32-bit signed
1150** integer is overwritten with the previous value of M.
1151**
1152** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1153** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1154** a database file. The argument is a pointer to a 32-bit unsigned integer.
1155** The "data version" for the pager is written into the pointer. The
1156** "data version" changes whenever any change occurs to the corresponding
1157** database file, either through SQL statements on the same database
1158** connection or through transactions committed by separate database
1159** connections possibly in other processes. The [sqlite3_total_changes()]
1160** interface can be used to find if any database on the connection has changed,
1161** but that interface responds to changes on TEMP as well as MAIN and does
1162** not provide a mechanism to detect changes to MAIN only. Also, the
1163** [sqlite3_total_changes()] interface responds to internal changes only and
1164** omits changes made by other database connections. The
1165** [PRAGMA data_version] command provides a mechanism to detect changes to
1166** a single attached database that occur due to other database connections,
1167** but omits changes implemented by the database connection on which it is
1168** called. This file control is the only mechanism to detect changes that
1169** happen either internally or externally and that are associated with
1170** a particular attached database.
1171**
1172** <li>[[SQLITE_FCNTL_CKPT_START]]
1173** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1174** in wal mode before the client starts to copy pages from the wal
1175** file to the database file.
1176**
1177** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1178** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1179** in wal mode after the client has finished copying pages from the wal
1180** file to the database file, but before the *-shm file is updated to
1181** record the fact that the pages have been checkpointed.
1182**
1183** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1184** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1185** whether or not there is a database client in another process with a wal-mode
1186** transaction open on the database or not. It is only available on unix.The
1187** (void*) argument passed with this file-control should be a pointer to a
1188** value of type (int). The integer value is set to 1 if the database is a wal
1189** mode database and there exists at least one client in another process that
1190** currently has an SQL transaction open on the database. It is set to 0 if
1191** the database is not a wal-mode db, or if there is no such connection in any
1192** other process. This opcode cannot be used to detect transactions opened
1193** by clients within the current process, only within other processes.
1194**
1195** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1196** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1197** [checksum VFS shim] only.
1198**
1199** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1200** If there is currently no transaction open on the database, and the
1201** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1202** purges the contents of the in-memory page cache. If there is an open
1203** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1204** </ul>
1205*/
1206#define SQLITE_FCNTL_LOCKSTATE 1
1207#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1208#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1209#define SQLITE_FCNTL_LAST_ERRNO 4
1210#define SQLITE_FCNTL_SIZE_HINT 5
1211#define SQLITE_FCNTL_CHUNK_SIZE 6
1212#define SQLITE_FCNTL_FILE_POINTER 7
1213#define SQLITE_FCNTL_SYNC_OMITTED 8
1214#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1215#define SQLITE_FCNTL_PERSIST_WAL 10
1216#define SQLITE_FCNTL_OVERWRITE 11
1217#define SQLITE_FCNTL_VFSNAME 12
1218#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1219#define SQLITE_FCNTL_PRAGMA 14
1220#define SQLITE_FCNTL_BUSYHANDLER 15
1221#define SQLITE_FCNTL_TEMPFILENAME 16
1222#define SQLITE_FCNTL_MMAP_SIZE 18
1223#define SQLITE_FCNTL_TRACE 19
1224#define SQLITE_FCNTL_HAS_MOVED 20
1225#define SQLITE_FCNTL_SYNC 21
1226#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1227#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1228#define SQLITE_FCNTL_WAL_BLOCK 24
1229#define SQLITE_FCNTL_ZIPVFS 25
1230#define SQLITE_FCNTL_RBU 26
1231#define SQLITE_FCNTL_VFS_POINTER 27
1232#define SQLITE_FCNTL_JOURNAL_POINTER 28
1233#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1234#define SQLITE_FCNTL_PDB 30
1235#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1236#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1237#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1238#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1239#define SQLITE_FCNTL_DATA_VERSION 35
1240#define SQLITE_FCNTL_SIZE_LIMIT 36
1241#define SQLITE_FCNTL_CKPT_DONE 37
1242#define SQLITE_FCNTL_RESERVE_BYTES 38
1243#define SQLITE_FCNTL_CKPT_START 39
1244#define SQLITE_FCNTL_EXTERNAL_READER 40
1245#define SQLITE_FCNTL_CKSM_FILE 41
1246#define SQLITE_FCNTL_RESET_CACHE 42
1247
1248/* deprecated names */
1249#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1250#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1251#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1252
1253
1254/*
1255** CAPI3REF: Mutex Handle
1256**
1257** The mutex module within SQLite defines [sqlite3_mutex] to be an
1258** abstract type for a mutex object. The SQLite core never looks
1259** at the internal representation of an [sqlite3_mutex]. It only
1260** deals with pointers to the [sqlite3_mutex] object.
1261**
1262** Mutexes are created using [sqlite3_mutex_alloc()].
1263*/
1264typedef struct sqlite3_mutex sqlite3_mutex;
1265
1266/*
1267** CAPI3REF: Loadable Extension Thunk
1268**
1269** A pointer to the opaque sqlite3_api_routines structure is passed as
1270** the third parameter to entry points of [loadable extensions]. This
1271** structure must be typedefed in order to work around compiler warnings
1272** on some platforms.
1273*/
1274typedef struct sqlite3_api_routines sqlite3_api_routines;
1275
1276/*
1277** CAPI3REF: File Name
1278**
1279** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1280** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1281** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1282** may also be passed to special APIs such as:
1283**
1284** <ul>
1285** <li> sqlite3_filename_database()
1286** <li> sqlite3_filename_journal()
1287** <li> sqlite3_filename_wal()
1288** <li> sqlite3_uri_parameter()
1289** <li> sqlite3_uri_boolean()
1290** <li> sqlite3_uri_int64()
1291** <li> sqlite3_uri_key()
1292** </ul>
1293*/
1294typedef const char *sqlite3_filename;
1295
1296/*
1297** CAPI3REF: OS Interface Object
1298**
1299** An instance of the sqlite3_vfs object defines the interface between
1300** the SQLite core and the underlying operating system. The "vfs"
1301** in the name of the object stands for "virtual file system". See
1302** the [VFS | VFS documentation] for further information.
1303**
1304** The VFS interface is sometimes extended by adding new methods onto
1305** the end. Each time such an extension occurs, the iVersion field
1306** is incremented. The iVersion value started out as 1 in
1307** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1308** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1309** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1310** may be appended to the sqlite3_vfs object and the iVersion value
1311** may increase again in future versions of SQLite.
1312** Note that due to an oversight, the structure
1313** of the sqlite3_vfs object changed in the transition from
1314** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1315** and yet the iVersion field was not increased.
1316**
1317** The szOsFile field is the size of the subclassed [sqlite3_file]
1318** structure used by this VFS. mxPathname is the maximum length of
1319** a pathname in this VFS.
1320**
1321** Registered sqlite3_vfs objects are kept on a linked list formed by
1322** the pNext pointer. The [sqlite3_vfs_register()]
1323** and [sqlite3_vfs_unregister()] interfaces manage this list
1324** in a thread-safe way. The [sqlite3_vfs_find()] interface
1325** searches the list. Neither the application code nor the VFS
1326** implementation should use the pNext pointer.
1327**
1328** The pNext field is the only field in the sqlite3_vfs
1329** structure that SQLite will ever modify. SQLite will only access
1330** or modify this field while holding a particular static mutex.
1331** The application should never modify anything within the sqlite3_vfs
1332** object once the object has been registered.
1333**
1334** The zName field holds the name of the VFS module. The name must
1335** be unique across all VFS modules.
1336**
1337** [[sqlite3_vfs.xOpen]]
1338** ^SQLite guarantees that the zFilename parameter to xOpen
1339** is either a NULL pointer or string obtained
1340** from xFullPathname() with an optional suffix added.
1341** ^If a suffix is added to the zFilename parameter, it will
1342** consist of a single "-" character followed by no more than
1343** 11 alphanumeric and/or "-" characters.
1344** ^SQLite further guarantees that
1345** the string will be valid and unchanged until xClose() is
1346** called. Because of the previous sentence,
1347** the [sqlite3_file] can safely store a pointer to the
1348** filename if it needs to remember the filename for some reason.
1349** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1350** must invent its own temporary name for the file. ^Whenever the
1351** xFilename parameter is NULL it will also be the case that the
1352** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1353**
1354** The flags argument to xOpen() includes all bits set in
1355** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1356** or [sqlite3_open16()] is used, then flags includes at least
1357** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1358** If xOpen() opens a file read-only then it sets *pOutFlags to
1359** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1360**
1361** ^(SQLite will also add one of the following flags to the xOpen()
1362** call, depending on the object being opened:
1363**
1364** <ul>
1365** <li> [SQLITE_OPEN_MAIN_DB]
1366** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1367** <li> [SQLITE_OPEN_TEMP_DB]
1368** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1369** <li> [SQLITE_OPEN_TRANSIENT_DB]
1370** <li> [SQLITE_OPEN_SUBJOURNAL]
1371** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1372** <li> [SQLITE_OPEN_WAL]
1373** </ul>)^
1374**
1375** The file I/O implementation can use the object type flags to
1376** change the way it deals with files. For example, an application
1377** that does not care about crash recovery or rollback might make
1378** the open of a journal file a no-op. Writes to this journal would
1379** also be no-ops, and any attempt to read the journal would return
1380** SQLITE_IOERR. Or the implementation might recognize that a database
1381** file will be doing page-aligned sector reads and writes in a random
1382** order and set up its I/O subsystem accordingly.
1383**
1384** SQLite might also add one of the following flags to the xOpen method:
1385**
1386** <ul>
1387** <li> [SQLITE_OPEN_DELETEONCLOSE]
1388** <li> [SQLITE_OPEN_EXCLUSIVE]
1389** </ul>
1390**
1391** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1392** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1393** will be set for TEMP databases and their journals, transient
1394** databases, and subjournals.
1395**
1396** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1397** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1398** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1399** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1400** SQLITE_OPEN_CREATE, is used to indicate that file should always
1401** be created, and that it is an error if it already exists.
1402** It is <i>not</i> used to indicate the file should be opened
1403** for exclusive access.
1404**
1405** ^At least szOsFile bytes of memory are allocated by SQLite
1406** to hold the [sqlite3_file] structure passed as the third
1407** argument to xOpen. The xOpen method does not have to
1408** allocate the structure; it should just fill it in. Note that
1409** the xOpen method must set the sqlite3_file.pMethods to either
1410** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1411** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1412** element will be valid after xOpen returns regardless of the success
1413** or failure of the xOpen call.
1414**
1415** [[sqlite3_vfs.xAccess]]
1416** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1417** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1418** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1419** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1420** flag is never actually used and is not implemented in the built-in
1421** VFSes of SQLite. The file is named by the second argument and can be a
1422** directory. The xAccess method returns [SQLITE_OK] on success or some
1423** non-zero error code if there is an I/O error or if the name of
1424** the file given in the second argument is illegal. If SQLITE_OK
1425** is returned, then non-zero or zero is written into *pResOut to indicate
1426** whether or not the file is accessible.
1427**
1428** ^SQLite will always allocate at least mxPathname+1 bytes for the
1429** output buffer xFullPathname. The exact size of the output buffer
1430** is also passed as a parameter to both methods. If the output buffer
1431** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1432** handled as a fatal error by SQLite, vfs implementations should endeavor
1433** to prevent this by setting mxPathname to a sufficiently large value.
1434**
1435** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1436** interfaces are not strictly a part of the filesystem, but they are
1437** included in the VFS structure for completeness.
1438** The xRandomness() function attempts to return nBytes bytes
1439** of good-quality randomness into zOut. The return value is
1440** the actual number of bytes of randomness obtained.
1441** The xSleep() method causes the calling thread to sleep for at
1442** least the number of microseconds given. ^The xCurrentTime()
1443** method returns a Julian Day Number for the current date and time as
1444** a floating point value.
1445** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1446** Day Number multiplied by 86400000 (the number of milliseconds in
1447** a 24-hour day).
1448** ^SQLite will use the xCurrentTimeInt64() method to get the current
1449** date and time if that method is available (if iVersion is 2 or
1450** greater and the function pointer is not NULL) and will fall back
1451** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1452**
1453** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1454** are not used by the SQLite core. These optional interfaces are provided
1455** by some VFSes to facilitate testing of the VFS code. By overriding
1456** system calls with functions under its control, a test program can
1457** simulate faults and error conditions that would otherwise be difficult
1458** or impossible to induce. The set of system calls that can be overridden
1459** varies from one VFS to another, and from one version of the same VFS to the
1460** next. Applications that use these interfaces must be prepared for any
1461** or all of these interfaces to be NULL or for their behavior to change
1462** from one release to the next. Applications must not attempt to access
1463** any of these methods if the iVersion of the VFS is less than 3.
1464*/
1465typedef struct sqlite3_vfs sqlite3_vfs;
1466typedef void (*sqlite3_syscall_ptr)(void);
1467struct sqlite3_vfs {
1468 int iVersion; /* Structure version number (currently 3) */
1469 int szOsFile; /* Size of subclassed sqlite3_file */
1470 int mxPathname; /* Maximum file pathname length */
1471 sqlite3_vfs *pNext; /* Next registered VFS */
1472 const char *zName; /* Name of this virtual file system */
1473 void *pAppData; /* Pointer to application-specific data */
1474 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1475 int flags, int *pOutFlags);
1476 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1477 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1478 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1479 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1480 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1481 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1482 void (*xDlClose)(sqlite3_vfs*, void*);
1483 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1484 int (*xSleep)(sqlite3_vfs*, int microseconds);
1485 int (*xCurrentTime)(sqlite3_vfs*, double*);
1486 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1487 /*
1488 ** The methods above are in version 1 of the sqlite_vfs object
1489 ** definition. Those that follow are added in version 2 or later
1490 */
1491 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1492 /*
1493 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1494 ** Those below are for version 3 and greater.
1495 */
1496 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1497 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1498 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1499 /*
1500 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1501 ** New fields may be appended in future versions. The iVersion
1502 ** value will increment whenever this happens.
1503 */
1504};
1505
1506/*
1507** CAPI3REF: Flags for the xAccess VFS method
1508**
1509** These integer constants can be used as the third parameter to
1510** the xAccess method of an [sqlite3_vfs] object. They determine
1511** what kind of permissions the xAccess method is looking for.
1512** With SQLITE_ACCESS_EXISTS, the xAccess method
1513** simply checks whether the file exists.
1514** With SQLITE_ACCESS_READWRITE, the xAccess method
1515** checks whether the named directory is both readable and writable
1516** (in other words, if files can be added, removed, and renamed within
1517** the directory).
1518** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1519** [temp_store_directory pragma], though this could change in a future
1520** release of SQLite.
1521** With SQLITE_ACCESS_READ, the xAccess method
1522** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1523** currently unused, though it might be used in a future release of
1524** SQLite.
1525*/
1526#define SQLITE_ACCESS_EXISTS 0
1527#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1528#define SQLITE_ACCESS_READ 2 /* Unused */
1529
1530/*
1531** CAPI3REF: Flags for the xShmLock VFS method
1532**
1533** These integer constants define the various locking operations
1534** allowed by the xShmLock method of [sqlite3_io_methods]. The
1535** following are the only legal combinations of flags to the
1536** xShmLock method:
1537**
1538** <ul>
1539** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1540** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1541** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1542** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1543** </ul>
1544**
1545** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1546** was given on the corresponding lock.
1547**
1548** The xShmLock method can transition between unlocked and SHARED or
1549** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1550** and EXCLUSIVE.
1551*/
1552#define SQLITE_SHM_UNLOCK 1
1553#define SQLITE_SHM_LOCK 2
1554#define SQLITE_SHM_SHARED 4
1555#define SQLITE_SHM_EXCLUSIVE 8
1556
1557/*
1558** CAPI3REF: Maximum xShmLock index
1559**
1560** The xShmLock method on [sqlite3_io_methods] may use values
1561** between 0 and this upper bound as its "offset" argument.
1562** The SQLite core will never attempt to acquire or release a
1563** lock outside of this range
1564*/
1565#define SQLITE_SHM_NLOCK 8
1566
1567
1568/*
1569** CAPI3REF: Initialize The SQLite Library
1570**
1571** ^The sqlite3_initialize() routine initializes the
1572** SQLite library. ^The sqlite3_shutdown() routine
1573** deallocates any resources that were allocated by sqlite3_initialize().
1574** These routines are designed to aid in process initialization and
1575** shutdown on embedded systems. Workstation applications using
1576** SQLite normally do not need to invoke either of these routines.
1577**
1578** A call to sqlite3_initialize() is an "effective" call if it is
1579** the first time sqlite3_initialize() is invoked during the lifetime of
1580** the process, or if it is the first time sqlite3_initialize() is invoked
1581** following a call to sqlite3_shutdown(). ^(Only an effective call
1582** of sqlite3_initialize() does any initialization. All other calls
1583** are harmless no-ops.)^
1584**
1585** A call to sqlite3_shutdown() is an "effective" call if it is the first
1586** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1587** an effective call to sqlite3_shutdown() does any deinitialization.
1588** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1589**
1590** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1591** is not. The sqlite3_shutdown() interface must only be called from a
1592** single thread. All open [database connections] must be closed and all
1593** other SQLite resources must be deallocated prior to invoking
1594** sqlite3_shutdown().
1595**
1596** Among other things, ^sqlite3_initialize() will invoke
1597** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1598** will invoke sqlite3_os_end().
1599**
1600** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1601** ^If for some reason, sqlite3_initialize() is unable to initialize
1602** the library (perhaps it is unable to allocate a needed resource such
1603** as a mutex) it returns an [error code] other than [SQLITE_OK].
1604**
1605** ^The sqlite3_initialize() routine is called internally by many other
1606** SQLite interfaces so that an application usually does not need to
1607** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1608** calls sqlite3_initialize() so the SQLite library will be automatically
1609** initialized when [sqlite3_open()] is called if it has not be initialized
1610** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1611** compile-time option, then the automatic calls to sqlite3_initialize()
1612** are omitted and the application must call sqlite3_initialize() directly
1613** prior to using any other SQLite interface. For maximum portability,
1614** it is recommended that applications always invoke sqlite3_initialize()
1615** directly prior to using any other SQLite interface. Future releases
1616** of SQLite may require this. In other words, the behavior exhibited
1617** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1618** default behavior in some future release of SQLite.
1619**
1620** The sqlite3_os_init() routine does operating-system specific
1621** initialization of the SQLite library. The sqlite3_os_end()
1622** routine undoes the effect of sqlite3_os_init(). Typical tasks
1623** performed by these routines include allocation or deallocation
1624** of static resources, initialization of global variables,
1625** setting up a default [sqlite3_vfs] module, or setting up
1626** a default configuration using [sqlite3_config()].
1627**
1628** The application should never invoke either sqlite3_os_init()
1629** or sqlite3_os_end() directly. The application should only invoke
1630** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1631** interface is called automatically by sqlite3_initialize() and
1632** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1633** implementations for sqlite3_os_init() and sqlite3_os_end()
1634** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1635** When [custom builds | built for other platforms]
1636** (using the [SQLITE_OS_OTHER=1] compile-time
1637** option) the application must supply a suitable implementation for
1638** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1639** implementation of sqlite3_os_init() or sqlite3_os_end()
1640** must return [SQLITE_OK] on success and some other [error code] upon
1641** failure.
1642*/
1643SQLITE_API int sqlite3_initialize(void);
1644SQLITE_API int sqlite3_shutdown(void);
1645SQLITE_API int sqlite3_os_init(void);
1646SQLITE_API int sqlite3_os_end(void);
1647
1648/*
1649** CAPI3REF: Configuring The SQLite Library
1650**
1651** The sqlite3_config() interface is used to make global configuration
1652** changes to SQLite in order to tune SQLite to the specific needs of
1653** the application. The default configuration is recommended for most
1654** applications and so this routine is usually not necessary. It is
1655** provided to support rare applications with unusual needs.
1656**
1657** <b>The sqlite3_config() interface is not threadsafe. The application
1658** must ensure that no other SQLite interfaces are invoked by other
1659** threads while sqlite3_config() is running.</b>
1660**
1661** The first argument to sqlite3_config() is an integer
1662** [configuration option] that determines
1663** what property of SQLite is to be configured. Subsequent arguments
1664** vary depending on the [configuration option]
1665** in the first argument.
1666**
1667** For most configuration options, the sqlite3_config() interface
1668** may only be invoked prior to library initialization using
1669** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1670** The exceptional configuration options that may be invoked at any time
1671** are called "anytime configuration options".
1672** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1673** [sqlite3_shutdown()] with a first argument that is not an anytime
1674** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1675** Note, however, that ^sqlite3_config() can be called as part of the
1676** implementation of an application-defined [sqlite3_os_init()].
1677**
1678** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1679** ^If the option is unknown or SQLite is unable to set the option
1680** then this routine returns a non-zero [error code].
1681*/
1682SQLITE_API int sqlite3_config(int, ...);
1683
1684/*
1685** CAPI3REF: Configure database connections
1686** METHOD: sqlite3
1687**
1688** The sqlite3_db_config() interface is used to make configuration
1689** changes to a [database connection]. The interface is similar to
1690** [sqlite3_config()] except that the changes apply to a single
1691** [database connection] (specified in the first argument).
1692**
1693** The second argument to sqlite3_db_config(D,V,...) is the
1694** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1695** that indicates what aspect of the [database connection] is being configured.
1696** Subsequent arguments vary depending on the configuration verb.
1697**
1698** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1699** the call is considered successful.
1700*/
1701SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1702
1703/*
1704** CAPI3REF: Memory Allocation Routines
1705**
1706** An instance of this object defines the interface between SQLite
1707** and low-level memory allocation routines.
1708**
1709** This object is used in only one place in the SQLite interface.
1710** A pointer to an instance of this object is the argument to
1711** [sqlite3_config()] when the configuration option is
1712** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1713** By creating an instance of this object
1714** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1715** during configuration, an application can specify an alternative
1716** memory allocation subsystem for SQLite to use for all of its
1717** dynamic memory needs.
1718**
1719** Note that SQLite comes with several [built-in memory allocators]
1720** that are perfectly adequate for the overwhelming majority of applications
1721** and that this object is only useful to a tiny minority of applications
1722** with specialized memory allocation requirements. This object is
1723** also used during testing of SQLite in order to specify an alternative
1724** memory allocator that simulates memory out-of-memory conditions in
1725** order to verify that SQLite recovers gracefully from such
1726** conditions.
1727**
1728** The xMalloc, xRealloc, and xFree methods must work like the
1729** malloc(), realloc() and free() functions from the standard C library.
1730** ^SQLite guarantees that the second argument to
1731** xRealloc is always a value returned by a prior call to xRoundup.
1732**
1733** xSize should return the allocated size of a memory allocation
1734** previously obtained from xMalloc or xRealloc. The allocated size
1735** is always at least as big as the requested size but may be larger.
1736**
1737** The xRoundup method returns what would be the allocated size of
1738** a memory allocation given a particular requested size. Most memory
1739** allocators round up memory allocations at least to the next multiple
1740** of 8. Some allocators round up to a larger multiple or to a power of 2.
1741** Every memory allocation request coming in through [sqlite3_malloc()]
1742** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1743** that causes the corresponding memory allocation to fail.
1744**
1745** The xInit method initializes the memory allocator. For example,
1746** it might allocate any required mutexes or initialize internal data
1747** structures. The xShutdown method is invoked (indirectly) by
1748** [sqlite3_shutdown()] and should deallocate any resources acquired
1749** by xInit. The pAppData pointer is used as the only parameter to
1750** xInit and xShutdown.
1751**
1752** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1753** the xInit method, so the xInit method need not be threadsafe. The
1754** xShutdown method is only called from [sqlite3_shutdown()] so it does
1755** not need to be threadsafe either. For all other methods, SQLite
1756** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1757** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1758** it is by default) and so the methods are automatically serialized.
1759** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1760** methods must be threadsafe or else make their own arrangements for
1761** serialization.
1762**
1763** SQLite will never invoke xInit() more than once without an intervening
1764** call to xShutdown().
1765*/
1766typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1767struct sqlite3_mem_methods {
1768 void *(*xMalloc)(int); /* Memory allocation function */
1769 void (*xFree)(void*); /* Free a prior allocation */
1770 void *(*xRealloc)(void*,int); /* Resize an allocation */
1771 int (*xSize)(void*); /* Return the size of an allocation */
1772 int (*xRoundup)(int); /* Round up request size to allocation size */
1773 int (*xInit)(void*); /* Initialize the memory allocator */
1774 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1775 void *pAppData; /* Argument to xInit() and xShutdown() */
1776};
1777
1778/*
1779** CAPI3REF: Configuration Options
1780** KEYWORDS: {configuration option}
1781**
1782** These constants are the available integer configuration options that
1783** can be passed as the first argument to the [sqlite3_config()] interface.
1784**
1785** Most of the configuration options for sqlite3_config()
1786** will only work if invoked prior to [sqlite3_initialize()] or after
1787** [sqlite3_shutdown()]. The few exceptions to this rule are called
1788** "anytime configuration options".
1789** ^Calling [sqlite3_config()] with a first argument that is not an
1790** anytime configuration option in between calls to [sqlite3_initialize()] and
1791** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1792**
1793** The set of anytime configuration options can change (by insertions
1794** and/or deletions) from one release of SQLite to the next.
1795** As of SQLite version 3.42.0, the complete set of anytime configuration
1796** options is:
1797** <ul>
1798** <li> SQLITE_CONFIG_LOG
1799** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1800** </ul>
1801**
1802** New configuration options may be added in future releases of SQLite.
1803** Existing configuration options might be discontinued. Applications
1804** should check the return code from [sqlite3_config()] to make sure that
1805** the call worked. The [sqlite3_config()] interface will return a
1806** non-zero [error code] if a discontinued or unsupported configuration option
1807** is invoked.
1808**
1809** <dl>
1810** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1811** <dd>There are no arguments to this option. ^This option sets the
1812** [threading mode] to Single-thread. In other words, it disables
1813** all mutexing and puts SQLite into a mode where it can only be used
1814** by a single thread. ^If SQLite is compiled with
1815** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1816** it is not possible to change the [threading mode] from its default
1817** value of Single-thread and so [sqlite3_config()] will return
1818** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1819** configuration option.</dd>
1820**
1821** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1822** <dd>There are no arguments to this option. ^This option sets the
1823** [threading mode] to Multi-thread. In other words, it disables
1824** mutexing on [database connection] and [prepared statement] objects.
1825** The application is responsible for serializing access to
1826** [database connections] and [prepared statements]. But other mutexes
1827** are enabled so that SQLite will be safe to use in a multi-threaded
1828** environment as long as no two threads attempt to use the same
1829** [database connection] at the same time. ^If SQLite is compiled with
1830** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1831** it is not possible to set the Multi-thread [threading mode] and
1832** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1833** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1834**
1835** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1836** <dd>There are no arguments to this option. ^This option sets the
1837** [threading mode] to Serialized. In other words, this option enables
1838** all mutexes including the recursive
1839** mutexes on [database connection] and [prepared statement] objects.
1840** In this mode (which is the default when SQLite is compiled with
1841** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1842** to [database connections] and [prepared statements] so that the
1843** application is free to use the same [database connection] or the
1844** same [prepared statement] in different threads at the same time.
1845** ^If SQLite is compiled with
1846** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1847** it is not possible to set the Serialized [threading mode] and
1848** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1849** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1850**
1851** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1852** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1853** a pointer to an instance of the [sqlite3_mem_methods] structure.
1854** The argument specifies
1855** alternative low-level memory allocation routines to be used in place of
1856** the memory allocation routines built into SQLite.)^ ^SQLite makes
1857** its own private copy of the content of the [sqlite3_mem_methods] structure
1858** before the [sqlite3_config()] call returns.</dd>
1859**
1860** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1861** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1862** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1863** The [sqlite3_mem_methods]
1864** structure is filled with the currently defined memory allocation routines.)^
1865** This option can be used to overload the default memory allocation
1866** routines with a wrapper that simulations memory allocation failure or
1867** tracks memory usage, for example. </dd>
1868**
1869** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1870** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1871** type int, interpreted as a boolean, which if true provides a hint to
1872** SQLite that it should avoid large memory allocations if possible.
1873** SQLite will run faster if it is free to make large memory allocations,
1874** but some application might prefer to run slower in exchange for
1875** guarantees about memory fragmentation that are possible if large
1876** allocations are avoided. This hint is normally off.
1877** </dd>
1878**
1879** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1880** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1881** interpreted as a boolean, which enables or disables the collection of
1882** memory allocation statistics. ^(When memory allocation statistics are
1883** disabled, the following SQLite interfaces become non-operational:
1884** <ul>
1885** <li> [sqlite3_hard_heap_limit64()]
1886** <li> [sqlite3_memory_used()]
1887** <li> [sqlite3_memory_highwater()]
1888** <li> [sqlite3_soft_heap_limit64()]
1889** <li> [sqlite3_status64()]
1890** </ul>)^
1891** ^Memory allocation statistics are enabled by default unless SQLite is
1892** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1893** allocation statistics are disabled by default.
1894** </dd>
1895**
1896** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1897** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1898** </dd>
1899**
1900** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1901** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1902** that SQLite can use for the database page cache with the default page
1903** cache implementation.
1904** This configuration option is a no-op if an application-defined page
1905** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1906** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1907** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1908** and the number of cache lines (N).
1909** The sz argument should be the size of the largest database page
1910** (a power of two between 512 and 65536) plus some extra bytes for each
1911** page header. ^The number of extra bytes needed by the page header
1912** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1913** ^It is harmless, apart from the wasted memory,
1914** for the sz parameter to be larger than necessary. The pMem
1915** argument must be either a NULL pointer or a pointer to an 8-byte
1916** aligned block of memory of at least sz*N bytes, otherwise
1917** subsequent behavior is undefined.
1918** ^When pMem is not NULL, SQLite will strive to use the memory provided
1919** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1920** a page cache line is larger than sz bytes or if all of the pMem buffer
1921** is exhausted.
1922** ^If pMem is NULL and N is non-zero, then each database connection
1923** does an initial bulk allocation for page cache memory
1924** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1925** of -1024*N bytes if N is negative, . ^If additional
1926** page cache memory is needed beyond what is provided by the initial
1927** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1928** additional cache line. </dd>
1929**
1930** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1931** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1932** that SQLite will use for all of its dynamic memory allocation needs
1933** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1934** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1935** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1936** [SQLITE_ERROR] if invoked otherwise.
1937** ^There are three arguments to SQLITE_CONFIG_HEAP:
1938** An 8-byte aligned pointer to the memory,
1939** the number of bytes in the memory buffer, and the minimum allocation size.
1940** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1941** to using its default memory allocator (the system malloc() implementation),
1942** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1943** memory pointer is not NULL then the alternative memory
1944** allocator is engaged to handle all of SQLites memory allocation needs.
1945** The first pointer (the memory pointer) must be aligned to an 8-byte
1946** boundary or subsequent behavior of SQLite will be undefined.
1947** The minimum allocation size is capped at 2**12. Reasonable values
1948** for the minimum allocation size are 2**5 through 2**8.</dd>
1949**
1950** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1951** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1952** pointer to an instance of the [sqlite3_mutex_methods] structure.
1953** The argument specifies alternative low-level mutex routines to be used
1954** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1955** the content of the [sqlite3_mutex_methods] structure before the call to
1956** [sqlite3_config()] returns. ^If SQLite is compiled with
1957** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1958** the entire mutexing subsystem is omitted from the build and hence calls to
1959** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1960** return [SQLITE_ERROR].</dd>
1961**
1962** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1963** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1964** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1965** [sqlite3_mutex_methods]
1966** structure is filled with the currently defined mutex routines.)^
1967** This option can be used to overload the default mutex allocation
1968** routines with a wrapper used to track mutex usage for performance
1969** profiling or testing, for example. ^If SQLite is compiled with
1970** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1971** the entire mutexing subsystem is omitted from the build and hence calls to
1972** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1973** return [SQLITE_ERROR].</dd>
1974**
1975** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1976** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1977** the default size of lookaside memory on each [database connection].
1978** The first argument is the
1979** size of each lookaside buffer slot and the second is the number of
1980** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1981** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1982** option to [sqlite3_db_config()] can be used to change the lookaside
1983** configuration on individual connections.)^ </dd>
1984**
1985** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1986** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1987** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1988** the interface to a custom page cache implementation.)^
1989** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1990**
1991** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1992** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1993** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1994** the current page cache implementation into that object.)^ </dd>
1995**
1996** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1997** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1998** global [error log].
1999** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2000** function with a call signature of void(*)(void*,int,const char*),
2001** and a pointer to void. ^If the function pointer is not NULL, it is
2002** invoked by [sqlite3_log()] to process each logging event. ^If the
2003** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2004** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2005** passed through as the first parameter to the application-defined logger
2006** function whenever that function is invoked. ^The second parameter to
2007** the logger function is a copy of the first parameter to the corresponding
2008** [sqlite3_log()] call and is intended to be a [result code] or an
2009** [extended result code]. ^The third parameter passed to the logger is
2010** log message after formatting via [sqlite3_snprintf()].
2011** The SQLite logging interface is not reentrant; the logger function
2012** supplied by the application must not invoke any SQLite interface.
2013** In a multi-threaded application, the application-defined logger
2014** function must be threadsafe. </dd>
2015**
2016** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2017** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2018** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2019** then URI handling is globally disabled.)^ ^If URI handling is globally
2020** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2021** [sqlite3_open16()] or
2022** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2023** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2024** connection is opened. ^If it is globally disabled, filenames are
2025** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2026** database connection is opened. ^(By default, URI handling is globally
2027** disabled. The default value may be changed by compiling with the
2028** [SQLITE_USE_URI] symbol defined.)^
2029**
2030** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2031** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2032** argument which is interpreted as a boolean in order to enable or disable
2033** the use of covering indices for full table scans in the query optimizer.
2034** ^The default setting is determined
2035** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2036** if that compile-time option is omitted.
2037** The ability to disable the use of covering indices for full table scans
2038** is because some incorrectly coded legacy applications might malfunction
2039** when the optimization is enabled. Providing the ability to
2040** disable the optimization allows the older, buggy application code to work
2041** without change even with newer versions of SQLite.
2042**
2043** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2044** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2045** <dd> These options are obsolete and should not be used by new code.
2046** They are retained for backwards compatibility but are now no-ops.
2047** </dd>
2048**
2049** [[SQLITE_CONFIG_SQLLOG]]
2050** <dt>SQLITE_CONFIG_SQLLOG
2051** <dd>This option is only available if sqlite is compiled with the
2052** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2053** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2054** The second should be of type (void*). The callback is invoked by the library
2055** in three separate circumstances, identified by the value passed as the
2056** fourth parameter. If the fourth parameter is 0, then the database connection
2057** passed as the second argument has just been opened. The third argument
2058** points to a buffer containing the name of the main database file. If the
2059** fourth parameter is 1, then the SQL statement that the third parameter
2060** points to has just been executed. Or, if the fourth parameter is 2, then
2061** the connection being passed as the second parameter is being closed. The
2062** third parameter is passed NULL In this case. An example of using this
2063** configuration option can be seen in the "test_sqllog.c" source file in
2064** the canonical SQLite source tree.</dd>
2065**
2066** [[SQLITE_CONFIG_MMAP_SIZE]]
2067** <dt>SQLITE_CONFIG_MMAP_SIZE
2068** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2069** that are the default mmap size limit (the default setting for
2070** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2071** ^The default setting can be overridden by each database connection using
2072** either the [PRAGMA mmap_size] command, or by using the
2073** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2074** will be silently truncated if necessary so that it does not exceed the
2075** compile-time maximum mmap size set by the
2076** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2077** ^If either argument to this option is negative, then that argument is
2078** changed to its compile-time default.
2079**
2080** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2081** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2082** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2083** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2084** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2085** that specifies the maximum size of the created heap.
2086**
2087** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2088** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2089** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2090** is a pointer to an integer and writes into that integer the number of extra
2091** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2092** The amount of extra space required can change depending on the compiler,
2093** target platform, and SQLite version.
2094**
2095** [[SQLITE_CONFIG_PMASZ]]
2096** <dt>SQLITE_CONFIG_PMASZ
2097** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2098** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2099** sorter to that integer. The default minimum PMA Size is set by the
2100** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2101** to help with sort operations when multithreaded sorting
2102** is enabled (using the [PRAGMA threads] command) and the amount of content
2103** to be sorted exceeds the page size times the minimum of the
2104** [PRAGMA cache_size] setting and this value.
2105**
2106** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2107** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2108** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2109** becomes the [statement journal] spill-to-disk threshold.
2110** [Statement journals] are held in memory until their size (in bytes)
2111** exceeds this threshold, at which point they are written to disk.
2112** Or if the threshold is -1, statement journals are always held
2113** exclusively in memory.
2114** Since many statement journals never become large, setting the spill
2115** threshold to a value such as 64KiB can greatly reduce the amount of
2116** I/O required to support statement rollback.
2117** The default value for this setting is controlled by the
2118** [SQLITE_STMTJRNL_SPILL] compile-time option.
2119**
2120** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2121** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2122** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2123** of type (int) - the new value of the sorter-reference size threshold.
2124** Usually, when SQLite uses an external sort to order records according
2125** to an ORDER BY clause, all fields required by the caller are present in the
2126** sorted records. However, if SQLite determines based on the declared type
2127** of a table column that its values are likely to be very large - larger
2128** than the configured sorter-reference size threshold - then a reference
2129** is stored in each sorted record and the required column values loaded
2130** from the database as records are returned in sorted order. The default
2131** value for this option is to never use this optimization. Specifying a
2132** negative value for this option restores the default behavior.
2133** This option is only available if SQLite is compiled with the
2134** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2135**
2136** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2137** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2138** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2139** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2140** database created using [sqlite3_deserialize()]. This default maximum
2141** size can be adjusted up or down for individual databases using the
2142** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2143** configuration setting is never used, then the default maximum is determined
2144** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2145** compile-time option is not set, then the default maximum is 1073741824.
2146**
2147** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2148** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2149** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2150** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2151** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2152** defaults to on. This configuration option queries the current setting or
2153** changes the setting to off or on. The argument is a pointer to an integer.
2154** If that integer initially holds a value of 1, then the ability for VIEWs to
2155** have ROWIDs is activated. If the integer initially holds zero, then the
2156** ability is deactivated. Any other initial value for the integer leaves the
2157** setting unchanged. After changes, if any, the integer is written with
2158** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2159** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2160** recommended case) then the integer is always filled with zero, regardless
2161** if its initial value.
2162** </dl>
2163*/
2164#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2165#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2166#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2167#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2168#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2169#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2170#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2171#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2172#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2173#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2174#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2175/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2176#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2177#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2178#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2179#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2180#define SQLITE_CONFIG_URI 17 /* int */
2181#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2182#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2183#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2184#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2185#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2186#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2187#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2188#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2189#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2190#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2191#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2192#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2193#define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2194
2195/*
2196** CAPI3REF: Database Connection Configuration Options
2197**
2198** These constants are the available integer configuration options that
2199** can be passed as the second argument to the [sqlite3_db_config()] interface.
2200**
2201** New configuration options may be added in future releases of SQLite.
2202** Existing configuration options might be discontinued. Applications
2203** should check the return code from [sqlite3_db_config()] to make sure that
2204** the call worked. ^The [sqlite3_db_config()] interface will return a
2205** non-zero [error code] if a discontinued or unsupported configuration option
2206** is invoked.
2207**
2208** <dl>
2209** [[SQLITE_DBCONFIG_LOOKASIDE]]
2210** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2211** <dd> ^This option takes three additional arguments that determine the
2212** [lookaside memory allocator] configuration for the [database connection].
2213** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2214** pointer to a memory buffer to use for lookaside memory.
2215** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2216** may be NULL in which case SQLite will allocate the
2217** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2218** size of each lookaside buffer slot. ^The third argument is the number of
2219** slots. The size of the buffer in the first argument must be greater than
2220** or equal to the product of the second and third arguments. The buffer
2221** must be aligned to an 8-byte boundary. ^If the second argument to
2222** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2223** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2224** configuration for a database connection can only be changed when that
2225** connection is not currently using lookaside memory, or in other words
2226** when the "current value" returned by
2227** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero.
2228** Any attempt to change the lookaside memory configuration when lookaside
2229** memory is in use leaves the configuration unchanged and returns
2230** [SQLITE_BUSY].)^</dd>
2231**
2232** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2233** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2234** <dd> ^This option is used to enable or disable the enforcement of
2235** [foreign key constraints]. There should be two additional arguments.
2236** The first argument is an integer which is 0 to disable FK enforcement,
2237** positive to enable FK enforcement or negative to leave FK enforcement
2238** unchanged. The second parameter is a pointer to an integer into which
2239** is written 0 or 1 to indicate whether FK enforcement is off or on
2240** following this call. The second parameter may be a NULL pointer, in
2241** which case the FK enforcement setting is not reported back. </dd>
2242**
2243** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2244** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2245** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2246** There should be two additional arguments.
2247** The first argument is an integer which is 0 to disable triggers,
2248** positive to enable triggers or negative to leave the setting unchanged.
2249** The second parameter is a pointer to an integer into which
2250** is written 0 or 1 to indicate whether triggers are disabled or enabled
2251** following this call. The second parameter may be a NULL pointer, in
2252** which case the trigger setting is not reported back.
2253**
2254** <p>Originally this option disabled all triggers. ^(However, since
2255** SQLite version 3.35.0, TEMP triggers are still allowed even if
2256** this option is off. So, in other words, this option now only disables
2257** triggers in the main database schema or in the schemas of ATTACH-ed
2258** databases.)^ </dd>
2259**
2260** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2261** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2262** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2263** There should be two additional arguments.
2264** The first argument is an integer which is 0 to disable views,
2265** positive to enable views or negative to leave the setting unchanged.
2266** The second parameter is a pointer to an integer into which
2267** is written 0 or 1 to indicate whether views are disabled or enabled
2268** following this call. The second parameter may be a NULL pointer, in
2269** which case the view setting is not reported back.
2270**
2271** <p>Originally this option disabled all views. ^(However, since
2272** SQLite version 3.35.0, TEMP views are still allowed even if
2273** this option is off. So, in other words, this option now only disables
2274** views in the main database schema or in the schemas of ATTACH-ed
2275** databases.)^ </dd>
2276**
2277** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2278** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2279** <dd> ^This option is used to enable or disable the
2280** [fts3_tokenizer()] function which is part of the
2281** [FTS3] full-text search engine extension.
2282** There should be two additional arguments.
2283** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2284** positive to enable fts3_tokenizer() or negative to leave the setting
2285** unchanged.
2286** The second parameter is a pointer to an integer into which
2287** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2288** following this call. The second parameter may be a NULL pointer, in
2289** which case the new setting is not reported back. </dd>
2290**
2291** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2292** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2293** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2294** interface independently of the [load_extension()] SQL function.
2295** The [sqlite3_enable_load_extension()] API enables or disables both the
2296** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2297** There should be two additional arguments.
2298** When the first argument to this interface is 1, then only the C-API is
2299** enabled and the SQL function remains disabled. If the first argument to
2300** this interface is 0, then both the C-API and the SQL function are disabled.
2301** If the first argument is -1, then no changes are made to state of either the
2302** C-API or the SQL function.
2303** The second parameter is a pointer to an integer into which
2304** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2305** is disabled or enabled following this call. The second parameter may
2306** be a NULL pointer, in which case the new setting is not reported back.
2307** </dd>
2308**
2309** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2310** <dd> ^This option is used to change the name of the "main" database
2311** schema. ^The sole argument is a pointer to a constant UTF8 string
2312** which will become the new schema name in place of "main". ^SQLite
2313** does not make a copy of the new main schema name string, so the application
2314** must ensure that the argument passed into this DBCONFIG option is unchanged
2315** until after the database connection closes.
2316** </dd>
2317**
2318** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2319** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2320** <dd> Usually, when a database in wal mode is closed or detached from a
2321** database handle, SQLite checks if this will mean that there are now no
2322** connections at all to the database. If so, it performs a checkpoint
2323** operation before closing the connection. This option may be used to
2324** override this behavior. The first parameter passed to this operation
2325** is an integer - positive to disable checkpoints-on-close, or zero (the
2326** default) to enable them, and negative to leave the setting unchanged.
2327** The second parameter is a pointer to an integer
2328** into which is written 0 or 1 to indicate whether checkpoints-on-close
2329** have been disabled - 0 if they are not disabled, 1 if they are.
2330** </dd>
2331**
2332** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2333** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2334** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2335** a single SQL query statement will always use the same algorithm regardless
2336** of values of [bound parameters].)^ The QPSG disables some query optimizations
2337** that look at the values of bound parameters, which can make some queries
2338** slower. But the QPSG has the advantage of more predictable behavior. With
2339** the QPSG active, SQLite will always use the same query plan in the field as
2340** was used during testing in the lab.
2341** The first argument to this setting is an integer which is 0 to disable
2342** the QPSG, positive to enable QPSG, or negative to leave the setting
2343** unchanged. The second parameter is a pointer to an integer into which
2344** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2345** following this call.
2346** </dd>
2347**
2348** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2349** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2350** include output for any operations performed by trigger programs. This
2351** option is used to set or clear (the default) a flag that governs this
2352** behavior. The first parameter passed to this operation is an integer -
2353** positive to enable output for trigger programs, or zero to disable it,
2354** or negative to leave the setting unchanged.
2355** The second parameter is a pointer to an integer into which is written
2356** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2357** it is not disabled, 1 if it is.
2358** </dd>
2359**
2360** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2361** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2362** [VACUUM] in order to reset a database back to an empty database
2363** with no schema and no content. The following process works even for
2364** a badly corrupted database file:
2365** <ol>
2366** <li> If the database connection is newly opened, make sure it has read the
2367** database schema by preparing then discarding some query against the
2368** database, or calling sqlite3_table_column_metadata(), ignoring any
2369** errors. This step is only necessary if the application desires to keep
2370** the database in WAL mode after the reset if it was in WAL mode before
2371** the reset.
2372** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2373** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2374** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2375** </ol>
2376** Because resetting a database is destructive and irreversible, the
2377** process requires the use of this obscure API and multiple steps to
2378** help ensure that it does not happen by accident. Because this
2379** feature must be capable of resetting corrupt databases, and
2380** shutting down virtual tables may require access to that corrupt
2381** storage, the library must abandon any installed virtual tables
2382** without calling their xDestroy() methods.
2383**
2384** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2385** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2386** "defensive" flag for a database connection. When the defensive
2387** flag is enabled, language features that allow ordinary SQL to
2388** deliberately corrupt the database file are disabled. The disabled
2389** features include but are not limited to the following:
2390** <ul>
2391** <li> The [PRAGMA writable_schema=ON] statement.
2392** <li> The [PRAGMA journal_mode=OFF] statement.
2393** <li> The [PRAGMA schema_version=N] statement.
2394** <li> Writes to the [sqlite_dbpage] virtual table.
2395** <li> Direct writes to [shadow tables].
2396** </ul>
2397** </dd>
2398**
2399** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2400** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2401** "writable_schema" flag. This has the same effect and is logically equivalent
2402** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2403** The first argument to this setting is an integer which is 0 to disable
2404** the writable_schema, positive to enable writable_schema, or negative to
2405** leave the setting unchanged. The second parameter is a pointer to an
2406** integer into which is written 0 or 1 to indicate whether the writable_schema
2407** is enabled or disabled following this call.
2408** </dd>
2409**
2410** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2411** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2412** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2413** the legacy behavior of the [ALTER TABLE RENAME] command such it
2414** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2415** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2416** additional information. This feature can also be turned on and off
2417** using the [PRAGMA legacy_alter_table] statement.
2418** </dd>
2419**
2420** [[SQLITE_DBCONFIG_DQS_DML]]
2421** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2422** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2423** the legacy [double-quoted string literal] misfeature for DML statements
2424** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2425** default value of this setting is determined by the [-DSQLITE_DQS]
2426** compile-time option.
2427** </dd>
2428**
2429** [[SQLITE_DBCONFIG_DQS_DDL]]
2430** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2431** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2432** the legacy [double-quoted string literal] misfeature for DDL statements,
2433** such as CREATE TABLE and CREATE INDEX. The
2434** default value of this setting is determined by the [-DSQLITE_DQS]
2435** compile-time option.
2436** </dd>
2437**
2438** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2439** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2440** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2441** assume that database schemas are untainted by malicious content.
2442** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2443** takes additional defensive steps to protect the application from harm
2444** including:
2445** <ul>
2446** <li> Prohibit the use of SQL functions inside triggers, views,
2447** CHECK constraints, DEFAULT clauses, expression indexes,
2448** partial indexes, or generated columns
2449** unless those functions are tagged with [SQLITE_INNOCUOUS].
2450** <li> Prohibit the use of virtual tables inside of triggers or views
2451** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2452** </ul>
2453** This setting defaults to "on" for legacy compatibility, however
2454** all applications are advised to turn it off if possible. This setting
2455** can also be controlled using the [PRAGMA trusted_schema] statement.
2456** </dd>
2457**
2458** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2459** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2460** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2461** the legacy file format flag. When activated, this flag causes all newly
2462** created database file to have a schema format version number (the 4-byte
2463** integer found at offset 44 into the database header) of 1. This in turn
2464** means that the resulting database file will be readable and writable by
2465** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2466** newly created databases are generally not understandable by SQLite versions
2467** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2468** is now scarcely any need to generate database files that are compatible
2469** all the way back to version 3.0.0, and so this setting is of little
2470** practical use, but is provided so that SQLite can continue to claim the
2471** ability to generate new database files that are compatible with version
2472** 3.0.0.
2473** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2474** the [VACUUM] command will fail with an obscure error when attempting to
2475** process a table with generated columns and a descending index. This is
2476** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2477** either generated columns or descending indexes.
2478** </dd>
2479**
2480** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2481** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2482** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2483** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2484** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2485** statistics. For statistics to be collected, the flag must be set on
2486** the database handle both when the SQL statement is prepared and when it
2487** is stepped. The flag is set (collection of statistics is enabled)
2488** by default. This option takes two arguments: an integer and a pointer to
2489** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2490** leave unchanged the statement scanstatus option. If the second argument
2491** is not NULL, then the value of the statement scanstatus setting after
2492** processing the first argument is written into the integer that the second
2493** argument points to.
2494** </dd>
2495**
2496** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2497** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2498** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2499** in which tables and indexes are scanned so that the scans start at the end
2500** and work toward the beginning rather than starting at the beginning and
2501** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2502** same as setting [PRAGMA reverse_unordered_selects]. This option takes
2503** two arguments which are an integer and a pointer to an integer. The first
2504** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2505** reverse scan order flag, respectively. If the second argument is not NULL,
2506** then 0 or 1 is written into the integer that the second argument points to
2507** depending on if the reverse scan order flag is set after processing the
2508** first argument.
2509** </dd>
2510**
2511** </dl>
2512*/
2513#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2514#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2515#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2516#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2517#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2518#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2519#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2520#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2521#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2522#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2523#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2524#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2525#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2526#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2527#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2528#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2529#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2530#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2531#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2532#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2533#define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */
2534
2535/*
2536** CAPI3REF: Enable Or Disable Extended Result Codes
2537** METHOD: sqlite3
2538**
2539** ^The sqlite3_extended_result_codes() routine enables or disables the
2540** [extended result codes] feature of SQLite. ^The extended result
2541** codes are disabled by default for historical compatibility.
2542*/
2543SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2544
2545/*
2546** CAPI3REF: Last Insert Rowid
2547** METHOD: sqlite3
2548**
2549** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2550** has a unique 64-bit signed
2551** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2552** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2553** names are not also used by explicitly declared columns. ^If
2554** the table has a column of type [INTEGER PRIMARY KEY] then that column
2555** is another alias for the rowid.
2556**
2557** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2558** the most recent successful [INSERT] into a rowid table or [virtual table]
2559** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2560** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2561** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2562** zero.
2563**
2564** As well as being set automatically as rows are inserted into database
2565** tables, the value returned by this function may be set explicitly by
2566** [sqlite3_set_last_insert_rowid()]
2567**
2568** Some virtual table implementations may INSERT rows into rowid tables as
2569** part of committing a transaction (e.g. to flush data accumulated in memory
2570** to disk). In this case subsequent calls to this function return the rowid
2571** associated with these internal INSERT operations, which leads to
2572** unintuitive results. Virtual table implementations that do write to rowid
2573** tables in this way can avoid this problem by restoring the original
2574** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2575** control to the user.
2576**
2577** ^(If an [INSERT] occurs within a trigger then this routine will
2578** return the [rowid] of the inserted row as long as the trigger is
2579** running. Once the trigger program ends, the value returned
2580** by this routine reverts to what it was before the trigger was fired.)^
2581**
2582** ^An [INSERT] that fails due to a constraint violation is not a
2583** successful [INSERT] and does not change the value returned by this
2584** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2585** and INSERT OR ABORT make no changes to the return value of this
2586** routine when their insertion fails. ^(When INSERT OR REPLACE
2587** encounters a constraint violation, it does not fail. The
2588** INSERT continues to completion after deleting rows that caused
2589** the constraint problem so INSERT OR REPLACE will always change
2590** the return value of this interface.)^
2591**
2592** ^For the purposes of this routine, an [INSERT] is considered to
2593** be successful even if it is subsequently rolled back.
2594**
2595** This function is accessible to SQL statements via the
2596** [last_insert_rowid() SQL function].
2597**
2598** If a separate thread performs a new [INSERT] on the same
2599** database connection while the [sqlite3_last_insert_rowid()]
2600** function is running and thus changes the last insert [rowid],
2601** then the value returned by [sqlite3_last_insert_rowid()] is
2602** unpredictable and might not equal either the old or the new
2603** last insert [rowid].
2604*/
2605SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2606
2607/*
2608** CAPI3REF: Set the Last Insert Rowid value.
2609** METHOD: sqlite3
2610**
2611** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2612** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2613** without inserting a row into the database.
2614*/
2615SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2616
2617/*
2618** CAPI3REF: Count The Number Of Rows Modified
2619** METHOD: sqlite3
2620**
2621** ^These functions return the number of rows modified, inserted or
2622** deleted by the most recently completed INSERT, UPDATE or DELETE
2623** statement on the database connection specified by the only parameter.
2624** The two functions are identical except for the type of the return value
2625** and that if the number of rows modified by the most recent INSERT, UPDATE
2626** or DELETE is greater than the maximum value supported by type "int", then
2627** the return value of sqlite3_changes() is undefined. ^Executing any other
2628** type of SQL statement does not modify the value returned by these functions.
2629**
2630** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2631** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2632** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2633**
2634** Changes to a view that are intercepted by
2635** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2636** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2637** DELETE statement run on a view is always zero. Only changes made to real
2638** tables are counted.
2639**
2640** Things are more complicated if the sqlite3_changes() function is
2641** executed while a trigger program is running. This may happen if the
2642** program uses the [changes() SQL function], or if some other callback
2643** function invokes sqlite3_changes() directly. Essentially:
2644**
2645** <ul>
2646** <li> ^(Before entering a trigger program the value returned by
2647** sqlite3_changes() function is saved. After the trigger program
2648** has finished, the original value is restored.)^
2649**
2650** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2651** statement sets the value returned by sqlite3_changes()
2652** upon completion as normal. Of course, this value will not include
2653** any changes performed by sub-triggers, as the sqlite3_changes()
2654** value will be saved and restored after each sub-trigger has run.)^
2655** </ul>
2656**
2657** ^This means that if the changes() SQL function (or similar) is used
2658** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2659** returns the value as set when the calling statement began executing.
2660** ^If it is used by the second or subsequent such statement within a trigger
2661** program, the value returned reflects the number of rows modified by the
2662** previous INSERT, UPDATE or DELETE statement within the same trigger.
2663**
2664** If a separate thread makes changes on the same database connection
2665** while [sqlite3_changes()] is running then the value returned
2666** is unpredictable and not meaningful.
2667**
2668** See also:
2669** <ul>
2670** <li> the [sqlite3_total_changes()] interface
2671** <li> the [count_changes pragma]
2672** <li> the [changes() SQL function]
2673** <li> the [data_version pragma]
2674** </ul>
2675*/
2676SQLITE_API int sqlite3_changes(sqlite3*);
2677SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2678
2679/*
2680** CAPI3REF: Total Number Of Rows Modified
2681** METHOD: sqlite3
2682**
2683** ^These functions return the total number of rows inserted, modified or
2684** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2685** since the database connection was opened, including those executed as
2686** part of trigger programs. The two functions are identical except for the
2687** type of the return value and that if the number of rows modified by the
2688** connection exceeds the maximum value supported by type "int", then
2689** the return value of sqlite3_total_changes() is undefined. ^Executing
2690** any other type of SQL statement does not affect the value returned by
2691** sqlite3_total_changes().
2692**
2693** ^Changes made as part of [foreign key actions] are included in the
2694** count, but those made as part of REPLACE constraint resolution are
2695** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2696** are not counted.
2697**
2698** The [sqlite3_total_changes(D)] interface only reports the number
2699** of rows that changed due to SQL statement run against database
2700** connection D. Any changes by other database connections are ignored.
2701** To detect changes against a database file from other database
2702** connections use the [PRAGMA data_version] command or the
2703** [SQLITE_FCNTL_DATA_VERSION] [file control].
2704**
2705** If a separate thread makes changes on the same database connection
2706** while [sqlite3_total_changes()] is running then the value
2707** returned is unpredictable and not meaningful.
2708**
2709** See also:
2710** <ul>
2711** <li> the [sqlite3_changes()] interface
2712** <li> the [count_changes pragma]
2713** <li> the [changes() SQL function]
2714** <li> the [data_version pragma]
2715** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2716** </ul>
2717*/
2718SQLITE_API int sqlite3_total_changes(sqlite3*);
2719SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2720
2721/*
2722** CAPI3REF: Interrupt A Long-Running Query
2723** METHOD: sqlite3
2724**
2725** ^This function causes any pending database operation to abort and
2726** return at its earliest opportunity. This routine is typically
2727** called in response to a user action such as pressing "Cancel"
2728** or Ctrl-C where the user wants a long query operation to halt
2729** immediately.
2730**
2731** ^It is safe to call this routine from a thread different from the
2732** thread that is currently running the database operation. But it
2733** is not safe to call this routine with a [database connection] that
2734** is closed or might close before sqlite3_interrupt() returns.
2735**
2736** ^If an SQL operation is very nearly finished at the time when
2737** sqlite3_interrupt() is called, then it might not have an opportunity
2738** to be interrupted and might continue to completion.
2739**
2740** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2741** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2742** that is inside an explicit transaction, then the entire transaction
2743** will be rolled back automatically.
2744**
2745** ^The sqlite3_interrupt(D) call is in effect until all currently running
2746** SQL statements on [database connection] D complete. ^Any new SQL statements
2747** that are started after the sqlite3_interrupt() call and before the
2748** running statement count reaches zero are interrupted as if they had been
2749** running prior to the sqlite3_interrupt() call. ^New SQL statements
2750** that are started after the running statement count reaches zero are
2751** not effected by the sqlite3_interrupt().
2752** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2753** SQL statements is a no-op and has no effect on SQL statements
2754** that are started after the sqlite3_interrupt() call returns.
2755**
2756** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2757** or not an interrupt is currently in effect for [database connection] D.
2758** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2759*/
2760SQLITE_API void sqlite3_interrupt(sqlite3*);
2761SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2762
2763/*
2764** CAPI3REF: Determine If An SQL Statement Is Complete
2765**
2766** These routines are useful during command-line input to determine if the
2767** currently entered text seems to form a complete SQL statement or
2768** if additional input is needed before sending the text into
2769** SQLite for parsing. ^These routines return 1 if the input string
2770** appears to be a complete SQL statement. ^A statement is judged to be
2771** complete if it ends with a semicolon token and is not a prefix of a
2772** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2773** string literals or quoted identifier names or comments are not
2774** independent tokens (they are part of the token in which they are
2775** embedded) and thus do not count as a statement terminator. ^Whitespace
2776** and comments that follow the final semicolon are ignored.
2777**
2778** ^These routines return 0 if the statement is incomplete. ^If a
2779** memory allocation fails, then SQLITE_NOMEM is returned.
2780**
2781** ^These routines do not parse the SQL statements thus
2782** will not detect syntactically incorrect SQL.
2783**
2784** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2785** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2786** automatically by sqlite3_complete16(). If that initialization fails,
2787** then the return value from sqlite3_complete16() will be non-zero
2788** regardless of whether or not the input SQL is complete.)^
2789**
2790** The input to [sqlite3_complete()] must be a zero-terminated
2791** UTF-8 string.
2792**
2793** The input to [sqlite3_complete16()] must be a zero-terminated
2794** UTF-16 string in native byte order.
2795*/
2796SQLITE_API int sqlite3_complete(const char *sql);
2797SQLITE_API int sqlite3_complete16(const void *sql);
2798
2799/*
2800** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2801** KEYWORDS: {busy-handler callback} {busy handler}
2802** METHOD: sqlite3
2803**
2804** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2805** that might be invoked with argument P whenever
2806** an attempt is made to access a database table associated with
2807** [database connection] D when another thread
2808** or process has the table locked.
2809** The sqlite3_busy_handler() interface is used to implement
2810** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2811**
2812** ^If the busy callback is NULL, then [SQLITE_BUSY]
2813** is returned immediately upon encountering the lock. ^If the busy callback
2814** is not NULL, then the callback might be invoked with two arguments.
2815**
2816** ^The first argument to the busy handler is a copy of the void* pointer which
2817** is the third argument to sqlite3_busy_handler(). ^The second argument to
2818** the busy handler callback is the number of times that the busy handler has
2819** been invoked previously for the same locking event. ^If the
2820** busy callback returns 0, then no additional attempts are made to
2821** access the database and [SQLITE_BUSY] is returned
2822** to the application.
2823** ^If the callback returns non-zero, then another attempt
2824** is made to access the database and the cycle repeats.
2825**
2826** The presence of a busy handler does not guarantee that it will be invoked
2827** when there is lock contention. ^If SQLite determines that invoking the busy
2828** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2829** to the application instead of invoking the
2830** busy handler.
2831** Consider a scenario where one process is holding a read lock that
2832** it is trying to promote to a reserved lock and
2833** a second process is holding a reserved lock that it is trying
2834** to promote to an exclusive lock. The first process cannot proceed
2835** because it is blocked by the second and the second process cannot
2836** proceed because it is blocked by the first. If both processes
2837** invoke the busy handlers, neither will make any progress. Therefore,
2838** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2839** will induce the first process to release its read lock and allow
2840** the second process to proceed.
2841**
2842** ^The default busy callback is NULL.
2843**
2844** ^(There can only be a single busy handler defined for each
2845** [database connection]. Setting a new busy handler clears any
2846** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2847** or evaluating [PRAGMA busy_timeout=N] will change the
2848** busy handler and thus clear any previously set busy handler.
2849**
2850** The busy callback should not take any actions which modify the
2851** database connection that invoked the busy handler. In other words,
2852** the busy handler is not reentrant. Any such actions
2853** result in undefined behavior.
2854**
2855** A busy handler must not close the database connection
2856** or [prepared statement] that invoked the busy handler.
2857*/
2858SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2859
2860/*
2861** CAPI3REF: Set A Busy Timeout
2862** METHOD: sqlite3
2863**
2864** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2865** for a specified amount of time when a table is locked. ^The handler
2866** will sleep multiple times until at least "ms" milliseconds of sleeping
2867** have accumulated. ^After at least "ms" milliseconds of sleeping,
2868** the handler returns 0 which causes [sqlite3_step()] to return
2869** [SQLITE_BUSY].
2870**
2871** ^Calling this routine with an argument less than or equal to zero
2872** turns off all busy handlers.
2873**
2874** ^(There can only be a single busy handler for a particular
2875** [database connection] at any given moment. If another busy handler
2876** was defined (using [sqlite3_busy_handler()]) prior to calling
2877** this routine, that other busy handler is cleared.)^
2878**
2879** See also: [PRAGMA busy_timeout]
2880*/
2881SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2882
2883/*
2884** CAPI3REF: Convenience Routines For Running Queries
2885** METHOD: sqlite3
2886**
2887** This is a legacy interface that is preserved for backwards compatibility.
2888** Use of this interface is not recommended.
2889**
2890** Definition: A <b>result table</b> is memory data structure created by the
2891** [sqlite3_get_table()] interface. A result table records the
2892** complete query results from one or more queries.
2893**
2894** The table conceptually has a number of rows and columns. But
2895** these numbers are not part of the result table itself. These
2896** numbers are obtained separately. Let N be the number of rows
2897** and M be the number of columns.
2898**
2899** A result table is an array of pointers to zero-terminated UTF-8 strings.
2900** There are (N+1)*M elements in the array. The first M pointers point
2901** to zero-terminated strings that contain the names of the columns.
2902** The remaining entries all point to query results. NULL values result
2903** in NULL pointers. All other values are in their UTF-8 zero-terminated
2904** string representation as returned by [sqlite3_column_text()].
2905**
2906** A result table might consist of one or more memory allocations.
2907** It is not safe to pass a result table directly to [sqlite3_free()].
2908** A result table should be deallocated using [sqlite3_free_table()].
2909**
2910** ^(As an example of the result table format, suppose a query result
2911** is as follows:
2912**
2913** <blockquote><pre>
2914** Name | Age
2915** -----------------------
2916** Alice | 43
2917** Bob | 28
2918** Cindy | 21
2919** </pre></blockquote>
2920**
2921** There are two columns (M==2) and three rows (N==3). Thus the
2922** result table has 8 entries. Suppose the result table is stored
2923** in an array named azResult. Then azResult holds this content:
2924**
2925** <blockquote><pre>
2926** azResult&#91;0] = "Name";
2927** azResult&#91;1] = "Age";
2928** azResult&#91;2] = "Alice";
2929** azResult&#91;3] = "43";
2930** azResult&#91;4] = "Bob";
2931** azResult&#91;5] = "28";
2932** azResult&#91;6] = "Cindy";
2933** azResult&#91;7] = "21";
2934** </pre></blockquote>)^
2935**
2936** ^The sqlite3_get_table() function evaluates one or more
2937** semicolon-separated SQL statements in the zero-terminated UTF-8
2938** string of its 2nd parameter and returns a result table to the
2939** pointer given in its 3rd parameter.
2940**
2941** After the application has finished with the result from sqlite3_get_table(),
2942** it must pass the result table pointer to sqlite3_free_table() in order to
2943** release the memory that was malloced. Because of the way the
2944** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2945** function must not try to call [sqlite3_free()] directly. Only
2946** [sqlite3_free_table()] is able to release the memory properly and safely.
2947**
2948** The sqlite3_get_table() interface is implemented as a wrapper around
2949** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2950** to any internal data structures of SQLite. It uses only the public
2951** interface defined here. As a consequence, errors that occur in the
2952** wrapper layer outside of the internal [sqlite3_exec()] call are not
2953** reflected in subsequent calls to [sqlite3_errcode()] or
2954** [sqlite3_errmsg()].
2955*/
2956SQLITE_API int sqlite3_get_table(
2957 sqlite3 *db, /* An open database */
2958 const char *zSql, /* SQL to be evaluated */
2959 char ***pazResult, /* Results of the query */
2960 int *pnRow, /* Number of result rows written here */
2961 int *pnColumn, /* Number of result columns written here */
2962 char **pzErrmsg /* Error msg written here */
2963);
2964SQLITE_API void sqlite3_free_table(char **result);
2965
2966/*
2967** CAPI3REF: Formatted String Printing Functions
2968**
2969** These routines are work-alikes of the "printf()" family of functions
2970** from the standard C library.
2971** These routines understand most of the common formatting options from
2972** the standard library printf()
2973** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2974** See the [built-in printf()] documentation for details.
2975**
2976** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2977** results into memory obtained from [sqlite3_malloc64()].
2978** The strings returned by these two routines should be
2979** released by [sqlite3_free()]. ^Both routines return a
2980** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2981** memory to hold the resulting string.
2982**
2983** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2984** the standard C library. The result is written into the
2985** buffer supplied as the second parameter whose size is given by
2986** the first parameter. Note that the order of the
2987** first two parameters is reversed from snprintf().)^ This is an
2988** historical accident that cannot be fixed without breaking
2989** backwards compatibility. ^(Note also that sqlite3_snprintf()
2990** returns a pointer to its buffer instead of the number of
2991** characters actually written into the buffer.)^ We admit that
2992** the number of characters written would be a more useful return
2993** value but we cannot change the implementation of sqlite3_snprintf()
2994** now without breaking compatibility.
2995**
2996** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2997** guarantees that the buffer is always zero-terminated. ^The first
2998** parameter "n" is the total size of the buffer, including space for
2999** the zero terminator. So the longest string that can be completely
3000** written will be n-1 characters.
3001**
3002** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3003**
3004** See also: [built-in printf()], [printf() SQL function]
3005*/
3006SQLITE_API char *sqlite3_mprintf(const char*,...);
3007SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3008SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3009SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3010
3011/*
3012** CAPI3REF: Memory Allocation Subsystem
3013**
3014** The SQLite core uses these three routines for all of its own
3015** internal memory allocation needs. "Core" in the previous sentence
3016** does not include operating-system specific [VFS] implementation. The
3017** Windows VFS uses native malloc() and free() for some operations.
3018**
3019** ^The sqlite3_malloc() routine returns a pointer to a block
3020** of memory at least N bytes in length, where N is the parameter.
3021** ^If sqlite3_malloc() is unable to obtain sufficient free
3022** memory, it returns a NULL pointer. ^If the parameter N to
3023** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3024** a NULL pointer.
3025**
3026** ^The sqlite3_malloc64(N) routine works just like
3027** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3028** of a signed 32-bit integer.
3029**
3030** ^Calling sqlite3_free() with a pointer previously returned
3031** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3032** that it might be reused. ^The sqlite3_free() routine is
3033** a no-op if is called with a NULL pointer. Passing a NULL pointer
3034** to sqlite3_free() is harmless. After being freed, memory
3035** should neither be read nor written. Even reading previously freed
3036** memory might result in a segmentation fault or other severe error.
3037** Memory corruption, a segmentation fault, or other severe error
3038** might result if sqlite3_free() is called with a non-NULL pointer that
3039** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3040**
3041** ^The sqlite3_realloc(X,N) interface attempts to resize a
3042** prior memory allocation X to be at least N bytes.
3043** ^If the X parameter to sqlite3_realloc(X,N)
3044** is a NULL pointer then its behavior is identical to calling
3045** sqlite3_malloc(N).
3046** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3047** negative then the behavior is exactly the same as calling
3048** sqlite3_free(X).
3049** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3050** of at least N bytes in size or NULL if insufficient memory is available.
3051** ^If M is the size of the prior allocation, then min(N,M) bytes
3052** of the prior allocation are copied into the beginning of buffer returned
3053** by sqlite3_realloc(X,N) and the prior allocation is freed.
3054** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3055** prior allocation is not freed.
3056**
3057** ^The sqlite3_realloc64(X,N) interfaces works the same as
3058** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3059** of a 32-bit signed integer.
3060**
3061** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3062** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3063** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3064** ^The value returned by sqlite3_msize(X) might be larger than the number
3065** of bytes requested when X was allocated. ^If X is a NULL pointer then
3066** sqlite3_msize(X) returns zero. If X points to something that is not
3067** the beginning of memory allocation, or if it points to a formerly
3068** valid memory allocation that has now been freed, then the behavior
3069** of sqlite3_msize(X) is undefined and possibly harmful.
3070**
3071** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3072** sqlite3_malloc64(), and sqlite3_realloc64()
3073** is always aligned to at least an 8 byte boundary, or to a
3074** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3075** option is used.
3076**
3077** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3078** must be either NULL or else pointers obtained from a prior
3079** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3080** not yet been released.
3081**
3082** The application must not read or write any part of
3083** a block of memory after it has been released using
3084** [sqlite3_free()] or [sqlite3_realloc()].
3085*/
3086SQLITE_API void *sqlite3_malloc(int);
3087SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3088SQLITE_API void *sqlite3_realloc(void*, int);
3089SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3090SQLITE_API void sqlite3_free(void*);
3091SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3092
3093/*
3094** CAPI3REF: Memory Allocator Statistics
3095**
3096** SQLite provides these two interfaces for reporting on the status
3097** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3098** routines, which form the built-in memory allocation subsystem.
3099**
3100** ^The [sqlite3_memory_used()] routine returns the number of bytes
3101** of memory currently outstanding (malloced but not freed).
3102** ^The [sqlite3_memory_highwater()] routine returns the maximum
3103** value of [sqlite3_memory_used()] since the high-water mark
3104** was last reset. ^The values returned by [sqlite3_memory_used()] and
3105** [sqlite3_memory_highwater()] include any overhead
3106** added by SQLite in its implementation of [sqlite3_malloc()],
3107** but not overhead added by the any underlying system library
3108** routines that [sqlite3_malloc()] may call.
3109**
3110** ^The memory high-water mark is reset to the current value of
3111** [sqlite3_memory_used()] if and only if the parameter to
3112** [sqlite3_memory_highwater()] is true. ^The value returned
3113** by [sqlite3_memory_highwater(1)] is the high-water mark
3114** prior to the reset.
3115*/
3116SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3117SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3118
3119/*
3120** CAPI3REF: Pseudo-Random Number Generator
3121**
3122** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3123** select random [ROWID | ROWIDs] when inserting new records into a table that
3124** already uses the largest possible [ROWID]. The PRNG is also used for
3125** the built-in random() and randomblob() SQL functions. This interface allows
3126** applications to access the same PRNG for other purposes.
3127**
3128** ^A call to this routine stores N bytes of randomness into buffer P.
3129** ^The P parameter can be a NULL pointer.
3130**
3131** ^If this routine has not been previously called or if the previous
3132** call had N less than one or a NULL pointer for P, then the PRNG is
3133** seeded using randomness obtained from the xRandomness method of
3134** the default [sqlite3_vfs] object.
3135** ^If the previous call to this routine had an N of 1 or more and a
3136** non-NULL P then the pseudo-randomness is generated
3137** internally and without recourse to the [sqlite3_vfs] xRandomness
3138** method.
3139*/
3140SQLITE_API void sqlite3_randomness(int N, void *P);
3141
3142/*
3143** CAPI3REF: Compile-Time Authorization Callbacks
3144** METHOD: sqlite3
3145** KEYWORDS: {authorizer callback}
3146**
3147** ^This routine registers an authorizer callback with a particular
3148** [database connection], supplied in the first argument.
3149** ^The authorizer callback is invoked as SQL statements are being compiled
3150** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3151** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3152** and [sqlite3_prepare16_v3()]. ^At various
3153** points during the compilation process, as logic is being created
3154** to perform various actions, the authorizer callback is invoked to
3155** see if those actions are allowed. ^The authorizer callback should
3156** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3157** specific action but allow the SQL statement to continue to be
3158** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3159** rejected with an error. ^If the authorizer callback returns
3160** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3161** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3162** the authorizer will fail with an error message.
3163**
3164** When the callback returns [SQLITE_OK], that means the operation
3165** requested is ok. ^When the callback returns [SQLITE_DENY], the
3166** [sqlite3_prepare_v2()] or equivalent call that triggered the
3167** authorizer will fail with an error message explaining that
3168** access is denied.
3169**
3170** ^The first parameter to the authorizer callback is a copy of the third
3171** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3172** to the callback is an integer [SQLITE_COPY | action code] that specifies
3173** the particular action to be authorized. ^The third through sixth parameters
3174** to the callback are either NULL pointers or zero-terminated strings
3175** that contain additional details about the action to be authorized.
3176** Applications must always be prepared to encounter a NULL pointer in any
3177** of the third through the sixth parameters of the authorization callback.
3178**
3179** ^If the action code is [SQLITE_READ]
3180** and the callback returns [SQLITE_IGNORE] then the
3181** [prepared statement] statement is constructed to substitute
3182** a NULL value in place of the table column that would have
3183** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3184** return can be used to deny an untrusted user access to individual
3185** columns of a table.
3186** ^When a table is referenced by a [SELECT] but no column values are
3187** extracted from that table (for example in a query like
3188** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3189** is invoked once for that table with a column name that is an empty string.
3190** ^If the action code is [SQLITE_DELETE] and the callback returns
3191** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3192** [truncate optimization] is disabled and all rows are deleted individually.
3193**
3194** An authorizer is used when [sqlite3_prepare | preparing]
3195** SQL statements from an untrusted source, to ensure that the SQL statements
3196** do not try to access data they are not allowed to see, or that they do not
3197** try to execute malicious statements that damage the database. For
3198** example, an application may allow a user to enter arbitrary
3199** SQL queries for evaluation by a database. But the application does
3200** not want the user to be able to make arbitrary changes to the
3201** database. An authorizer could then be put in place while the
3202** user-entered SQL is being [sqlite3_prepare | prepared] that
3203** disallows everything except [SELECT] statements.
3204**
3205** Applications that need to process SQL from untrusted sources
3206** might also consider lowering resource limits using [sqlite3_limit()]
3207** and limiting database size using the [max_page_count] [PRAGMA]
3208** in addition to using an authorizer.
3209**
3210** ^(Only a single authorizer can be in place on a database connection
3211** at a time. Each call to sqlite3_set_authorizer overrides the
3212** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3213** The authorizer is disabled by default.
3214**
3215** The authorizer callback must not do anything that will modify
3216** the database connection that invoked the authorizer callback.
3217** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3218** database connections for the meaning of "modify" in this paragraph.
3219**
3220** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3221** statement might be re-prepared during [sqlite3_step()] due to a
3222** schema change. Hence, the application should ensure that the
3223** correct authorizer callback remains in place during the [sqlite3_step()].
3224**
3225** ^Note that the authorizer callback is invoked only during
3226** [sqlite3_prepare()] or its variants. Authorization is not
3227** performed during statement evaluation in [sqlite3_step()], unless
3228** as stated in the previous paragraph, sqlite3_step() invokes
3229** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3230*/
3231SQLITE_API int sqlite3_set_authorizer(
3232 sqlite3*,
3233 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3234 void *pUserData
3235);
3236
3237/*
3238** CAPI3REF: Authorizer Return Codes
3239**
3240** The [sqlite3_set_authorizer | authorizer callback function] must
3241** return either [SQLITE_OK] or one of these two constants in order
3242** to signal SQLite whether or not the action is permitted. See the
3243** [sqlite3_set_authorizer | authorizer documentation] for additional
3244** information.
3245**
3246** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3247** returned from the [sqlite3_vtab_on_conflict()] interface.
3248*/
3249#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3250#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3251
3252/*
3253** CAPI3REF: Authorizer Action Codes
3254**
3255** The [sqlite3_set_authorizer()] interface registers a callback function
3256** that is invoked to authorize certain SQL statement actions. The
3257** second parameter to the callback is an integer code that specifies
3258** what action is being authorized. These are the integer action codes that
3259** the authorizer callback may be passed.
3260**
3261** These action code values signify what kind of operation is to be
3262** authorized. The 3rd and 4th parameters to the authorization
3263** callback function will be parameters or NULL depending on which of these
3264** codes is used as the second parameter. ^(The 5th parameter to the
3265** authorizer callback is the name of the database ("main", "temp",
3266** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3267** is the name of the inner-most trigger or view that is responsible for
3268** the access attempt or NULL if this access attempt is directly from
3269** top-level SQL code.
3270*/
3271/******************************************* 3rd ************ 4th ***********/
3272#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3273#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3274#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3275#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3276#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3277#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3278#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3279#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3280#define SQLITE_DELETE 9 /* Table Name NULL */
3281#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3282#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3283#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3284#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3285#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3286#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3287#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3288#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3289#define SQLITE_INSERT 18 /* Table Name NULL */
3290#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3291#define SQLITE_READ 20 /* Table Name Column Name */
3292#define SQLITE_SELECT 21 /* NULL NULL */
3293#define SQLITE_TRANSACTION 22 /* Operation NULL */
3294#define SQLITE_UPDATE 23 /* Table Name Column Name */
3295#define SQLITE_ATTACH 24 /* Filename NULL */
3296#define SQLITE_DETACH 25 /* Database Name NULL */
3297#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3298#define SQLITE_REINDEX 27 /* Index Name NULL */
3299#define SQLITE_ANALYZE 28 /* Table Name NULL */
3300#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3301#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3302#define SQLITE_FUNCTION 31 /* NULL Function Name */
3303#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3304#define SQLITE_COPY 0 /* No longer used */
3305#define SQLITE_RECURSIVE 33 /* NULL NULL */
3306
3307/*
3308** CAPI3REF: Deprecated Tracing And Profiling Functions
3309** DEPRECATED
3310**
3311** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3312** instead of the routines described here.
3313**
3314** These routines register callback functions that can be used for
3315** tracing and profiling the execution of SQL statements.
3316**
3317** ^The callback function registered by sqlite3_trace() is invoked at
3318** various times when an SQL statement is being run by [sqlite3_step()].
3319** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3320** SQL statement text as the statement first begins executing.
3321** ^(Additional sqlite3_trace() callbacks might occur
3322** as each triggered subprogram is entered. The callbacks for triggers
3323** contain a UTF-8 SQL comment that identifies the trigger.)^
3324**
3325** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3326** the length of [bound parameter] expansion in the output of sqlite3_trace().
3327**
3328** ^The callback function registered by sqlite3_profile() is invoked
3329** as each SQL statement finishes. ^The profile callback contains
3330** the original statement text and an estimate of wall-clock time
3331** of how long that statement took to run. ^The profile callback
3332** time is in units of nanoseconds, however the current implementation
3333** is only capable of millisecond resolution so the six least significant
3334** digits in the time are meaningless. Future versions of SQLite
3335** might provide greater resolution on the profiler callback. Invoking
3336** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3337** profile callback.
3338*/
3339SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3340 void(*xTrace)(void*,const char*), void*);
3341SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3342 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3343
3344/*
3345** CAPI3REF: SQL Trace Event Codes
3346** KEYWORDS: SQLITE_TRACE
3347**
3348** These constants identify classes of events that can be monitored
3349** using the [sqlite3_trace_v2()] tracing logic. The M argument
3350** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3351** the following constants. ^The first argument to the trace callback
3352** is one of the following constants.
3353**
3354** New tracing constants may be added in future releases.
3355**
3356** ^A trace callback has four arguments: xCallback(T,C,P,X).
3357** ^The T argument is one of the integer type codes above.
3358** ^The C argument is a copy of the context pointer passed in as the
3359** fourth argument to [sqlite3_trace_v2()].
3360** The P and X arguments are pointers whose meanings depend on T.
3361**
3362** <dl>
3363** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3364** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3365** first begins running and possibly at other times during the
3366** execution of the prepared statement, such as at the start of each
3367** trigger subprogram. ^The P argument is a pointer to the
3368** [prepared statement]. ^The X argument is a pointer to a string which
3369** is the unexpanded SQL text of the prepared statement or an SQL comment
3370** that indicates the invocation of a trigger. ^The callback can compute
3371** the same text that would have been returned by the legacy [sqlite3_trace()]
3372** interface by using the X argument when X begins with "--" and invoking
3373** [sqlite3_expanded_sql(P)] otherwise.
3374**
3375** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3376** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3377** information as is provided by the [sqlite3_profile()] callback.
3378** ^The P argument is a pointer to the [prepared statement] and the
3379** X argument points to a 64-bit integer which is approximately
3380** the number of nanoseconds that the prepared statement took to run.
3381** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3382**
3383** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3384** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3385** statement generates a single row of result.
3386** ^The P argument is a pointer to the [prepared statement] and the
3387** X argument is unused.
3388**
3389** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3390** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3391** connection closes.
3392** ^The P argument is a pointer to the [database connection] object
3393** and the X argument is unused.
3394** </dl>
3395*/
3396#define SQLITE_TRACE_STMT 0x01
3397#define SQLITE_TRACE_PROFILE 0x02
3398#define SQLITE_TRACE_ROW 0x04
3399#define SQLITE_TRACE_CLOSE 0x08
3400
3401/*
3402** CAPI3REF: SQL Trace Hook
3403** METHOD: sqlite3
3404**
3405** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3406** function X against [database connection] D, using property mask M
3407** and context pointer P. ^If the X callback is
3408** NULL or if the M mask is zero, then tracing is disabled. The
3409** M argument should be the bitwise OR-ed combination of
3410** zero or more [SQLITE_TRACE] constants.
3411**
3412** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3413** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3414** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3415** database connection may have at most one trace callback.
3416**
3417** ^The X callback is invoked whenever any of the events identified by
3418** mask M occur. ^The integer return value from the callback is currently
3419** ignored, though this may change in future releases. Callback
3420** implementations should return zero to ensure future compatibility.
3421**
3422** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3423** ^The T argument is one of the [SQLITE_TRACE]
3424** constants to indicate why the callback was invoked.
3425** ^The C argument is a copy of the context pointer.
3426** The P and X arguments are pointers whose meanings depend on T.
3427**
3428** The sqlite3_trace_v2() interface is intended to replace the legacy
3429** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3430** are deprecated.
3431*/
3432SQLITE_API int sqlite3_trace_v2(
3433 sqlite3*,
3434 unsigned uMask,
3435 int(*xCallback)(unsigned,void*,void*,void*),
3436 void *pCtx
3437);
3438
3439/*
3440** CAPI3REF: Query Progress Callbacks
3441** METHOD: sqlite3
3442**
3443** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3444** function X to be invoked periodically during long running calls to
3445** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3446** database connection D. An example use for this
3447** interface is to keep a GUI updated during a large query.
3448**
3449** ^The parameter P is passed through as the only parameter to the
3450** callback function X. ^The parameter N is the approximate number of
3451** [virtual machine instructions] that are evaluated between successive
3452** invocations of the callback X. ^If N is less than one then the progress
3453** handler is disabled.
3454**
3455** ^Only a single progress handler may be defined at one time per
3456** [database connection]; setting a new progress handler cancels the
3457** old one. ^Setting parameter X to NULL disables the progress handler.
3458** ^The progress handler is also disabled by setting N to a value less
3459** than 1.
3460**
3461** ^If the progress callback returns non-zero, the operation is
3462** interrupted. This feature can be used to implement a
3463** "Cancel" button on a GUI progress dialog box.
3464**
3465** The progress handler callback must not do anything that will modify
3466** the database connection that invoked the progress handler.
3467** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3468** database connections for the meaning of "modify" in this paragraph.
3469**
3470** The progress handler callback would originally only be invoked from the
3471** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3472** and similar because those routines might force a reparse of the schema
3473** which involves running the bytecode engine. However, beginning with
3474** SQLite version 3.41.0, the progress handler callback might also be
3475** invoked directly from [sqlite3_prepare()] while analyzing and generating
3476** code for complex queries.
3477*/
3478SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3479
3480/*
3481** CAPI3REF: Opening A New Database Connection
3482** CONSTRUCTOR: sqlite3
3483**
3484** ^These routines open an SQLite database file as specified by the
3485** filename argument. ^The filename argument is interpreted as UTF-8 for
3486** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3487** order for sqlite3_open16(). ^(A [database connection] handle is usually
3488** returned in *ppDb, even if an error occurs. The only exception is that
3489** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3490** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3491** object.)^ ^(If the database is opened (and/or created) successfully, then
3492** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3493** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3494** an English language description of the error following a failure of any
3495** of the sqlite3_open() routines.
3496**
3497** ^The default encoding will be UTF-8 for databases created using
3498** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3499** created using sqlite3_open16() will be UTF-16 in the native byte order.
3500**
3501** Whether or not an error occurs when it is opened, resources
3502** associated with the [database connection] handle should be released by
3503** passing it to [sqlite3_close()] when it is no longer required.
3504**
3505** The sqlite3_open_v2() interface works like sqlite3_open()
3506** except that it accepts two additional parameters for additional control
3507** over the new database connection. ^(The flags parameter to
3508** sqlite3_open_v2() must include, at a minimum, one of the following
3509** three flag combinations:)^
3510**
3511** <dl>
3512** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3513** <dd>The database is opened in read-only mode. If the database does
3514** not already exist, an error is returned.</dd>)^
3515**
3516** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3517** <dd>The database is opened for reading and writing if possible, or
3518** reading only if the file is write protected by the operating
3519** system. In either case the database must already exist, otherwise
3520** an error is returned. For historical reasons, if opening in
3521** read-write mode fails due to OS-level permissions, an attempt is
3522** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3523** used to determine whether the database is actually
3524** read-write.</dd>)^
3525**
3526** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3527** <dd>The database is opened for reading and writing, and is created if
3528** it does not already exist. This is the behavior that is always used for
3529** sqlite3_open() and sqlite3_open16().</dd>)^
3530** </dl>
3531**
3532** In addition to the required flags, the following optional flags are
3533** also supported:
3534**
3535** <dl>
3536** ^(<dt>[SQLITE_OPEN_URI]</dt>
3537** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3538**
3539** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3540** <dd>The database will be opened as an in-memory database. The database
3541** is named by the "filename" argument for the purposes of cache-sharing,
3542** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3543** </dd>)^
3544**
3545** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3546** <dd>The new database connection will use the "multi-thread"
3547** [threading mode].)^ This means that separate threads are allowed
3548** to use SQLite at the same time, as long as each thread is using
3549** a different [database connection].
3550**
3551** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3552** <dd>The new database connection will use the "serialized"
3553** [threading mode].)^ This means the multiple threads can safely
3554** attempt to use the same database connection at the same time.
3555** (Mutexes will block any actual concurrency, but in this mode
3556** there is no harm in trying.)
3557**
3558** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3559** <dd>The database is opened [shared cache] enabled, overriding
3560** the default shared cache setting provided by
3561** [sqlite3_enable_shared_cache()].)^
3562** The [use of shared cache mode is discouraged] and hence shared cache
3563** capabilities may be omitted from many builds of SQLite. In such cases,
3564** this option is a no-op.
3565**
3566** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3567** <dd>The database is opened [shared cache] disabled, overriding
3568** the default shared cache setting provided by
3569** [sqlite3_enable_shared_cache()].)^
3570**
3571** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3572** <dd>The database connection comes up in "extended result code mode".
3573** In other words, the database behaves has if
3574** [sqlite3_extended_result_codes(db,1)] where called on the database
3575** connection as soon as the connection is created. In addition to setting
3576** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3577** to return an extended result code.</dd>
3578**
3579** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3580** <dd>The database filename is not allowed to contain a symbolic link</dd>
3581** </dl>)^
3582**
3583** If the 3rd parameter to sqlite3_open_v2() is not one of the
3584** required combinations shown above optionally combined with other
3585** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3586** then the behavior is undefined. Historic versions of SQLite
3587** have silently ignored surplus bits in the flags parameter to
3588** sqlite3_open_v2(), however that behavior might not be carried through
3589** into future versions of SQLite and so applications should not rely
3590** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3591** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3592** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3593** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3594** by sqlite3_open_v2().
3595**
3596** ^The fourth parameter to sqlite3_open_v2() is the name of the
3597** [sqlite3_vfs] object that defines the operating system interface that
3598** the new database connection should use. ^If the fourth parameter is
3599** a NULL pointer then the default [sqlite3_vfs] object is used.
3600**
3601** ^If the filename is ":memory:", then a private, temporary in-memory database
3602** is created for the connection. ^This in-memory database will vanish when
3603** the database connection is closed. Future versions of SQLite might
3604** make use of additional special filenames that begin with the ":" character.
3605** It is recommended that when a database filename actually does begin with
3606** a ":" character you should prefix the filename with a pathname such as
3607** "./" to avoid ambiguity.
3608**
3609** ^If the filename is an empty string, then a private, temporary
3610** on-disk database will be created. ^This private database will be
3611** automatically deleted as soon as the database connection is closed.
3612**
3613** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3614**
3615** ^If [URI filename] interpretation is enabled, and the filename argument
3616** begins with "file:", then the filename is interpreted as a URI. ^URI
3617** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3618** set in the third argument to sqlite3_open_v2(), or if it has
3619** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3620** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3621** URI filename interpretation is turned off
3622** by default, but future releases of SQLite might enable URI filename
3623** interpretation by default. See "[URI filenames]" for additional
3624** information.
3625**
3626** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3627** authority, then it must be either an empty string or the string
3628** "localhost". ^If the authority is not an empty string or "localhost", an
3629** error is returned to the caller. ^The fragment component of a URI, if
3630** present, is ignored.
3631**
3632** ^SQLite uses the path component of the URI as the name of the disk file
3633** which contains the database. ^If the path begins with a '/' character,
3634** then it is interpreted as an absolute path. ^If the path does not begin
3635** with a '/' (meaning that the authority section is omitted from the URI)
3636** then the path is interpreted as a relative path.
3637** ^(On windows, the first component of an absolute path
3638** is a drive specification (e.g. "C:").)^
3639**
3640** [[core URI query parameters]]
3641** The query component of a URI may contain parameters that are interpreted
3642** either by SQLite itself, or by a [VFS | custom VFS implementation].
3643** SQLite and its built-in [VFSes] interpret the
3644** following query parameters:
3645**
3646** <ul>
3647** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3648** a VFS object that provides the operating system interface that should
3649** be used to access the database file on disk. ^If this option is set to
3650** an empty string the default VFS object is used. ^Specifying an unknown
3651** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3652** present, then the VFS specified by the option takes precedence over
3653** the value passed as the fourth parameter to sqlite3_open_v2().
3654**
3655** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3656** "rwc", or "memory". Attempting to set it to any other value is
3657** an error)^.
3658** ^If "ro" is specified, then the database is opened for read-only
3659** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3660** third argument to sqlite3_open_v2(). ^If the mode option is set to
3661** "rw", then the database is opened for read-write (but not create)
3662** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3663** been set. ^Value "rwc" is equivalent to setting both
3664** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3665** set to "memory" then a pure [in-memory database] that never reads
3666** or writes from disk is used. ^It is an error to specify a value for
3667** the mode parameter that is less restrictive than that specified by
3668** the flags passed in the third parameter to sqlite3_open_v2().
3669**
3670** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3671** "private". ^Setting it to "shared" is equivalent to setting the
3672** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3673** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3674** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3675** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3676** a URI filename, its value overrides any behavior requested by setting
3677** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3678**
3679** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3680** [powersafe overwrite] property does or does not apply to the
3681** storage media on which the database file resides.
3682**
3683** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3684** which if set disables file locking in rollback journal modes. This
3685** is useful for accessing a database on a filesystem that does not
3686** support locking. Caution: Database corruption might result if two
3687** or more processes write to the same database and any one of those
3688** processes uses nolock=1.
3689**
3690** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3691** parameter that indicates that the database file is stored on
3692** read-only media. ^When immutable is set, SQLite assumes that the
3693** database file cannot be changed, even by a process with higher
3694** privilege, and so the database is opened read-only and all locking
3695** and change detection is disabled. Caution: Setting the immutable
3696** property on a database file that does in fact change can result
3697** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3698** See also: [SQLITE_IOCAP_IMMUTABLE].
3699**
3700** </ul>
3701**
3702** ^Specifying an unknown parameter in the query component of a URI is not an
3703** error. Future versions of SQLite might understand additional query
3704** parameters. See "[query parameters with special meaning to SQLite]" for
3705** additional information.
3706**
3707** [[URI filename examples]] <h3>URI filename examples</h3>
3708**
3709** <table border="1" align=center cellpadding=5>
3710** <tr><th> URI filenames <th> Results
3711** <tr><td> file:data.db <td>
3712** Open the file "data.db" in the current directory.
3713** <tr><td> file:/home/fred/data.db<br>
3714** file:///home/fred/data.db <br>
3715** file://localhost/home/fred/data.db <br> <td>
3716** Open the database file "/home/fred/data.db".
3717** <tr><td> file://darkstar/home/fred/data.db <td>
3718** An error. "darkstar" is not a recognized authority.
3719** <tr><td style="white-space:nowrap">
3720** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3721** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3722** C:. Note that the %20 escaping in this example is not strictly
3723** necessary - space characters can be used literally
3724** in URI filenames.
3725** <tr><td> file:data.db?mode=ro&cache=private <td>
3726** Open file "data.db" in the current directory for read-only access.
3727** Regardless of whether or not shared-cache mode is enabled by
3728** default, use a private cache.
3729** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3730** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3731** that uses dot-files in place of posix advisory locking.
3732** <tr><td> file:data.db?mode=readonly <td>
3733** An error. "readonly" is not a valid option for the "mode" parameter.
3734** Use "ro" instead: "file:data.db?mode=ro".
3735** </table>
3736**
3737** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3738** query components of a URI. A hexadecimal escape sequence consists of a
3739** percent sign - "%" - followed by exactly two hexadecimal digits
3740** specifying an octet value. ^Before the path or query components of a
3741** URI filename are interpreted, they are encoded using UTF-8 and all
3742** hexadecimal escape sequences replaced by a single byte containing the
3743** corresponding octet. If this process generates an invalid UTF-8 encoding,
3744** the results are undefined.
3745**
3746** <b>Note to Windows users:</b> The encoding used for the filename argument
3747** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3748** codepage is currently defined. Filenames containing international
3749** characters must be converted to UTF-8 prior to passing them into
3750** sqlite3_open() or sqlite3_open_v2().
3751**
3752** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3753** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3754** features that require the use of temporary files may fail.
3755**
3756** See also: [sqlite3_temp_directory]
3757*/
3758SQLITE_API int sqlite3_open(
3759 const char *filename, /* Database filename (UTF-8) */
3760 sqlite3 **ppDb /* OUT: SQLite db handle */
3761);
3762SQLITE_API int sqlite3_open16(
3763 const void *filename, /* Database filename (UTF-16) */
3764 sqlite3 **ppDb /* OUT: SQLite db handle */
3765);
3766SQLITE_API int sqlite3_open_v2(
3767 const char *filename, /* Database filename (UTF-8) */
3768 sqlite3 **ppDb, /* OUT: SQLite db handle */
3769 int flags, /* Flags */
3770 const char *zVfs /* Name of VFS module to use */
3771);
3772
3773/*
3774** CAPI3REF: Obtain Values For URI Parameters
3775**
3776** These are utility routines, useful to [VFS|custom VFS implementations],
3777** that check if a database file was a URI that contained a specific query
3778** parameter, and if so obtains the value of that query parameter.
3779**
3780** The first parameter to these interfaces (hereafter referred to
3781** as F) must be one of:
3782** <ul>
3783** <li> A database filename pointer created by the SQLite core and
3784** passed into the xOpen() method of a VFS implementation, or
3785** <li> A filename obtained from [sqlite3_db_filename()], or
3786** <li> A new filename constructed using [sqlite3_create_filename()].
3787** </ul>
3788** If the F parameter is not one of the above, then the behavior is
3789** undefined and probably undesirable. Older versions of SQLite were
3790** more tolerant of invalid F parameters than newer versions.
3791**
3792** If F is a suitable filename (as described in the previous paragraph)
3793** and if P is the name of the query parameter, then
3794** sqlite3_uri_parameter(F,P) returns the value of the P
3795** parameter if it exists or a NULL pointer if P does not appear as a
3796** query parameter on F. If P is a query parameter of F and it
3797** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3798** a pointer to an empty string.
3799**
3800** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3801** parameter and returns true (1) or false (0) according to the value
3802** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3803** value of query parameter P is one of "yes", "true", or "on" in any
3804** case or if the value begins with a non-zero number. The
3805** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3806** query parameter P is one of "no", "false", or "off" in any case or
3807** if the value begins with a numeric zero. If P is not a query
3808** parameter on F or if the value of P does not match any of the
3809** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3810**
3811** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3812** 64-bit signed integer and returns that integer, or D if P does not
3813** exist. If the value of P is something other than an integer, then
3814** zero is returned.
3815**
3816** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3817** the value) of the N-th query parameter for filename F, or a NULL
3818** pointer if N is less than zero or greater than the number of query
3819** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3820** the name of the first query parameter, 1 for the second parameter, and
3821** so forth.
3822**
3823** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3824** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3825** is not a database file pathname pointer that the SQLite core passed
3826** into the xOpen VFS method, then the behavior of this routine is undefined
3827** and probably undesirable.
3828**
3829** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3830** parameter can also be the name of a rollback journal file or WAL file
3831** in addition to the main database file. Prior to version 3.31.0, these
3832** routines would only work if F was the name of the main database file.
3833** When the F parameter is the name of the rollback journal or WAL file,
3834** it has access to all the same query parameters as were found on the
3835** main database file.
3836**
3837** See the [URI filename] documentation for additional information.
3838*/
3839SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
3840SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
3841SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
3842SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
3843
3844/*
3845** CAPI3REF: Translate filenames
3846**
3847** These routines are available to [VFS|custom VFS implementations] for
3848** translating filenames between the main database file, the journal file,
3849** and the WAL file.
3850**
3851** If F is the name of an sqlite database file, journal file, or WAL file
3852** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3853** returns the name of the corresponding database file.
3854**
3855** If F is the name of an sqlite database file, journal file, or WAL file
3856** passed by the SQLite core into the VFS, or if F is a database filename
3857** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3858** returns the name of the corresponding rollback journal file.
3859**
3860** If F is the name of an sqlite database file, journal file, or WAL file
3861** that was passed by the SQLite core into the VFS, or if F is a database
3862** filename obtained from [sqlite3_db_filename()], then
3863** sqlite3_filename_wal(F) returns the name of the corresponding
3864** WAL file.
3865**
3866** In all of the above, if F is not the name of a database, journal or WAL
3867** filename passed into the VFS from the SQLite core and F is not the
3868** return value from [sqlite3_db_filename()], then the result is
3869** undefined and is likely a memory access violation.
3870*/
3871SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
3872SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
3873SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
3874
3875/*
3876** CAPI3REF: Database File Corresponding To A Journal
3877**
3878** ^If X is the name of a rollback or WAL-mode journal file that is
3879** passed into the xOpen method of [sqlite3_vfs], then
3880** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3881** object that represents the main database file.
3882**
3883** This routine is intended for use in custom [VFS] implementations
3884** only. It is not a general-purpose interface.
3885** The argument sqlite3_file_object(X) must be a filename pointer that
3886** has been passed into [sqlite3_vfs].xOpen method where the
3887** flags parameter to xOpen contains one of the bits
3888** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3889** of this routine results in undefined and probably undesirable
3890** behavior.
3891*/
3892SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3893
3894/*
3895** CAPI3REF: Create and Destroy VFS Filenames
3896**
3897** These interfaces are provided for use by [VFS shim] implementations and
3898** are not useful outside of that context.
3899**
3900** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3901** database filename D with corresponding journal file J and WAL file W and
3902** with N URI parameters key/values pairs in the array P. The result from
3903** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3904** is safe to pass to routines like:
3905** <ul>
3906** <li> [sqlite3_uri_parameter()],
3907** <li> [sqlite3_uri_boolean()],
3908** <li> [sqlite3_uri_int64()],
3909** <li> [sqlite3_uri_key()],
3910** <li> [sqlite3_filename_database()],
3911** <li> [sqlite3_filename_journal()], or
3912** <li> [sqlite3_filename_wal()].
3913** </ul>
3914** If a memory allocation error occurs, sqlite3_create_filename() might
3915** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3916** must be released by a corresponding call to sqlite3_free_filename(Y).
3917**
3918** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3919** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3920** to a key and value for a query parameter. The P parameter may be a NULL
3921** pointer if N is zero. None of the 2*N pointers in the P array may be
3922** NULL pointers and key pointers should not be empty strings.
3923** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3924** be NULL pointers, though they can be empty strings.
3925**
3926** The sqlite3_free_filename(Y) routine releases a memory allocation
3927** previously obtained from sqlite3_create_filename(). Invoking
3928** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3929**
3930** If the Y parameter to sqlite3_free_filename(Y) is anything other
3931** than a NULL pointer or a pointer previously acquired from
3932** sqlite3_create_filename(), then bad things such as heap
3933** corruption or segfaults may occur. The value Y should not be
3934** used again after sqlite3_free_filename(Y) has been called. This means
3935** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3936** then the corresponding [sqlite3_module.xClose() method should also be
3937** invoked prior to calling sqlite3_free_filename(Y).
3938*/
3939SQLITE_API sqlite3_filename sqlite3_create_filename(
3940 const char *zDatabase,
3941 const char *zJournal,
3942 const char *zWal,
3943 int nParam,
3944 const char **azParam
3945);
3946SQLITE_API void sqlite3_free_filename(sqlite3_filename);
3947
3948/*
3949** CAPI3REF: Error Codes And Messages
3950** METHOD: sqlite3
3951**
3952** ^If the most recent sqlite3_* API call associated with
3953** [database connection] D failed, then the sqlite3_errcode(D) interface
3954** returns the numeric [result code] or [extended result code] for that
3955** API call.
3956** ^The sqlite3_extended_errcode()
3957** interface is the same except that it always returns the
3958** [extended result code] even when extended result codes are
3959** disabled.
3960**
3961** The values returned by sqlite3_errcode() and/or
3962** sqlite3_extended_errcode() might change with each API call.
3963** Except, there are some interfaces that are guaranteed to never
3964** change the value of the error code. The error-code preserving
3965** interfaces include the following:
3966**
3967** <ul>
3968** <li> sqlite3_errcode()
3969** <li> sqlite3_extended_errcode()
3970** <li> sqlite3_errmsg()
3971** <li> sqlite3_errmsg16()
3972** <li> sqlite3_error_offset()
3973** </ul>
3974**
3975** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3976** text that describes the error, as either UTF-8 or UTF-16 respectively,
3977** or NULL if no error message is available.
3978** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
3979** ^(Memory to hold the error message string is managed internally.
3980** The application does not need to worry about freeing the result.
3981** However, the error string might be overwritten or deallocated by
3982** subsequent calls to other SQLite interface functions.)^
3983**
3984** ^The sqlite3_errstr(E) interface returns the English-language text
3985** that describes the [result code] E, as UTF-8, or NULL if E is not an
3986** result code for which a text error message is available.
3987** ^(Memory to hold the error message string is managed internally
3988** and must not be freed by the application)^.
3989**
3990** ^If the most recent error references a specific token in the input
3991** SQL, the sqlite3_error_offset() interface returns the byte offset
3992** of the start of that token. ^The byte offset returned by
3993** sqlite3_error_offset() assumes that the input SQL is UTF8.
3994** ^If the most recent error does not reference a specific token in the input
3995** SQL, then the sqlite3_error_offset() function returns -1.
3996**
3997** When the serialized [threading mode] is in use, it might be the
3998** case that a second error occurs on a separate thread in between
3999** the time of the first error and the call to these interfaces.
4000** When that happens, the second error will be reported since these
4001** interfaces always report the most recent result. To avoid
4002** this, each thread can obtain exclusive use of the [database connection] D
4003** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4004** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4005** all calls to the interfaces listed here are completed.
4006**
4007** If an interface fails with SQLITE_MISUSE, that means the interface
4008** was invoked incorrectly by the application. In that case, the
4009** error code and message may or may not be set.
4010*/
4011SQLITE_API int sqlite3_errcode(sqlite3 *db);
4012SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4013SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4014SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4015SQLITE_API const char *sqlite3_errstr(int);
4016SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4017
4018/*
4019** CAPI3REF: Prepared Statement Object
4020** KEYWORDS: {prepared statement} {prepared statements}
4021**
4022** An instance of this object represents a single SQL statement that
4023** has been compiled into binary form and is ready to be evaluated.
4024**
4025** Think of each SQL statement as a separate computer program. The
4026** original SQL text is source code. A prepared statement object
4027** is the compiled object code. All SQL must be converted into a
4028** prepared statement before it can be run.
4029**
4030** The life-cycle of a prepared statement object usually goes like this:
4031**
4032** <ol>
4033** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4034** <li> Bind values to [parameters] using the sqlite3_bind_*()
4035** interfaces.
4036** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4037** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4038** to step 2. Do this zero or more times.
4039** <li> Destroy the object using [sqlite3_finalize()].
4040** </ol>
4041*/
4042typedef struct sqlite3_stmt sqlite3_stmt;
4043
4044/*
4045** CAPI3REF: Run-time Limits
4046** METHOD: sqlite3
4047**
4048** ^(This interface allows the size of various constructs to be limited
4049** on a connection by connection basis. The first parameter is the
4050** [database connection] whose limit is to be set or queried. The
4051** second parameter is one of the [limit categories] that define a
4052** class of constructs to be size limited. The third parameter is the
4053** new limit for that construct.)^
4054**
4055** ^If the new limit is a negative number, the limit is unchanged.
4056** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4057** [limits | hard upper bound]
4058** set at compile-time by a C preprocessor macro called
4059** [limits | SQLITE_MAX_<i>NAME</i>].
4060** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4061** ^Attempts to increase a limit above its hard upper bound are
4062** silently truncated to the hard upper bound.
4063**
4064** ^Regardless of whether or not the limit was changed, the
4065** [sqlite3_limit()] interface returns the prior value of the limit.
4066** ^Hence, to find the current value of a limit without changing it,
4067** simply invoke this interface with the third parameter set to -1.
4068**
4069** Run-time limits are intended for use in applications that manage
4070** both their own internal database and also databases that are controlled
4071** by untrusted external sources. An example application might be a
4072** web browser that has its own databases for storing history and
4073** separate databases controlled by JavaScript applications downloaded
4074** off the Internet. The internal databases can be given the
4075** large, default limits. Databases managed by external sources can
4076** be given much smaller limits designed to prevent a denial of service
4077** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4078** interface to further control untrusted SQL. The size of the database
4079** created by an untrusted script can be contained using the
4080** [max_page_count] [PRAGMA].
4081**
4082** New run-time limit categories may be added in future releases.
4083*/
4084SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4085
4086/*
4087** CAPI3REF: Run-Time Limit Categories
4088** KEYWORDS: {limit category} {*limit categories}
4089**
4090** These constants define various performance limits
4091** that can be lowered at run-time using [sqlite3_limit()].
4092** The synopsis of the meanings of the various limits is shown below.
4093** Additional information is available at [limits | Limits in SQLite].
4094**
4095** <dl>
4096** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4097** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4098**
4099** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4100** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4101**
4102** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4103** <dd>The maximum number of columns in a table definition or in the
4104** result set of a [SELECT] or the maximum number of columns in an index
4105** or in an ORDER BY or GROUP BY clause.</dd>)^
4106**
4107** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4108** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4109**
4110** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4111** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4112**
4113** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4114** <dd>The maximum number of instructions in a virtual machine program
4115** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4116** the equivalent tries to allocate space for more than this many opcodes
4117** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4118**
4119** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4120** <dd>The maximum number of arguments on a function.</dd>)^
4121**
4122** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4123** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4124**
4125** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4126** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4127** <dd>The maximum length of the pattern argument to the [LIKE] or
4128** [GLOB] operators.</dd>)^
4129**
4130** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4131** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4132** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4133**
4134** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4135** <dd>The maximum depth of recursion for triggers.</dd>)^
4136**
4137** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4138** <dd>The maximum number of auxiliary worker threads that a single
4139** [prepared statement] may start.</dd>)^
4140** </dl>
4141*/
4142#define SQLITE_LIMIT_LENGTH 0
4143#define SQLITE_LIMIT_SQL_LENGTH 1
4144#define SQLITE_LIMIT_COLUMN 2
4145#define SQLITE_LIMIT_EXPR_DEPTH 3
4146#define SQLITE_LIMIT_COMPOUND_SELECT 4
4147#define SQLITE_LIMIT_VDBE_OP 5
4148#define SQLITE_LIMIT_FUNCTION_ARG 6
4149#define SQLITE_LIMIT_ATTACHED 7
4150#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4151#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4152#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4153#define SQLITE_LIMIT_WORKER_THREADS 11
4154
4155/*
4156** CAPI3REF: Prepare Flags
4157**
4158** These constants define various flags that can be passed into
4159** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4160** [sqlite3_prepare16_v3()] interfaces.
4161**
4162** New flags may be added in future releases of SQLite.
4163**
4164** <dl>
4165** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4166** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4167** that the prepared statement will be retained for a long time and
4168** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4169** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4170** be used just once or at most a few times and then destroyed using
4171** [sqlite3_finalize()] relatively soon. The current implementation acts
4172** on this hint by avoiding the use of [lookaside memory] so as not to
4173** deplete the limited store of lookaside memory. Future versions of
4174** SQLite may act on this hint differently.
4175**
4176** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4177** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4178** to be required for any prepared statement that wanted to use the
4179** [sqlite3_normalized_sql()] interface. However, the
4180** [sqlite3_normalized_sql()] interface is now available to all
4181** prepared statements, regardless of whether or not they use this
4182** flag.
4183**
4184** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4185** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4186** to return an error (error code SQLITE_ERROR) if the statement uses
4187** any virtual tables.
4188** </dl>
4189*/
4190#define SQLITE_PREPARE_PERSISTENT 0x01
4191#define SQLITE_PREPARE_NORMALIZE 0x02
4192#define SQLITE_PREPARE_NO_VTAB 0x04
4193
4194/*
4195** CAPI3REF: Compiling An SQL Statement
4196** KEYWORDS: {SQL statement compiler}
4197** METHOD: sqlite3
4198** CONSTRUCTOR: sqlite3_stmt
4199**
4200** To execute an SQL statement, it must first be compiled into a byte-code
4201** program using one of these routines. Or, in other words, these routines
4202** are constructors for the [prepared statement] object.
4203**
4204** The preferred routine to use is [sqlite3_prepare_v2()]. The
4205** [sqlite3_prepare()] interface is legacy and should be avoided.
4206** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4207** for special purposes.
4208**
4209** The use of the UTF-8 interfaces is preferred, as SQLite currently
4210** does all parsing using UTF-8. The UTF-16 interfaces are provided
4211** as a convenience. The UTF-16 interfaces work by converting the
4212** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4213**
4214** The first argument, "db", is a [database connection] obtained from a
4215** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4216** [sqlite3_open16()]. The database connection must not have been closed.
4217**
4218** The second argument, "zSql", is the statement to be compiled, encoded
4219** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4220** and sqlite3_prepare_v3()
4221** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4222** and sqlite3_prepare16_v3() use UTF-16.
4223**
4224** ^If the nByte argument is negative, then zSql is read up to the
4225** first zero terminator. ^If nByte is positive, then it is the
4226** number of bytes read from zSql. ^If nByte is zero, then no prepared
4227** statement is generated.
4228** If the caller knows that the supplied string is nul-terminated, then
4229** there is a small performance advantage to passing an nByte parameter that
4230** is the number of bytes in the input string <i>including</i>
4231** the nul-terminator.
4232**
4233** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4234** past the end of the first SQL statement in zSql. These routines only
4235** compile the first statement in zSql, so *pzTail is left pointing to
4236** what remains uncompiled.
4237**
4238** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4239** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4240** to NULL. ^If the input text contains no SQL (if the input is an empty
4241** string or a comment) then *ppStmt is set to NULL.
4242** The calling procedure is responsible for deleting the compiled
4243** SQL statement using [sqlite3_finalize()] after it has finished with it.
4244** ppStmt may not be NULL.
4245**
4246** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4247** otherwise an [error code] is returned.
4248**
4249** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4250** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4251** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4252** are retained for backwards compatibility, but their use is discouraged.
4253** ^In the "vX" interfaces, the prepared statement
4254** that is returned (the [sqlite3_stmt] object) contains a copy of the
4255** original SQL text. This causes the [sqlite3_step()] interface to
4256** behave differently in three ways:
4257**
4258** <ol>
4259** <li>
4260** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4261** always used to do, [sqlite3_step()] will automatically recompile the SQL
4262** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4263** retries will occur before sqlite3_step() gives up and returns an error.
4264** </li>
4265**
4266** <li>
4267** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4268** [error codes] or [extended error codes]. ^The legacy behavior was that
4269** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4270** and the application would have to make a second call to [sqlite3_reset()]
4271** in order to find the underlying cause of the problem. With the "v2" prepare
4272** interfaces, the underlying reason for the error is returned immediately.
4273** </li>
4274**
4275** <li>
4276** ^If the specific value bound to a [parameter | host parameter] in the
4277** WHERE clause might influence the choice of query plan for a statement,
4278** then the statement will be automatically recompiled, as if there had been
4279** a schema change, on the first [sqlite3_step()] call following any change
4280** to the [sqlite3_bind_text | bindings] of that [parameter].
4281** ^The specific value of a WHERE-clause [parameter] might influence the
4282** choice of query plan if the parameter is the left-hand side of a [LIKE]
4283** or [GLOB] operator or if the parameter is compared to an indexed column
4284** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4285** </li>
4286** </ol>
4287**
4288** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4289** the extra prepFlags parameter, which is a bit array consisting of zero or
4290** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4291** sqlite3_prepare_v2() interface works exactly the same as
4292** sqlite3_prepare_v3() with a zero prepFlags parameter.
4293*/
4294SQLITE_API int sqlite3_prepare(
4295 sqlite3 *db, /* Database handle */
4296 const char *zSql, /* SQL statement, UTF-8 encoded */
4297 int nByte, /* Maximum length of zSql in bytes. */
4298 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4299 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4300);
4301SQLITE_API int sqlite3_prepare_v2(
4302 sqlite3 *db, /* Database handle */
4303 const char *zSql, /* SQL statement, UTF-8 encoded */
4304 int nByte, /* Maximum length of zSql in bytes. */
4305 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4306 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4307);
4308SQLITE_API int sqlite3_prepare_v3(
4309 sqlite3 *db, /* Database handle */
4310 const char *zSql, /* SQL statement, UTF-8 encoded */
4311 int nByte, /* Maximum length of zSql in bytes. */
4312 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4313 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4314 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4315);
4316SQLITE_API int sqlite3_prepare16(
4317 sqlite3 *db, /* Database handle */
4318 const void *zSql, /* SQL statement, UTF-16 encoded */
4319 int nByte, /* Maximum length of zSql in bytes. */
4320 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4321 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4322);
4323SQLITE_API int sqlite3_prepare16_v2(
4324 sqlite3 *db, /* Database handle */
4325 const void *zSql, /* SQL statement, UTF-16 encoded */
4326 int nByte, /* Maximum length of zSql in bytes. */
4327 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4328 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4329);
4330SQLITE_API int sqlite3_prepare16_v3(
4331 sqlite3 *db, /* Database handle */
4332 const void *zSql, /* SQL statement, UTF-16 encoded */
4333 int nByte, /* Maximum length of zSql in bytes. */
4334 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4335 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4336 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4337);
4338
4339/*
4340** CAPI3REF: Retrieving Statement SQL
4341** METHOD: sqlite3_stmt
4342**
4343** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4344** SQL text used to create [prepared statement] P if P was
4345** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4346** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4347** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4348** string containing the SQL text of prepared statement P with
4349** [bound parameters] expanded.
4350** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4351** string containing the normalized SQL text of prepared statement P. The
4352** semantics used to normalize a SQL statement are unspecified and subject
4353** to change. At a minimum, literal values will be replaced with suitable
4354** placeholders.
4355**
4356** ^(For example, if a prepared statement is created using the SQL
4357** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4358** and parameter :xyz is unbound, then sqlite3_sql() will return
4359** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4360** will return "SELECT 2345,NULL".)^
4361**
4362** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4363** is available to hold the result, or if the result would exceed the
4364** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4365**
4366** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4367** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4368** option causes sqlite3_expanded_sql() to always return NULL.
4369**
4370** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4371** are managed by SQLite and are automatically freed when the prepared
4372** statement is finalized.
4373** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4374** is obtained from [sqlite3_malloc()] and must be freed by the application
4375** by passing it to [sqlite3_free()].
4376**
4377** ^The sqlite3_normalized_sql() interface is only available if
4378** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4379*/
4380SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4381SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4382#ifdef SQLITE_ENABLE_NORMALIZE
4383SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4384#endif
4385
4386/*
4387** CAPI3REF: Determine If An SQL Statement Writes The Database
4388** METHOD: sqlite3_stmt
4389**
4390** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4391** and only if the [prepared statement] X makes no direct changes to
4392** the content of the database file.
4393**
4394** Note that [application-defined SQL functions] or
4395** [virtual tables] might change the database indirectly as a side effect.
4396** ^(For example, if an application defines a function "eval()" that
4397** calls [sqlite3_exec()], then the following SQL statement would
4398** change the database file through side-effects:
4399**
4400** <blockquote><pre>
4401** SELECT eval('DELETE FROM t1') FROM t2;
4402** </pre></blockquote>
4403**
4404** But because the [SELECT] statement does not change the database file
4405** directly, sqlite3_stmt_readonly() would still return true.)^
4406**
4407** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4408** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4409** since the statements themselves do not actually modify the database but
4410** rather they control the timing of when other statements modify the
4411** database. ^The [ATTACH] and [DETACH] statements also cause
4412** sqlite3_stmt_readonly() to return true since, while those statements
4413** change the configuration of a database connection, they do not make
4414** changes to the content of the database files on disk.
4415** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4416** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4417** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4418** sqlite3_stmt_readonly() returns false for those commands.
4419**
4420** ^This routine returns false if there is any possibility that the
4421** statement might change the database file. ^A false return does
4422** not guarantee that the statement will change the database file.
4423** ^For example, an UPDATE statement might have a WHERE clause that
4424** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4425** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4426** read-only no-op if the table already exists, but
4427** sqlite3_stmt_readonly() still returns false for such a statement.
4428**
4429** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4430** statement, then sqlite3_stmt_readonly(X) returns the same value as
4431** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4432*/
4433SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4434
4435/*
4436** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4437** METHOD: sqlite3_stmt
4438**
4439** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4440** prepared statement S is an EXPLAIN statement, or 2 if the
4441** statement S is an EXPLAIN QUERY PLAN.
4442** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4443** an ordinary statement or a NULL pointer.
4444*/
4445SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4446
4447/*
4448** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4449** METHOD: sqlite3_stmt
4450**
4451** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4452** setting for [prepared statement] S. If E is zero, then S becomes
4453** a normal prepared statement. If E is 1, then S behaves as if
4454** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4455** its SQL text began with "[EXPLAIN QUERY PLAN]".
4456**
4457** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4458** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4459** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4460**
4461** Because of the potential need to reprepare, a call to
4462** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4463** reprepared because it was created using [sqlite3_prepare()] instead of
4464** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4465** hence has no saved SQL text with which to reprepare.
4466**
4467** Changing the explain setting for a prepared statement does not change
4468** the original SQL text for the statement. Hence, if the SQL text originally
4469** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4470** is called to convert the statement into an ordinary statement, the EXPLAIN
4471** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4472** output, even though the statement now acts like a normal SQL statement.
4473**
4474** This routine returns SQLITE_OK if the explain mode is successfully
4475** changed, or an error code if the explain mode could not be changed.
4476** The explain mode cannot be changed while a statement is active.
4477** Hence, it is good practice to call [sqlite3_reset(S)]
4478** immediately prior to calling sqlite3_stmt_explain(S,E).
4479*/
4480SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4481
4482/*
4483** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4484** METHOD: sqlite3_stmt
4485**
4486** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4487** [prepared statement] S has been stepped at least once using
4488** [sqlite3_step(S)] but has neither run to completion (returned
4489** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4490** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4491** interface returns false if S is a NULL pointer. If S is not a
4492** NULL pointer and is not a pointer to a valid [prepared statement]
4493** object, then the behavior is undefined and probably undesirable.
4494**
4495** This interface can be used in combination [sqlite3_next_stmt()]
4496** to locate all prepared statements associated with a database
4497** connection that are in need of being reset. This can be used,
4498** for example, in diagnostic routines to search for prepared
4499** statements that are holding a transaction open.
4500*/
4501SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4502
4503/*
4504** CAPI3REF: Dynamically Typed Value Object
4505** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4506**
4507** SQLite uses the sqlite3_value object to represent all values
4508** that can be stored in a database table. SQLite uses dynamic typing
4509** for the values it stores. ^Values stored in sqlite3_value objects
4510** can be integers, floating point values, strings, BLOBs, or NULL.
4511**
4512** An sqlite3_value object may be either "protected" or "unprotected".
4513** Some interfaces require a protected sqlite3_value. Other interfaces
4514** will accept either a protected or an unprotected sqlite3_value.
4515** Every interface that accepts sqlite3_value arguments specifies
4516** whether or not it requires a protected sqlite3_value. The
4517** [sqlite3_value_dup()] interface can be used to construct a new
4518** protected sqlite3_value from an unprotected sqlite3_value.
4519**
4520** The terms "protected" and "unprotected" refer to whether or not
4521** a mutex is held. An internal mutex is held for a protected
4522** sqlite3_value object but no mutex is held for an unprotected
4523** sqlite3_value object. If SQLite is compiled to be single-threaded
4524** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4525** or if SQLite is run in one of reduced mutex modes
4526** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4527** then there is no distinction between protected and unprotected
4528** sqlite3_value objects and they can be used interchangeably. However,
4529** for maximum code portability it is recommended that applications
4530** still make the distinction between protected and unprotected
4531** sqlite3_value objects even when not strictly required.
4532**
4533** ^The sqlite3_value objects that are passed as parameters into the
4534** implementation of [application-defined SQL functions] are protected.
4535** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4536** are protected.
4537** ^The sqlite3_value object returned by
4538** [sqlite3_column_value()] is unprotected.
4539** Unprotected sqlite3_value objects may only be used as arguments
4540** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4541** [sqlite3_value_dup()].
4542** The [sqlite3_value_blob | sqlite3_value_type()] family of
4543** interfaces require protected sqlite3_value objects.
4544*/
4545typedef struct sqlite3_value sqlite3_value;
4546
4547/*
4548** CAPI3REF: SQL Function Context Object
4549**
4550** The context in which an SQL function executes is stored in an
4551** sqlite3_context object. ^A pointer to an sqlite3_context object
4552** is always first parameter to [application-defined SQL functions].
4553** The application-defined SQL function implementation will pass this
4554** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4555** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4556** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4557** and/or [sqlite3_set_auxdata()].
4558*/
4559typedef struct sqlite3_context sqlite3_context;
4560
4561/*
4562** CAPI3REF: Binding Values To Prepared Statements
4563** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4564** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4565** METHOD: sqlite3_stmt
4566**
4567** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4568** literals may be replaced by a [parameter] that matches one of following
4569** templates:
4570**
4571** <ul>
4572** <li> ?
4573** <li> ?NNN
4574** <li> :VVV
4575** <li> @VVV
4576** <li> $VVV
4577** </ul>
4578**
4579** In the templates above, NNN represents an integer literal,
4580** and VVV represents an alphanumeric identifier.)^ ^The values of these
4581** parameters (also called "host parameter names" or "SQL parameters")
4582** can be set using the sqlite3_bind_*() routines defined here.
4583**
4584** ^The first argument to the sqlite3_bind_*() routines is always
4585** a pointer to the [sqlite3_stmt] object returned from
4586** [sqlite3_prepare_v2()] or its variants.
4587**
4588** ^The second argument is the index of the SQL parameter to be set.
4589** ^The leftmost SQL parameter has an index of 1. ^When the same named
4590** SQL parameter is used more than once, second and subsequent
4591** occurrences have the same index as the first occurrence.
4592** ^The index for named parameters can be looked up using the
4593** [sqlite3_bind_parameter_index()] API if desired. ^The index
4594** for "?NNN" parameters is the value of NNN.
4595** ^The NNN value must be between 1 and the [sqlite3_limit()]
4596** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4597**
4598** ^The third argument is the value to bind to the parameter.
4599** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4600** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4601** is ignored and the end result is the same as sqlite3_bind_null().
4602** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4603** it should be a pointer to well-formed UTF8 text.
4604** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4605** it should be a pointer to well-formed UTF16 text.
4606** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4607** it should be a pointer to a well-formed unicode string that is
4608** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4609** otherwise.
4610**
4611** [[byte-order determination rules]] ^The byte-order of
4612** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4613** found in first character, which is removed, or in the absence of a BOM
4614** the byte order is the native byte order of the host
4615** machine for sqlite3_bind_text16() or the byte order specified in
4616** the 6th parameter for sqlite3_bind_text64().)^
4617** ^If UTF16 input text contains invalid unicode
4618** characters, then SQLite might change those invalid characters
4619** into the unicode replacement character: U+FFFD.
4620**
4621** ^(In those routines that have a fourth argument, its value is the
4622** number of bytes in the parameter. To be clear: the value is the
4623** number of <u>bytes</u> in the value, not the number of characters.)^
4624** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4625** is negative, then the length of the string is
4626** the number of bytes up to the first zero terminator.
4627** If the fourth parameter to sqlite3_bind_blob() is negative, then
4628** the behavior is undefined.
4629** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4630** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4631** that parameter must be the byte offset
4632** where the NUL terminator would occur assuming the string were NUL
4633** terminated. If any NUL characters occurs at byte offsets less than
4634** the value of the fourth parameter then the resulting string value will
4635** contain embedded NULs. The result of expressions involving strings
4636** with embedded NULs is undefined.
4637**
4638** ^The fifth argument to the BLOB and string binding interfaces controls
4639** or indicates the lifetime of the object referenced by the third parameter.
4640** These three options exist:
4641** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4642** with it may be passed. ^It is called to dispose of the BLOB or string even
4643** if the call to the bind API fails, except the destructor is not called if
4644** the third parameter is a NULL pointer or the fourth parameter is negative.
4645** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4646** the application remains responsible for disposing of the object. ^In this
4647** case, the object and the provided pointer to it must remain valid until
4648** either the prepared statement is finalized or the same SQL parameter is
4649** bound to something else, whichever occurs sooner.
4650** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4651** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4652** object and pointer to it must remain valid until then. ^SQLite will then
4653** manage the lifetime of its private copy.
4654**
4655** ^The sixth argument to sqlite3_bind_text64() must be one of
4656** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4657** to specify the encoding of the text in the third parameter. If
4658** the sixth argument to sqlite3_bind_text64() is not one of the
4659** allowed values shown above, or if the text encoding is different
4660** from the encoding specified by the sixth parameter, then the behavior
4661** is undefined.
4662**
4663** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4664** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4665** (just an integer to hold its size) while it is being processed.
4666** Zeroblobs are intended to serve as placeholders for BLOBs whose
4667** content is later written using
4668** [sqlite3_blob_open | incremental BLOB I/O] routines.
4669** ^A negative value for the zeroblob results in a zero-length BLOB.
4670**
4671** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4672** [prepared statement] S to have an SQL value of NULL, but to also be
4673** associated with the pointer P of type T. ^D is either a NULL pointer or
4674** a pointer to a destructor function for P. ^SQLite will invoke the
4675** destructor D with a single argument of P when it is finished using
4676** P. The T parameter should be a static string, preferably a string
4677** literal. The sqlite3_bind_pointer() routine is part of the
4678** [pointer passing interface] added for SQLite 3.20.0.
4679**
4680** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4681** for the [prepared statement] or with a prepared statement for which
4682** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4683** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4684** routine is passed a [prepared statement] that has been finalized, the
4685** result is undefined and probably harmful.
4686**
4687** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4688** ^Unbound parameters are interpreted as NULL.
4689**
4690** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4691** [error code] if anything goes wrong.
4692** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4693** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4694** [SQLITE_MAX_LENGTH].
4695** ^[SQLITE_RANGE] is returned if the parameter
4696** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4697**
4698** See also: [sqlite3_bind_parameter_count()],
4699** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4700*/
4701SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4702SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4703 void(*)(void*));
4704SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4705SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4706SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4707SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4708SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4709SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4710SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4711 void(*)(void*), unsigned char encoding);
4712SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4713SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4714SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4715SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4716
4717/*
4718** CAPI3REF: Number Of SQL Parameters
4719** METHOD: sqlite3_stmt
4720**
4721** ^This routine can be used to find the number of [SQL parameters]
4722** in a [prepared statement]. SQL parameters are tokens of the
4723** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4724** placeholders for values that are [sqlite3_bind_blob | bound]
4725** to the parameters at a later time.
4726**
4727** ^(This routine actually returns the index of the largest (rightmost)
4728** parameter. For all forms except ?NNN, this will correspond to the
4729** number of unique parameters. If parameters of the ?NNN form are used,
4730** there may be gaps in the list.)^
4731**
4732** See also: [sqlite3_bind_blob|sqlite3_bind()],
4733** [sqlite3_bind_parameter_name()], and
4734** [sqlite3_bind_parameter_index()].
4735*/
4736SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4737
4738/*
4739** CAPI3REF: Name Of A Host Parameter
4740** METHOD: sqlite3_stmt
4741**
4742** ^The sqlite3_bind_parameter_name(P,N) interface returns
4743** the name of the N-th [SQL parameter] in the [prepared statement] P.
4744** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4745** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4746** respectively.
4747** In other words, the initial ":" or "$" or "@" or "?"
4748** is included as part of the name.)^
4749** ^Parameters of the form "?" without a following integer have no name
4750** and are referred to as "nameless" or "anonymous parameters".
4751**
4752** ^The first host parameter has an index of 1, not 0.
4753**
4754** ^If the value N is out of range or if the N-th parameter is
4755** nameless, then NULL is returned. ^The returned string is
4756** always in UTF-8 encoding even if the named parameter was
4757** originally specified as UTF-16 in [sqlite3_prepare16()],
4758** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4759**
4760** See also: [sqlite3_bind_blob|sqlite3_bind()],
4761** [sqlite3_bind_parameter_count()], and
4762** [sqlite3_bind_parameter_index()].
4763*/
4764SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4765
4766/*
4767** CAPI3REF: Index Of A Parameter With A Given Name
4768** METHOD: sqlite3_stmt
4769**
4770** ^Return the index of an SQL parameter given its name. ^The
4771** index value returned is suitable for use as the second
4772** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4773** is returned if no matching parameter is found. ^The parameter
4774** name must be given in UTF-8 even if the original statement
4775** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4776** [sqlite3_prepare16_v3()].
4777**
4778** See also: [sqlite3_bind_blob|sqlite3_bind()],
4779** [sqlite3_bind_parameter_count()], and
4780** [sqlite3_bind_parameter_name()].
4781*/
4782SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4783
4784/*
4785** CAPI3REF: Reset All Bindings On A Prepared Statement
4786** METHOD: sqlite3_stmt
4787**
4788** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4789** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4790** ^Use this routine to reset all host parameters to NULL.
4791*/
4792SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4793
4794/*
4795** CAPI3REF: Number Of Columns In A Result Set
4796** METHOD: sqlite3_stmt
4797**
4798** ^Return the number of columns in the result set returned by the
4799** [prepared statement]. ^If this routine returns 0, that means the
4800** [prepared statement] returns no data (for example an [UPDATE]).
4801** ^However, just because this routine returns a positive number does not
4802** mean that one or more rows of data will be returned. ^A SELECT statement
4803** will always have a positive sqlite3_column_count() but depending on the
4804** WHERE clause constraints and the table content, it might return no rows.
4805**
4806** See also: [sqlite3_data_count()]
4807*/
4808SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4809
4810/*
4811** CAPI3REF: Column Names In A Result Set
4812** METHOD: sqlite3_stmt
4813**
4814** ^These routines return the name assigned to a particular column
4815** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4816** interface returns a pointer to a zero-terminated UTF-8 string
4817** and sqlite3_column_name16() returns a pointer to a zero-terminated
4818** UTF-16 string. ^The first parameter is the [prepared statement]
4819** that implements the [SELECT] statement. ^The second parameter is the
4820** column number. ^The leftmost column is number 0.
4821**
4822** ^The returned string pointer is valid until either the [prepared statement]
4823** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4824** reprepared by the first call to [sqlite3_step()] for a particular run
4825** or until the next call to
4826** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4827**
4828** ^If sqlite3_malloc() fails during the processing of either routine
4829** (for example during a conversion from UTF-8 to UTF-16) then a
4830** NULL pointer is returned.
4831**
4832** ^The name of a result column is the value of the "AS" clause for
4833** that column, if there is an AS clause. If there is no AS clause
4834** then the name of the column is unspecified and may change from
4835** one release of SQLite to the next.
4836*/
4837SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4838SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4839
4840/*
4841** CAPI3REF: Source Of Data In A Query Result
4842** METHOD: sqlite3_stmt
4843**
4844** ^These routines provide a means to determine the database, table, and
4845** table column that is the origin of a particular result column in
4846** [SELECT] statement.
4847** ^The name of the database or table or column can be returned as
4848** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4849** the database name, the _table_ routines return the table name, and
4850** the origin_ routines return the column name.
4851** ^The returned string is valid until the [prepared statement] is destroyed
4852** using [sqlite3_finalize()] or until the statement is automatically
4853** reprepared by the first call to [sqlite3_step()] for a particular run
4854** or until the same information is requested
4855** again in a different encoding.
4856**
4857** ^The names returned are the original un-aliased names of the
4858** database, table, and column.
4859**
4860** ^The first argument to these interfaces is a [prepared statement].
4861** ^These functions return information about the Nth result column returned by
4862** the statement, where N is the second function argument.
4863** ^The left-most column is column 0 for these routines.
4864**
4865** ^If the Nth column returned by the statement is an expression or
4866** subquery and is not a column value, then all of these functions return
4867** NULL. ^These routines might also return NULL if a memory allocation error
4868** occurs. ^Otherwise, they return the name of the attached database, table,
4869** or column that query result column was extracted from.
4870**
4871** ^As with all other SQLite APIs, those whose names end with "16" return
4872** UTF-16 encoded strings and the other functions return UTF-8.
4873**
4874** ^These APIs are only available if the library was compiled with the
4875** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4876**
4877** If two or more threads call one or more
4878** [sqlite3_column_database_name | column metadata interfaces]
4879** for the same [prepared statement] and result column
4880** at the same time then the results are undefined.
4881*/
4882SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4883SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4884SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4885SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4886SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4887SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4888
4889/*
4890** CAPI3REF: Declared Datatype Of A Query Result
4891** METHOD: sqlite3_stmt
4892**
4893** ^(The first parameter is a [prepared statement].
4894** If this statement is a [SELECT] statement and the Nth column of the
4895** returned result set of that [SELECT] is a table column (not an
4896** expression or subquery) then the declared type of the table
4897** column is returned.)^ ^If the Nth column of the result set is an
4898** expression or subquery, then a NULL pointer is returned.
4899** ^The returned string is always UTF-8 encoded.
4900**
4901** ^(For example, given the database schema:
4902**
4903** CREATE TABLE t1(c1 VARIANT);
4904**
4905** and the following statement to be compiled:
4906**
4907** SELECT c1 + 1, c1 FROM t1;
4908**
4909** this routine would return the string "VARIANT" for the second result
4910** column (i==1), and a NULL pointer for the first result column (i==0).)^
4911**
4912** ^SQLite uses dynamic run-time typing. ^So just because a column
4913** is declared to contain a particular type does not mean that the
4914** data stored in that column is of the declared type. SQLite is
4915** strongly typed, but the typing is dynamic not static. ^Type
4916** is associated with individual values, not with the containers
4917** used to hold those values.
4918*/
4919SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4920SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4921
4922/*
4923** CAPI3REF: Evaluate An SQL Statement
4924** METHOD: sqlite3_stmt
4925**
4926** After a [prepared statement] has been prepared using any of
4927** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4928** or [sqlite3_prepare16_v3()] or one of the legacy
4929** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4930** must be called one or more times to evaluate the statement.
4931**
4932** The details of the behavior of the sqlite3_step() interface depend
4933** on whether the statement was prepared using the newer "vX" interfaces
4934** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4935** [sqlite3_prepare16_v2()] or the older legacy
4936** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4937** new "vX" interface is recommended for new applications but the legacy
4938** interface will continue to be supported.
4939**
4940** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4941** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4942** ^With the "v2" interface, any of the other [result codes] or
4943** [extended result codes] might be returned as well.
4944**
4945** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4946** database locks it needs to do its job. ^If the statement is a [COMMIT]
4947** or occurs outside of an explicit transaction, then you can retry the
4948** statement. If the statement is not a [COMMIT] and occurs within an
4949** explicit transaction then you should rollback the transaction before
4950** continuing.
4951**
4952** ^[SQLITE_DONE] means that the statement has finished executing
4953** successfully. sqlite3_step() should not be called again on this virtual
4954** machine without first calling [sqlite3_reset()] to reset the virtual
4955** machine back to its initial state.
4956**
4957** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4958** is returned each time a new row of data is ready for processing by the
4959** caller. The values may be accessed using the [column access functions].
4960** sqlite3_step() is called again to retrieve the next row of data.
4961**
4962** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4963** violation) has occurred. sqlite3_step() should not be called again on
4964** the VM. More information may be found by calling [sqlite3_errmsg()].
4965** ^With the legacy interface, a more specific error code (for example,
4966** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4967** can be obtained by calling [sqlite3_reset()] on the
4968** [prepared statement]. ^In the "v2" interface,
4969** the more specific error code is returned directly by sqlite3_step().
4970**
4971** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4972** Perhaps it was called on a [prepared statement] that has
4973** already been [sqlite3_finalize | finalized] or on one that had
4974** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4975** be the case that the same database connection is being used by two or
4976** more threads at the same moment in time.
4977**
4978** For all versions of SQLite up to and including 3.6.23.1, a call to
4979** [sqlite3_reset()] was required after sqlite3_step() returned anything
4980** other than [SQLITE_ROW] before any subsequent invocation of
4981** sqlite3_step(). Failure to reset the prepared statement using
4982** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4983** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4984** sqlite3_step() began
4985** calling [sqlite3_reset()] automatically in this circumstance rather
4986** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4987** break because any application that ever receives an SQLITE_MISUSE error
4988** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4989** can be used to restore the legacy behavior.
4990**
4991** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4992** API always returns a generic error code, [SQLITE_ERROR], following any
4993** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4994** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4995** specific [error codes] that better describes the error.
4996** We admit that this is a goofy design. The problem has been fixed
4997** with the "v2" interface. If you prepare all of your SQL statements
4998** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4999** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5000** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5001** then the more specific [error codes] are returned directly
5002** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5003*/
5004SQLITE_API int sqlite3_step(sqlite3_stmt*);
5005
5006/*
5007** CAPI3REF: Number of columns in a result set
5008** METHOD: sqlite3_stmt
5009**
5010** ^The sqlite3_data_count(P) interface returns the number of columns in the
5011** current row of the result set of [prepared statement] P.
5012** ^If prepared statement P does not have results ready to return
5013** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5014** interfaces) then sqlite3_data_count(P) returns 0.
5015** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5016** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5017** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5018** will return non-zero if previous call to [sqlite3_step](P) returned
5019** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5020** where it always returns zero since each step of that multi-step
5021** pragma returns 0 columns of data.
5022**
5023** See also: [sqlite3_column_count()]
5024*/
5025SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5026
5027/*
5028** CAPI3REF: Fundamental Datatypes
5029** KEYWORDS: SQLITE_TEXT
5030**
5031** ^(Every value in SQLite has one of five fundamental datatypes:
5032**
5033** <ul>
5034** <li> 64-bit signed integer
5035** <li> 64-bit IEEE floating point number
5036** <li> string
5037** <li> BLOB
5038** <li> NULL
5039** </ul>)^
5040**
5041** These constants are codes for each of those types.
5042**
5043** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5044** for a completely different meaning. Software that links against both
5045** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5046** SQLITE_TEXT.
5047*/
5048#define SQLITE_INTEGER 1
5049#define SQLITE_FLOAT 2
5050#define SQLITE_BLOB 4
5051#define SQLITE_NULL 5
5052#ifdef SQLITE_TEXT
5053# undef SQLITE_TEXT
5054#else
5055# define SQLITE_TEXT 3
5056#endif
5057#define SQLITE3_TEXT 3
5058
5059/*
5060** CAPI3REF: Result Values From A Query
5061** KEYWORDS: {column access functions}
5062** METHOD: sqlite3_stmt
5063**
5064** <b>Summary:</b>
5065** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5066** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5067** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5068** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5069** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5070** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5071** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5072** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5073** [sqlite3_value|unprotected sqlite3_value] object.
5074** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5075** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5076** or a UTF-8 TEXT result in bytes
5077** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5078** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5079** TEXT in bytes
5080** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5081** datatype of the result
5082** </table></blockquote>
5083**
5084** <b>Details:</b>
5085**
5086** ^These routines return information about a single column of the current
5087** result row of a query. ^In every case the first argument is a pointer
5088** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5089** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5090** and the second argument is the index of the column for which information
5091** should be returned. ^The leftmost column of the result set has the index 0.
5092** ^The number of columns in the result can be determined using
5093** [sqlite3_column_count()].
5094**
5095** If the SQL statement does not currently point to a valid row, or if the
5096** column index is out of range, the result is undefined.
5097** These routines may only be called when the most recent call to
5098** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5099** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5100** If any of these routines are called after [sqlite3_reset()] or
5101** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5102** something other than [SQLITE_ROW], the results are undefined.
5103** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5104** are called from a different thread while any of these routines
5105** are pending, then the results are undefined.
5106**
5107** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5108** each return the value of a result column in a specific data format. If
5109** the result column is not initially in the requested format (for example,
5110** if the query returns an integer but the sqlite3_column_text() interface
5111** is used to extract the value) then an automatic type conversion is performed.
5112**
5113** ^The sqlite3_column_type() routine returns the
5114** [SQLITE_INTEGER | datatype code] for the initial data type
5115** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5116** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5117** The return value of sqlite3_column_type() can be used to decide which
5118** of the first six interface should be used to extract the column value.
5119** The value returned by sqlite3_column_type() is only meaningful if no
5120** automatic type conversions have occurred for the value in question.
5121** After a type conversion, the result of calling sqlite3_column_type()
5122** is undefined, though harmless. Future
5123** versions of SQLite may change the behavior of sqlite3_column_type()
5124** following a type conversion.
5125**
5126** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5127** or sqlite3_column_bytes16() interfaces can be used to determine the size
5128** of that BLOB or string.
5129**
5130** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5131** routine returns the number of bytes in that BLOB or string.
5132** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5133** the string to UTF-8 and then returns the number of bytes.
5134** ^If the result is a numeric value then sqlite3_column_bytes() uses
5135** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5136** the number of bytes in that string.
5137** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5138**
5139** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5140** routine returns the number of bytes in that BLOB or string.
5141** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5142** the string to UTF-16 and then returns the number of bytes.
5143** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5144** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5145** the number of bytes in that string.
5146** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5147**
5148** ^The values returned by [sqlite3_column_bytes()] and
5149** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5150** of the string. ^For clarity: the values returned by
5151** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5152** bytes in the string, not the number of characters.
5153**
5154** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5155** even empty strings, are always zero-terminated. ^The return
5156** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5157**
5158** ^Strings returned by sqlite3_column_text16() always have the endianness
5159** which is native to the platform, regardless of the text encoding set
5160** for the database.
5161**
5162** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5163** [unprotected sqlite3_value] object. In a multithreaded environment,
5164** an unprotected sqlite3_value object may only be used safely with
5165** [sqlite3_bind_value()] and [sqlite3_result_value()].
5166** If the [unprotected sqlite3_value] object returned by
5167** [sqlite3_column_value()] is used in any other way, including calls
5168** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5169** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5170** Hence, the sqlite3_column_value() interface
5171** is normally only useful within the implementation of
5172** [application-defined SQL functions] or [virtual tables], not within
5173** top-level application code.
5174**
5175** These routines may attempt to convert the datatype of the result.
5176** ^For example, if the internal representation is FLOAT and a text result
5177** is requested, [sqlite3_snprintf()] is used internally to perform the
5178** conversion automatically. ^(The following table details the conversions
5179** that are applied:
5180**
5181** <blockquote>
5182** <table border="1">
5183** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5184**
5185** <tr><td> NULL <td> INTEGER <td> Result is 0
5186** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5187** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5188** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5189** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5190** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5191** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5192** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5193** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5194** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5195** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5196** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5197** <tr><td> TEXT <td> BLOB <td> No change
5198** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5199** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5200** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5201** </table>
5202** </blockquote>)^
5203**
5204** Note that when type conversions occur, pointers returned by prior
5205** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5206** sqlite3_column_text16() may be invalidated.
5207** Type conversions and pointer invalidations might occur
5208** in the following cases:
5209**
5210** <ul>
5211** <li> The initial content is a BLOB and sqlite3_column_text() or
5212** sqlite3_column_text16() is called. A zero-terminator might
5213** need to be added to the string.</li>
5214** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5215** sqlite3_column_text16() is called. The content must be converted
5216** to UTF-16.</li>
5217** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5218** sqlite3_column_text() is called. The content must be converted
5219** to UTF-8.</li>
5220** </ul>
5221**
5222** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5223** not invalidate a prior pointer, though of course the content of the buffer
5224** that the prior pointer references will have been modified. Other kinds
5225** of conversion are done in place when it is possible, but sometimes they
5226** are not possible and in those cases prior pointers are invalidated.
5227**
5228** The safest policy is to invoke these routines
5229** in one of the following ways:
5230**
5231** <ul>
5232** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5233** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5234** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5235** </ul>
5236**
5237** In other words, you should call sqlite3_column_text(),
5238** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5239** into the desired format, then invoke sqlite3_column_bytes() or
5240** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5241** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5242** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5243** with calls to sqlite3_column_bytes().
5244**
5245** ^The pointers returned are valid until a type conversion occurs as
5246** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5247** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5248** and BLOBs is freed automatically. Do not pass the pointers returned
5249** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5250** [sqlite3_free()].
5251**
5252** As long as the input parameters are correct, these routines will only
5253** fail if an out-of-memory error occurs during a format conversion.
5254** Only the following subset of interfaces are subject to out-of-memory
5255** errors:
5256**
5257** <ul>
5258** <li> sqlite3_column_blob()
5259** <li> sqlite3_column_text()
5260** <li> sqlite3_column_text16()
5261** <li> sqlite3_column_bytes()
5262** <li> sqlite3_column_bytes16()
5263** </ul>
5264**
5265** If an out-of-memory error occurs, then the return value from these
5266** routines is the same as if the column had contained an SQL NULL value.
5267** Valid SQL NULL returns can be distinguished from out-of-memory errors
5268** by invoking the [sqlite3_errcode()] immediately after the suspect
5269** return value is obtained and before any
5270** other SQLite interface is called on the same [database connection].
5271*/
5272SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5273SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5274SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5275SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5276SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5277SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5278SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5279SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5280SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5281SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5282
5283/*
5284** CAPI3REF: Destroy A Prepared Statement Object
5285** DESTRUCTOR: sqlite3_stmt
5286**
5287** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5288** ^If the most recent evaluation of the statement encountered no errors
5289** or if the statement is never been evaluated, then sqlite3_finalize() returns
5290** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5291** sqlite3_finalize(S) returns the appropriate [error code] or
5292** [extended error code].
5293**
5294** ^The sqlite3_finalize(S) routine can be called at any point during
5295** the life cycle of [prepared statement] S:
5296** before statement S is ever evaluated, after
5297** one or more calls to [sqlite3_reset()], or after any call
5298** to [sqlite3_step()] regardless of whether or not the statement has
5299** completed execution.
5300**
5301** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5302**
5303** The application must finalize every [prepared statement] in order to avoid
5304** resource leaks. It is a grievous error for the application to try to use
5305** a prepared statement after it has been finalized. Any use of a prepared
5306** statement after it has been finalized can result in undefined and
5307** undesirable behavior such as segfaults and heap corruption.
5308*/
5309SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5310
5311/*
5312** CAPI3REF: Reset A Prepared Statement Object
5313** METHOD: sqlite3_stmt
5314**
5315** The sqlite3_reset() function is called to reset a [prepared statement]
5316** object back to its initial state, ready to be re-executed.
5317** ^Any SQL statement variables that had values bound to them using
5318** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5319** Use [sqlite3_clear_bindings()] to reset the bindings.
5320**
5321** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5322** back to the beginning of its program.
5323**
5324** ^The return code from [sqlite3_reset(S)] indicates whether or not
5325** the previous evaluation of prepared statement S completed successfully.
5326** ^If [sqlite3_step(S)] has never before been called on S or if
5327** [sqlite3_step(S)] has not been called since the previous call
5328** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5329** [SQLITE_OK].
5330**
5331** ^If the most recent call to [sqlite3_step(S)] for the
5332** [prepared statement] S indicated an error, then
5333** [sqlite3_reset(S)] returns an appropriate [error code].
5334** ^The [sqlite3_reset(S)] interface might also return an [error code]
5335** if there were no prior errors but the process of resetting
5336** the prepared statement caused a new error. ^For example, if an
5337** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5338** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5339** the overall statement might still fail and the [sqlite3_reset(S)] call
5340** might return SQLITE_BUSY if locking constraints prevent the
5341** database change from committing. Therefore, it is important that
5342** applications check the return code from [sqlite3_reset(S)] even if
5343** no prior call to [sqlite3_step(S)] indicated a problem.
5344**
5345** ^The [sqlite3_reset(S)] interface does not change the values
5346** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5347*/
5348SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5349
5350
5351/*
5352** CAPI3REF: Create Or Redefine SQL Functions
5353** KEYWORDS: {function creation routines}
5354** METHOD: sqlite3
5355**
5356** ^These functions (collectively known as "function creation routines")
5357** are used to add SQL functions or aggregates or to redefine the behavior
5358** of existing SQL functions or aggregates. The only differences between
5359** the three "sqlite3_create_function*" routines are the text encoding
5360** expected for the second parameter (the name of the function being
5361** created) and the presence or absence of a destructor callback for
5362** the application data pointer. Function sqlite3_create_window_function()
5363** is similar, but allows the user to supply the extra callback functions
5364** needed by [aggregate window functions].
5365**
5366** ^The first parameter is the [database connection] to which the SQL
5367** function is to be added. ^If an application uses more than one database
5368** connection then application-defined SQL functions must be added
5369** to each database connection separately.
5370**
5371** ^The second parameter is the name of the SQL function to be created or
5372** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5373** representation, exclusive of the zero-terminator. ^Note that the name
5374** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5375** ^Any attempt to create a function with a longer name
5376** will result in [SQLITE_MISUSE] being returned.
5377**
5378** ^The third parameter (nArg)
5379** is the number of arguments that the SQL function or
5380** aggregate takes. ^If this parameter is -1, then the SQL function or
5381** aggregate may take any number of arguments between 0 and the limit
5382** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5383** parameter is less than -1 or greater than 127 then the behavior is
5384** undefined.
5385**
5386** ^The fourth parameter, eTextRep, specifies what
5387** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5388** its parameters. The application should set this parameter to
5389** [SQLITE_UTF16LE] if the function implementation invokes
5390** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5391** implementation invokes [sqlite3_value_text16be()] on an input, or
5392** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5393** otherwise. ^The same SQL function may be registered multiple times using
5394** different preferred text encodings, with different implementations for
5395** each encoding.
5396** ^When multiple implementations of the same function are available, SQLite
5397** will pick the one that involves the least amount of data conversion.
5398**
5399** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5400** to signal that the function will always return the same result given
5401** the same inputs within a single SQL statement. Most SQL functions are
5402** deterministic. The built-in [random()] SQL function is an example of a
5403** function that is not deterministic. The SQLite query planner is able to
5404** perform additional optimizations on deterministic functions, so use
5405** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5406**
5407** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5408** flag, which if present prevents the function from being invoked from
5409** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5410** index expressions, or the WHERE clause of partial indexes.
5411**
5412** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5413** all application-defined SQL functions that do not need to be
5414** used inside of triggers, view, CHECK constraints, or other elements of
5415** the database schema. This flags is especially recommended for SQL
5416** functions that have side effects or reveal internal application state.
5417** Without this flag, an attacker might be able to modify the schema of
5418** a database file to include invocations of the function with parameters
5419** chosen by the attacker, which the application will then execute when
5420** the database file is opened and read.
5421**
5422** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5423** function can gain access to this pointer using [sqlite3_user_data()].)^
5424**
5425** ^The sixth, seventh and eighth parameters passed to the three
5426** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5427** pointers to C-language functions that implement the SQL function or
5428** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5429** callback only; NULL pointers must be passed as the xStep and xFinal
5430** parameters. ^An aggregate SQL function requires an implementation of xStep
5431** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5432** SQL function or aggregate, pass NULL pointers for all three function
5433** callbacks.
5434**
5435** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5436** and xInverse) passed to sqlite3_create_window_function are pointers to
5437** C-language callbacks that implement the new function. xStep and xFinal
5438** must both be non-NULL. xValue and xInverse may either both be NULL, in
5439** which case a regular aggregate function is created, or must both be
5440** non-NULL, in which case the new function may be used as either an aggregate
5441** or aggregate window function. More details regarding the implementation
5442** of aggregate window functions are
5443** [user-defined window functions|available here].
5444**
5445** ^(If the final parameter to sqlite3_create_function_v2() or
5446** sqlite3_create_window_function() is not NULL, then it is destructor for
5447** the application data pointer. The destructor is invoked when the function
5448** is deleted, either by being overloaded or when the database connection
5449** closes.)^ ^The destructor is also invoked if the call to
5450** sqlite3_create_function_v2() fails. ^When the destructor callback is
5451** invoked, it is passed a single argument which is a copy of the application
5452** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5453**
5454** ^It is permitted to register multiple implementations of the same
5455** functions with the same name but with either differing numbers of
5456** arguments or differing preferred text encodings. ^SQLite will use
5457** the implementation that most closely matches the way in which the
5458** SQL function is used. ^A function implementation with a non-negative
5459** nArg parameter is a better match than a function implementation with
5460** a negative nArg. ^A function where the preferred text encoding
5461** matches the database encoding is a better
5462** match than a function where the encoding is different.
5463** ^A function where the encoding difference is between UTF16le and UTF16be
5464** is a closer match than a function where the encoding difference is
5465** between UTF8 and UTF16.
5466**
5467** ^Built-in functions may be overloaded by new application-defined functions.
5468**
5469** ^An application-defined function is permitted to call other
5470** SQLite interfaces. However, such calls must not
5471** close the database connection nor finalize or reset the prepared
5472** statement in which the function is running.
5473*/
5474SQLITE_API int sqlite3_create_function(
5475 sqlite3 *db,
5476 const char *zFunctionName,
5477 int nArg,
5478 int eTextRep,
5479 void *pApp,
5480 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5481 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5482 void (*xFinal)(sqlite3_context*)
5483);
5484SQLITE_API int sqlite3_create_function16(
5485 sqlite3 *db,
5486 const void *zFunctionName,
5487 int nArg,
5488 int eTextRep,
5489 void *pApp,
5490 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5491 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5492 void (*xFinal)(sqlite3_context*)
5493);
5494SQLITE_API int sqlite3_create_function_v2(
5495 sqlite3 *db,
5496 const char *zFunctionName,
5497 int nArg,
5498 int eTextRep,
5499 void *pApp,
5500 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5501 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5502 void (*xFinal)(sqlite3_context*),
5503 void(*xDestroy)(void*)
5504);
5505SQLITE_API int sqlite3_create_window_function(
5506 sqlite3 *db,
5507 const char *zFunctionName,
5508 int nArg,
5509 int eTextRep,
5510 void *pApp,
5511 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5512 void (*xFinal)(sqlite3_context*),
5513 void (*xValue)(sqlite3_context*),
5514 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5515 void(*xDestroy)(void*)
5516);
5517
5518/*
5519** CAPI3REF: Text Encodings
5520**
5521** These constant define integer codes that represent the various
5522** text encodings supported by SQLite.
5523*/
5524#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5525#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5526#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5527#define SQLITE_UTF16 4 /* Use native byte order */
5528#define SQLITE_ANY 5 /* Deprecated */
5529#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5530
5531/*
5532** CAPI3REF: Function Flags
5533**
5534** These constants may be ORed together with the
5535** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5536** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5537** [sqlite3_create_function_v2()].
5538**
5539** <dl>
5540** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5541** The SQLITE_DETERMINISTIC flag means that the new function always gives
5542** the same output when the input parameters are the same.
5543** The [abs|abs() function] is deterministic, for example, but
5544** [randomblob|randomblob()] is not. Functions must
5545** be deterministic in order to be used in certain contexts such as
5546** with the WHERE clause of [partial indexes] or in [generated columns].
5547** SQLite might also optimize deterministic functions by factoring them
5548** out of inner loops.
5549** </dd>
5550**
5551** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5552** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5553** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5554** schema structures such as [CHECK constraints], [DEFAULT clauses],
5555** [expression indexes], [partial indexes], or [generated columns].
5556** <p>
5557** The SQLITE_DIRECTONLY flag is recommended for any
5558** [application-defined SQL function]
5559** that has side-effects or that could potentially leak sensitive information.
5560** This will prevent attacks in which an application is tricked
5561** into using a database file that has had its schema surreptitiously
5562** modified to invoke the application-defined function in ways that are
5563** harmful.
5564** <p>
5565** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5566** [application-defined SQL functions], regardless of whether or not they
5567** are security sensitive, as doing so prevents those functions from being used
5568** inside of the database schema, and thus ensures that the database
5569** can be inspected and modified using generic tools (such as the [CLI])
5570** that do not have access to the application-defined functions.
5571** </dd>
5572**
5573** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5574** The SQLITE_INNOCUOUS flag means that the function is unlikely
5575** to cause problems even if misused. An innocuous function should have
5576** no side effects and should not depend on any values other than its
5577** input parameters. The [abs|abs() function] is an example of an
5578** innocuous function.
5579** The [load_extension() SQL function] is not innocuous because of its
5580** side effects.
5581** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5582** exactly the same. The [random|random() function] is an example of a
5583** function that is innocuous but not deterministic.
5584** <p>Some heightened security settings
5585** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5586** disable the use of SQL functions inside views and triggers and in
5587** schema structures such as [CHECK constraints], [DEFAULT clauses],
5588** [expression indexes], [partial indexes], and [generated columns] unless
5589** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5590** are innocuous. Developers are advised to avoid using the
5591** SQLITE_INNOCUOUS flag for application-defined functions unless the
5592** function has been carefully audited and found to be free of potentially
5593** security-adverse side-effects and information-leaks.
5594** </dd>
5595**
5596** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5597** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5598** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5599** This flag instructs SQLite to omit some corner-case optimizations that
5600** might disrupt the operation of the [sqlite3_value_subtype()] function,
5601** causing it to return zero rather than the correct subtype().
5602** SQL functions that invokes [sqlite3_value_subtype()] should have this
5603** property. If the SQLITE_SUBTYPE property is omitted, then the return
5604** value from [sqlite3_value_subtype()] might sometimes be zero even though
5605** a non-zero subtype was specified by the function argument expression.
5606**
5607** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5608** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5609** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5610** result.
5611** Every function that invokes [sqlite3_result_subtype()] should have this
5612** property. If it does not, then the call to [sqlite3_result_subtype()]
5613** might become a no-op if the function is used as term in an
5614** [expression index]. On the other hand, SQL functions that never invoke
5615** [sqlite3_result_subtype()] should avoid setting this property, as the
5616** purpose of this property is to disable certain optimizations that are
5617** incompatible with subtypes.
5618** </dd>
5619** </dl>
5620*/
5621#define SQLITE_DETERMINISTIC 0x000000800
5622#define SQLITE_DIRECTONLY 0x000080000
5623#define SQLITE_SUBTYPE 0x000100000
5624#define SQLITE_INNOCUOUS 0x000200000
5625#define SQLITE_RESULT_SUBTYPE 0x001000000
5626
5627/*
5628** CAPI3REF: Deprecated Functions
5629** DEPRECATED
5630**
5631** These functions are [deprecated]. In order to maintain
5632** backwards compatibility with older code, these functions continue
5633** to be supported. However, new applications should avoid
5634** the use of these functions. To encourage programmers to avoid
5635** these functions, we will not explain what they do.
5636*/
5637#ifndef SQLITE_OMIT_DEPRECATED
5638SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5639SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5640SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5641SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5642SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5643SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5644 void*,sqlite3_int64);
5645#endif
5646
5647/*
5648** CAPI3REF: Obtaining SQL Values
5649** METHOD: sqlite3_value
5650**
5651** <b>Summary:</b>
5652** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5653** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5654** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5655** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5656** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5657** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5658** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5659** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5660** the native byteorder
5661** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5662** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5663** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5664** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5665** or a UTF-8 TEXT in bytes
5666** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5667** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5668** TEXT in bytes
5669** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5670** datatype of the value
5671** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5672** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5673** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5674** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5675** against a virtual table.
5676** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5677** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5678** </table></blockquote>
5679**
5680** <b>Details:</b>
5681**
5682** These routines extract type, size, and content information from
5683** [protected sqlite3_value] objects. Protected sqlite3_value objects
5684** are used to pass parameter information into the functions that
5685** implement [application-defined SQL functions] and [virtual tables].
5686**
5687** These routines work only with [protected sqlite3_value] objects.
5688** Any attempt to use these routines on an [unprotected sqlite3_value]
5689** is not threadsafe.
5690**
5691** ^These routines work just like the corresponding [column access functions]
5692** except that these routines take a single [protected sqlite3_value] object
5693** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5694**
5695** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5696** in the native byte-order of the host machine. ^The
5697** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5698** extract UTF-16 strings as big-endian and little-endian respectively.
5699**
5700** ^If [sqlite3_value] object V was initialized
5701** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5702** and if X and Y are strings that compare equal according to strcmp(X,Y),
5703** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5704** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5705** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5706**
5707** ^(The sqlite3_value_type(V) interface returns the
5708** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5709** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5710** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5711** Other interfaces might change the datatype for an sqlite3_value object.
5712** For example, if the datatype is initially SQLITE_INTEGER and
5713** sqlite3_value_text(V) is called to extract a text value for that
5714** integer, then subsequent calls to sqlite3_value_type(V) might return
5715** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5716** occurs is undefined and may change from one release of SQLite to the next.
5717**
5718** ^(The sqlite3_value_numeric_type() interface attempts to apply
5719** numeric affinity to the value. This means that an attempt is
5720** made to convert the value to an integer or floating point. If
5721** such a conversion is possible without loss of information (in other
5722** words, if the value is a string that looks like a number)
5723** then the conversion is performed. Otherwise no conversion occurs.
5724** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5725**
5726** ^Within the [xUpdate] method of a [virtual table], the
5727** sqlite3_value_nochange(X) interface returns true if and only if
5728** the column corresponding to X is unchanged by the UPDATE operation
5729** that the xUpdate method call was invoked to implement and if
5730** and the prior [xColumn] method call that was invoked to extracted
5731** the value for that column returned without setting a result (probably
5732** because it queried [sqlite3_vtab_nochange()] and found that the column
5733** was unchanging). ^Within an [xUpdate] method, any value for which
5734** sqlite3_value_nochange(X) is true will in all other respects appear
5735** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5736** than within an [xUpdate] method call for an UPDATE statement, then
5737** the return value is arbitrary and meaningless.
5738**
5739** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5740** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5741** interfaces. ^If X comes from an SQL literal value, or a table column,
5742** or an expression, then sqlite3_value_frombind(X) returns zero.
5743**
5744** Please pay particular attention to the fact that the pointer returned
5745** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5746** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5747** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5748** or [sqlite3_value_text16()].
5749**
5750** These routines must be called from the same thread as
5751** the SQL function that supplied the [sqlite3_value*] parameters.
5752**
5753** As long as the input parameter is correct, these routines can only
5754** fail if an out-of-memory error occurs during a format conversion.
5755** Only the following subset of interfaces are subject to out-of-memory
5756** errors:
5757**
5758** <ul>
5759** <li> sqlite3_value_blob()
5760** <li> sqlite3_value_text()
5761** <li> sqlite3_value_text16()
5762** <li> sqlite3_value_text16le()
5763** <li> sqlite3_value_text16be()
5764** <li> sqlite3_value_bytes()
5765** <li> sqlite3_value_bytes16()
5766** </ul>
5767**
5768** If an out-of-memory error occurs, then the return value from these
5769** routines is the same as if the column had contained an SQL NULL value.
5770** Valid SQL NULL returns can be distinguished from out-of-memory errors
5771** by invoking the [sqlite3_errcode()] immediately after the suspect
5772** return value is obtained and before any
5773** other SQLite interface is called on the same [database connection].
5774*/
5775SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5776SQLITE_API double sqlite3_value_double(sqlite3_value*);
5777SQLITE_API int sqlite3_value_int(sqlite3_value*);
5778SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5779SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5780SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5781SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5782SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5783SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5784SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5785SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5786SQLITE_API int sqlite3_value_type(sqlite3_value*);
5787SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5788SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5789SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5790
5791/*
5792** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5793** METHOD: sqlite3_value
5794**
5795** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
5796** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
5797** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
5798** returns something other than SQLITE_TEXT, then the return value from
5799** sqlite3_value_encoding(X) is meaningless. ^Calls to
5800** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
5801** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
5802** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
5803** thus change the return from subsequent calls to sqlite3_value_encoding(X).
5804**
5805** This routine is intended for used by applications that test and validate
5806** the SQLite implementation. This routine is inquiring about the opaque
5807** internal state of an [sqlite3_value] object. Ordinary applications should
5808** not need to know what the internal state of an sqlite3_value object is and
5809** hence should not need to use this interface.
5810*/
5811SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
5812
5813/*
5814** CAPI3REF: Finding The Subtype Of SQL Values
5815** METHOD: sqlite3_value
5816**
5817** The sqlite3_value_subtype(V) function returns the subtype for
5818** an [application-defined SQL function] argument V. The subtype
5819** information can be used to pass a limited amount of context from
5820** one SQL function to another. Use the [sqlite3_result_subtype()]
5821** routine to set the subtype for the return value of an SQL function.
5822**
5823** Every [application-defined SQL function] that invoke this interface
5824** should include the [SQLITE_SUBTYPE] property in the text
5825** encoding argument when the function is [sqlite3_create_function|registered].
5826** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
5827** might return zero instead of the upstream subtype in some corner cases.
5828*/
5829SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5830
5831/*
5832** CAPI3REF: Copy And Free SQL Values
5833** METHOD: sqlite3_value
5834**
5835** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5836** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5837** is a [protected sqlite3_value] object even if the input is not.
5838** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5839** memory allocation fails. ^If V is a [pointer value], then the result
5840** of sqlite3_value_dup(V) is a NULL value.
5841**
5842** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5843** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5844** then sqlite3_value_free(V) is a harmless no-op.
5845*/
5846SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5847SQLITE_API void sqlite3_value_free(sqlite3_value*);
5848
5849/*
5850** CAPI3REF: Obtain Aggregate Function Context
5851** METHOD: sqlite3_context
5852**
5853** Implementations of aggregate SQL functions use this
5854** routine to allocate memory for storing their state.
5855**
5856** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5857** for a particular aggregate function, SQLite allocates
5858** N bytes of memory, zeroes out that memory, and returns a pointer
5859** to the new memory. ^On second and subsequent calls to
5860** sqlite3_aggregate_context() for the same aggregate function instance,
5861** the same buffer is returned. Sqlite3_aggregate_context() is normally
5862** called once for each invocation of the xStep callback and then one
5863** last time when the xFinal callback is invoked. ^(When no rows match
5864** an aggregate query, the xStep() callback of the aggregate function
5865** implementation is never called and xFinal() is called exactly once.
5866** In those cases, sqlite3_aggregate_context() might be called for the
5867** first time from within xFinal().)^
5868**
5869** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5870** when first called if N is less than or equal to zero or if a memory
5871** allocation error occurs.
5872**
5873** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5874** determined by the N parameter on first successful call. Changing the
5875** value of N in any subsequent call to sqlite3_aggregate_context() within
5876** the same aggregate function instance will not resize the memory
5877** allocation.)^ Within the xFinal callback, it is customary to set
5878** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5879** pointless memory allocations occur.
5880**
5881** ^SQLite automatically frees the memory allocated by
5882** sqlite3_aggregate_context() when the aggregate query concludes.
5883**
5884** The first parameter must be a copy of the
5885** [sqlite3_context | SQL function context] that is the first parameter
5886** to the xStep or xFinal callback routine that implements the aggregate
5887** function.
5888**
5889** This routine must be called from the same thread in which
5890** the aggregate SQL function is running.
5891*/
5892SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5893
5894/*
5895** CAPI3REF: User Data For Functions
5896** METHOD: sqlite3_context
5897**
5898** ^The sqlite3_user_data() interface returns a copy of
5899** the pointer that was the pUserData parameter (the 5th parameter)
5900** of the [sqlite3_create_function()]
5901** and [sqlite3_create_function16()] routines that originally
5902** registered the application defined function.
5903**
5904** This routine must be called from the same thread in which
5905** the application-defined function is running.
5906*/
5907SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5908
5909/*
5910** CAPI3REF: Database Connection For Functions
5911** METHOD: sqlite3_context
5912**
5913** ^The sqlite3_context_db_handle() interface returns a copy of
5914** the pointer to the [database connection] (the 1st parameter)
5915** of the [sqlite3_create_function()]
5916** and [sqlite3_create_function16()] routines that originally
5917** registered the application defined function.
5918*/
5919SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5920
5921/*
5922** CAPI3REF: Function Auxiliary Data
5923** METHOD: sqlite3_context
5924**
5925** These functions may be used by (non-aggregate) SQL functions to
5926** associate auxiliary data with argument values. If the same argument
5927** value is passed to multiple invocations of the same SQL function during
5928** query execution, under some circumstances the associated auxiliary data
5929** might be preserved. An example of where this might be useful is in a
5930** regular-expression matching function. The compiled version of the regular
5931** expression can be stored as auxiliary data associated with the pattern string.
5932** Then as long as the pattern string remains the same,
5933** the compiled regular expression can be reused on multiple
5934** invocations of the same function.
5935**
5936** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
5937** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5938** value to the application-defined function. ^N is zero for the left-most
5939** function argument. ^If there is no auxiliary data
5940** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5941** returns a NULL pointer.
5942**
5943** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
5944** N-th argument of the application-defined function. ^Subsequent
5945** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5946** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
5947** NULL if the auxiliary data has been discarded.
5948** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5949** SQLite will invoke the destructor function X with parameter P exactly
5950** once, when the auxiliary data is discarded.
5951** SQLite is free to discard the auxiliary data at any time, including: <ul>
5952** <li> ^(when the corresponding function parameter changes)^, or
5953** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5954** SQL statement)^, or
5955** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5956** parameter)^, or
5957** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5958** allocation error occurs.)^
5959** <li> ^(during the original sqlite3_set_auxdata() call if the function
5960** is evaluated during query planning instead of during query execution,
5961** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
5962**
5963** Note the last two bullets in particular. The destructor X in
5964** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5965** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5966** should be called near the end of the function implementation and the
5967** function implementation should not make any use of P after
5968** sqlite3_set_auxdata() has been called. Furthermore, a call to
5969** sqlite3_get_auxdata() that occurs immediately after a corresponding call
5970** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
5971** condition occurred during the sqlite3_set_auxdata() call or if the
5972** function is being evaluated during query planning rather than during
5973** query execution.
5974**
5975** ^(In practice, auxiliary data is preserved between function calls for
5976** function parameters that are compile-time constants, including literal
5977** values and [parameters] and expressions composed from the same.)^
5978**
5979** The value of the N parameter to these interfaces should be non-negative.
5980** Future enhancements may make use of negative N values to define new
5981** kinds of function caching behavior.
5982**
5983** These routines must be called from the same thread in which
5984** the SQL function is running.
5985**
5986** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
5987*/
5988SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5989SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5990
5991/*
5992** CAPI3REF: Database Connection Client Data
5993** METHOD: sqlite3
5994**
5995** These functions are used to associate one or more named pointers
5996** with a [database connection].
5997** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
5998** to be attached to [database connection] D using name N. Subsequent
5999** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6000** or a NULL pointer if there were no prior calls to
6001** sqlite3_set_clientdata() with the same values of D and N.
6002** Names are compared using strcmp() and are thus case sensitive.
6003**
6004** If P and X are both non-NULL, then the destructor X is invoked with
6005** argument P on the first of the following occurrences:
6006** <ul>
6007** <li> An out-of-memory error occurs during the call to
6008** sqlite3_set_clientdata() which attempts to register pointer P.
6009** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6010** with the same D and N parameters.
6011** <li> The database connection closes. SQLite does not make any guarantees
6012** about the order in which destructors are called, only that all
6013** destructors will be called exactly once at some point during the
6014** database connection closing process.
6015** </ul>
6016**
6017** SQLite does not do anything with client data other than invoke
6018** destructors on the client data at the appropriate time. The intended
6019** use for client data is to provide a mechanism for wrapper libraries
6020** to store additional information about an SQLite database connection.
6021**
6022** There is no limit (other than available memory) on the number of different
6023** client data pointers (with different names) that can be attached to a
6024** single database connection. However, the implementation is optimized
6025** for the case of having only one or two different client data names.
6026** Applications and wrapper libraries are discouraged from using more than
6027** one client data name each.
6028**
6029** There is no way to enumerate the client data pointers
6030** associated with a database connection. The N parameter can be thought
6031** of as a secret key such that only code that knows the secret key is able
6032** to access the associated data.
6033**
6034** Security Warning: These interfaces should not be exposed in scripting
6035** languages or in other circumstances where it might be possible for an
6036** an attacker to invoke them. Any agent that can invoke these interfaces
6037** can probably also take control of the process.
6038**
6039** Database connection client data is only available for SQLite
6040** version 3.44.0 ([dateof:3.44.0]) and later.
6041**
6042** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6043*/
6044SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6045SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6046
6047/*
6048** CAPI3REF: Constants Defining Special Destructor Behavior
6049**
6050** These are special values for the destructor that is passed in as the
6051** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6052** argument is SQLITE_STATIC, it means that the content pointer is constant
6053** and will never change. It does not need to be destroyed. ^The
6054** SQLITE_TRANSIENT value means that the content will likely change in
6055** the near future and that SQLite should make its own private copy of
6056** the content before returning.
6057**
6058** The typedef is necessary to work around problems in certain
6059** C++ compilers.
6060*/
6061typedef void (*sqlite3_destructor_type)(void*);
6062#define SQLITE_STATIC ((sqlite3_destructor_type)0)
6063#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6064
6065/*
6066** CAPI3REF: Setting The Result Of An SQL Function
6067** METHOD: sqlite3_context
6068**
6069** These routines are used by the xFunc or xFinal callbacks that
6070** implement SQL functions and aggregates. See
6071** [sqlite3_create_function()] and [sqlite3_create_function16()]
6072** for additional information.
6073**
6074** These functions work very much like the [parameter binding] family of
6075** functions used to bind values to host parameters in prepared statements.
6076** Refer to the [SQL parameter] documentation for additional information.
6077**
6078** ^The sqlite3_result_blob() interface sets the result from
6079** an application-defined function to be the BLOB whose content is pointed
6080** to by the second parameter and which is N bytes long where N is the
6081** third parameter.
6082**
6083** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6084** interfaces set the result of the application-defined function to be
6085** a BLOB containing all zero bytes and N bytes in size.
6086**
6087** ^The sqlite3_result_double() interface sets the result from
6088** an application-defined function to be a floating point value specified
6089** by its 2nd argument.
6090**
6091** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6092** cause the implemented SQL function to throw an exception.
6093** ^SQLite uses the string pointed to by the
6094** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6095** as the text of an error message. ^SQLite interprets the error
6096** message string from sqlite3_result_error() as UTF-8. ^SQLite
6097** interprets the string from sqlite3_result_error16() as UTF-16 using
6098** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6099** ^If the third parameter to sqlite3_result_error()
6100** or sqlite3_result_error16() is negative then SQLite takes as the error
6101** message all text up through the first zero character.
6102** ^If the third parameter to sqlite3_result_error() or
6103** sqlite3_result_error16() is non-negative then SQLite takes that many
6104** bytes (not characters) from the 2nd parameter as the error message.
6105** ^The sqlite3_result_error() and sqlite3_result_error16()
6106** routines make a private copy of the error message text before
6107** they return. Hence, the calling function can deallocate or
6108** modify the text after they return without harm.
6109** ^The sqlite3_result_error_code() function changes the error code
6110** returned by SQLite as a result of an error in a function. ^By default,
6111** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6112** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6113**
6114** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6115** error indicating that a string or BLOB is too long to represent.
6116**
6117** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6118** error indicating that a memory allocation failed.
6119**
6120** ^The sqlite3_result_int() interface sets the return value
6121** of the application-defined function to be the 32-bit signed integer
6122** value given in the 2nd argument.
6123** ^The sqlite3_result_int64() interface sets the return value
6124** of the application-defined function to be the 64-bit signed integer
6125** value given in the 2nd argument.
6126**
6127** ^The sqlite3_result_null() interface sets the return value
6128** of the application-defined function to be NULL.
6129**
6130** ^The sqlite3_result_text(), sqlite3_result_text16(),
6131** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6132** set the return value of the application-defined function to be
6133** a text string which is represented as UTF-8, UTF-16 native byte order,
6134** UTF-16 little endian, or UTF-16 big endian, respectively.
6135** ^The sqlite3_result_text64() interface sets the return value of an
6136** application-defined function to be a text string in an encoding
6137** specified by the fifth (and last) parameter, which must be one
6138** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6139** ^SQLite takes the text result from the application from
6140** the 2nd parameter of the sqlite3_result_text* interfaces.
6141** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6142** other than sqlite3_result_text64() is negative, then SQLite computes
6143** the string length itself by searching the 2nd parameter for the first
6144** zero character.
6145** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6146** is non-negative, then as many bytes (not characters) of the text
6147** pointed to by the 2nd parameter are taken as the application-defined
6148** function result. If the 3rd parameter is non-negative, then it
6149** must be the byte offset into the string where the NUL terminator would
6150** appear if the string where NUL terminated. If any NUL characters occur
6151** in the string at a byte offset that is less than the value of the 3rd
6152** parameter, then the resulting string will contain embedded NULs and the
6153** result of expressions operating on strings with embedded NULs is undefined.
6154** ^If the 4th parameter to the sqlite3_result_text* interfaces
6155** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6156** function as the destructor on the text or BLOB result when it has
6157** finished using that result.
6158** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6159** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6160** assumes that the text or BLOB result is in constant space and does not
6161** copy the content of the parameter nor call a destructor on the content
6162** when it has finished using that result.
6163** ^If the 4th parameter to the sqlite3_result_text* interfaces
6164** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6165** then SQLite makes a copy of the result into space obtained
6166** from [sqlite3_malloc()] before it returns.
6167**
6168** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6169** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6170** when the encoding is not UTF8, if the input UTF16 begins with a
6171** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6172** string and the rest of the string is interpreted according to the
6173** byte-order specified by the BOM. ^The byte-order specified by
6174** the BOM at the beginning of the text overrides the byte-order
6175** specified by the interface procedure. ^So, for example, if
6176** sqlite3_result_text16le() is invoked with text that begins
6177** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6178** first two bytes of input are skipped and the remaining input
6179** is interpreted as UTF16BE text.
6180**
6181** ^For UTF16 input text to the sqlite3_result_text16(),
6182** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6183** sqlite3_result_text64() routines, if the text contains invalid
6184** UTF16 characters, the invalid characters might be converted
6185** into the unicode replacement character, U+FFFD.
6186**
6187** ^The sqlite3_result_value() interface sets the result of
6188** the application-defined function to be a copy of the
6189** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6190** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6191** so that the [sqlite3_value] specified in the parameter may change or
6192** be deallocated after sqlite3_result_value() returns without harm.
6193** ^A [protected sqlite3_value] object may always be used where an
6194** [unprotected sqlite3_value] object is required, so either
6195** kind of [sqlite3_value] object can be used with this interface.
6196**
6197** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6198** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6199** also associates the host-language pointer P or type T with that
6200** NULL value such that the pointer can be retrieved within an
6201** [application-defined SQL function] using [sqlite3_value_pointer()].
6202** ^If the D parameter is not NULL, then it is a pointer to a destructor
6203** for the P parameter. ^SQLite invokes D with P as its only argument
6204** when SQLite is finished with P. The T parameter should be a static
6205** string and preferably a string literal. The sqlite3_result_pointer()
6206** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6207**
6208** If these routines are called from within the different thread
6209** than the one containing the application-defined function that received
6210** the [sqlite3_context] pointer, the results are undefined.
6211*/
6212SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6213SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6214 sqlite3_uint64,void(*)(void*));
6215SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6216SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6217SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6218SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6219SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6220SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6221SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6222SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6223SQLITE_API void sqlite3_result_null(sqlite3_context*);
6224SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6225SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6226 void(*)(void*), unsigned char encoding);
6227SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6228SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6229SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6230SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6231SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6232SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6233SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6234
6235
6236/*
6237** CAPI3REF: Setting The Subtype Of An SQL Function
6238** METHOD: sqlite3_context
6239**
6240** The sqlite3_result_subtype(C,T) function causes the subtype of
6241** the result from the [application-defined SQL function] with
6242** [sqlite3_context] C to be the value T. Only the lower 8 bits
6243** of the subtype T are preserved in current versions of SQLite;
6244** higher order bits are discarded.
6245** The number of subtype bytes preserved by SQLite might increase
6246** in future releases of SQLite.
6247**
6248** Every [application-defined SQL function] that invokes this interface
6249** should include the [SQLITE_RESULT_SUBTYPE] property in its
6250** text encoding argument when the SQL function is
6251** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6252** property is omitted from the function that invokes sqlite3_result_subtype(),
6253** then in some cases the sqlite3_result_subtype() might fail to set
6254** the result subtype.
6255**
6256** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6257** SQL function that invokes the sqlite3_result_subtype() interface
6258** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6259** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6260** by default.
6261*/
6262SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6263
6264/*
6265** CAPI3REF: Define New Collating Sequences
6266** METHOD: sqlite3
6267**
6268** ^These functions add, remove, or modify a [collation] associated
6269** with the [database connection] specified as the first argument.
6270**
6271** ^The name of the collation is a UTF-8 string
6272** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6273** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6274** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6275** considered to be the same name.
6276**
6277** ^(The third argument (eTextRep) must be one of the constants:
6278** <ul>
6279** <li> [SQLITE_UTF8],
6280** <li> [SQLITE_UTF16LE],
6281** <li> [SQLITE_UTF16BE],
6282** <li> [SQLITE_UTF16], or
6283** <li> [SQLITE_UTF16_ALIGNED].
6284** </ul>)^
6285** ^The eTextRep argument determines the encoding of strings passed
6286** to the collating function callback, xCompare.
6287** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6288** force strings to be UTF16 with native byte order.
6289** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6290** on an even byte address.
6291**
6292** ^The fourth argument, pArg, is an application data pointer that is passed
6293** through as the first argument to the collating function callback.
6294**
6295** ^The fifth argument, xCompare, is a pointer to the collating function.
6296** ^Multiple collating functions can be registered using the same name but
6297** with different eTextRep parameters and SQLite will use whichever
6298** function requires the least amount of data transformation.
6299** ^If the xCompare argument is NULL then the collating function is
6300** deleted. ^When all collating functions having the same name are deleted,
6301** that collation is no longer usable.
6302**
6303** ^The collating function callback is invoked with a copy of the pArg
6304** application data pointer and with two strings in the encoding specified
6305** by the eTextRep argument. The two integer parameters to the collating
6306** function callback are the length of the two strings, in bytes. The collating
6307** function must return an integer that is negative, zero, or positive
6308** if the first string is less than, equal to, or greater than the second,
6309** respectively. A collating function must always return the same answer
6310** given the same inputs. If two or more collating functions are registered
6311** to the same collation name (using different eTextRep values) then all
6312** must give an equivalent answer when invoked with equivalent strings.
6313** The collating function must obey the following properties for all
6314** strings A, B, and C:
6315**
6316** <ol>
6317** <li> If A==B then B==A.
6318** <li> If A==B and B==C then A==C.
6319** <li> If A&lt;B THEN B&gt;A.
6320** <li> If A&lt;B and B&lt;C then A&lt;C.
6321** </ol>
6322**
6323** If a collating function fails any of the above constraints and that
6324** collating function is registered and used, then the behavior of SQLite
6325** is undefined.
6326**
6327** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6328** with the addition that the xDestroy callback is invoked on pArg when
6329** the collating function is deleted.
6330** ^Collating functions are deleted when they are overridden by later
6331** calls to the collation creation functions or when the
6332** [database connection] is closed using [sqlite3_close()].
6333**
6334** ^The xDestroy callback is <u>not</u> called if the
6335** sqlite3_create_collation_v2() function fails. Applications that invoke
6336** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6337** check the return code and dispose of the application data pointer
6338** themselves rather than expecting SQLite to deal with it for them.
6339** This is different from every other SQLite interface. The inconsistency
6340** is unfortunate but cannot be changed without breaking backwards
6341** compatibility.
6342**
6343** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6344*/
6345SQLITE_API int sqlite3_create_collation(
6346 sqlite3*,
6347 const char *zName,
6348 int eTextRep,
6349 void *pArg,
6350 int(*xCompare)(void*,int,const void*,int,const void*)
6351);
6352SQLITE_API int sqlite3_create_collation_v2(
6353 sqlite3*,
6354 const char *zName,
6355 int eTextRep,
6356 void *pArg,
6357 int(*xCompare)(void*,int,const void*,int,const void*),
6358 void(*xDestroy)(void*)
6359);
6360SQLITE_API int sqlite3_create_collation16(
6361 sqlite3*,
6362 const void *zName,
6363 int eTextRep,
6364 void *pArg,
6365 int(*xCompare)(void*,int,const void*,int,const void*)
6366);
6367
6368/*
6369** CAPI3REF: Collation Needed Callbacks
6370** METHOD: sqlite3
6371**
6372** ^To avoid having to register all collation sequences before a database
6373** can be used, a single callback function may be registered with the
6374** [database connection] to be invoked whenever an undefined collation
6375** sequence is required.
6376**
6377** ^If the function is registered using the sqlite3_collation_needed() API,
6378** then it is passed the names of undefined collation sequences as strings
6379** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6380** the names are passed as UTF-16 in machine native byte order.
6381** ^A call to either function replaces the existing collation-needed callback.
6382**
6383** ^(When the callback is invoked, the first argument passed is a copy
6384** of the second argument to sqlite3_collation_needed() or
6385** sqlite3_collation_needed16(). The second argument is the database
6386** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6387** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6388** sequence function required. The fourth parameter is the name of the
6389** required collation sequence.)^
6390**
6391** The callback function should register the desired collation using
6392** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6393** [sqlite3_create_collation_v2()].
6394*/
6395SQLITE_API int sqlite3_collation_needed(
6396 sqlite3*,
6397 void*,
6398 void(*)(void*,sqlite3*,int eTextRep,const char*)
6399);
6400SQLITE_API int sqlite3_collation_needed16(
6401 sqlite3*,
6402 void*,
6403 void(*)(void*,sqlite3*,int eTextRep,const void*)
6404);
6405
6406#ifdef SQLITE_ENABLE_CEROD
6407/*
6408** Specify the activation key for a CEROD database. Unless
6409** activated, none of the CEROD routines will work.
6410*/
6411SQLITE_API void sqlite3_activate_cerod(
6412 const char *zPassPhrase /* Activation phrase */
6413);
6414#endif
6415
6416/*
6417** CAPI3REF: Suspend Execution For A Short Time
6418**
6419** The sqlite3_sleep() function causes the current thread to suspend execution
6420** for at least a number of milliseconds specified in its parameter.
6421**
6422** If the operating system does not support sleep requests with
6423** millisecond time resolution, then the time will be rounded up to
6424** the nearest second. The number of milliseconds of sleep actually
6425** requested from the operating system is returned.
6426**
6427** ^SQLite implements this interface by calling the xSleep()
6428** method of the default [sqlite3_vfs] object. If the xSleep() method
6429** of the default VFS is not implemented correctly, or not implemented at
6430** all, then the behavior of sqlite3_sleep() may deviate from the description
6431** in the previous paragraphs.
6432**
6433** If a negative argument is passed to sqlite3_sleep() the results vary by
6434** VFS and operating system. Some system treat a negative argument as an
6435** instruction to sleep forever. Others understand it to mean do not sleep
6436** at all. ^In SQLite version 3.42.0 and later, a negative
6437** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6438** down into the xSleep method of the VFS.
6439*/
6440SQLITE_API int sqlite3_sleep(int);
6441
6442/*
6443** CAPI3REF: Name Of The Folder Holding Temporary Files
6444**
6445** ^(If this global variable is made to point to a string which is
6446** the name of a folder (a.k.a. directory), then all temporary files
6447** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6448** will be placed in that directory.)^ ^If this variable
6449** is a NULL pointer, then SQLite performs a search for an appropriate
6450** temporary file directory.
6451**
6452** Applications are strongly discouraged from using this global variable.
6453** It is required to set a temporary folder on Windows Runtime (WinRT).
6454** But for all other platforms, it is highly recommended that applications
6455** neither read nor write this variable. This global variable is a relic
6456** that exists for backwards compatibility of legacy applications and should
6457** be avoided in new projects.
6458**
6459** It is not safe to read or modify this variable in more than one
6460** thread at a time. It is not safe to read or modify this variable
6461** if a [database connection] is being used at the same time in a separate
6462** thread.
6463** It is intended that this variable be set once
6464** as part of process initialization and before any SQLite interface
6465** routines have been called and that this variable remain unchanged
6466** thereafter.
6467**
6468** ^The [temp_store_directory pragma] may modify this variable and cause
6469** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6470** the [temp_store_directory pragma] always assumes that any string
6471** that this variable points to is held in memory obtained from
6472** [sqlite3_malloc] and the pragma may attempt to free that memory
6473** using [sqlite3_free].
6474** Hence, if this variable is modified directly, either it should be
6475** made NULL or made to point to memory obtained from [sqlite3_malloc]
6476** or else the use of the [temp_store_directory pragma] should be avoided.
6477** Except when requested by the [temp_store_directory pragma], SQLite
6478** does not free the memory that sqlite3_temp_directory points to. If
6479** the application wants that memory to be freed, it must do
6480** so itself, taking care to only do so after all [database connection]
6481** objects have been destroyed.
6482**
6483** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6484** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6485** features that require the use of temporary files may fail. Here is an
6486** example of how to do this using C++ with the Windows Runtime:
6487**
6488** <blockquote><pre>
6489** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6490** &nbsp; TemporaryFolder->Path->Data();
6491** char zPathBuf&#91;MAX_PATH + 1&#93;;
6492** memset(zPathBuf, 0, sizeof(zPathBuf));
6493** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6494** &nbsp; NULL, NULL);
6495** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6496** </pre></blockquote>
6497*/
6498SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6499
6500/*
6501** CAPI3REF: Name Of The Folder Holding Database Files
6502**
6503** ^(If this global variable is made to point to a string which is
6504** the name of a folder (a.k.a. directory), then all database files
6505** specified with a relative pathname and created or accessed by
6506** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6507** to be relative to that directory.)^ ^If this variable is a NULL
6508** pointer, then SQLite assumes that all database files specified
6509** with a relative pathname are relative to the current directory
6510** for the process. Only the windows VFS makes use of this global
6511** variable; it is ignored by the unix VFS.
6512**
6513** Changing the value of this variable while a database connection is
6514** open can result in a corrupt database.
6515**
6516** It is not safe to read or modify this variable in more than one
6517** thread at a time. It is not safe to read or modify this variable
6518** if a [database connection] is being used at the same time in a separate
6519** thread.
6520** It is intended that this variable be set once
6521** as part of process initialization and before any SQLite interface
6522** routines have been called and that this variable remain unchanged
6523** thereafter.
6524**
6525** ^The [data_store_directory pragma] may modify this variable and cause
6526** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6527** the [data_store_directory pragma] always assumes that any string
6528** that this variable points to is held in memory obtained from
6529** [sqlite3_malloc] and the pragma may attempt to free that memory
6530** using [sqlite3_free].
6531** Hence, if this variable is modified directly, either it should be
6532** made NULL or made to point to memory obtained from [sqlite3_malloc]
6533** or else the use of the [data_store_directory pragma] should be avoided.
6534*/
6535SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6536
6537/*
6538** CAPI3REF: Win32 Specific Interface
6539**
6540** These interfaces are available only on Windows. The
6541** [sqlite3_win32_set_directory] interface is used to set the value associated
6542** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6543** zValue, depending on the value of the type parameter. The zValue parameter
6544** should be NULL to cause the previous value to be freed via [sqlite3_free];
6545** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6546** prior to being used. The [sqlite3_win32_set_directory] interface returns
6547** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6548** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6549** [sqlite3_data_directory] variable is intended to act as a replacement for
6550** the current directory on the sub-platforms of Win32 where that concept is
6551** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6552** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6553** sqlite3_win32_set_directory interface except the string parameter must be
6554** UTF-8 or UTF-16, respectively.
6555*/
6556SQLITE_API int sqlite3_win32_set_directory(
6557 unsigned long type, /* Identifier for directory being set or reset */
6558 void *zValue /* New value for directory being set or reset */
6559);
6560SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6561SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6562
6563/*
6564** CAPI3REF: Win32 Directory Types
6565**
6566** These macros are only available on Windows. They define the allowed values
6567** for the type argument to the [sqlite3_win32_set_directory] interface.
6568*/
6569#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6570#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6571
6572/*
6573** CAPI3REF: Test For Auto-Commit Mode
6574** KEYWORDS: {autocommit mode}
6575** METHOD: sqlite3
6576**
6577** ^The sqlite3_get_autocommit() interface returns non-zero or
6578** zero if the given database connection is or is not in autocommit mode,
6579** respectively. ^Autocommit mode is on by default.
6580** ^Autocommit mode is disabled by a [BEGIN] statement.
6581** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6582**
6583** If certain kinds of errors occur on a statement within a multi-statement
6584** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6585** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6586** transaction might be rolled back automatically. The only way to
6587** find out whether SQLite automatically rolled back the transaction after
6588** an error is to use this function.
6589**
6590** If another thread changes the autocommit status of the database
6591** connection while this routine is running, then the return value
6592** is undefined.
6593*/
6594SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6595
6596/*
6597** CAPI3REF: Find The Database Handle Of A Prepared Statement
6598** METHOD: sqlite3_stmt
6599**
6600** ^The sqlite3_db_handle interface returns the [database connection] handle
6601** to which a [prepared statement] belongs. ^The [database connection]
6602** returned by sqlite3_db_handle is the same [database connection]
6603** that was the first argument
6604** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6605** create the statement in the first place.
6606*/
6607SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6608
6609/*
6610** CAPI3REF: Return The Schema Name For A Database Connection
6611** METHOD: sqlite3
6612**
6613** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6614** for the N-th database on database connection D, or a NULL pointer of N is
6615** out of range. An N value of 0 means the main database file. An N of 1 is
6616** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6617** databases.
6618**
6619** Space to hold the string that is returned by sqlite3_db_name() is managed
6620** by SQLite itself. The string might be deallocated by any operation that
6621** changes the schema, including [ATTACH] or [DETACH] or calls to
6622** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6623** occur on a different thread. Applications that need to
6624** remember the string long-term should make their own copy. Applications that
6625** are accessing the same database connection simultaneously on multiple
6626** threads should mutex-protect calls to this API and should make their own
6627** private copy of the result prior to releasing the mutex.
6628*/
6629SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6630
6631/*
6632** CAPI3REF: Return The Filename For A Database Connection
6633** METHOD: sqlite3
6634**
6635** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6636** associated with database N of connection D.
6637** ^If there is no attached database N on the database
6638** connection D, or if database N is a temporary or in-memory database, then
6639** this function will return either a NULL pointer or an empty string.
6640**
6641** ^The string value returned by this routine is owned and managed by
6642** the database connection. ^The value will be valid until the database N
6643** is [DETACH]-ed or until the database connection closes.
6644**
6645** ^The filename returned by this function is the output of the
6646** xFullPathname method of the [VFS]. ^In other words, the filename
6647** will be an absolute pathname, even if the filename used
6648** to open the database originally was a URI or relative pathname.
6649**
6650** If the filename pointer returned by this routine is not NULL, then it
6651** can be used as the filename input parameter to these routines:
6652** <ul>
6653** <li> [sqlite3_uri_parameter()]
6654** <li> [sqlite3_uri_boolean()]
6655** <li> [sqlite3_uri_int64()]
6656** <li> [sqlite3_filename_database()]
6657** <li> [sqlite3_filename_journal()]
6658** <li> [sqlite3_filename_wal()]
6659** </ul>
6660*/
6661SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6662
6663/*
6664** CAPI3REF: Determine if a database is read-only
6665** METHOD: sqlite3
6666**
6667** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6668** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6669** the name of a database on connection D.
6670*/
6671SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6672
6673/*
6674** CAPI3REF: Determine the transaction state of a database
6675** METHOD: sqlite3
6676**
6677** ^The sqlite3_txn_state(D,S) interface returns the current
6678** [transaction state] of schema S in database connection D. ^If S is NULL,
6679** then the highest transaction state of any schema on database connection D
6680** is returned. Transaction states are (in order of lowest to highest):
6681** <ol>
6682** <li value="0"> SQLITE_TXN_NONE
6683** <li value="1"> SQLITE_TXN_READ
6684** <li value="2"> SQLITE_TXN_WRITE
6685** </ol>
6686** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6687** a valid schema, then -1 is returned.
6688*/
6689SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6690
6691/*
6692** CAPI3REF: Allowed return values from sqlite3_txn_state()
6693** KEYWORDS: {transaction state}
6694**
6695** These constants define the current transaction state of a database file.
6696** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6697** constants in order to describe the transaction state of schema S
6698** in [database connection] D.
6699**
6700** <dl>
6701** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6702** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6703** pending.</dd>
6704**
6705** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6706** <dd>The SQLITE_TXN_READ state means that the database is currently
6707** in a read transaction. Content has been read from the database file
6708** but nothing in the database file has changed. The transaction state
6709** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6710** no other conflicting concurrent write transactions. The transaction
6711** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6712** [COMMIT].</dd>
6713**
6714** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6715** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6716** in a write transaction. Content has been written to the database file
6717** but has not yet committed. The transaction state will change to
6718** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6719*/
6720#define SQLITE_TXN_NONE 0
6721#define SQLITE_TXN_READ 1
6722#define SQLITE_TXN_WRITE 2
6723
6724/*
6725** CAPI3REF: Find the next prepared statement
6726** METHOD: sqlite3
6727**
6728** ^This interface returns a pointer to the next [prepared statement] after
6729** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6730** then this interface returns a pointer to the first prepared statement
6731** associated with the database connection pDb. ^If no prepared statement
6732** satisfies the conditions of this routine, it returns NULL.
6733**
6734** The [database connection] pointer D in a call to
6735** [sqlite3_next_stmt(D,S)] must refer to an open database
6736** connection and in particular must not be a NULL pointer.
6737*/
6738SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6739
6740/*
6741** CAPI3REF: Commit And Rollback Notification Callbacks
6742** METHOD: sqlite3
6743**
6744** ^The sqlite3_commit_hook() interface registers a callback
6745** function to be invoked whenever a transaction is [COMMIT | committed].
6746** ^Any callback set by a previous call to sqlite3_commit_hook()
6747** for the same database connection is overridden.
6748** ^The sqlite3_rollback_hook() interface registers a callback
6749** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6750** ^Any callback set by a previous call to sqlite3_rollback_hook()
6751** for the same database connection is overridden.
6752** ^The pArg argument is passed through to the callback.
6753** ^If the callback on a commit hook function returns non-zero,
6754** then the commit is converted into a rollback.
6755**
6756** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6757** return the P argument from the previous call of the same function
6758** on the same [database connection] D, or NULL for
6759** the first call for each function on D.
6760**
6761** The commit and rollback hook callbacks are not reentrant.
6762** The callback implementation must not do anything that will modify
6763** the database connection that invoked the callback. Any actions
6764** to modify the database connection must be deferred until after the
6765** completion of the [sqlite3_step()] call that triggered the commit
6766** or rollback hook in the first place.
6767** Note that running any other SQL statements, including SELECT statements,
6768** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6769** the database connections for the meaning of "modify" in this paragraph.
6770**
6771** ^Registering a NULL function disables the callback.
6772**
6773** ^When the commit hook callback routine returns zero, the [COMMIT]
6774** operation is allowed to continue normally. ^If the commit hook
6775** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6776** ^The rollback hook is invoked on a rollback that results from a commit
6777** hook returning non-zero, just as it would be with any other rollback.
6778**
6779** ^For the purposes of this API, a transaction is said to have been
6780** rolled back if an explicit "ROLLBACK" statement is executed, or
6781** an error or constraint causes an implicit rollback to occur.
6782** ^The rollback callback is not invoked if a transaction is
6783** automatically rolled back because the database connection is closed.
6784**
6785** See also the [sqlite3_update_hook()] interface.
6786*/
6787SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6788SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6789
6790/*
6791** CAPI3REF: Autovacuum Compaction Amount Callback
6792** METHOD: sqlite3
6793**
6794** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6795** function C that is invoked prior to each autovacuum of the database
6796** file. ^The callback is passed a copy of the generic data pointer (P),
6797** the schema-name of the attached database that is being autovacuumed,
6798** the size of the database file in pages, the number of free pages,
6799** and the number of bytes per page, respectively. The callback should
6800** return the number of free pages that should be removed by the
6801** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6802** ^If the value returned is greater than or equal to the number of
6803** free pages, then a complete autovacuum happens.
6804**
6805** <p>^If there are multiple ATTACH-ed database files that are being
6806** modified as part of a transaction commit, then the autovacuum pages
6807** callback is invoked separately for each file.
6808**
6809** <p><b>The callback is not reentrant.</b> The callback function should
6810** not attempt to invoke any other SQLite interface. If it does, bad
6811** things may happen, including segmentation faults and corrupt database
6812** files. The callback function should be a simple function that
6813** does some arithmetic on its input parameters and returns a result.
6814**
6815** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6816** destructor for the P parameter. ^If X is not NULL, then X(P) is
6817** invoked whenever the database connection closes or when the callback
6818** is overwritten by another invocation of sqlite3_autovacuum_pages().
6819**
6820** <p>^There is only one autovacuum pages callback per database connection.
6821** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6822** previous invocations for that database connection. ^If the callback
6823** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6824** then the autovacuum steps callback is canceled. The return value
6825** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6826** be some other error code if something goes wrong. The current
6827** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6828** return codes might be added in future releases.
6829**
6830** <p>If no autovacuum pages callback is specified (the usual case) or
6831** a NULL pointer is provided for the callback,
6832** then the default behavior is to vacuum all free pages. So, in other
6833** words, the default behavior is the same as if the callback function
6834** were something like this:
6835**
6836** <blockquote><pre>
6837** &nbsp; unsigned int demonstration_autovac_pages_callback(
6838** &nbsp; void *pClientData,
6839** &nbsp; const char *zSchema,
6840** &nbsp; unsigned int nDbPage,
6841** &nbsp; unsigned int nFreePage,
6842** &nbsp; unsigned int nBytePerPage
6843** &nbsp; ){
6844** &nbsp; return nFreePage;
6845** &nbsp; }
6846** </pre></blockquote>
6847*/
6848SQLITE_API int sqlite3_autovacuum_pages(
6849 sqlite3 *db,
6850 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6851 void*,
6852 void(*)(void*)
6853);
6854
6855
6856/*
6857** CAPI3REF: Data Change Notification Callbacks
6858** METHOD: sqlite3
6859**
6860** ^The sqlite3_update_hook() interface registers a callback function
6861** with the [database connection] identified by the first argument
6862** to be invoked whenever a row is updated, inserted or deleted in
6863** a [rowid table].
6864** ^Any callback set by a previous call to this function
6865** for the same database connection is overridden.
6866**
6867** ^The second argument is a pointer to the function to invoke when a
6868** row is updated, inserted or deleted in a rowid table.
6869** ^The first argument to the callback is a copy of the third argument
6870** to sqlite3_update_hook().
6871** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6872** or [SQLITE_UPDATE], depending on the operation that caused the callback
6873** to be invoked.
6874** ^The third and fourth arguments to the callback contain pointers to the
6875** database and table name containing the affected row.
6876** ^The final callback parameter is the [rowid] of the row.
6877** ^In the case of an update, this is the [rowid] after the update takes place.
6878**
6879** ^(The update hook is not invoked when internal system tables are
6880** modified (i.e. sqlite_sequence).)^
6881** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6882**
6883** ^In the current implementation, the update hook
6884** is not invoked when conflicting rows are deleted because of an
6885** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6886** invoked when rows are deleted using the [truncate optimization].
6887** The exceptions defined in this paragraph might change in a future
6888** release of SQLite.
6889**
6890** Whether the update hook is invoked before or after the
6891** corresponding change is currently unspecified and may differ
6892** depending on the type of change. Do not rely on the order of the
6893** hook call with regards to the final result of the operation which
6894** triggers the hook.
6895**
6896** The update hook implementation must not do anything that will modify
6897** the database connection that invoked the update hook. Any actions
6898** to modify the database connection must be deferred until after the
6899** completion of the [sqlite3_step()] call that triggered the update hook.
6900** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6901** database connections for the meaning of "modify" in this paragraph.
6902**
6903** ^The sqlite3_update_hook(D,C,P) function
6904** returns the P argument from the previous call
6905** on the same [database connection] D, or NULL for
6906** the first call on D.
6907**
6908** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6909** and [sqlite3_preupdate_hook()] interfaces.
6910*/
6911SQLITE_API void *sqlite3_update_hook(
6912 sqlite3*,
6913 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6914 void*
6915);
6916
6917/*
6918** CAPI3REF: Enable Or Disable Shared Pager Cache
6919**
6920** ^(This routine enables or disables the sharing of the database cache
6921** and schema data structures between [database connection | connections]
6922** to the same database. Sharing is enabled if the argument is true
6923** and disabled if the argument is false.)^
6924**
6925** This interface is omitted if SQLite is compiled with
6926** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
6927** compile-time option is recommended because the
6928** [use of shared cache mode is discouraged].
6929**
6930** ^Cache sharing is enabled and disabled for an entire process.
6931** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6932** In prior versions of SQLite,
6933** sharing was enabled or disabled for each thread separately.
6934**
6935** ^(The cache sharing mode set by this interface effects all subsequent
6936** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6937** Existing database connections continue to use the sharing mode
6938** that was in effect at the time they were opened.)^
6939**
6940** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6941** successfully. An [error code] is returned otherwise.)^
6942**
6943** ^Shared cache is disabled by default. It is recommended that it stay
6944** that way. In other words, do not use this routine. This interface
6945** continues to be provided for historical compatibility, but its use is
6946** discouraged. Any use of shared cache is discouraged. If shared cache
6947** must be used, it is recommended that shared cache only be enabled for
6948** individual database connections using the [sqlite3_open_v2()] interface
6949** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6950**
6951** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6952** and will always return SQLITE_MISUSE. On those systems,
6953** shared cache mode should be enabled per-database connection via
6954** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6955**
6956** This interface is threadsafe on processors where writing a
6957** 32-bit integer is atomic.
6958**
6959** See Also: [SQLite Shared-Cache Mode]
6960*/
6961SQLITE_API int sqlite3_enable_shared_cache(int);
6962
6963/*
6964** CAPI3REF: Attempt To Free Heap Memory
6965**
6966** ^The sqlite3_release_memory() interface attempts to free N bytes
6967** of heap memory by deallocating non-essential memory allocations
6968** held by the database library. Memory used to cache database
6969** pages to improve performance is an example of non-essential memory.
6970** ^sqlite3_release_memory() returns the number of bytes actually freed,
6971** which might be more or less than the amount requested.
6972** ^The sqlite3_release_memory() routine is a no-op returning zero
6973** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6974**
6975** See also: [sqlite3_db_release_memory()]
6976*/
6977SQLITE_API int sqlite3_release_memory(int);
6978
6979/*
6980** CAPI3REF: Free Memory Used By A Database Connection
6981** METHOD: sqlite3
6982**
6983** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6984** memory as possible from database connection D. Unlike the
6985** [sqlite3_release_memory()] interface, this interface is in effect even
6986** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6987** omitted.
6988**
6989** See also: [sqlite3_release_memory()]
6990*/
6991SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6992
6993/*
6994** CAPI3REF: Impose A Limit On Heap Size
6995**
6996** These interfaces impose limits on the amount of heap memory that will be
6997** by all database connections within a single process.
6998**
6999** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7000** soft limit on the amount of heap memory that may be allocated by SQLite.
7001** ^SQLite strives to keep heap memory utilization below the soft heap
7002** limit by reducing the number of pages held in the page cache
7003** as heap memory usages approaches the limit.
7004** ^The soft heap limit is "soft" because even though SQLite strives to stay
7005** below the limit, it will exceed the limit rather than generate
7006** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7007** is advisory only.
7008**
7009** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7010** N bytes on the amount of memory that will be allocated. ^The
7011** sqlite3_hard_heap_limit64(N) interface is similar to
7012** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7013** when the hard heap limit is reached.
7014**
7015** ^The return value from both sqlite3_soft_heap_limit64() and
7016** sqlite3_hard_heap_limit64() is the size of
7017** the heap limit prior to the call, or negative in the case of an
7018** error. ^If the argument N is negative
7019** then no change is made to the heap limit. Hence, the current
7020** size of heap limits can be determined by invoking
7021** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7022**
7023** ^Setting the heap limits to zero disables the heap limiter mechanism.
7024**
7025** ^The soft heap limit may not be greater than the hard heap limit.
7026** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7027** is invoked with a value of N that is greater than the hard heap limit,
7028** the soft heap limit is set to the value of the hard heap limit.
7029** ^The soft heap limit is automatically enabled whenever the hard heap
7030** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7031** the soft heap limit is outside the range of 1..N, then the soft heap
7032** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7033** hard heap limit is enabled makes the soft heap limit equal to the
7034** hard heap limit.
7035**
7036** The memory allocation limits can also be adjusted using
7037** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7038**
7039** ^(The heap limits are not enforced in the current implementation
7040** if one or more of following conditions are true:
7041**
7042** <ul>
7043** <li> The limit value is set to zero.
7044** <li> Memory accounting is disabled using a combination of the
7045** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7046** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7047** <li> An alternative page cache implementation is specified using
7048** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7049** <li> The page cache allocates from its own memory pool supplied
7050** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7051** from the heap.
7052** </ul>)^
7053**
7054** The circumstances under which SQLite will enforce the heap limits may
7055** changes in future releases of SQLite.
7056*/
7057SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7058SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7059
7060/*
7061** CAPI3REF: Deprecated Soft Heap Limit Interface
7062** DEPRECATED
7063**
7064** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7065** interface. This routine is provided for historical compatibility
7066** only. All new applications should use the
7067** [sqlite3_soft_heap_limit64()] interface rather than this one.
7068*/
7069SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7070
7071
7072/*
7073** CAPI3REF: Extract Metadata About A Column Of A Table
7074** METHOD: sqlite3
7075**
7076** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7077** information about column C of table T in database D
7078** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7079** interface returns SQLITE_OK and fills in the non-NULL pointers in
7080** the final five arguments with appropriate values if the specified
7081** column exists. ^The sqlite3_table_column_metadata() interface returns
7082** SQLITE_ERROR if the specified column does not exist.
7083** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7084** NULL pointer, then this routine simply checks for the existence of the
7085** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7086** does not. If the table name parameter T in a call to
7087** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7088** undefined behavior.
7089**
7090** ^The column is identified by the second, third and fourth parameters to
7091** this function. ^(The second parameter is either the name of the database
7092** (i.e. "main", "temp", or an attached database) containing the specified
7093** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7094** for the table using the same algorithm used by the database engine to
7095** resolve unqualified table references.
7096**
7097** ^The third and fourth parameters to this function are the table and column
7098** name of the desired column, respectively.
7099**
7100** ^Metadata is returned by writing to the memory locations passed as the 5th
7101** and subsequent parameters to this function. ^Any of these arguments may be
7102** NULL, in which case the corresponding element of metadata is omitted.
7103**
7104** ^(<blockquote>
7105** <table border="1">
7106** <tr><th> Parameter <th> Output<br>Type <th> Description
7107**
7108** <tr><td> 5th <td> const char* <td> Data type
7109** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7110** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7111** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7112** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7113** </table>
7114** </blockquote>)^
7115**
7116** ^The memory pointed to by the character pointers returned for the
7117** declaration type and collation sequence is valid until the next
7118** call to any SQLite API function.
7119**
7120** ^If the specified table is actually a view, an [error code] is returned.
7121**
7122** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7123** is not a [WITHOUT ROWID] table and an
7124** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7125** parameters are set for the explicitly declared column. ^(If there is no
7126** [INTEGER PRIMARY KEY] column, then the outputs
7127** for the [rowid] are set as follows:
7128**
7129** <pre>
7130** data type: "INTEGER"
7131** collation sequence: "BINARY"
7132** not null: 0
7133** primary key: 1
7134** auto increment: 0
7135** </pre>)^
7136**
7137** ^This function causes all database schemas to be read from disk and
7138** parsed, if that has not already been done, and returns an error if
7139** any errors are encountered while loading the schema.
7140*/
7141SQLITE_API int sqlite3_table_column_metadata(
7142 sqlite3 *db, /* Connection handle */
7143 const char *zDbName, /* Database name or NULL */
7144 const char *zTableName, /* Table name */
7145 const char *zColumnName, /* Column name */
7146 char const **pzDataType, /* OUTPUT: Declared data type */
7147 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7148 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7149 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7150 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7151);
7152
7153/*
7154** CAPI3REF: Load An Extension
7155** METHOD: sqlite3
7156**
7157** ^This interface loads an SQLite extension library from the named file.
7158**
7159** ^The sqlite3_load_extension() interface attempts to load an
7160** [SQLite extension] library contained in the file zFile. If
7161** the file cannot be loaded directly, attempts are made to load
7162** with various operating-system specific extensions added.
7163** So for example, if "samplelib" cannot be loaded, then names like
7164** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7165** be tried also.
7166**
7167** ^The entry point is zProc.
7168** ^(zProc may be 0, in which case SQLite will try to come up with an
7169** entry point name on its own. It first tries "sqlite3_extension_init".
7170** If that does not work, it constructs a name "sqlite3_X_init" where the
7171** X is consists of the lower-case equivalent of all ASCII alphabetic
7172** characters in the filename from the last "/" to the first following
7173** "." and omitting any initial "lib".)^
7174** ^The sqlite3_load_extension() interface returns
7175** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7176** ^If an error occurs and pzErrMsg is not 0, then the
7177** [sqlite3_load_extension()] interface shall attempt to
7178** fill *pzErrMsg with error message text stored in memory
7179** obtained from [sqlite3_malloc()]. The calling function
7180** should free this memory by calling [sqlite3_free()].
7181**
7182** ^Extension loading must be enabled using
7183** [sqlite3_enable_load_extension()] or
7184** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7185** prior to calling this API,
7186** otherwise an error will be returned.
7187**
7188** <b>Security warning:</b> It is recommended that the
7189** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7190** interface. The use of the [sqlite3_enable_load_extension()] interface
7191** should be avoided. This will keep the SQL function [load_extension()]
7192** disabled and prevent SQL injections from giving attackers
7193** access to extension loading capabilities.
7194**
7195** See also the [load_extension() SQL function].
7196*/
7197SQLITE_API int sqlite3_load_extension(
7198 sqlite3 *db, /* Load the extension into this database connection */
7199 const char *zFile, /* Name of the shared library containing extension */
7200 const char *zProc, /* Entry point. Derived from zFile if 0 */
7201 char **pzErrMsg /* Put error message here if not 0 */
7202);
7203
7204/*
7205** CAPI3REF: Enable Or Disable Extension Loading
7206** METHOD: sqlite3
7207**
7208** ^So as not to open security holes in older applications that are
7209** unprepared to deal with [extension loading], and as a means of disabling
7210** [extension loading] while evaluating user-entered SQL, the following API
7211** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7212**
7213** ^Extension loading is off by default.
7214** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7215** to turn extension loading on and call it with onoff==0 to turn
7216** it back off again.
7217**
7218** ^This interface enables or disables both the C-API
7219** [sqlite3_load_extension()] and the SQL function [load_extension()].
7220** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7221** to enable or disable only the C-API.)^
7222**
7223** <b>Security warning:</b> It is recommended that extension loading
7224** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7225** rather than this interface, so the [load_extension()] SQL function
7226** remains disabled. This will prevent SQL injections from giving attackers
7227** access to extension loading capabilities.
7228*/
7229SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7230
7231/*
7232** CAPI3REF: Automatically Load Statically Linked Extensions
7233**
7234** ^This interface causes the xEntryPoint() function to be invoked for
7235** each new [database connection] that is created. The idea here is that
7236** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7237** that is to be automatically loaded into all new database connections.
7238**
7239** ^(Even though the function prototype shows that xEntryPoint() takes
7240** no arguments and returns void, SQLite invokes xEntryPoint() with three
7241** arguments and expects an integer result as if the signature of the
7242** entry point where as follows:
7243**
7244** <blockquote><pre>
7245** &nbsp; int xEntryPoint(
7246** &nbsp; sqlite3 *db,
7247** &nbsp; const char **pzErrMsg,
7248** &nbsp; const struct sqlite3_api_routines *pThunk
7249** &nbsp; );
7250** </pre></blockquote>)^
7251**
7252** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7253** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7254** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7255** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7256** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7257** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7258** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7259**
7260** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7261** on the list of automatic extensions is a harmless no-op. ^No entry point
7262** will be called more than once for each database connection that is opened.
7263**
7264** See also: [sqlite3_reset_auto_extension()]
7265** and [sqlite3_cancel_auto_extension()]
7266*/
7267SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7268
7269/*
7270** CAPI3REF: Cancel Automatic Extension Loading
7271**
7272** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7273** initialization routine X that was registered using a prior call to
7274** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7275** routine returns 1 if initialization routine X was successfully
7276** unregistered and it returns 0 if X was not on the list of initialization
7277** routines.
7278*/
7279SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7280
7281/*
7282** CAPI3REF: Reset Automatic Extension Loading
7283**
7284** ^This interface disables all automatic extensions previously
7285** registered using [sqlite3_auto_extension()].
7286*/
7287SQLITE_API void sqlite3_reset_auto_extension(void);
7288
7289/*
7290** Structures used by the virtual table interface
7291*/
7292typedef struct sqlite3_vtab sqlite3_vtab;
7293typedef struct sqlite3_index_info sqlite3_index_info;
7294typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7295typedef struct sqlite3_module sqlite3_module;
7296
7297/*
7298** CAPI3REF: Virtual Table Object
7299** KEYWORDS: sqlite3_module {virtual table module}
7300**
7301** This structure, sometimes called a "virtual table module",
7302** defines the implementation of a [virtual table].
7303** This structure consists mostly of methods for the module.
7304**
7305** ^A virtual table module is created by filling in a persistent
7306** instance of this structure and passing a pointer to that instance
7307** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7308** ^The registration remains valid until it is replaced by a different
7309** module or until the [database connection] closes. The content
7310** of this structure must not change while it is registered with
7311** any database connection.
7312*/
7313struct sqlite3_module {
7314 int iVersion;
7315 int (*xCreate)(sqlite3*, void *pAux,
7316 int argc, const char *const*argv,
7317 sqlite3_vtab **ppVTab, char**);
7318 int (*xConnect)(sqlite3*, void *pAux,
7319 int argc, const char *const*argv,
7320 sqlite3_vtab **ppVTab, char**);
7321 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7322 int (*xDisconnect)(sqlite3_vtab *pVTab);
7323 int (*xDestroy)(sqlite3_vtab *pVTab);
7324 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7325 int (*xClose)(sqlite3_vtab_cursor*);
7326 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7327 int argc, sqlite3_value **argv);
7328 int (*xNext)(sqlite3_vtab_cursor*);
7329 int (*xEof)(sqlite3_vtab_cursor*);
7330 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7331 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7332 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7333 int (*xBegin)(sqlite3_vtab *pVTab);
7334 int (*xSync)(sqlite3_vtab *pVTab);
7335 int (*xCommit)(sqlite3_vtab *pVTab);
7336 int (*xRollback)(sqlite3_vtab *pVTab);
7337 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7338 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7339 void **ppArg);
7340 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7341 /* The methods above are in version 1 of the sqlite_module object. Those
7342 ** below are for version 2 and greater. */
7343 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7344 int (*xRelease)(sqlite3_vtab *pVTab, int);
7345 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7346 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7347 ** Those below are for version 3 and greater. */
7348 int (*xShadowName)(const char*);
7349 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7350 ** Those below are for version 4 and greater. */
7351 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7352 const char *zTabName, int mFlags, char **pzErr);
7353};
7354
7355/*
7356** CAPI3REF: Virtual Table Indexing Information
7357** KEYWORDS: sqlite3_index_info
7358**
7359** The sqlite3_index_info structure and its substructures is used as part
7360** of the [virtual table] interface to
7361** pass information into and receive the reply from the [xBestIndex]
7362** method of a [virtual table module]. The fields under **Inputs** are the
7363** inputs to xBestIndex and are read-only. xBestIndex inserts its
7364** results into the **Outputs** fields.
7365**
7366** ^(The aConstraint[] array records WHERE clause constraints of the form:
7367**
7368** <blockquote>column OP expr</blockquote>
7369**
7370** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7371** stored in aConstraint[].op using one of the
7372** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7373** ^(The index of the column is stored in
7374** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7375** expr on the right-hand side can be evaluated (and thus the constraint
7376** is usable) and false if it cannot.)^
7377**
7378** ^The optimizer automatically inverts terms of the form "expr OP column"
7379** and makes other simplifications to the WHERE clause in an attempt to
7380** get as many WHERE clause terms into the form shown above as possible.
7381** ^The aConstraint[] array only reports WHERE clause terms that are
7382** relevant to the particular virtual table being queried.
7383**
7384** ^Information about the ORDER BY clause is stored in aOrderBy[].
7385** ^Each term of aOrderBy records a column of the ORDER BY clause.
7386**
7387** The colUsed field indicates which columns of the virtual table may be
7388** required by the current scan. Virtual table columns are numbered from
7389** zero in the order in which they appear within the CREATE TABLE statement
7390** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7391** the corresponding bit is set within the colUsed mask if the column may be
7392** required by SQLite. If the table has at least 64 columns and any column
7393** to the right of the first 63 is required, then bit 63 of colUsed is also
7394** set. In other words, column iCol may be required if the expression
7395** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7396** non-zero.
7397**
7398** The [xBestIndex] method must fill aConstraintUsage[] with information
7399** about what parameters to pass to xFilter. ^If argvIndex>0 then
7400** the right-hand side of the corresponding aConstraint[] is evaluated
7401** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7402** is true, then the constraint is assumed to be fully handled by the
7403** virtual table and might not be checked again by the byte code.)^ ^(The
7404** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7405** is left in its default setting of false, the constraint will always be
7406** checked separately in byte code. If the omit flag is change to true, then
7407** the constraint may or may not be checked in byte code. In other words,
7408** when the omit flag is true there is no guarantee that the constraint will
7409** not be checked again using byte code.)^
7410**
7411** ^The idxNum and idxStr values are recorded and passed into the
7412** [xFilter] method.
7413** ^[sqlite3_free()] is used to free idxStr if and only if
7414** needToFreeIdxStr is true.
7415**
7416** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7417** the correct order to satisfy the ORDER BY clause so that no separate
7418** sorting step is required.
7419**
7420** ^The estimatedCost value is an estimate of the cost of a particular
7421** strategy. A cost of N indicates that the cost of the strategy is similar
7422** to a linear scan of an SQLite table with N rows. A cost of log(N)
7423** indicates that the expense of the operation is similar to that of a
7424** binary search on a unique indexed field of an SQLite table with N rows.
7425**
7426** ^The estimatedRows value is an estimate of the number of rows that
7427** will be returned by the strategy.
7428**
7429** The xBestIndex method may optionally populate the idxFlags field with a
7430** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7431** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7432** assumes that the strategy may visit at most one row.
7433**
7434** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7435** SQLite also assumes that if a call to the xUpdate() method is made as
7436** part of the same statement to delete or update a virtual table row and the
7437** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7438** any database changes. In other words, if the xUpdate() returns
7439** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7440** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7441** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7442** the xUpdate method are automatically rolled back by SQLite.
7443**
7444** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7445** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7446** If a virtual table extension is
7447** used with an SQLite version earlier than 3.8.2, the results of attempting
7448** to read or write the estimatedRows field are undefined (but are likely
7449** to include crashing the application). The estimatedRows field should
7450** therefore only be used if [sqlite3_libversion_number()] returns a
7451** value greater than or equal to 3008002. Similarly, the idxFlags field
7452** was added for [version 3.9.0] ([dateof:3.9.0]).
7453** It may therefore only be used if
7454** sqlite3_libversion_number() returns a value greater than or equal to
7455** 3009000.
7456*/
7457struct sqlite3_index_info {
7458 /* Inputs */
7459 int nConstraint; /* Number of entries in aConstraint */
7460 struct sqlite3_index_constraint {
7461 int iColumn; /* Column constrained. -1 for ROWID */
7462 unsigned char op; /* Constraint operator */
7463 unsigned char usable; /* True if this constraint is usable */
7464 int iTermOffset; /* Used internally - xBestIndex should ignore */
7465 } *aConstraint; /* Table of WHERE clause constraints */
7466 int nOrderBy; /* Number of terms in the ORDER BY clause */
7467 struct sqlite3_index_orderby {
7468 int iColumn; /* Column number */
7469 unsigned char desc; /* True for DESC. False for ASC. */
7470 } *aOrderBy; /* The ORDER BY clause */
7471 /* Outputs */
7472 struct sqlite3_index_constraint_usage {
7473 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7474 unsigned char omit; /* Do not code a test for this constraint */
7475 } *aConstraintUsage;
7476 int idxNum; /* Number used to identify the index */
7477 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7478 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7479 int orderByConsumed; /* True if output is already ordered */
7480 double estimatedCost; /* Estimated cost of using this index */
7481 /* Fields below are only available in SQLite 3.8.2 and later */
7482 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7483 /* Fields below are only available in SQLite 3.9.0 and later */
7484 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7485 /* Fields below are only available in SQLite 3.10.0 and later */
7486 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7487};
7488
7489/*
7490** CAPI3REF: Virtual Table Scan Flags
7491**
7492** Virtual table implementations are allowed to set the
7493** [sqlite3_index_info].idxFlags field to some combination of
7494** these bits.
7495*/
7496#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7497
7498/*
7499** CAPI3REF: Virtual Table Constraint Operator Codes
7500**
7501** These macros define the allowed values for the
7502** [sqlite3_index_info].aConstraint[].op field. Each value represents
7503** an operator that is part of a constraint term in the WHERE clause of
7504** a query that uses a [virtual table].
7505**
7506** ^The left-hand operand of the operator is given by the corresponding
7507** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7508** operand is the rowid.
7509** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7510** operators have no left-hand operand, and so for those operators the
7511** corresponding aConstraint[].iColumn is meaningless and should not be
7512** used.
7513**
7514** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7515** value 255 are reserved to represent functions that are overloaded
7516** by the [xFindFunction|xFindFunction method] of the virtual table
7517** implementation.
7518**
7519** The right-hand operands for each constraint might be accessible using
7520** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7521** operand is only available if it appears as a single constant literal
7522** in the input SQL. If the right-hand operand is another column or an
7523** expression (even a constant expression) or a parameter, then the
7524** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7525** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7526** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7527** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7528** always return SQLITE_NOTFOUND.
7529**
7530** The collating sequence to be used for comparison can be found using
7531** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7532** tables, the collating sequence of constraints does not matter (for example
7533** because the constraints are numeric) and so the sqlite3_vtab_collation()
7534** interface is not commonly needed.
7535*/
7536#define SQLITE_INDEX_CONSTRAINT_EQ 2
7537#define SQLITE_INDEX_CONSTRAINT_GT 4
7538#define SQLITE_INDEX_CONSTRAINT_LE 8
7539#define SQLITE_INDEX_CONSTRAINT_LT 16
7540#define SQLITE_INDEX_CONSTRAINT_GE 32
7541#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7542#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7543#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7544#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7545#define SQLITE_INDEX_CONSTRAINT_NE 68
7546#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7547#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7548#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7549#define SQLITE_INDEX_CONSTRAINT_IS 72
7550#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7551#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7552#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7553
7554/*
7555** CAPI3REF: Register A Virtual Table Implementation
7556** METHOD: sqlite3
7557**
7558** ^These routines are used to register a new [virtual table module] name.
7559** ^Module names must be registered before
7560** creating a new [virtual table] using the module and before using a
7561** preexisting [virtual table] for the module.
7562**
7563** ^The module name is registered on the [database connection] specified
7564** by the first parameter. ^The name of the module is given by the
7565** second parameter. ^The third parameter is a pointer to
7566** the implementation of the [virtual table module]. ^The fourth
7567** parameter is an arbitrary client data pointer that is passed through
7568** into the [xCreate] and [xConnect] methods of the virtual table module
7569** when a new virtual table is be being created or reinitialized.
7570**
7571** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7572** is a pointer to a destructor for the pClientData. ^SQLite will
7573** invoke the destructor function (if it is not NULL) when SQLite
7574** no longer needs the pClientData pointer. ^The destructor will also
7575** be invoked if the call to sqlite3_create_module_v2() fails.
7576** ^The sqlite3_create_module()
7577** interface is equivalent to sqlite3_create_module_v2() with a NULL
7578** destructor.
7579**
7580** ^If the third parameter (the pointer to the sqlite3_module object) is
7581** NULL then no new module is created and any existing modules with the
7582** same name are dropped.
7583**
7584** See also: [sqlite3_drop_modules()]
7585*/
7586SQLITE_API int sqlite3_create_module(
7587 sqlite3 *db, /* SQLite connection to register module with */
7588 const char *zName, /* Name of the module */
7589 const sqlite3_module *p, /* Methods for the module */
7590 void *pClientData /* Client data for xCreate/xConnect */
7591);
7592SQLITE_API int sqlite3_create_module_v2(
7593 sqlite3 *db, /* SQLite connection to register module with */
7594 const char *zName, /* Name of the module */
7595 const sqlite3_module *p, /* Methods for the module */
7596 void *pClientData, /* Client data for xCreate/xConnect */
7597 void(*xDestroy)(void*) /* Module destructor function */
7598);
7599
7600/*
7601** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7602** METHOD: sqlite3
7603**
7604** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7605** table modules from database connection D except those named on list L.
7606** The L parameter must be either NULL or a pointer to an array of pointers
7607** to strings where the array is terminated by a single NULL pointer.
7608** ^If the L parameter is NULL, then all virtual table modules are removed.
7609**
7610** See also: [sqlite3_create_module()]
7611*/
7612SQLITE_API int sqlite3_drop_modules(
7613 sqlite3 *db, /* Remove modules from this connection */
7614 const char **azKeep /* Except, do not remove the ones named here */
7615);
7616
7617/*
7618** CAPI3REF: Virtual Table Instance Object
7619** KEYWORDS: sqlite3_vtab
7620**
7621** Every [virtual table module] implementation uses a subclass
7622** of this object to describe a particular instance
7623** of the [virtual table]. Each subclass will
7624** be tailored to the specific needs of the module implementation.
7625** The purpose of this superclass is to define certain fields that are
7626** common to all module implementations.
7627**
7628** ^Virtual tables methods can set an error message by assigning a
7629** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7630** take care that any prior string is freed by a call to [sqlite3_free()]
7631** prior to assigning a new string to zErrMsg. ^After the error message
7632** is delivered up to the client application, the string will be automatically
7633** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7634*/
7635struct sqlite3_vtab {
7636 const sqlite3_module *pModule; /* The module for this virtual table */
7637 int nRef; /* Number of open cursors */
7638 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7639 /* Virtual table implementations will typically add additional fields */
7640};
7641
7642/*
7643** CAPI3REF: Virtual Table Cursor Object
7644** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7645**
7646** Every [virtual table module] implementation uses a subclass of the
7647** following structure to describe cursors that point into the
7648** [virtual table] and are used
7649** to loop through the virtual table. Cursors are created using the
7650** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7651** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7652** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7653** of the module. Each module implementation will define
7654** the content of a cursor structure to suit its own needs.
7655**
7656** This superclass exists in order to define fields of the cursor that
7657** are common to all implementations.
7658*/
7659struct sqlite3_vtab_cursor {
7660 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7661 /* Virtual table implementations will typically add additional fields */
7662};
7663
7664/*
7665** CAPI3REF: Declare The Schema Of A Virtual Table
7666**
7667** ^The [xCreate] and [xConnect] methods of a
7668** [virtual table module] call this interface
7669** to declare the format (the names and datatypes of the columns) of
7670** the virtual tables they implement.
7671*/
7672SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7673
7674/*
7675** CAPI3REF: Overload A Function For A Virtual Table
7676** METHOD: sqlite3
7677**
7678** ^(Virtual tables can provide alternative implementations of functions
7679** using the [xFindFunction] method of the [virtual table module].
7680** But global versions of those functions
7681** must exist in order to be overloaded.)^
7682**
7683** ^(This API makes sure a global version of a function with a particular
7684** name and number of parameters exists. If no such function exists
7685** before this API is called, a new function is created.)^ ^The implementation
7686** of the new function always causes an exception to be thrown. So
7687** the new function is not good for anything by itself. Its only
7688** purpose is to be a placeholder function that can be overloaded
7689** by a [virtual table].
7690*/
7691SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7692
7693/*
7694** CAPI3REF: A Handle To An Open BLOB
7695** KEYWORDS: {BLOB handle} {BLOB handles}
7696**
7697** An instance of this object represents an open BLOB on which
7698** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7699** ^Objects of this type are created by [sqlite3_blob_open()]
7700** and destroyed by [sqlite3_blob_close()].
7701** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7702** can be used to read or write small subsections of the BLOB.
7703** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7704*/
7705typedef struct sqlite3_blob sqlite3_blob;
7706
7707/*
7708** CAPI3REF: Open A BLOB For Incremental I/O
7709** METHOD: sqlite3
7710** CONSTRUCTOR: sqlite3_blob
7711**
7712** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7713** in row iRow, column zColumn, table zTable in database zDb;
7714** in other words, the same BLOB that would be selected by:
7715**
7716** <pre>
7717** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7718** </pre>)^
7719**
7720** ^(Parameter zDb is not the filename that contains the database, but
7721** rather the symbolic name of the database. For attached databases, this is
7722** the name that appears after the AS keyword in the [ATTACH] statement.
7723** For the main database file, the database name is "main". For TEMP
7724** tables, the database name is "temp".)^
7725**
7726** ^If the flags parameter is non-zero, then the BLOB is opened for read
7727** and write access. ^If the flags parameter is zero, the BLOB is opened for
7728** read-only access.
7729**
7730** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7731** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7732** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7733** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7734** on *ppBlob after this function it returns.
7735**
7736** This function fails with SQLITE_ERROR if any of the following are true:
7737** <ul>
7738** <li> ^(Database zDb does not exist)^,
7739** <li> ^(Table zTable does not exist within database zDb)^,
7740** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7741** <li> ^(Column zColumn does not exist)^,
7742** <li> ^(Row iRow is not present in the table)^,
7743** <li> ^(The specified column of row iRow contains a value that is not
7744** a TEXT or BLOB value)^,
7745** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7746** constraint and the blob is being opened for read/write access)^,
7747** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7748** column zColumn is part of a [child key] definition and the blob is
7749** being opened for read/write access)^.
7750** </ul>
7751**
7752** ^Unless it returns SQLITE_MISUSE, this function sets the
7753** [database connection] error code and message accessible via
7754** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7755**
7756** A BLOB referenced by sqlite3_blob_open() may be read using the
7757** [sqlite3_blob_read()] interface and modified by using
7758** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7759** different row of the same table using the [sqlite3_blob_reopen()]
7760** interface. However, the column, table, or database of a [BLOB handle]
7761** cannot be changed after the [BLOB handle] is opened.
7762**
7763** ^(If the row that a BLOB handle points to is modified by an
7764** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7765** then the BLOB handle is marked as "expired".
7766** This is true if any column of the row is changed, even a column
7767** other than the one the BLOB handle is open on.)^
7768** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7769** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7770** ^(Changes written into a BLOB prior to the BLOB expiring are not
7771** rolled back by the expiration of the BLOB. Such changes will eventually
7772** commit if the transaction continues to completion.)^
7773**
7774** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7775** the opened blob. ^The size of a blob may not be changed by this
7776** interface. Use the [UPDATE] SQL command to change the size of a
7777** blob.
7778**
7779** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7780** and the built-in [zeroblob] SQL function may be used to create a
7781** zero-filled blob to read or write using the incremental-blob interface.
7782**
7783** To avoid a resource leak, every open [BLOB handle] should eventually
7784** be released by a call to [sqlite3_blob_close()].
7785**
7786** See also: [sqlite3_blob_close()],
7787** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7788** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7789*/
7790SQLITE_API int sqlite3_blob_open(
7791 sqlite3*,
7792 const char *zDb,
7793 const char *zTable,
7794 const char *zColumn,
7795 sqlite3_int64 iRow,
7796 int flags,
7797 sqlite3_blob **ppBlob
7798);
7799
7800/*
7801** CAPI3REF: Move a BLOB Handle to a New Row
7802** METHOD: sqlite3_blob
7803**
7804** ^This function is used to move an existing [BLOB handle] so that it points
7805** to a different row of the same database table. ^The new row is identified
7806** by the rowid value passed as the second argument. Only the row can be
7807** changed. ^The database, table and column on which the blob handle is open
7808** remain the same. Moving an existing [BLOB handle] to a new row is
7809** faster than closing the existing handle and opening a new one.
7810**
7811** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7812** it must exist and there must be either a blob or text value stored in
7813** the nominated column.)^ ^If the new row is not present in the table, or if
7814** it does not contain a blob or text value, or if another error occurs, an
7815** SQLite error code is returned and the blob handle is considered aborted.
7816** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7817** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7818** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7819** always returns zero.
7820**
7821** ^This function sets the database handle error code and message.
7822*/
7823SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7824
7825/*
7826** CAPI3REF: Close A BLOB Handle
7827** DESTRUCTOR: sqlite3_blob
7828**
7829** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7830** unconditionally. Even if this routine returns an error code, the
7831** handle is still closed.)^
7832**
7833** ^If the blob handle being closed was opened for read-write access, and if
7834** the database is in auto-commit mode and there are no other open read-write
7835** blob handles or active write statements, the current transaction is
7836** committed. ^If an error occurs while committing the transaction, an error
7837** code is returned and the transaction rolled back.
7838**
7839** Calling this function with an argument that is not a NULL pointer or an
7840** open blob handle results in undefined behavior. ^Calling this routine
7841** with a null pointer (such as would be returned by a failed call to
7842** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7843** is passed a valid open blob handle, the values returned by the
7844** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7845*/
7846SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7847
7848/*
7849** CAPI3REF: Return The Size Of An Open BLOB
7850** METHOD: sqlite3_blob
7851**
7852** ^Returns the size in bytes of the BLOB accessible via the
7853** successfully opened [BLOB handle] in its only argument. ^The
7854** incremental blob I/O routines can only read or overwriting existing
7855** blob content; they cannot change the size of a blob.
7856**
7857** This routine only works on a [BLOB handle] which has been created
7858** by a prior successful call to [sqlite3_blob_open()] and which has not
7859** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7860** to this routine results in undefined and probably undesirable behavior.
7861*/
7862SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7863
7864/*
7865** CAPI3REF: Read Data From A BLOB Incrementally
7866** METHOD: sqlite3_blob
7867**
7868** ^(This function is used to read data from an open [BLOB handle] into a
7869** caller-supplied buffer. N bytes of data are copied into buffer Z
7870** from the open BLOB, starting at offset iOffset.)^
7871**
7872** ^If offset iOffset is less than N bytes from the end of the BLOB,
7873** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7874** less than zero, [SQLITE_ERROR] is returned and no data is read.
7875** ^The size of the blob (and hence the maximum value of N+iOffset)
7876** can be determined using the [sqlite3_blob_bytes()] interface.
7877**
7878** ^An attempt to read from an expired [BLOB handle] fails with an
7879** error code of [SQLITE_ABORT].
7880**
7881** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7882** Otherwise, an [error code] or an [extended error code] is returned.)^
7883**
7884** This routine only works on a [BLOB handle] which has been created
7885** by a prior successful call to [sqlite3_blob_open()] and which has not
7886** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7887** to this routine results in undefined and probably undesirable behavior.
7888**
7889** See also: [sqlite3_blob_write()].
7890*/
7891SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7892
7893/*
7894** CAPI3REF: Write Data Into A BLOB Incrementally
7895** METHOD: sqlite3_blob
7896**
7897** ^(This function is used to write data into an open [BLOB handle] from a
7898** caller-supplied buffer. N bytes of data are copied from the buffer Z
7899** into the open BLOB, starting at offset iOffset.)^
7900**
7901** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7902** Otherwise, an [error code] or an [extended error code] is returned.)^
7903** ^Unless SQLITE_MISUSE is returned, this function sets the
7904** [database connection] error code and message accessible via
7905** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7906**
7907** ^If the [BLOB handle] passed as the first argument was not opened for
7908** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7909** this function returns [SQLITE_READONLY].
7910**
7911** This function may only modify the contents of the BLOB; it is
7912** not possible to increase the size of a BLOB using this API.
7913** ^If offset iOffset is less than N bytes from the end of the BLOB,
7914** [SQLITE_ERROR] is returned and no data is written. The size of the
7915** BLOB (and hence the maximum value of N+iOffset) can be determined
7916** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7917** than zero [SQLITE_ERROR] is returned and no data is written.
7918**
7919** ^An attempt to write to an expired [BLOB handle] fails with an
7920** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7921** before the [BLOB handle] expired are not rolled back by the
7922** expiration of the handle, though of course those changes might
7923** have been overwritten by the statement that expired the BLOB handle
7924** or by other independent statements.
7925**
7926** This routine only works on a [BLOB handle] which has been created
7927** by a prior successful call to [sqlite3_blob_open()] and which has not
7928** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7929** to this routine results in undefined and probably undesirable behavior.
7930**
7931** See also: [sqlite3_blob_read()].
7932*/
7933SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7934
7935/*
7936** CAPI3REF: Virtual File System Objects
7937**
7938** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7939** that SQLite uses to interact
7940** with the underlying operating system. Most SQLite builds come with a
7941** single default VFS that is appropriate for the host computer.
7942** New VFSes can be registered and existing VFSes can be unregistered.
7943** The following interfaces are provided.
7944**
7945** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7946** ^Names are case sensitive.
7947** ^Names are zero-terminated UTF-8 strings.
7948** ^If there is no match, a NULL pointer is returned.
7949** ^If zVfsName is NULL then the default VFS is returned.
7950**
7951** ^New VFSes are registered with sqlite3_vfs_register().
7952** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7953** ^The same VFS can be registered multiple times without injury.
7954** ^To make an existing VFS into the default VFS, register it again
7955** with the makeDflt flag set. If two different VFSes with the
7956** same name are registered, the behavior is undefined. If a
7957** VFS is registered with a name that is NULL or an empty string,
7958** then the behavior is undefined.
7959**
7960** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7961** ^(If the default VFS is unregistered, another VFS is chosen as
7962** the default. The choice for the new VFS is arbitrary.)^
7963*/
7964SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7965SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7966SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7967
7968/*
7969** CAPI3REF: Mutexes
7970**
7971** The SQLite core uses these routines for thread
7972** synchronization. Though they are intended for internal
7973** use by SQLite, code that links against SQLite is
7974** permitted to use any of these routines.
7975**
7976** The SQLite source code contains multiple implementations
7977** of these mutex routines. An appropriate implementation
7978** is selected automatically at compile-time. The following
7979** implementations are available in the SQLite core:
7980**
7981** <ul>
7982** <li> SQLITE_MUTEX_PTHREADS
7983** <li> SQLITE_MUTEX_W32
7984** <li> SQLITE_MUTEX_NOOP
7985** </ul>
7986**
7987** The SQLITE_MUTEX_NOOP implementation is a set of routines
7988** that does no real locking and is appropriate for use in
7989** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7990** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7991** and Windows.
7992**
7993** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7994** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7995** implementation is included with the library. In this case the
7996** application must supply a custom mutex implementation using the
7997** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7998** before calling sqlite3_initialize() or any other public sqlite3_
7999** function that calls sqlite3_initialize().
8000**
8001** ^The sqlite3_mutex_alloc() routine allocates a new
8002** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8003** routine returns NULL if it is unable to allocate the requested
8004** mutex. The argument to sqlite3_mutex_alloc() must one of these
8005** integer constants:
8006**
8007** <ul>
8008** <li> SQLITE_MUTEX_FAST
8009** <li> SQLITE_MUTEX_RECURSIVE
8010** <li> SQLITE_MUTEX_STATIC_MAIN
8011** <li> SQLITE_MUTEX_STATIC_MEM
8012** <li> SQLITE_MUTEX_STATIC_OPEN
8013** <li> SQLITE_MUTEX_STATIC_PRNG
8014** <li> SQLITE_MUTEX_STATIC_LRU
8015** <li> SQLITE_MUTEX_STATIC_PMEM
8016** <li> SQLITE_MUTEX_STATIC_APP1
8017** <li> SQLITE_MUTEX_STATIC_APP2
8018** <li> SQLITE_MUTEX_STATIC_APP3
8019** <li> SQLITE_MUTEX_STATIC_VFS1
8020** <li> SQLITE_MUTEX_STATIC_VFS2
8021** <li> SQLITE_MUTEX_STATIC_VFS3
8022** </ul>
8023**
8024** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8025** cause sqlite3_mutex_alloc() to create
8026** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8027** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8028** The mutex implementation does not need to make a distinction
8029** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8030** not want to. SQLite will only request a recursive mutex in
8031** cases where it really needs one. If a faster non-recursive mutex
8032** implementation is available on the host platform, the mutex subsystem
8033** might return such a mutex in response to SQLITE_MUTEX_FAST.
8034**
8035** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8036** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8037** a pointer to a static preexisting mutex. ^Nine static mutexes are
8038** used by the current version of SQLite. Future versions of SQLite
8039** may add additional static mutexes. Static mutexes are for internal
8040** use by SQLite only. Applications that use SQLite mutexes should
8041** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8042** SQLITE_MUTEX_RECURSIVE.
8043**
8044** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8045** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8046** returns a different mutex on every call. ^For the static
8047** mutex types, the same mutex is returned on every call that has
8048** the same type number.
8049**
8050** ^The sqlite3_mutex_free() routine deallocates a previously
8051** allocated dynamic mutex. Attempting to deallocate a static
8052** mutex results in undefined behavior.
8053**
8054** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8055** to enter a mutex. ^If another thread is already within the mutex,
8056** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8057** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8058** upon successful entry. ^(Mutexes created using
8059** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8060** In such cases, the
8061** mutex must be exited an equal number of times before another thread
8062** can enter.)^ If the same thread tries to enter any mutex other
8063** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8064**
8065** ^(Some systems (for example, Windows 95) do not support the operation
8066** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8067** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8068** sqlite3_mutex_try() as an optimization, so this is acceptable
8069** behavior. The exceptions are unix builds that set the
8070** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8071** sqlite3_mutex_try() is required.)^
8072**
8073** ^The sqlite3_mutex_leave() routine exits a mutex that was
8074** previously entered by the same thread. The behavior
8075** is undefined if the mutex is not currently entered by the
8076** calling thread or is not currently allocated.
8077**
8078** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8079** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8080** then any of the four routines behaves as a no-op.
8081**
8082** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8083*/
8084SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8085SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8086SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8087SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8088SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8089
8090/*
8091** CAPI3REF: Mutex Methods Object
8092**
8093** An instance of this structure defines the low-level routines
8094** used to allocate and use mutexes.
8095**
8096** Usually, the default mutex implementations provided by SQLite are
8097** sufficient, however the application has the option of substituting a custom
8098** implementation for specialized deployments or systems for which SQLite
8099** does not provide a suitable implementation. In this case, the application
8100** creates and populates an instance of this structure to pass
8101** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8102** Additionally, an instance of this structure can be used as an
8103** output variable when querying the system for the current mutex
8104** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8105**
8106** ^The xMutexInit method defined by this structure is invoked as
8107** part of system initialization by the sqlite3_initialize() function.
8108** ^The xMutexInit routine is called by SQLite exactly once for each
8109** effective call to [sqlite3_initialize()].
8110**
8111** ^The xMutexEnd method defined by this structure is invoked as
8112** part of system shutdown by the sqlite3_shutdown() function. The
8113** implementation of this method is expected to release all outstanding
8114** resources obtained by the mutex methods implementation, especially
8115** those obtained by the xMutexInit method. ^The xMutexEnd()
8116** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8117**
8118** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8119** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8120** xMutexNotheld) implement the following interfaces (respectively):
8121**
8122** <ul>
8123** <li> [sqlite3_mutex_alloc()] </li>
8124** <li> [sqlite3_mutex_free()] </li>
8125** <li> [sqlite3_mutex_enter()] </li>
8126** <li> [sqlite3_mutex_try()] </li>
8127** <li> [sqlite3_mutex_leave()] </li>
8128** <li> [sqlite3_mutex_held()] </li>
8129** <li> [sqlite3_mutex_notheld()] </li>
8130** </ul>)^
8131**
8132** The only difference is that the public sqlite3_XXX functions enumerated
8133** above silently ignore any invocations that pass a NULL pointer instead
8134** of a valid mutex handle. The implementations of the methods defined
8135** by this structure are not required to handle this case. The results
8136** of passing a NULL pointer instead of a valid mutex handle are undefined
8137** (i.e. it is acceptable to provide an implementation that segfaults if
8138** it is passed a NULL pointer).
8139**
8140** The xMutexInit() method must be threadsafe. It must be harmless to
8141** invoke xMutexInit() multiple times within the same process and without
8142** intervening calls to xMutexEnd(). Second and subsequent calls to
8143** xMutexInit() must be no-ops.
8144**
8145** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8146** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8147** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8148** memory allocation for a fast or recursive mutex.
8149**
8150** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8151** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8152** If xMutexInit fails in any way, it is expected to clean up after itself
8153** prior to returning.
8154*/
8155typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8156struct sqlite3_mutex_methods {
8157 int (*xMutexInit)(void);
8158 int (*xMutexEnd)(void);
8159 sqlite3_mutex *(*xMutexAlloc)(int);
8160 void (*xMutexFree)(sqlite3_mutex *);
8161 void (*xMutexEnter)(sqlite3_mutex *);
8162 int (*xMutexTry)(sqlite3_mutex *);
8163 void (*xMutexLeave)(sqlite3_mutex *);
8164 int (*xMutexHeld)(sqlite3_mutex *);
8165 int (*xMutexNotheld)(sqlite3_mutex *);
8166};
8167
8168/*
8169** CAPI3REF: Mutex Verification Routines
8170**
8171** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8172** are intended for use inside assert() statements. The SQLite core
8173** never uses these routines except inside an assert() and applications
8174** are advised to follow the lead of the core. The SQLite core only
8175** provides implementations for these routines when it is compiled
8176** with the SQLITE_DEBUG flag. External mutex implementations
8177** are only required to provide these routines if SQLITE_DEBUG is
8178** defined and if NDEBUG is not defined.
8179**
8180** These routines should return true if the mutex in their argument
8181** is held or not held, respectively, by the calling thread.
8182**
8183** The implementation is not required to provide versions of these
8184** routines that actually work. If the implementation does not provide working
8185** versions of these routines, it should at least provide stubs that always
8186** return true so that one does not get spurious assertion failures.
8187**
8188** If the argument to sqlite3_mutex_held() is a NULL pointer then
8189** the routine should return 1. This seems counter-intuitive since
8190** clearly the mutex cannot be held if it does not exist. But
8191** the reason the mutex does not exist is because the build is not
8192** using mutexes. And we do not want the assert() containing the
8193** call to sqlite3_mutex_held() to fail, so a non-zero return is
8194** the appropriate thing to do. The sqlite3_mutex_notheld()
8195** interface should also return 1 when given a NULL pointer.
8196*/
8197#ifndef NDEBUG
8198SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8199SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8200#endif
8201
8202/*
8203** CAPI3REF: Mutex Types
8204**
8205** The [sqlite3_mutex_alloc()] interface takes a single argument
8206** which is one of these integer constants.
8207**
8208** The set of static mutexes may change from one SQLite release to the
8209** next. Applications that override the built-in mutex logic must be
8210** prepared to accommodate additional static mutexes.
8211*/
8212#define SQLITE_MUTEX_FAST 0
8213#define SQLITE_MUTEX_RECURSIVE 1
8214#define SQLITE_MUTEX_STATIC_MAIN 2
8215#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8216#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8217#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8218#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8219#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8220#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8221#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8222#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8223#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8224#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8225#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8226#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8227#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8228
8229/* Legacy compatibility: */
8230#define SQLITE_MUTEX_STATIC_MASTER 2
8231
8232
8233/*
8234** CAPI3REF: Retrieve the mutex for a database connection
8235** METHOD: sqlite3
8236**
8237** ^This interface returns a pointer the [sqlite3_mutex] object that
8238** serializes access to the [database connection] given in the argument
8239** when the [threading mode] is Serialized.
8240** ^If the [threading mode] is Single-thread or Multi-thread then this
8241** routine returns a NULL pointer.
8242*/
8243SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8244
8245/*
8246** CAPI3REF: Low-Level Control Of Database Files
8247** METHOD: sqlite3
8248** KEYWORDS: {file control}
8249**
8250** ^The [sqlite3_file_control()] interface makes a direct call to the
8251** xFileControl method for the [sqlite3_io_methods] object associated
8252** with a particular database identified by the second argument. ^The
8253** name of the database is "main" for the main database or "temp" for the
8254** TEMP database, or the name that appears after the AS keyword for
8255** databases that are added using the [ATTACH] SQL command.
8256** ^A NULL pointer can be used in place of "main" to refer to the
8257** main database file.
8258** ^The third and fourth parameters to this routine
8259** are passed directly through to the second and third parameters of
8260** the xFileControl method. ^The return value of the xFileControl
8261** method becomes the return value of this routine.
8262**
8263** A few opcodes for [sqlite3_file_control()] are handled directly
8264** by the SQLite core and never invoke the
8265** sqlite3_io_methods.xFileControl method.
8266** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8267** a pointer to the underlying [sqlite3_file] object to be written into
8268** the space pointed to by the 4th parameter. The
8269** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8270** the [sqlite3_file] object associated with the journal file instead of
8271** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8272** a pointer to the underlying [sqlite3_vfs] object for the file.
8273** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8274** from the pager.
8275**
8276** ^If the second parameter (zDbName) does not match the name of any
8277** open database file, then SQLITE_ERROR is returned. ^This error
8278** code is not remembered and will not be recalled by [sqlite3_errcode()]
8279** or [sqlite3_errmsg()]. The underlying xFileControl method might
8280** also return SQLITE_ERROR. There is no way to distinguish between
8281** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8282** xFileControl method.
8283**
8284** See also: [file control opcodes]
8285*/
8286SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8287
8288/*
8289** CAPI3REF: Testing Interface
8290**
8291** ^The sqlite3_test_control() interface is used to read out internal
8292** state of SQLite and to inject faults into SQLite for testing
8293** purposes. ^The first parameter is an operation code that determines
8294** the number, meaning, and operation of all subsequent parameters.
8295**
8296** This interface is not for use by applications. It exists solely
8297** for verifying the correct operation of the SQLite library. Depending
8298** on how the SQLite library is compiled, this interface might not exist.
8299**
8300** The details of the operation codes, their meanings, the parameters
8301** they take, and what they do are all subject to change without notice.
8302** Unlike most of the SQLite API, this function is not guaranteed to
8303** operate consistently from one release to the next.
8304*/
8305SQLITE_API int sqlite3_test_control(int op, ...);
8306
8307/*
8308** CAPI3REF: Testing Interface Operation Codes
8309**
8310** These constants are the valid operation code parameters used
8311** as the first argument to [sqlite3_test_control()].
8312**
8313** These parameters and their meanings are subject to change
8314** without notice. These values are for testing purposes only.
8315** Applications should not use any of these parameters or the
8316** [sqlite3_test_control()] interface.
8317*/
8318#define SQLITE_TESTCTRL_FIRST 5
8319#define SQLITE_TESTCTRL_PRNG_SAVE 5
8320#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8321#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8322#define SQLITE_TESTCTRL_FK_NO_ACTION 7
8323#define SQLITE_TESTCTRL_BITVEC_TEST 8
8324#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8325#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8326#define SQLITE_TESTCTRL_PENDING_BYTE 11
8327#define SQLITE_TESTCTRL_ASSERT 12
8328#define SQLITE_TESTCTRL_ALWAYS 13
8329#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8330#define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8331#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8332#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8333#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8334#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8335#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8336#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8337#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8338#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8339#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8340#define SQLITE_TESTCTRL_BYTEORDER 22
8341#define SQLITE_TESTCTRL_ISINIT 23
8342#define SQLITE_TESTCTRL_SORTER_MMAP 24
8343#define SQLITE_TESTCTRL_IMPOSTER 25
8344#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8345#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8346#define SQLITE_TESTCTRL_PRNG_SEED 28
8347#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8348#define SQLITE_TESTCTRL_SEEK_COUNT 30
8349#define SQLITE_TESTCTRL_TRACEFLAGS 31
8350#define SQLITE_TESTCTRL_TUNE 32
8351#define SQLITE_TESTCTRL_LOGEST 33
8352#define SQLITE_TESTCTRL_USELONGDOUBLE 34
8353#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8354
8355/*
8356** CAPI3REF: SQL Keyword Checking
8357**
8358** These routines provide access to the set of SQL language keywords
8359** recognized by SQLite. Applications can uses these routines to determine
8360** whether or not a specific identifier needs to be escaped (for example,
8361** by enclosing in double-quotes) so as not to confuse the parser.
8362**
8363** The sqlite3_keyword_count() interface returns the number of distinct
8364** keywords understood by SQLite.
8365**
8366** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8367** makes *Z point to that keyword expressed as UTF8 and writes the number
8368** of bytes in the keyword into *L. The string that *Z points to is not
8369** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8370** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8371** or L are NULL or invalid pointers then calls to
8372** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8373**
8374** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8375** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8376** if it is and zero if not.
8377**
8378** The parser used by SQLite is forgiving. It is often possible to use
8379** a keyword as an identifier as long as such use does not result in a
8380** parsing ambiguity. For example, the statement
8381** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8382** creates a new table named "BEGIN" with three columns named
8383** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8384** using keywords as identifiers. Common techniques used to avoid keyword
8385** name collisions include:
8386** <ul>
8387** <li> Put all identifier names inside double-quotes. This is the official
8388** SQL way to escape identifier names.
8389** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8390** but it is what SQL Server does and so lots of programmers use this
8391** technique.
8392** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8393** with "Z".
8394** <li> Include a digit somewhere in every identifier name.
8395** </ul>
8396**
8397** Note that the number of keywords understood by SQLite can depend on
8398** compile-time options. For example, "VACUUM" is not a keyword if
8399** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8400** new keywords may be added to future releases of SQLite.
8401*/
8402SQLITE_API int sqlite3_keyword_count(void);
8403SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8404SQLITE_API int sqlite3_keyword_check(const char*,int);
8405
8406/*
8407** CAPI3REF: Dynamic String Object
8408** KEYWORDS: {dynamic string}
8409**
8410** An instance of the sqlite3_str object contains a dynamically-sized
8411** string under construction.
8412**
8413** The lifecycle of an sqlite3_str object is as follows:
8414** <ol>
8415** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8416** <li> ^Text is appended to the sqlite3_str object using various
8417** methods, such as [sqlite3_str_appendf()].
8418** <li> ^The sqlite3_str object is destroyed and the string it created
8419** is returned using the [sqlite3_str_finish()] interface.
8420** </ol>
8421*/
8422typedef struct sqlite3_str sqlite3_str;
8423
8424/*
8425** CAPI3REF: Create A New Dynamic String Object
8426** CONSTRUCTOR: sqlite3_str
8427**
8428** ^The [sqlite3_str_new(D)] interface allocates and initializes
8429** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8430** [sqlite3_str_new()] must be freed by a subsequent call to
8431** [sqlite3_str_finish(X)].
8432**
8433** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8434** valid [sqlite3_str] object, though in the event of an out-of-memory
8435** error the returned object might be a special singleton that will
8436** silently reject new text, always return SQLITE_NOMEM from
8437** [sqlite3_str_errcode()], always return 0 for
8438** [sqlite3_str_length()], and always return NULL from
8439** [sqlite3_str_finish(X)]. It is always safe to use the value
8440** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8441** to any of the other [sqlite3_str] methods.
8442**
8443** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8444** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8445** length of the string contained in the [sqlite3_str] object will be
8446** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8447** of [SQLITE_MAX_LENGTH].
8448*/
8449SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8450
8451/*
8452** CAPI3REF: Finalize A Dynamic String
8453** DESTRUCTOR: sqlite3_str
8454**
8455** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8456** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8457** that contains the constructed string. The calling application should
8458** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8459** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8460** errors were encountered during construction of the string. ^The
8461** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8462** string in [sqlite3_str] object X is zero bytes long.
8463*/
8464SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8465
8466/*
8467** CAPI3REF: Add Content To A Dynamic String
8468** METHOD: sqlite3_str
8469**
8470** These interfaces add content to an sqlite3_str object previously obtained
8471** from [sqlite3_str_new()].
8472**
8473** ^The [sqlite3_str_appendf(X,F,...)] and
8474** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8475** functionality of SQLite to append formatted text onto the end of
8476** [sqlite3_str] object X.
8477**
8478** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8479** onto the end of the [sqlite3_str] object X. N must be non-negative.
8480** S must contain at least N non-zero bytes of content. To append a
8481** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8482** method instead.
8483**
8484** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8485** zero-terminated string S onto the end of [sqlite3_str] object X.
8486**
8487** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8488** single-byte character C onto the end of [sqlite3_str] object X.
8489** ^This method can be used, for example, to add whitespace indentation.
8490**
8491** ^The [sqlite3_str_reset(X)] method resets the string under construction
8492** inside [sqlite3_str] object X back to zero bytes in length.
8493**
8494** These methods do not return a result code. ^If an error occurs, that fact
8495** is recorded in the [sqlite3_str] object and can be recovered by a
8496** subsequent call to [sqlite3_str_errcode(X)].
8497*/
8498SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8499SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8500SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8501SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8502SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8503SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8504
8505/*
8506** CAPI3REF: Status Of A Dynamic String
8507** METHOD: sqlite3_str
8508**
8509** These interfaces return the current status of an [sqlite3_str] object.
8510**
8511** ^If any prior errors have occurred while constructing the dynamic string
8512** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8513** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8514** [SQLITE_NOMEM] following any out-of-memory error, or
8515** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8516** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8517**
8518** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8519** of the dynamic string under construction in [sqlite3_str] object X.
8520** ^The length returned by [sqlite3_str_length(X)] does not include the
8521** zero-termination byte.
8522**
8523** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8524** content of the dynamic string under construction in X. The value
8525** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8526** and might be freed or altered by any subsequent method on the same
8527** [sqlite3_str] object. Applications must not used the pointer returned
8528** [sqlite3_str_value(X)] after any subsequent method call on the same
8529** object. ^Applications may change the content of the string returned
8530** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8531** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8532** write any byte after any subsequent sqlite3_str method call.
8533*/
8534SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8535SQLITE_API int sqlite3_str_length(sqlite3_str*);
8536SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8537
8538/*
8539** CAPI3REF: SQLite Runtime Status
8540**
8541** ^These interfaces are used to retrieve runtime status information
8542** about the performance of SQLite, and optionally to reset various
8543** highwater marks. ^The first argument is an integer code for
8544** the specific parameter to measure. ^(Recognized integer codes
8545** are of the form [status parameters | SQLITE_STATUS_...].)^
8546** ^The current value of the parameter is returned into *pCurrent.
8547** ^The highest recorded value is returned in *pHighwater. ^If the
8548** resetFlag is true, then the highest record value is reset after
8549** *pHighwater is written. ^(Some parameters do not record the highest
8550** value. For those parameters
8551** nothing is written into *pHighwater and the resetFlag is ignored.)^
8552** ^(Other parameters record only the highwater mark and not the current
8553** value. For these latter parameters nothing is written into *pCurrent.)^
8554**
8555** ^The sqlite3_status() and sqlite3_status64() routines return
8556** SQLITE_OK on success and a non-zero [error code] on failure.
8557**
8558** If either the current value or the highwater mark is too large to
8559** be represented by a 32-bit integer, then the values returned by
8560** sqlite3_status() are undefined.
8561**
8562** See also: [sqlite3_db_status()]
8563*/
8564SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8565SQLITE_API int sqlite3_status64(
8566 int op,
8567 sqlite3_int64 *pCurrent,
8568 sqlite3_int64 *pHighwater,
8569 int resetFlag
8570);
8571
8572
8573/*
8574** CAPI3REF: Status Parameters
8575** KEYWORDS: {status parameters}
8576**
8577** These integer constants designate various run-time status parameters
8578** that can be returned by [sqlite3_status()].
8579**
8580** <dl>
8581** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8582** <dd>This parameter is the current amount of memory checked out
8583** using [sqlite3_malloc()], either directly or indirectly. The
8584** figure includes calls made to [sqlite3_malloc()] by the application
8585** and internal memory usage by the SQLite library. Auxiliary page-cache
8586** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8587** this parameter. The amount returned is the sum of the allocation
8588** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8589**
8590** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8591** <dd>This parameter records the largest memory allocation request
8592** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8593** internal equivalents). Only the value returned in the
8594** *pHighwater parameter to [sqlite3_status()] is of interest.
8595** The value written into the *pCurrent parameter is undefined.</dd>)^
8596**
8597** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8598** <dd>This parameter records the number of separate memory allocations
8599** currently checked out.</dd>)^
8600**
8601** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8602** <dd>This parameter returns the number of pages used out of the
8603** [pagecache memory allocator] that was configured using
8604** [SQLITE_CONFIG_PAGECACHE]. The
8605** value returned is in pages, not in bytes.</dd>)^
8606**
8607** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8608** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8609** <dd>This parameter returns the number of bytes of page cache
8610** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8611** buffer and where forced to overflow to [sqlite3_malloc()]. The
8612** returned value includes allocations that overflowed because they
8613** where too large (they were larger than the "sz" parameter to
8614** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8615** no space was left in the page cache.</dd>)^
8616**
8617** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8618** <dd>This parameter records the largest memory allocation request
8619** handed to the [pagecache memory allocator]. Only the value returned in the
8620** *pHighwater parameter to [sqlite3_status()] is of interest.
8621** The value written into the *pCurrent parameter is undefined.</dd>)^
8622**
8623** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8624** <dd>No longer used.</dd>
8625**
8626** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8627** <dd>No longer used.</dd>
8628**
8629** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8630** <dd>No longer used.</dd>
8631**
8632** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8633** <dd>The *pHighwater parameter records the deepest parser stack.
8634** The *pCurrent value is undefined. The *pHighwater value is only
8635** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8636** </dl>
8637**
8638** New status parameters may be added from time to time.
8639*/
8640#define SQLITE_STATUS_MEMORY_USED 0
8641#define SQLITE_STATUS_PAGECACHE_USED 1
8642#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8643#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8644#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8645#define SQLITE_STATUS_MALLOC_SIZE 5
8646#define SQLITE_STATUS_PARSER_STACK 6
8647#define SQLITE_STATUS_PAGECACHE_SIZE 7
8648#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8649#define SQLITE_STATUS_MALLOC_COUNT 9
8650
8651/*
8652** CAPI3REF: Database Connection Status
8653** METHOD: sqlite3
8654**
8655** ^This interface is used to retrieve runtime status information
8656** about a single [database connection]. ^The first argument is the
8657** database connection object to be interrogated. ^The second argument
8658** is an integer constant, taken from the set of
8659** [SQLITE_DBSTATUS options], that
8660** determines the parameter to interrogate. The set of
8661** [SQLITE_DBSTATUS options] is likely
8662** to grow in future releases of SQLite.
8663**
8664** ^The current value of the requested parameter is written into *pCur
8665** and the highest instantaneous value is written into *pHiwtr. ^If
8666** the resetFlg is true, then the highest instantaneous value is
8667** reset back down to the current value.
8668**
8669** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8670** non-zero [error code] on failure.
8671**
8672** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8673*/
8674SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8675
8676/*
8677** CAPI3REF: Status Parameters for database connections
8678** KEYWORDS: {SQLITE_DBSTATUS options}
8679**
8680** These constants are the available integer "verbs" that can be passed as
8681** the second argument to the [sqlite3_db_status()] interface.
8682**
8683** New verbs may be added in future releases of SQLite. Existing verbs
8684** might be discontinued. Applications should check the return code from
8685** [sqlite3_db_status()] to make sure that the call worked.
8686** The [sqlite3_db_status()] interface will return a non-zero error code
8687** if a discontinued or unsupported verb is invoked.
8688**
8689** <dl>
8690** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8691** <dd>This parameter returns the number of lookaside memory slots currently
8692** checked out.</dd>)^
8693**
8694** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8695** <dd>This parameter returns the number of malloc attempts that were
8696** satisfied using lookaside memory. Only the high-water value is meaningful;
8697** the current value is always zero.)^
8698**
8699** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8700** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8701** <dd>This parameter returns the number malloc attempts that might have
8702** been satisfied using lookaside memory but failed due to the amount of
8703** memory requested being larger than the lookaside slot size.
8704** Only the high-water value is meaningful;
8705** the current value is always zero.)^
8706**
8707** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8708** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8709** <dd>This parameter returns the number malloc attempts that might have
8710** been satisfied using lookaside memory but failed due to all lookaside
8711** memory already being in use.
8712** Only the high-water value is meaningful;
8713** the current value is always zero.)^
8714**
8715** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8716** <dd>This parameter returns the approximate number of bytes of heap
8717** memory used by all pager caches associated with the database connection.)^
8718** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8719**
8720** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8721** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8722** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8723** pager cache is shared between two or more connections the bytes of heap
8724** memory used by that pager cache is divided evenly between the attached
8725** connections.)^ In other words, if none of the pager caches associated
8726** with the database connection are shared, this request returns the same
8727** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8728** shared, the value returned by this call will be smaller than that returned
8729** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8730** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8731**
8732** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8733** <dd>This parameter returns the approximate number of bytes of heap
8734** memory used to store the schema for all databases associated
8735** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8736** ^The full amount of memory used by the schemas is reported, even if the
8737** schema memory is shared with other database connections due to
8738** [shared cache mode] being enabled.
8739** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8740**
8741** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8742** <dd>This parameter returns the approximate number of bytes of heap
8743** and lookaside memory used by all prepared statements associated with
8744** the database connection.)^
8745** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8746** </dd>
8747**
8748** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8749** <dd>This parameter returns the number of pager cache hits that have
8750** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8751** is always 0.
8752** </dd>
8753**
8754** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8755** <dd>This parameter returns the number of pager cache misses that have
8756** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8757** is always 0.
8758** </dd>
8759**
8760** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8761** <dd>This parameter returns the number of dirty cache entries that have
8762** been written to disk. Specifically, the number of pages written to the
8763** wal file in wal mode databases, or the number of pages written to the
8764** database file in rollback mode databases. Any pages written as part of
8765** transaction rollback or database recovery operations are not included.
8766** If an IO or other error occurs while writing a page to disk, the effect
8767** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8768** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8769** </dd>
8770**
8771** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8772** <dd>This parameter returns the number of dirty cache entries that have
8773** been written to disk in the middle of a transaction due to the page
8774** cache overflowing. Transactions are more efficient if they are written
8775** to disk all at once. When pages spill mid-transaction, that introduces
8776** additional overhead. This parameter can be used help identify
8777** inefficiencies that can be resolved by increasing the cache size.
8778** </dd>
8779**
8780** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8781** <dd>This parameter returns zero for the current value if and only if
8782** all foreign key constraints (deferred or immediate) have been
8783** resolved.)^ ^The highwater mark is always 0.
8784** </dd>
8785** </dl>
8786*/
8787#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8788#define SQLITE_DBSTATUS_CACHE_USED 1
8789#define SQLITE_DBSTATUS_SCHEMA_USED 2
8790#define SQLITE_DBSTATUS_STMT_USED 3
8791#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8792#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8793#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8794#define SQLITE_DBSTATUS_CACHE_HIT 7
8795#define SQLITE_DBSTATUS_CACHE_MISS 8
8796#define SQLITE_DBSTATUS_CACHE_WRITE 9
8797#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8798#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8799#define SQLITE_DBSTATUS_CACHE_SPILL 12
8800#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8801
8802
8803/*
8804** CAPI3REF: Prepared Statement Status
8805** METHOD: sqlite3_stmt
8806**
8807** ^(Each prepared statement maintains various
8808** [SQLITE_STMTSTATUS counters] that measure the number
8809** of times it has performed specific operations.)^ These counters can
8810** be used to monitor the performance characteristics of the prepared
8811** statements. For example, if the number of table steps greatly exceeds
8812** the number of table searches or result rows, that would tend to indicate
8813** that the prepared statement is using a full table scan rather than
8814** an index.
8815**
8816** ^(This interface is used to retrieve and reset counter values from
8817** a [prepared statement]. The first argument is the prepared statement
8818** object to be interrogated. The second argument
8819** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8820** to be interrogated.)^
8821** ^The current value of the requested counter is returned.
8822** ^If the resetFlg is true, then the counter is reset to zero after this
8823** interface call returns.
8824**
8825** See also: [sqlite3_status()] and [sqlite3_db_status()].
8826*/
8827SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8828
8829/*
8830** CAPI3REF: Status Parameters for prepared statements
8831** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8832**
8833** These preprocessor macros define integer codes that name counter
8834** values associated with the [sqlite3_stmt_status()] interface.
8835** The meanings of the various counters are as follows:
8836**
8837** <dl>
8838** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8839** <dd>^This is the number of times that SQLite has stepped forward in
8840** a table as part of a full table scan. Large numbers for this counter
8841** may indicate opportunities for performance improvement through
8842** careful use of indices.</dd>
8843**
8844** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8845** <dd>^This is the number of sort operations that have occurred.
8846** A non-zero value in this counter may indicate an opportunity to
8847** improvement performance through careful use of indices.</dd>
8848**
8849** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8850** <dd>^This is the number of rows inserted into transient indices that
8851** were created automatically in order to help joins run faster.
8852** A non-zero value in this counter may indicate an opportunity to
8853** improvement performance by adding permanent indices that do not
8854** need to be reinitialized each time the statement is run.</dd>
8855**
8856** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8857** <dd>^This is the number of virtual machine operations executed
8858** by the prepared statement if that number is less than or equal
8859** to 2147483647. The number of virtual machine operations can be
8860** used as a proxy for the total work done by the prepared statement.
8861** If the number of virtual machine operations exceeds 2147483647
8862** then the value returned by this statement status code is undefined.
8863**
8864** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8865** <dd>^This is the number of times that the prepare statement has been
8866** automatically regenerated due to schema changes or changes to
8867** [bound parameters] that might affect the query plan.
8868**
8869** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8870** <dd>^This is the number of times that the prepared statement has
8871** been run. A single "run" for the purposes of this counter is one
8872** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8873** The counter is incremented on the first [sqlite3_step()] call of each
8874** cycle.
8875**
8876** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8877** [[SQLITE_STMTSTATUS_FILTER HIT]]
8878** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8879** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8880** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8881** step was bypassed because a Bloom filter returned not-found. The
8882** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8883** times that the Bloom filter returned a find, and thus the join step
8884** had to be processed as normal.
8885**
8886** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8887** <dd>^This is the approximate number of bytes of heap memory
8888** used to store the prepared statement. ^This value is not actually
8889** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8890** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8891** </dd>
8892** </dl>
8893*/
8894#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8895#define SQLITE_STMTSTATUS_SORT 2
8896#define SQLITE_STMTSTATUS_AUTOINDEX 3
8897#define SQLITE_STMTSTATUS_VM_STEP 4
8898#define SQLITE_STMTSTATUS_REPREPARE 5
8899#define SQLITE_STMTSTATUS_RUN 6
8900#define SQLITE_STMTSTATUS_FILTER_MISS 7
8901#define SQLITE_STMTSTATUS_FILTER_HIT 8
8902#define SQLITE_STMTSTATUS_MEMUSED 99
8903
8904/*
8905** CAPI3REF: Custom Page Cache Object
8906**
8907** The sqlite3_pcache type is opaque. It is implemented by
8908** the pluggable module. The SQLite core has no knowledge of
8909** its size or internal structure and never deals with the
8910** sqlite3_pcache object except by holding and passing pointers
8911** to the object.
8912**
8913** See [sqlite3_pcache_methods2] for additional information.
8914*/
8915typedef struct sqlite3_pcache sqlite3_pcache;
8916
8917/*
8918** CAPI3REF: Custom Page Cache Object
8919**
8920** The sqlite3_pcache_page object represents a single page in the
8921** page cache. The page cache will allocate instances of this
8922** object. Various methods of the page cache use pointers to instances
8923** of this object as parameters or as their return value.
8924**
8925** See [sqlite3_pcache_methods2] for additional information.
8926*/
8927typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8928struct sqlite3_pcache_page {
8929 void *pBuf; /* The content of the page */
8930 void *pExtra; /* Extra information associated with the page */
8931};
8932
8933/*
8934** CAPI3REF: Application Defined Page Cache.
8935** KEYWORDS: {page cache}
8936**
8937** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8938** register an alternative page cache implementation by passing in an
8939** instance of the sqlite3_pcache_methods2 structure.)^
8940** In many applications, most of the heap memory allocated by
8941** SQLite is used for the page cache.
8942** By implementing a
8943** custom page cache using this API, an application can better control
8944** the amount of memory consumed by SQLite, the way in which
8945** that memory is allocated and released, and the policies used to
8946** determine exactly which parts of a database file are cached and for
8947** how long.
8948**
8949** The alternative page cache mechanism is an
8950** extreme measure that is only needed by the most demanding applications.
8951** The built-in page cache is recommended for most uses.
8952**
8953** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8954** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8955** the application may discard the parameter after the call to
8956** [sqlite3_config()] returns.)^
8957**
8958** [[the xInit() page cache method]]
8959** ^(The xInit() method is called once for each effective
8960** call to [sqlite3_initialize()])^
8961** (usually only once during the lifetime of the process). ^(The xInit()
8962** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8963** The intent of the xInit() method is to set up global data structures
8964** required by the custom page cache implementation.
8965** ^(If the xInit() method is NULL, then the
8966** built-in default page cache is used instead of the application defined
8967** page cache.)^
8968**
8969** [[the xShutdown() page cache method]]
8970** ^The xShutdown() method is called by [sqlite3_shutdown()].
8971** It can be used to clean up
8972** any outstanding resources before process shutdown, if required.
8973** ^The xShutdown() method may be NULL.
8974**
8975** ^SQLite automatically serializes calls to the xInit method,
8976** so the xInit method need not be threadsafe. ^The
8977** xShutdown method is only called from [sqlite3_shutdown()] so it does
8978** not need to be threadsafe either. All other methods must be threadsafe
8979** in multithreaded applications.
8980**
8981** ^SQLite will never invoke xInit() more than once without an intervening
8982** call to xShutdown().
8983**
8984** [[the xCreate() page cache methods]]
8985** ^SQLite invokes the xCreate() method to construct a new cache instance.
8986** SQLite will typically create one cache instance for each open database file,
8987** though this is not guaranteed. ^The
8988** first parameter, szPage, is the size in bytes of the pages that must
8989** be allocated by the cache. ^szPage will always a power of two. ^The
8990** second parameter szExtra is a number of bytes of extra storage
8991** associated with each page cache entry. ^The szExtra parameter will
8992** a number less than 250. SQLite will use the
8993** extra szExtra bytes on each page to store metadata about the underlying
8994** database page on disk. The value passed into szExtra depends
8995** on the SQLite version, the target platform, and how SQLite was compiled.
8996** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8997** created will be used to cache database pages of a file stored on disk, or
8998** false if it is used for an in-memory database. The cache implementation
8999** does not have to do anything special based with the value of bPurgeable;
9000** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9001** never invoke xUnpin() except to deliberately delete a page.
9002** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9003** false will always have the "discard" flag set to true.
9004** ^Hence, a cache created with bPurgeable false will
9005** never contain any unpinned pages.
9006**
9007** [[the xCachesize() page cache method]]
9008** ^(The xCachesize() method may be called at any time by SQLite to set the
9009** suggested maximum cache-size (number of pages stored by) the cache
9010** instance passed as the first argument. This is the value configured using
9011** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9012** parameter, the implementation is not required to do anything with this
9013** value; it is advisory only.
9014**
9015** [[the xPagecount() page cache methods]]
9016** The xPagecount() method must return the number of pages currently
9017** stored in the cache, both pinned and unpinned.
9018**
9019** [[the xFetch() page cache methods]]
9020** The xFetch() method locates a page in the cache and returns a pointer to
9021** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9022** The pBuf element of the returned sqlite3_pcache_page object will be a
9023** pointer to a buffer of szPage bytes used to store the content of a
9024** single database page. The pExtra element of sqlite3_pcache_page will be
9025** a pointer to the szExtra bytes of extra storage that SQLite has requested
9026** for each entry in the page cache.
9027**
9028** The page to be fetched is determined by the key. ^The minimum key value
9029** is 1. After it has been retrieved using xFetch, the page is considered
9030** to be "pinned".
9031**
9032** If the requested page is already in the page cache, then the page cache
9033** implementation must return a pointer to the page buffer with its content
9034** intact. If the requested page is not already in the cache, then the
9035** cache implementation should use the value of the createFlag
9036** parameter to help it determined what action to take:
9037**
9038** <table border=1 width=85% align=center>
9039** <tr><th> createFlag <th> Behavior when page is not already in cache
9040** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9041** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
9042** Otherwise return NULL.
9043** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9044** NULL if allocating a new page is effectively impossible.
9045** </table>
9046**
9047** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9048** will only use a createFlag of 2 after a prior call with a createFlag of 1
9049** failed.)^ In between the xFetch() calls, SQLite may
9050** attempt to unpin one or more cache pages by spilling the content of
9051** pinned pages to disk and synching the operating system disk cache.
9052**
9053** [[the xUnpin() page cache method]]
9054** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9055** as its second argument. If the third parameter, discard, is non-zero,
9056** then the page must be evicted from the cache.
9057** ^If the discard parameter is
9058** zero, then the page may be discarded or retained at the discretion of
9059** page cache implementation. ^The page cache implementation
9060** may choose to evict unpinned pages at any time.
9061**
9062** The cache must not perform any reference counting. A single
9063** call to xUnpin() unpins the page regardless of the number of prior calls
9064** to xFetch().
9065**
9066** [[the xRekey() page cache methods]]
9067** The xRekey() method is used to change the key value associated with the
9068** page passed as the second argument. If the cache
9069** previously contains an entry associated with newKey, it must be
9070** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9071** to be pinned.
9072**
9073** When SQLite calls the xTruncate() method, the cache must discard all
9074** existing cache entries with page numbers (keys) greater than or equal
9075** to the value of the iLimit parameter passed to xTruncate(). If any
9076** of these pages are pinned, they are implicitly unpinned, meaning that
9077** they can be safely discarded.
9078**
9079** [[the xDestroy() page cache method]]
9080** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9081** All resources associated with the specified cache should be freed. ^After
9082** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9083** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9084** functions.
9085**
9086** [[the xShrink() page cache method]]
9087** ^SQLite invokes the xShrink() method when it wants the page cache to
9088** free up as much of heap memory as possible. The page cache implementation
9089** is not obligated to free any memory, but well-behaved implementations should
9090** do their best.
9091*/
9092typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9093struct sqlite3_pcache_methods2 {
9094 int iVersion;
9095 void *pArg;
9096 int (*xInit)(void*);
9097 void (*xShutdown)(void*);
9098 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9099 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9100 int (*xPagecount)(sqlite3_pcache*);
9101 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9102 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9103 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9104 unsigned oldKey, unsigned newKey);
9105 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9106 void (*xDestroy)(sqlite3_pcache*);
9107 void (*xShrink)(sqlite3_pcache*);
9108};
9109
9110/*
9111** This is the obsolete pcache_methods object that has now been replaced
9112** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9113** retained in the header file for backwards compatibility only.
9114*/
9115typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9116struct sqlite3_pcache_methods {
9117 void *pArg;
9118 int (*xInit)(void*);
9119 void (*xShutdown)(void*);
9120 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9121 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9122 int (*xPagecount)(sqlite3_pcache*);
9123 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9124 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9125 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9126 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9127 void (*xDestroy)(sqlite3_pcache*);
9128};
9129
9130
9131/*
9132** CAPI3REF: Online Backup Object
9133**
9134** The sqlite3_backup object records state information about an ongoing
9135** online backup operation. ^The sqlite3_backup object is created by
9136** a call to [sqlite3_backup_init()] and is destroyed by a call to
9137** [sqlite3_backup_finish()].
9138**
9139** See Also: [Using the SQLite Online Backup API]
9140*/
9141typedef struct sqlite3_backup sqlite3_backup;
9142
9143/*
9144** CAPI3REF: Online Backup API.
9145**
9146** The backup API copies the content of one database into another.
9147** It is useful either for creating backups of databases or
9148** for copying in-memory databases to or from persistent files.
9149**
9150** See Also: [Using the SQLite Online Backup API]
9151**
9152** ^SQLite holds a write transaction open on the destination database file
9153** for the duration of the backup operation.
9154** ^The source database is read-locked only while it is being read;
9155** it is not locked continuously for the entire backup operation.
9156** ^Thus, the backup may be performed on a live source database without
9157** preventing other database connections from
9158** reading or writing to the source database while the backup is underway.
9159**
9160** ^(To perform a backup operation:
9161** <ol>
9162** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9163** backup,
9164** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9165** the data between the two databases, and finally
9166** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9167** associated with the backup operation.
9168** </ol>)^
9169** There should be exactly one call to sqlite3_backup_finish() for each
9170** successful call to sqlite3_backup_init().
9171**
9172** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9173**
9174** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9175** [database connection] associated with the destination database
9176** and the database name, respectively.
9177** ^The database name is "main" for the main database, "temp" for the
9178** temporary database, or the name specified after the AS keyword in
9179** an [ATTACH] statement for an attached database.
9180** ^The S and M arguments passed to
9181** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9182** and database name of the source database, respectively.
9183** ^The source and destination [database connections] (parameters S and D)
9184** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9185** an error.
9186**
9187** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9188** there is already a read or read-write transaction open on the
9189** destination database.
9190**
9191** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9192** returned and an error code and error message are stored in the
9193** destination [database connection] D.
9194** ^The error code and message for the failed call to sqlite3_backup_init()
9195** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9196** [sqlite3_errmsg16()] functions.
9197** ^A successful call to sqlite3_backup_init() returns a pointer to an
9198** [sqlite3_backup] object.
9199** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9200** sqlite3_backup_finish() functions to perform the specified backup
9201** operation.
9202**
9203** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9204**
9205** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9206** the source and destination databases specified by [sqlite3_backup] object B.
9207** ^If N is negative, all remaining source pages are copied.
9208** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9209** are still more pages to be copied, then the function returns [SQLITE_OK].
9210** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9211** from source to destination, then it returns [SQLITE_DONE].
9212** ^If an error occurs while running sqlite3_backup_step(B,N),
9213** then an [error code] is returned. ^As well as [SQLITE_OK] and
9214** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9215** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9216** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9217**
9218** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9219** <ol>
9220** <li> the destination database was opened read-only, or
9221** <li> the destination database is using write-ahead-log journaling
9222** and the destination and source page sizes differ, or
9223** <li> the destination database is an in-memory database and the
9224** destination and source page sizes differ.
9225** </ol>)^
9226**
9227** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9228** the [sqlite3_busy_handler | busy-handler function]
9229** is invoked (if one is specified). ^If the
9230** busy-handler returns non-zero before the lock is available, then
9231** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9232** sqlite3_backup_step() can be retried later. ^If the source
9233** [database connection]
9234** is being used to write to the source database when sqlite3_backup_step()
9235** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9236** case the call to sqlite3_backup_step() can be retried later on. ^(If
9237** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9238** [SQLITE_READONLY] is returned, then
9239** there is no point in retrying the call to sqlite3_backup_step(). These
9240** errors are considered fatal.)^ The application must accept
9241** that the backup operation has failed and pass the backup operation handle
9242** to the sqlite3_backup_finish() to release associated resources.
9243**
9244** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9245** on the destination file. ^The exclusive lock is not released until either
9246** sqlite3_backup_finish() is called or the backup operation is complete
9247** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9248** sqlite3_backup_step() obtains a [shared lock] on the source database that
9249** lasts for the duration of the sqlite3_backup_step() call.
9250** ^Because the source database is not locked between calls to
9251** sqlite3_backup_step(), the source database may be modified mid-way
9252** through the backup process. ^If the source database is modified by an
9253** external process or via a database connection other than the one being
9254** used by the backup operation, then the backup will be automatically
9255** restarted by the next call to sqlite3_backup_step(). ^If the source
9256** database is modified by the using the same database connection as is used
9257** by the backup operation, then the backup database is automatically
9258** updated at the same time.
9259**
9260** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9261**
9262** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9263** application wishes to abandon the backup operation, the application
9264** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9265** ^The sqlite3_backup_finish() interfaces releases all
9266** resources associated with the [sqlite3_backup] object.
9267** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9268** active write-transaction on the destination database is rolled back.
9269** The [sqlite3_backup] object is invalid
9270** and may not be used following a call to sqlite3_backup_finish().
9271**
9272** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9273** sqlite3_backup_step() errors occurred, regardless or whether or not
9274** sqlite3_backup_step() completed.
9275** ^If an out-of-memory condition or IO error occurred during any prior
9276** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9277** sqlite3_backup_finish() returns the corresponding [error code].
9278**
9279** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9280** is not a permanent error and does not affect the return value of
9281** sqlite3_backup_finish().
9282**
9283** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9284** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9285**
9286** ^The sqlite3_backup_remaining() routine returns the number of pages still
9287** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9288** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9289** in the source database at the conclusion of the most recent
9290** sqlite3_backup_step().
9291** ^(The values returned by these functions are only updated by
9292** sqlite3_backup_step(). If the source database is modified in a way that
9293** changes the size of the source database or the number of pages remaining,
9294** those changes are not reflected in the output of sqlite3_backup_pagecount()
9295** and sqlite3_backup_remaining() until after the next
9296** sqlite3_backup_step().)^
9297**
9298** <b>Concurrent Usage of Database Handles</b>
9299**
9300** ^The source [database connection] may be used by the application for other
9301** purposes while a backup operation is underway or being initialized.
9302** ^If SQLite is compiled and configured to support threadsafe database
9303** connections, then the source database connection may be used concurrently
9304** from within other threads.
9305**
9306** However, the application must guarantee that the destination
9307** [database connection] is not passed to any other API (by any thread) after
9308** sqlite3_backup_init() is called and before the corresponding call to
9309** sqlite3_backup_finish(). SQLite does not currently check to see
9310** if the application incorrectly accesses the destination [database connection]
9311** and so no error code is reported, but the operations may malfunction
9312** nevertheless. Use of the destination database connection while a
9313** backup is in progress might also cause a mutex deadlock.
9314**
9315** If running in [shared cache mode], the application must
9316** guarantee that the shared cache used by the destination database
9317** is not accessed while the backup is running. In practice this means
9318** that the application must guarantee that the disk file being
9319** backed up to is not accessed by any connection within the process,
9320** not just the specific connection that was passed to sqlite3_backup_init().
9321**
9322** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9323** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9324** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9325** APIs are not strictly speaking threadsafe. If they are invoked at the
9326** same time as another thread is invoking sqlite3_backup_step() it is
9327** possible that they return invalid values.
9328*/
9329SQLITE_API sqlite3_backup *sqlite3_backup_init(
9330 sqlite3 *pDest, /* Destination database handle */
9331 const char *zDestName, /* Destination database name */
9332 sqlite3 *pSource, /* Source database handle */
9333 const char *zSourceName /* Source database name */
9334);
9335SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9336SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9337SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9338SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9339
9340/*
9341** CAPI3REF: Unlock Notification
9342** METHOD: sqlite3
9343**
9344** ^When running in shared-cache mode, a database operation may fail with
9345** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9346** individual tables within the shared-cache cannot be obtained. See
9347** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9348** ^This API may be used to register a callback that SQLite will invoke
9349** when the connection currently holding the required lock relinquishes it.
9350** ^This API is only available if the library was compiled with the
9351** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9352**
9353** See Also: [Using the SQLite Unlock Notification Feature].
9354**
9355** ^Shared-cache locks are released when a database connection concludes
9356** its current transaction, either by committing it or rolling it back.
9357**
9358** ^When a connection (known as the blocked connection) fails to obtain a
9359** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9360** identity of the database connection (the blocking connection) that
9361** has locked the required resource is stored internally. ^After an
9362** application receives an SQLITE_LOCKED error, it may call the
9363** sqlite3_unlock_notify() method with the blocked connection handle as
9364** the first argument to register for a callback that will be invoked
9365** when the blocking connections current transaction is concluded. ^The
9366** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9367** call that concludes the blocking connection's transaction.
9368**
9369** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9370** there is a chance that the blocking connection will have already
9371** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9372** If this happens, then the specified callback is invoked immediately,
9373** from within the call to sqlite3_unlock_notify().)^
9374**
9375** ^If the blocked connection is attempting to obtain a write-lock on a
9376** shared-cache table, and more than one other connection currently holds
9377** a read-lock on the same table, then SQLite arbitrarily selects one of
9378** the other connections to use as the blocking connection.
9379**
9380** ^(There may be at most one unlock-notify callback registered by a
9381** blocked connection. If sqlite3_unlock_notify() is called when the
9382** blocked connection already has a registered unlock-notify callback,
9383** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9384** called with a NULL pointer as its second argument, then any existing
9385** unlock-notify callback is canceled. ^The blocked connections
9386** unlock-notify callback may also be canceled by closing the blocked
9387** connection using [sqlite3_close()].
9388**
9389** The unlock-notify callback is not reentrant. If an application invokes
9390** any sqlite3_xxx API functions from within an unlock-notify callback, a
9391** crash or deadlock may be the result.
9392**
9393** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9394** returns SQLITE_OK.
9395**
9396** <b>Callback Invocation Details</b>
9397**
9398** When an unlock-notify callback is registered, the application provides a
9399** single void* pointer that is passed to the callback when it is invoked.
9400** However, the signature of the callback function allows SQLite to pass
9401** it an array of void* context pointers. The first argument passed to
9402** an unlock-notify callback is a pointer to an array of void* pointers,
9403** and the second is the number of entries in the array.
9404**
9405** When a blocking connection's transaction is concluded, there may be
9406** more than one blocked connection that has registered for an unlock-notify
9407** callback. ^If two or more such blocked connections have specified the
9408** same callback function, then instead of invoking the callback function
9409** multiple times, it is invoked once with the set of void* context pointers
9410** specified by the blocked connections bundled together into an array.
9411** This gives the application an opportunity to prioritize any actions
9412** related to the set of unblocked database connections.
9413**
9414** <b>Deadlock Detection</b>
9415**
9416** Assuming that after registering for an unlock-notify callback a
9417** database waits for the callback to be issued before taking any further
9418** action (a reasonable assumption), then using this API may cause the
9419** application to deadlock. For example, if connection X is waiting for
9420** connection Y's transaction to be concluded, and similarly connection
9421** Y is waiting on connection X's transaction, then neither connection
9422** will proceed and the system may remain deadlocked indefinitely.
9423**
9424** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9425** detection. ^If a given call to sqlite3_unlock_notify() would put the
9426** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9427** unlock-notify callback is registered. The system is said to be in
9428** a deadlocked state if connection A has registered for an unlock-notify
9429** callback on the conclusion of connection B's transaction, and connection
9430** B has itself registered for an unlock-notify callback when connection
9431** A's transaction is concluded. ^Indirect deadlock is also detected, so
9432** the system is also considered to be deadlocked if connection B has
9433** registered for an unlock-notify callback on the conclusion of connection
9434** C's transaction, where connection C is waiting on connection A. ^Any
9435** number of levels of indirection are allowed.
9436**
9437** <b>The "DROP TABLE" Exception</b>
9438**
9439** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9440** always appropriate to call sqlite3_unlock_notify(). There is however,
9441** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9442** SQLite checks if there are any currently executing SELECT statements
9443** that belong to the same connection. If there are, SQLITE_LOCKED is
9444** returned. In this case there is no "blocking connection", so invoking
9445** sqlite3_unlock_notify() results in the unlock-notify callback being
9446** invoked immediately. If the application then re-attempts the "DROP TABLE"
9447** or "DROP INDEX" query, an infinite loop might be the result.
9448**
9449** One way around this problem is to check the extended error code returned
9450** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9451** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9452** the special "DROP TABLE/INDEX" case, the extended error code is just
9453** SQLITE_LOCKED.)^
9454*/
9455SQLITE_API int sqlite3_unlock_notify(
9456 sqlite3 *pBlocked, /* Waiting connection */
9457 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9458 void *pNotifyArg /* Argument to pass to xNotify */
9459);
9460
9461
9462/*
9463** CAPI3REF: String Comparison
9464**
9465** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9466** and extensions to compare the contents of two buffers containing UTF-8
9467** strings in a case-independent fashion, using the same definition of "case
9468** independence" that SQLite uses internally when comparing identifiers.
9469*/
9470SQLITE_API int sqlite3_stricmp(const char *, const char *);
9471SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9472
9473/*
9474** CAPI3REF: String Globbing
9475*
9476** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9477** string X matches the [GLOB] pattern P.
9478** ^The definition of [GLOB] pattern matching used in
9479** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9480** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9481** is case sensitive.
9482**
9483** Note that this routine returns zero on a match and non-zero if the strings
9484** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9485**
9486** See also: [sqlite3_strlike()].
9487*/
9488SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9489
9490/*
9491** CAPI3REF: String LIKE Matching
9492*
9493** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9494** string X matches the [LIKE] pattern P with escape character E.
9495** ^The definition of [LIKE] pattern matching used in
9496** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9497** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9498** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9499** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9500** insensitive - equivalent upper and lower case ASCII characters match
9501** one another.
9502**
9503** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9504** only ASCII characters are case folded.
9505**
9506** Note that this routine returns zero on a match and non-zero if the strings
9507** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9508**
9509** See also: [sqlite3_strglob()].
9510*/
9511SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9512
9513/*
9514** CAPI3REF: Error Logging Interface
9515**
9516** ^The [sqlite3_log()] interface writes a message into the [error log]
9517** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9518** ^If logging is enabled, the zFormat string and subsequent arguments are
9519** used with [sqlite3_snprintf()] to generate the final output string.
9520**
9521** The sqlite3_log() interface is intended for use by extensions such as
9522** virtual tables, collating functions, and SQL functions. While there is
9523** nothing to prevent an application from calling sqlite3_log(), doing so
9524** is considered bad form.
9525**
9526** The zFormat string must not be NULL.
9527**
9528** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9529** will not use dynamically allocated memory. The log message is stored in
9530** a fixed-length buffer on the stack. If the log message is longer than
9531** a few hundred characters, it will be truncated to the length of the
9532** buffer.
9533*/
9534SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9535
9536/*
9537** CAPI3REF: Write-Ahead Log Commit Hook
9538** METHOD: sqlite3
9539**
9540** ^The [sqlite3_wal_hook()] function is used to register a callback that
9541** is invoked each time data is committed to a database in wal mode.
9542**
9543** ^(The callback is invoked by SQLite after the commit has taken place and
9544** the associated write-lock on the database released)^, so the implementation
9545** may read, write or [checkpoint] the database as required.
9546**
9547** ^The first parameter passed to the callback function when it is invoked
9548** is a copy of the third parameter passed to sqlite3_wal_hook() when
9549** registering the callback. ^The second is a copy of the database handle.
9550** ^The third parameter is the name of the database that was written to -
9551** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9552** is the number of pages currently in the write-ahead log file,
9553** including those that were just committed.
9554**
9555** The callback function should normally return [SQLITE_OK]. ^If an error
9556** code is returned, that error will propagate back up through the
9557** SQLite code base to cause the statement that provoked the callback
9558** to report an error, though the commit will have still occurred. If the
9559** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9560** that does not correspond to any valid SQLite error code, the results
9561** are undefined.
9562**
9563** A single database handle may have at most a single write-ahead log callback
9564** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9565** previously registered write-ahead log callback. ^The return value is
9566** a copy of the third parameter from the previous call, if any, or 0.
9567** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9568** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9569** overwrite any prior [sqlite3_wal_hook()] settings.
9570*/
9571SQLITE_API void *sqlite3_wal_hook(
9572 sqlite3*,
9573 int(*)(void *,sqlite3*,const char*,int),
9574 void*
9575);
9576
9577/*
9578** CAPI3REF: Configure an auto-checkpoint
9579** METHOD: sqlite3
9580**
9581** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9582** [sqlite3_wal_hook()] that causes any database on [database connection] D
9583** to automatically [checkpoint]
9584** after committing a transaction if there are N or
9585** more frames in the [write-ahead log] file. ^Passing zero or
9586** a negative value as the nFrame parameter disables automatic
9587** checkpoints entirely.
9588**
9589** ^The callback registered by this function replaces any existing callback
9590** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9591** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9592** configured by this function.
9593**
9594** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9595** from SQL.
9596**
9597** ^Checkpoints initiated by this mechanism are
9598** [sqlite3_wal_checkpoint_v2|PASSIVE].
9599**
9600** ^Every new [database connection] defaults to having the auto-checkpoint
9601** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9602** pages. The use of this interface
9603** is only necessary if the default setting is found to be suboptimal
9604** for a particular application.
9605*/
9606SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9607
9608/*
9609** CAPI3REF: Checkpoint a database
9610** METHOD: sqlite3
9611**
9612** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9613** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9614**
9615** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9616** [write-ahead log] for database X on [database connection] D to be
9617** transferred into the database file and for the write-ahead log to
9618** be reset. See the [checkpointing] documentation for addition
9619** information.
9620**
9621** This interface used to be the only way to cause a checkpoint to
9622** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9623** interface was added. This interface is retained for backwards
9624** compatibility and as a convenience for applications that need to manually
9625** start a callback but which do not need the full power (and corresponding
9626** complication) of [sqlite3_wal_checkpoint_v2()].
9627*/
9628SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9629
9630/*
9631** CAPI3REF: Checkpoint a database
9632** METHOD: sqlite3
9633**
9634** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9635** operation on database X of [database connection] D in mode M. Status
9636** information is written back into integers pointed to by L and C.)^
9637** ^(The M parameter must be a valid [checkpoint mode]:)^
9638**
9639** <dl>
9640** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9641** ^Checkpoint as many frames as possible without waiting for any database
9642** readers or writers to finish, then sync the database file if all frames
9643** in the log were checkpointed. ^The [busy-handler callback]
9644** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9645** ^On the other hand, passive mode might leave the checkpoint unfinished
9646** if there are concurrent readers or writers.
9647**
9648** <dt>SQLITE_CHECKPOINT_FULL<dd>
9649** ^This mode blocks (it invokes the
9650** [sqlite3_busy_handler|busy-handler callback]) until there is no
9651** database writer and all readers are reading from the most recent database
9652** snapshot. ^It then checkpoints all frames in the log file and syncs the
9653** database file. ^This mode blocks new database writers while it is pending,
9654** but new database readers are allowed to continue unimpeded.
9655**
9656** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9657** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9658** that after checkpointing the log file it blocks (calls the
9659** [busy-handler callback])
9660** until all readers are reading from the database file only. ^This ensures
9661** that the next writer will restart the log file from the beginning.
9662** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9663** database writer attempts while it is pending, but does not impede readers.
9664**
9665** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9666** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9667** addition that it also truncates the log file to zero bytes just prior
9668** to a successful return.
9669** </dl>
9670**
9671** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9672** the log file or to -1 if the checkpoint could not run because
9673** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9674** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9675** log file (including any that were already checkpointed before the function
9676** was called) or to -1 if the checkpoint could not run due to an error or
9677** because the database is not in WAL mode. ^Note that upon successful
9678** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9679** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9680**
9681** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9682** any other process is running a checkpoint operation at the same time, the
9683** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9684** busy-handler configured, it will not be invoked in this case.
9685**
9686** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9687** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9688** obtained immediately, and a busy-handler is configured, it is invoked and
9689** the writer lock retried until either the busy-handler returns 0 or the lock
9690** is successfully obtained. ^The busy-handler is also invoked while waiting for
9691** database readers as described above. ^If the busy-handler returns 0 before
9692** the writer lock is obtained or while waiting for database readers, the
9693** checkpoint operation proceeds from that point in the same way as
9694** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9695** without blocking any further. ^SQLITE_BUSY is returned in this case.
9696**
9697** ^If parameter zDb is NULL or points to a zero length string, then the
9698** specified operation is attempted on all WAL databases [attached] to
9699** [database connection] db. In this case the
9700** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9701** an SQLITE_BUSY error is encountered when processing one or more of the
9702** attached WAL databases, the operation is still attempted on any remaining
9703** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9704** error occurs while processing an attached database, processing is abandoned
9705** and the error code is returned to the caller immediately. ^If no error
9706** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9707** databases, SQLITE_OK is returned.
9708**
9709** ^If database zDb is the name of an attached database that is not in WAL
9710** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9711** zDb is not NULL (or a zero length string) and is not the name of any
9712** attached database, SQLITE_ERROR is returned to the caller.
9713**
9714** ^Unless it returns SQLITE_MISUSE,
9715** the sqlite3_wal_checkpoint_v2() interface
9716** sets the error information that is queried by
9717** [sqlite3_errcode()] and [sqlite3_errmsg()].
9718**
9719** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9720** from SQL.
9721*/
9722SQLITE_API int sqlite3_wal_checkpoint_v2(
9723 sqlite3 *db, /* Database handle */
9724 const char *zDb, /* Name of attached database (or NULL) */
9725 int eMode, /* SQLITE_CHECKPOINT_* value */
9726 int *pnLog, /* OUT: Size of WAL log in frames */
9727 int *pnCkpt /* OUT: Total number of frames checkpointed */
9728);
9729
9730/*
9731** CAPI3REF: Checkpoint Mode Values
9732** KEYWORDS: {checkpoint mode}
9733**
9734** These constants define all valid values for the "checkpoint mode" passed
9735** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9736** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9737** meaning of each of these checkpoint modes.
9738*/
9739#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9740#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9741#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9742#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9743
9744/*
9745** CAPI3REF: Virtual Table Interface Configuration
9746**
9747** This function may be called by either the [xConnect] or [xCreate] method
9748** of a [virtual table] implementation to configure
9749** various facets of the virtual table interface.
9750**
9751** If this interface is invoked outside the context of an xConnect or
9752** xCreate virtual table method then the behavior is undefined.
9753**
9754** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9755** [database connection] in which the virtual table is being created and
9756** which is passed in as the first argument to the [xConnect] or [xCreate]
9757** method that is invoking sqlite3_vtab_config(). The C parameter is one
9758** of the [virtual table configuration options]. The presence and meaning
9759** of parameters after C depend on which [virtual table configuration option]
9760** is used.
9761*/
9762SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9763
9764/*
9765** CAPI3REF: Virtual Table Configuration Options
9766** KEYWORDS: {virtual table configuration options}
9767** KEYWORDS: {virtual table configuration option}
9768**
9769** These macros define the various options to the
9770** [sqlite3_vtab_config()] interface that [virtual table] implementations
9771** can use to customize and optimize their behavior.
9772**
9773** <dl>
9774** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9775** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9776** <dd>Calls of the form
9777** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9778** where X is an integer. If X is zero, then the [virtual table] whose
9779** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9780** support constraints. In this configuration (which is the default) if
9781** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9782** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9783** specified as part of the users SQL statement, regardless of the actual
9784** ON CONFLICT mode specified.
9785**
9786** If X is non-zero, then the virtual table implementation guarantees
9787** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9788** any modifications to internal or persistent data structures have been made.
9789** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9790** is able to roll back a statement or database transaction, and abandon
9791** or continue processing the current SQL statement as appropriate.
9792** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9793** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9794** had been ABORT.
9795**
9796** Virtual table implementations that are required to handle OR REPLACE
9797** must do so within the [xUpdate] method. If a call to the
9798** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9799** CONFLICT policy is REPLACE, the virtual table implementation should
9800** silently replace the appropriate rows within the xUpdate callback and
9801** return SQLITE_OK. Or, if this is not possible, it may return
9802** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9803** constraint handling.
9804** </dd>
9805**
9806** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9807** <dd>Calls of the form
9808** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9809** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9810** prohibits that virtual table from being used from within triggers and
9811** views.
9812** </dd>
9813**
9814** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9815** <dd>Calls of the form
9816** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9817** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9818** identify that virtual table as being safe to use from within triggers
9819** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9820** virtual table can do no serious harm even if it is controlled by a
9821** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9822** flag unless absolutely necessary.
9823** </dd>
9824**
9825** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
9826** <dd>Calls of the form
9827** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
9828** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9829** instruct the query planner to begin at least a read transaction on
9830** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
9831** virtual table is used.
9832** </dd>
9833** </dl>
9834*/
9835#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9836#define SQLITE_VTAB_INNOCUOUS 2
9837#define SQLITE_VTAB_DIRECTONLY 3
9838#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
9839
9840/*
9841** CAPI3REF: Determine The Virtual Table Conflict Policy
9842**
9843** This function may only be called from within a call to the [xUpdate] method
9844** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9845** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9846** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9847** of the SQL statement that triggered the call to the [xUpdate] method of the
9848** [virtual table].
9849*/
9850SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9851
9852/*
9853** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9854**
9855** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9856** method of a [virtual table], then it might return true if the
9857** column is being fetched as part of an UPDATE operation during which the
9858** column value will not change. The virtual table implementation can use
9859** this hint as permission to substitute a return value that is less
9860** expensive to compute and that the corresponding
9861** [xUpdate] method understands as a "no-change" value.
9862**
9863** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9864** the column is not changed by the UPDATE statement, then the xColumn
9865** method can optionally return without setting a result, without calling
9866** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9867** In that case, [sqlite3_value_nochange(X)] will return true for the
9868** same column in the [xUpdate] method.
9869**
9870** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9871** implementations should continue to give a correct answer even if the
9872** sqlite3_vtab_nochange() interface were to always return false. In the
9873** current implementation, the sqlite3_vtab_nochange() interface does always
9874** returns false for the enhanced [UPDATE FROM] statement.
9875*/
9876SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9877
9878/*
9879** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9880** METHOD: sqlite3_index_info
9881**
9882** This function may only be called from within a call to the [xBestIndex]
9883** method of a [virtual table]. This function returns a pointer to a string
9884** that is the name of the appropriate collation sequence to use for text
9885** comparisons on the constraint identified by its arguments.
9886**
9887** The first argument must be the pointer to the [sqlite3_index_info] object
9888** that is the first parameter to the xBestIndex() method. The second argument
9889** must be an index into the aConstraint[] array belonging to the
9890** sqlite3_index_info structure passed to xBestIndex.
9891**
9892** Important:
9893** The first parameter must be the same pointer that is passed into the
9894** xBestMethod() method. The first parameter may not be a pointer to a
9895** different [sqlite3_index_info] object, even an exact copy.
9896**
9897** The return value is computed as follows:
9898**
9899** <ol>
9900** <li><p> If the constraint comes from a WHERE clause expression that contains
9901** a [COLLATE operator], then the name of the collation specified by
9902** that COLLATE operator is returned.
9903** <li><p> If there is no COLLATE operator, but the column that is the subject
9904** of the constraint specifies an alternative collating sequence via
9905** a [COLLATE clause] on the column definition within the CREATE TABLE
9906** statement that was passed into [sqlite3_declare_vtab()], then the
9907** name of that alternative collating sequence is returned.
9908** <li><p> Otherwise, "BINARY" is returned.
9909** </ol>
9910*/
9911SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9912
9913/*
9914** CAPI3REF: Determine if a virtual table query is DISTINCT
9915** METHOD: sqlite3_index_info
9916**
9917** This API may only be used from within an [xBestIndex|xBestIndex method]
9918** of a [virtual table] implementation. The result of calling this
9919** interface from outside of xBestIndex() is undefined and probably harmful.
9920**
9921** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9922** 3. The integer returned by sqlite3_vtab_distinct()
9923** gives the virtual table additional information about how the query
9924** planner wants the output to be ordered. As long as the virtual table
9925** can meet the ordering requirements of the query planner, it may set
9926** the "orderByConsumed" flag.
9927**
9928** <ol><li value="0"><p>
9929** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9930** that the query planner needs the virtual table to return all rows in the
9931** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9932** [sqlite3_index_info] object. This is the default expectation. If the
9933** virtual table outputs all rows in sorted order, then it is always safe for
9934** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9935** the return value from sqlite3_vtab_distinct().
9936** <li value="1"><p>
9937** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9938** that the query planner does not need the rows to be returned in sorted order
9939** as long as all rows with the same values in all columns identified by the
9940** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9941** is doing a GROUP BY.
9942** <li value="2"><p>
9943** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9944** that the query planner does not need the rows returned in any particular
9945** order, as long as rows with the same values in all columns identified
9946** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
9947** contain the same values for all columns identified by "colUsed", all but
9948** one such row may optionally be omitted from the result.)^
9949** The virtual table is not required to omit rows that are duplicates
9950** over the "colUsed" columns, but if the virtual table can do that without
9951** too much extra effort, it could potentially help the query to run faster.
9952** This mode is used for a DISTINCT query.
9953** <li value="3"><p>
9954** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
9955** virtual table must return rows in the order defined by "aOrderBy" as
9956** if the sqlite3_vtab_distinct() interface had returned 0. However if
9957** two or more rows in the result have the same values for all columns
9958** identified by "colUsed", then all but one such row may optionally be
9959** omitted.)^ Like when the return value is 2, the virtual table
9960** is not required to omit rows that are duplicates over the "colUsed"
9961** columns, but if the virtual table can do that without
9962** too much extra effort, it could potentially help the query to run faster.
9963** This mode is used for queries
9964** that have both DISTINCT and ORDER BY clauses.
9965** </ol>
9966**
9967** <p>The following table summarizes the conditions under which the
9968** virtual table is allowed to set the "orderByConsumed" flag based on
9969** the value returned by sqlite3_vtab_distinct(). This table is a
9970** restatement of the previous four paragraphs:
9971**
9972** <table border=1 cellspacing=0 cellpadding=10 width="90%">
9973** <tr>
9974** <td valign="top">sqlite3_vtab_distinct() return value
9975** <td valign="top">Rows are returned in aOrderBy order
9976** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
9977** <td valign="top">Duplicates over all colUsed columns may be omitted
9978** <tr><td>0<td>yes<td>yes<td>no
9979** <tr><td>1<td>no<td>yes<td>no
9980** <tr><td>2<td>no<td>yes<td>yes
9981** <tr><td>3<td>yes<td>yes<td>yes
9982** </table>
9983**
9984** ^For the purposes of comparing virtual table output values to see if the
9985** values are same value for sorting purposes, two NULL values are considered
9986** to be the same. In other words, the comparison operator is "IS"
9987** (or "IS NOT DISTINCT FROM") and not "==".
9988**
9989** If a virtual table implementation is unable to meet the requirements
9990** specified above, then it must not set the "orderByConsumed" flag in the
9991** [sqlite3_index_info] object or an incorrect answer may result.
9992**
9993** ^A virtual table implementation is always free to return rows in any order
9994** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9995** the "orderByConsumed" flag is unset, the query planner will add extra
9996** [bytecode] to ensure that the final results returned by the SQL query are
9997** ordered correctly. The use of the "orderByConsumed" flag and the
9998** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9999** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10000** flag might help queries against a virtual table to run faster. Being
10001** overly aggressive and setting the "orderByConsumed" flag when it is not
10002** valid to do so, on the other hand, might cause SQLite to return incorrect
10003** results.
10004*/
10005SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10006
10007/*
10008** CAPI3REF: Identify and handle IN constraints in xBestIndex
10009**
10010** This interface may only be used from within an
10011** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10012** The result of invoking this interface from any other context is
10013** undefined and probably harmful.
10014**
10015** ^(A constraint on a virtual table of the form
10016** "[IN operator|column IN (...)]" is
10017** communicated to the xBestIndex method as a
10018** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10019** this constraint, it must set the corresponding
10020** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10021** the usual mode of handling IN operators, SQLite generates [bytecode]
10022** that invokes the [xFilter|xFilter() method] once for each value
10023** on the right-hand side of the IN operator.)^ Thus the virtual table
10024** only sees a single value from the right-hand side of the IN operator
10025** at a time.
10026**
10027** In some cases, however, it would be advantageous for the virtual
10028** table to see all values on the right-hand of the IN operator all at
10029** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10030**
10031** <ol>
10032** <li><p>
10033** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10034** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10035** is an [IN operator] that can be processed all at once. ^In other words,
10036** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10037** by which the virtual table can ask SQLite if all-at-once processing
10038** of the IN operator is even possible.
10039**
10040** <li><p>
10041** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10042** to SQLite that the virtual table does or does not want to process
10043** the IN operator all-at-once, respectively. ^Thus when the third
10044** parameter (F) is non-negative, this interface is the mechanism by
10045** which the virtual table tells SQLite how it wants to process the
10046** IN operator.
10047** </ol>
10048**
10049** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10050** within the same xBestIndex method call. ^For any given P,N pair,
10051** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10052** within the same xBestIndex call. ^If the interface returns true
10053** (non-zero), that means that the constraint is an IN operator
10054** that can be processed all-at-once. ^If the constraint is not an IN
10055** operator or cannot be processed all-at-once, then the interface returns
10056** false.
10057**
10058** ^(All-at-once processing of the IN operator is selected if both of the
10059** following conditions are met:
10060**
10061** <ol>
10062** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10063** integer. This is how the virtual table tells SQLite that it wants to
10064** use the N-th constraint.
10065**
10066** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10067** non-negative had F>=1.
10068** </ol>)^
10069**
10070** ^If either or both of the conditions above are false, then SQLite uses
10071** the traditional one-at-a-time processing strategy for the IN constraint.
10072** ^If both conditions are true, then the argvIndex-th parameter to the
10073** xFilter method will be an [sqlite3_value] that appears to be NULL,
10074** but which can be passed to [sqlite3_vtab_in_first()] and
10075** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10076** of the IN constraint.
10077*/
10078SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10079
10080/*
10081** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10082**
10083** These interfaces are only useful from within the
10084** [xFilter|xFilter() method] of a [virtual table] implementation.
10085** The result of invoking these interfaces from any other context
10086** is undefined and probably harmful.
10087**
10088** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10089** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10090** xFilter method which invokes these routines, and specifically
10091** a parameter that was previously selected for all-at-once IN constraint
10092** processing use the [sqlite3_vtab_in()] interface in the
10093** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10094** an xFilter argument that was selected for all-at-once IN constraint
10095** processing, then these routines return [SQLITE_ERROR].)^
10096**
10097** ^(Use these routines to access all values on the right-hand side
10098** of the IN constraint using code like the following:
10099**
10100** <blockquote><pre>
10101** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
10102** &nbsp; rc==SQLITE_OK && pVal;
10103** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
10104** &nbsp; ){
10105** &nbsp; // do something with pVal
10106** &nbsp; }
10107** &nbsp; if( rc!=SQLITE_OK ){
10108** &nbsp; // an error has occurred
10109** &nbsp; }
10110** </pre></blockquote>)^
10111**
10112** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10113** routines return SQLITE_OK and set *P to point to the first or next value
10114** on the RHS of the IN constraint. ^If there are no more values on the
10115** right hand side of the IN constraint, then *P is set to NULL and these
10116** routines return [SQLITE_DONE]. ^The return value might be
10117** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10118**
10119** The *ppOut values returned by these routines are only valid until the
10120** next call to either of these routines or until the end of the xFilter
10121** method from which these routines were called. If the virtual table
10122** implementation needs to retain the *ppOut values for longer, it must make
10123** copies. The *ppOut values are [protected sqlite3_value|protected].
10124*/
10125SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10126SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10127
10128/*
10129** CAPI3REF: Constraint values in xBestIndex()
10130** METHOD: sqlite3_index_info
10131**
10132** This API may only be used from within the [xBestIndex|xBestIndex method]
10133** of a [virtual table] implementation. The result of calling this interface
10134** from outside of an xBestIndex method are undefined and probably harmful.
10135**
10136** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10137** the [xBestIndex] method of a [virtual table] implementation, with P being
10138** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10139** J being a 0-based index into P->aConstraint[], then this routine
10140** attempts to set *V to the value of the right-hand operand of
10141** that constraint if the right-hand operand is known. ^If the
10142** right-hand operand is not known, then *V is set to a NULL pointer.
10143** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10144** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10145** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10146** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10147** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
10148** something goes wrong.
10149**
10150** The sqlite3_vtab_rhs_value() interface is usually only successful if
10151** the right-hand operand of a constraint is a literal value in the original
10152** SQL statement. If the right-hand operand is an expression or a reference
10153** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10154** will probably return [SQLITE_NOTFOUND].
10155**
10156** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10157** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10158** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10159**
10160** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10161** and remains valid for the duration of the xBestIndex method call.
10162** ^When xBestIndex returns, the sqlite3_value object returned by
10163** sqlite3_vtab_rhs_value() is automatically deallocated.
10164**
10165** The "_rhs_" in the name of this routine is an abbreviation for
10166** "Right-Hand Side".
10167*/
10168SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10169
10170/*
10171** CAPI3REF: Conflict resolution modes
10172** KEYWORDS: {conflict resolution mode}
10173**
10174** These constants are returned by [sqlite3_vtab_on_conflict()] to
10175** inform a [virtual table] implementation what the [ON CONFLICT] mode
10176** is for the SQL statement being evaluated.
10177**
10178** Note that the [SQLITE_IGNORE] constant is also used as a potential
10179** return value from the [sqlite3_set_authorizer()] callback and that
10180** [SQLITE_ABORT] is also a [result code].
10181*/
10182#define SQLITE_ROLLBACK 1
10183/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10184#define SQLITE_FAIL 3
10185/* #define SQLITE_ABORT 4 // Also an error code */
10186#define SQLITE_REPLACE 5
10187
10188/*
10189** CAPI3REF: Prepared Statement Scan Status Opcodes
10190** KEYWORDS: {scanstatus options}
10191**
10192** The following constants can be used for the T parameter to the
10193** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10194** different metric for sqlite3_stmt_scanstatus() to return.
10195**
10196** When the value returned to V is a string, space to hold that string is
10197** managed by the prepared statement S and will be automatically freed when
10198** S is finalized.
10199**
10200** Not all values are available for all query elements. When a value is
10201** not available, the output variable is set to -1 if the value is numeric,
10202** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10203**
10204** <dl>
10205** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10206** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10207** set to the total number of times that the X-th loop has run.</dd>
10208**
10209** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10210** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10211** to the total number of rows examined by all iterations of the X-th loop.</dd>
10212**
10213** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10214** <dd>^The "double" variable pointed to by the V parameter will be set to the
10215** query planner's estimate for the average number of rows output from each
10216** iteration of the X-th loop. If the query planner's estimates was accurate,
10217** then this value will approximate the quotient NVISIT/NLOOP and the
10218** product of this value for all prior loops with the same SELECTID will
10219** be the NLOOP value for the current loop.
10220**
10221** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10222** <dd>^The "const char *" variable pointed to by the V parameter will be set
10223** to a zero-terminated UTF-8 string containing the name of the index or table
10224** used for the X-th loop.
10225**
10226** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10227** <dd>^The "const char *" variable pointed to by the V parameter will be set
10228** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10229** description for the X-th loop.
10230**
10231** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10232** <dd>^The "int" variable pointed to by the V parameter will be set to the
10233** id for the X-th query plan element. The id value is unique within the
10234** statement. The select-id is the same value as is output in the first
10235** column of an [EXPLAIN QUERY PLAN] query.
10236**
10237** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10238** <dd>The "int" variable pointed to by the V parameter will be set to the
10239** the id of the parent of the current query element, if applicable, or
10240** to zero if the query element has no parent. This is the same value as
10241** returned in the second column of an [EXPLAIN QUERY PLAN] query.
10242**
10243** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10244** <dd>The sqlite3_int64 output value is set to the number of cycles,
10245** according to the processor time-stamp counter, that elapsed while the
10246** query element was being processed. This value is not available for
10247** all query elements - if it is unavailable the output variable is
10248** set to -1.
10249** </dl>
10250*/
10251#define SQLITE_SCANSTAT_NLOOP 0
10252#define SQLITE_SCANSTAT_NVISIT 1
10253#define SQLITE_SCANSTAT_EST 2
10254#define SQLITE_SCANSTAT_NAME 3
10255#define SQLITE_SCANSTAT_EXPLAIN 4
10256#define SQLITE_SCANSTAT_SELECTID 5
10257#define SQLITE_SCANSTAT_PARENTID 6
10258#define SQLITE_SCANSTAT_NCYCLE 7
10259
10260/*
10261** CAPI3REF: Prepared Statement Scan Status
10262** METHOD: sqlite3_stmt
10263**
10264** These interfaces return information about the predicted and measured
10265** performance for pStmt. Advanced applications can use this
10266** interface to compare the predicted and the measured performance and
10267** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10268**
10269** Since this interface is expected to be rarely used, it is only
10270** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10271** compile-time option.
10272**
10273** The "iScanStatusOp" parameter determines which status information to return.
10274** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10275** of this interface is undefined. ^The requested measurement is written into
10276** a variable pointed to by the "pOut" parameter.
10277**
10278** The "flags" parameter must be passed a mask of flags. At present only
10279** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10280** is specified, then status information is available for all elements
10281** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10282** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10283** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10284** the EXPLAIN QUERY PLAN output) are available. Invoking API
10285** sqlite3_stmt_scanstatus() is equivalent to calling
10286** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10287**
10288** Parameter "idx" identifies the specific query element to retrieve statistics
10289** for. Query elements are numbered starting from zero. A value of -1 may be
10290** to query for statistics regarding the entire query. ^If idx is out of range
10291** - less than -1 or greater than or equal to the total number of query
10292** elements used to implement the statement - a non-zero value is returned and
10293** the variable that pOut points to is unchanged.
10294**
10295** See also: [sqlite3_stmt_scanstatus_reset()]
10296*/
10297SQLITE_API int sqlite3_stmt_scanstatus(
10298 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10299 int idx, /* Index of loop to report on */
10300 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10301 void *pOut /* Result written here */
10302);
10303SQLITE_API int sqlite3_stmt_scanstatus_v2(
10304 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10305 int idx, /* Index of loop to report on */
10306 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10307 int flags, /* Mask of flags defined below */
10308 void *pOut /* Result written here */
10309);
10310
10311/*
10312** CAPI3REF: Prepared Statement Scan Status
10313** KEYWORDS: {scan status flags}
10314*/
10315#define SQLITE_SCANSTAT_COMPLEX 0x0001
10316
10317/*
10318** CAPI3REF: Zero Scan-Status Counters
10319** METHOD: sqlite3_stmt
10320**
10321** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10322**
10323** This API is only available if the library is built with pre-processor
10324** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10325*/
10326SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10327
10328/*
10329** CAPI3REF: Flush caches to disk mid-transaction
10330** METHOD: sqlite3
10331**
10332** ^If a write-transaction is open on [database connection] D when the
10333** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
10334** pages in the pager-cache that are not currently in use are written out
10335** to disk. A dirty page may be in use if a database cursor created by an
10336** active SQL statement is reading from it, or if it is page 1 of a database
10337** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10338** interface flushes caches for all schemas - "main", "temp", and
10339** any [attached] databases.
10340**
10341** ^If this function needs to obtain extra database locks before dirty pages
10342** can be flushed to disk, it does so. ^If those locks cannot be obtained
10343** immediately and there is a busy-handler callback configured, it is invoked
10344** in the usual manner. ^If the required lock still cannot be obtained, then
10345** the database is skipped and an attempt made to flush any dirty pages
10346** belonging to the next (if any) database. ^If any databases are skipped
10347** because locks cannot be obtained, but no other error occurs, this
10348** function returns SQLITE_BUSY.
10349**
10350** ^If any other error occurs while flushing dirty pages to disk (for
10351** example an IO error or out-of-memory condition), then processing is
10352** abandoned and an SQLite [error code] is returned to the caller immediately.
10353**
10354** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10355**
10356** ^This function does not set the database handle error code or message
10357** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10358*/
10359SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10360
10361/*
10362** CAPI3REF: The pre-update hook.
10363** METHOD: sqlite3
10364**
10365** ^These interfaces are only available if SQLite is compiled using the
10366** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10367**
10368** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10369** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10370** on a database table.
10371** ^At most one preupdate hook may be registered at a time on a single
10372** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10373** the previous setting.
10374** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10375** with a NULL pointer as the second parameter.
10376** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10377** the first parameter to callbacks.
10378**
10379** ^The preupdate hook only fires for changes to real database tables; the
10380** preupdate hook is not invoked for changes to [virtual tables] or to
10381** system tables like sqlite_sequence or sqlite_stat1.
10382**
10383** ^The second parameter to the preupdate callback is a pointer to
10384** the [database connection] that registered the preupdate hook.
10385** ^The third parameter to the preupdate callback is one of the constants
10386** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10387** kind of update operation that is about to occur.
10388** ^(The fourth parameter to the preupdate callback is the name of the
10389** database within the database connection that is being modified. This
10390** will be "main" for the main database or "temp" for TEMP tables or
10391** the name given after the AS keyword in the [ATTACH] statement for attached
10392** databases.)^
10393** ^The fifth parameter to the preupdate callback is the name of the
10394** table that is being modified.
10395**
10396** For an UPDATE or DELETE operation on a [rowid table], the sixth
10397** parameter passed to the preupdate callback is the initial [rowid] of the
10398** row being modified or deleted. For an INSERT operation on a rowid table,
10399** or any operation on a WITHOUT ROWID table, the value of the sixth
10400** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10401** seventh parameter is the final rowid value of the row being inserted
10402** or updated. The value of the seventh parameter passed to the callback
10403** function is not defined for operations on WITHOUT ROWID tables, or for
10404** DELETE operations on rowid tables.
10405**
10406** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10407** the previous call on the same [database connection] D, or NULL for
10408** the first call on D.
10409**
10410** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10411** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10412** provide additional information about a preupdate event. These routines
10413** may only be called from within a preupdate callback. Invoking any of
10414** these routines from outside of a preupdate callback or with a
10415** [database connection] pointer that is different from the one supplied
10416** to the preupdate callback results in undefined and probably undesirable
10417** behavior.
10418**
10419** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10420** in the row that is being inserted, updated, or deleted.
10421**
10422** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10423** a [protected sqlite3_value] that contains the value of the Nth column of
10424** the table row before it is updated. The N parameter must be between 0
10425** and one less than the number of columns or the behavior will be
10426** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10427** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10428** behavior is undefined. The [sqlite3_value] that P points to
10429** will be destroyed when the preupdate callback returns.
10430**
10431** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10432** a [protected sqlite3_value] that contains the value of the Nth column of
10433** the table row after it is updated. The N parameter must be between 0
10434** and one less than the number of columns or the behavior will be
10435** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10436** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10437** behavior is undefined. The [sqlite3_value] that P points to
10438** will be destroyed when the preupdate callback returns.
10439**
10440** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10441** callback was invoked as a result of a direct insert, update, or delete
10442** operation; or 1 for inserts, updates, or deletes invoked by top-level
10443** triggers; or 2 for changes resulting from triggers called by top-level
10444** triggers; and so forth.
10445**
10446** When the [sqlite3_blob_write()] API is used to update a blob column,
10447** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10448** in this case the new values are not available. In this case, when a
10449** callback made with op==SQLITE_DELETE is actually a write using the
10450** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10451** the index of the column being written. In other cases, where the
10452** pre-update hook is being invoked for some other reason, including a
10453** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10454**
10455** See also: [sqlite3_update_hook()]
10456*/
10457#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10458SQLITE_API void *sqlite3_preupdate_hook(
10459 sqlite3 *db,
10460 void(*xPreUpdate)(
10461 void *pCtx, /* Copy of third arg to preupdate_hook() */
10462 sqlite3 *db, /* Database handle */
10463 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10464 char const *zDb, /* Database name */
10465 char const *zName, /* Table name */
10466 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10467 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10468 ),
10469 void*
10470);
10471SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10472SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10473SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10474SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10475SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10476#endif
10477
10478/*
10479** CAPI3REF: Low-level system error code
10480** METHOD: sqlite3
10481**
10482** ^Attempt to return the underlying operating system error code or error
10483** number that caused the most recent I/O error or failure to open a file.
10484** The return value is OS-dependent. For example, on unix systems, after
10485** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10486** called to get back the underlying "errno" that caused the problem, such
10487** as ENOSPC, EAUTH, EISDIR, and so forth.
10488*/
10489SQLITE_API int sqlite3_system_errno(sqlite3*);
10490
10491/*
10492** CAPI3REF: Database Snapshot
10493** KEYWORDS: {snapshot} {sqlite3_snapshot}
10494**
10495** An instance of the snapshot object records the state of a [WAL mode]
10496** database for some specific point in history.
10497**
10498** In [WAL mode], multiple [database connections] that are open on the
10499** same database file can each be reading a different historical version
10500** of the database file. When a [database connection] begins a read
10501** transaction, that connection sees an unchanging copy of the database
10502** as it existed for the point in time when the transaction first started.
10503** Subsequent changes to the database from other connections are not seen
10504** by the reader until a new read transaction is started.
10505**
10506** The sqlite3_snapshot object records state information about an historical
10507** version of the database file so that it is possible to later open a new read
10508** transaction that sees that historical version of the database rather than
10509** the most recent version.
10510*/
10511typedef struct sqlite3_snapshot {
10512 unsigned char hidden[48];
10513} sqlite3_snapshot;
10514
10515/*
10516** CAPI3REF: Record A Database Snapshot
10517** CONSTRUCTOR: sqlite3_snapshot
10518**
10519** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10520** new [sqlite3_snapshot] object that records the current state of
10521** schema S in database connection D. ^On success, the
10522** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10523** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10524** If there is not already a read-transaction open on schema S when
10525** this function is called, one is opened automatically.
10526**
10527** The following must be true for this function to succeed. If any of
10528** the following statements are false when sqlite3_snapshot_get() is
10529** called, SQLITE_ERROR is returned. The final value of *P is undefined
10530** in this case.
10531**
10532** <ul>
10533** <li> The database handle must not be in [autocommit mode].
10534**
10535** <li> Schema S of [database connection] D must be a [WAL mode] database.
10536**
10537** <li> There must not be a write transaction open on schema S of database
10538** connection D.
10539**
10540** <li> One or more transactions must have been written to the current wal
10541** file since it was created on disk (by any connection). This means
10542** that a snapshot cannot be taken on a wal mode database with no wal
10543** file immediately after it is first opened. At least one transaction
10544** must be written to it first.
10545** </ul>
10546**
10547** This function may also return SQLITE_NOMEM. If it is called with the
10548** database handle in autocommit mode but fails for some other reason,
10549** whether or not a read transaction is opened on schema S is undefined.
10550**
10551** The [sqlite3_snapshot] object returned from a successful call to
10552** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10553** to avoid a memory leak.
10554**
10555** The [sqlite3_snapshot_get()] interface is only available when the
10556** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10557*/
10558SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10559 sqlite3 *db,
10560 const char *zSchema,
10561 sqlite3_snapshot **ppSnapshot
10562);
10563
10564/*
10565** CAPI3REF: Start a read transaction on an historical snapshot
10566** METHOD: sqlite3_snapshot
10567**
10568** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10569** transaction or upgrades an existing one for schema S of
10570** [database connection] D such that the read transaction refers to
10571** historical [snapshot] P, rather than the most recent change to the
10572** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10573** on success or an appropriate [error code] if it fails.
10574**
10575** ^In order to succeed, the database connection must not be in
10576** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10577** is already a read transaction open on schema S, then the database handle
10578** must have no active statements (SELECT statements that have been passed
10579** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10580** SQLITE_ERROR is returned if either of these conditions is violated, or
10581** if schema S does not exist, or if the snapshot object is invalid.
10582**
10583** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10584** snapshot has been overwritten by a [checkpoint]. In this case
10585** SQLITE_ERROR_SNAPSHOT is returned.
10586**
10587** If there is already a read transaction open when this function is
10588** invoked, then the same read transaction remains open (on the same
10589** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10590** is returned. If another error code - for example SQLITE_PROTOCOL or an
10591** SQLITE_IOERR error code - is returned, then the final state of the
10592** read transaction is undefined. If SQLITE_OK is returned, then the
10593** read transaction is now open on database snapshot P.
10594**
10595** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10596** database connection D does not know that the database file for
10597** schema S is in [WAL mode]. A database connection might not know
10598** that the database file is in [WAL mode] if there has been no prior
10599** I/O on that database connection, or if the database entered [WAL mode]
10600** after the most recent I/O on the database connection.)^
10601** (Hint: Run "[PRAGMA application_id]" against a newly opened
10602** database connection in order to make it ready to use snapshots.)
10603**
10604** The [sqlite3_snapshot_open()] interface is only available when the
10605** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10606*/
10607SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10608 sqlite3 *db,
10609 const char *zSchema,
10610 sqlite3_snapshot *pSnapshot
10611);
10612
10613/*
10614** CAPI3REF: Destroy a snapshot
10615** DESTRUCTOR: sqlite3_snapshot
10616**
10617** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10618** The application must eventually free every [sqlite3_snapshot] object
10619** using this routine to avoid a memory leak.
10620**
10621** The [sqlite3_snapshot_free()] interface is only available when the
10622** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10623*/
10624SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10625
10626/*
10627** CAPI3REF: Compare the ages of two snapshot handles.
10628** METHOD: sqlite3_snapshot
10629**
10630** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10631** of two valid snapshot handles.
10632**
10633** If the two snapshot handles are not associated with the same database
10634** file, the result of the comparison is undefined.
10635**
10636** Additionally, the result of the comparison is only valid if both of the
10637** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10638** last time the wal file was deleted. The wal file is deleted when the
10639** database is changed back to rollback mode or when the number of database
10640** clients drops to zero. If either snapshot handle was obtained before the
10641** wal file was last deleted, the value returned by this function
10642** is undefined.
10643**
10644** Otherwise, this API returns a negative value if P1 refers to an older
10645** snapshot than P2, zero if the two handles refer to the same database
10646** snapshot, and a positive value if P1 is a newer snapshot than P2.
10647**
10648** This interface is only available if SQLite is compiled with the
10649** [SQLITE_ENABLE_SNAPSHOT] option.
10650*/
10651SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10652 sqlite3_snapshot *p1,
10653 sqlite3_snapshot *p2
10654);
10655
10656/*
10657** CAPI3REF: Recover snapshots from a wal file
10658** METHOD: sqlite3_snapshot
10659**
10660** If a [WAL file] remains on disk after all database connections close
10661** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10662** or because the last process to have the database opened exited without
10663** calling [sqlite3_close()]) and a new connection is subsequently opened
10664** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10665** will only be able to open the last transaction added to the WAL file
10666** even though the WAL file contains other valid transactions.
10667**
10668** This function attempts to scan the WAL file associated with database zDb
10669** of database handle db and make all valid snapshots available to
10670** sqlite3_snapshot_open(). It is an error if there is already a read
10671** transaction open on the database, or if the database is not a WAL mode
10672** database.
10673**
10674** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10675**
10676** This interface is only available if SQLite is compiled with the
10677** [SQLITE_ENABLE_SNAPSHOT] option.
10678*/
10679SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10680
10681/*
10682** CAPI3REF: Serialize a database
10683**
10684** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10685** that is a serialization of the S database on [database connection] D.
10686** If P is not a NULL pointer, then the size of the database in bytes
10687** is written into *P.
10688**
10689** For an ordinary on-disk database file, the serialization is just a
10690** copy of the disk file. For an in-memory database or a "TEMP" database,
10691** the serialization is the same sequence of bytes which would be written
10692** to disk if that database where backed up to disk.
10693**
10694** The usual case is that sqlite3_serialize() copies the serialization of
10695** the database into memory obtained from [sqlite3_malloc64()] and returns
10696** a pointer to that memory. The caller is responsible for freeing the
10697** returned value to avoid a memory leak. However, if the F argument
10698** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10699** are made, and the sqlite3_serialize() function will return a pointer
10700** to the contiguous memory representation of the database that SQLite
10701** is currently using for that database, or NULL if the no such contiguous
10702** memory representation of the database exists. A contiguous memory
10703** representation of the database will usually only exist if there has
10704** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10705** values of D and S.
10706** The size of the database is written into *P even if the
10707** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10708** of the database exists.
10709**
10710** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
10711** the returned buffer content will remain accessible and unchanged
10712** until either the next write operation on the connection or when
10713** the connection is closed, and applications must not modify the
10714** buffer. If the bit had been clear, the returned buffer will not
10715** be accessed by SQLite after the call.
10716**
10717** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10718** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10719** allocation error occurs.
10720**
10721** This interface is omitted if SQLite is compiled with the
10722** [SQLITE_OMIT_DESERIALIZE] option.
10723*/
10724SQLITE_API unsigned char *sqlite3_serialize(
10725 sqlite3 *db, /* The database connection */
10726 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10727 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10728 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10729);
10730
10731/*
10732** CAPI3REF: Flags for sqlite3_serialize
10733**
10734** Zero or more of the following constants can be OR-ed together for
10735** the F argument to [sqlite3_serialize(D,S,P,F)].
10736**
10737** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10738** a pointer to contiguous in-memory database that it is currently using,
10739** without making a copy of the database. If SQLite is not currently using
10740** a contiguous in-memory database, then this option causes
10741** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10742** using a contiguous in-memory database if it has been initialized by a
10743** prior call to [sqlite3_deserialize()].
10744*/
10745#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10746
10747/*
10748** CAPI3REF: Deserialize a database
10749**
10750** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10751** [database connection] D to disconnect from database S and then
10752** reopen S as an in-memory database based on the serialization contained
10753** in P. The serialized database P is N bytes in size. M is the size of
10754** the buffer P, which might be larger than N. If M is larger than N, and
10755** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10756** permitted to add content to the in-memory database as long as the total
10757** size does not exceed M bytes.
10758**
10759** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10760** invoke sqlite3_free() on the serialization buffer when the database
10761** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10762** SQLite will try to increase the buffer size using sqlite3_realloc64()
10763** if writes on the database cause it to grow larger than M bytes.
10764**
10765** Applications must not modify the buffer P or invalidate it before
10766** the database connection D is closed.
10767**
10768** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10769** database is currently in a read transaction or is involved in a backup
10770** operation.
10771**
10772** It is not possible to deserialized into the TEMP database. If the
10773** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10774** function returns SQLITE_ERROR.
10775**
10776** The deserialized database should not be in [WAL mode]. If the database
10777** is in WAL mode, then any attempt to use the database file will result
10778** in an [SQLITE_CANTOPEN] error. The application can set the
10779** [file format version numbers] (bytes 18 and 19) of the input database P
10780** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
10781** database file into rollback mode and work around this limitation.
10782**
10783** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10784** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10785** [sqlite3_free()] is invoked on argument P prior to returning.
10786**
10787** This interface is omitted if SQLite is compiled with the
10788** [SQLITE_OMIT_DESERIALIZE] option.
10789*/
10790SQLITE_API int sqlite3_deserialize(
10791 sqlite3 *db, /* The database connection */
10792 const char *zSchema, /* Which DB to reopen with the deserialization */
10793 unsigned char *pData, /* The serialized database content */
10794 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10795 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10796 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10797);
10798
10799/*
10800** CAPI3REF: Flags for sqlite3_deserialize()
10801**
10802** The following are allowed values for 6th argument (the F argument) to
10803** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10804**
10805** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10806** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10807** and that SQLite should take ownership of this memory and automatically
10808** free it when it has finished using it. Without this flag, the caller
10809** is responsible for freeing any dynamically allocated memory.
10810**
10811** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10812** grow the size of the database using calls to [sqlite3_realloc64()]. This
10813** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10814** Without this flag, the deserialized database cannot increase in size beyond
10815** the number of bytes specified by the M parameter.
10816**
10817** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10818** should be treated as read-only.
10819*/
10820#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10821#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10822#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10823
10824/*
10825** Undo the hack that converts floating point types to integer for
10826** builds on processors without floating point support.
10827*/
10828#ifdef SQLITE_OMIT_FLOATING_POINT
10829# undef double
10830#endif
10831
10832#if defined(__wasi__)
10833# undef SQLITE_WASI
10834# define SQLITE_WASI 1
10835# undef SQLITE_OMIT_WAL
10836# define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */
10837# ifndef SQLITE_OMIT_LOAD_EXTENSION
10838# define SQLITE_OMIT_LOAD_EXTENSION
10839# endif
10840# ifndef SQLITE_THREADSAFE
10841# define SQLITE_THREADSAFE 0
10842# endif
10843#endif
10844
10845#ifdef __cplusplus
10846} /* End of the 'extern "C"' block */
10847#endif
10848#endif /* SQLITE3_H */
10849
10850/******** Begin file sqlite3rtree.h *********/
10851/*
10852** 2010 August 30
10853**
10854** The author disclaims copyright to this source code. In place of
10855** a legal notice, here is a blessing:
10856**
10857** May you do good and not evil.
10858** May you find forgiveness for yourself and forgive others.
10859** May you share freely, never taking more than you give.
10860**
10861*************************************************************************
10862*/
10863
10864#ifndef _SQLITE3RTREE_H_
10865#define _SQLITE3RTREE_H_
10866
10867
10868#ifdef __cplusplus
10869extern "C" {
10870#endif
10871
10872typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10873typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10874
10875/* The double-precision datatype used by RTree depends on the
10876** SQLITE_RTREE_INT_ONLY compile-time option.
10877*/
10878#ifdef SQLITE_RTREE_INT_ONLY
10879 typedef sqlite3_int64 sqlite3_rtree_dbl;
10880#else
10881 typedef double sqlite3_rtree_dbl;
10882#endif
10883
10884/*
10885** Register a geometry callback named zGeom that can be used as part of an
10886** R-Tree geometry query as follows:
10887**
10888** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10889*/
10890SQLITE_API int sqlite3_rtree_geometry_callback(
10891 sqlite3 *db,
10892 const char *zGeom,
10893 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10894 void *pContext
10895);
10896
10897
10898/*
10899** A pointer to a structure of the following type is passed as the first
10900** argument to callbacks registered using rtree_geometry_callback().
10901*/
10902struct sqlite3_rtree_geometry {
10903 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10904 int nParam; /* Size of array aParam[] */
10905 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10906 void *pUser; /* Callback implementation user data */
10907 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10908};
10909
10910/*
10911** Register a 2nd-generation geometry callback named zScore that can be
10912** used as part of an R-Tree geometry query as follows:
10913**
10914** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10915*/
10916SQLITE_API int sqlite3_rtree_query_callback(
10917 sqlite3 *db,
10918 const char *zQueryFunc,
10919 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10920 void *pContext,
10921 void (*xDestructor)(void*)
10922);
10923
10924
10925/*
10926** A pointer to a structure of the following type is passed as the
10927** argument to scored geometry callback registered using
10928** sqlite3_rtree_query_callback().
10929**
10930** Note that the first 5 fields of this structure are identical to
10931** sqlite3_rtree_geometry. This structure is a subclass of
10932** sqlite3_rtree_geometry.
10933*/
10934struct sqlite3_rtree_query_info {
10935 void *pContext; /* pContext from when function registered */
10936 int nParam; /* Number of function parameters */
10937 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10938 void *pUser; /* callback can use this, if desired */
10939 void (*xDelUser)(void*); /* function to free pUser */
10940 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10941 unsigned int *anQueue; /* Number of pending entries in the queue */
10942 int nCoord; /* Number of coordinates */
10943 int iLevel; /* Level of current node or entry */
10944 int mxLevel; /* The largest iLevel value in the tree */
10945 sqlite3_int64 iRowid; /* Rowid for current entry */
10946 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10947 int eParentWithin; /* Visibility of parent node */
10948 int eWithin; /* OUT: Visibility */
10949 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10950 /* The following fields are only available in 3.8.11 and later */
10951 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10952};
10953
10954/*
10955** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10956*/
10957#define NOT_WITHIN 0 /* Object completely outside of query region */
10958#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10959#define FULLY_WITHIN 2 /* Object fully contained within query region */
10960
10961
10962#ifdef __cplusplus
10963} /* end of the 'extern "C"' block */
10964#endif
10965
10966#endif /* ifndef _SQLITE3RTREE_H_ */
10967
10968/******** End of sqlite3rtree.h *********/
10969/******** Begin file sqlite3session.h *********/
10970
10971#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10972#define __SQLITESESSION_H_ 1
10973
10974/*
10975** Make sure we can call this stuff from C++.
10976*/
10977#ifdef __cplusplus
10978extern "C" {
10979#endif
10980
10981
10982/*
10983** CAPI3REF: Session Object Handle
10984**
10985** An instance of this object is a [session] that can be used to
10986** record changes to a database.
10987*/
10988typedef struct sqlite3_session sqlite3_session;
10989
10990/*
10991** CAPI3REF: Changeset Iterator Handle
10992**
10993** An instance of this object acts as a cursor for iterating
10994** over the elements of a [changeset] or [patchset].
10995*/
10996typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10997
10998/*
10999** CAPI3REF: Create A New Session Object
11000** CONSTRUCTOR: sqlite3_session
11001**
11002** Create a new session object attached to database handle db. If successful,
11003** a pointer to the new object is written to *ppSession and SQLITE_OK is
11004** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11005** error code (e.g. SQLITE_NOMEM) is returned.
11006**
11007** It is possible to create multiple session objects attached to a single
11008** database handle.
11009**
11010** Session objects created using this function should be deleted using the
11011** [sqlite3session_delete()] function before the database handle that they
11012** are attached to is itself closed. If the database handle is closed before
11013** the session object is deleted, then the results of calling any session
11014** module function, including [sqlite3session_delete()] on the session object
11015** are undefined.
11016**
11017** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11018** is not possible for an application to register a pre-update hook on a
11019** database handle that has one or more session objects attached. Nor is
11020** it possible to create a session object attached to a database handle for
11021** which a pre-update hook is already defined. The results of attempting
11022** either of these things are undefined.
11023**
11024** The session object will be used to create changesets for tables in
11025** database zDb, where zDb is either "main", or "temp", or the name of an
11026** attached database. It is not an error if database zDb is not attached
11027** to the database when the session object is created.
11028*/
11029SQLITE_API int sqlite3session_create(
11030 sqlite3 *db, /* Database handle */
11031 const char *zDb, /* Name of db (e.g. "main") */
11032 sqlite3_session **ppSession /* OUT: New session object */
11033);
11034
11035/*
11036** CAPI3REF: Delete A Session Object
11037** DESTRUCTOR: sqlite3_session
11038**
11039** Delete a session object previously allocated using
11040** [sqlite3session_create()]. Once a session object has been deleted, the
11041** results of attempting to use pSession with any other session module
11042** function are undefined.
11043**
11044** Session objects must be deleted before the database handle to which they
11045** are attached is closed. Refer to the documentation for
11046** [sqlite3session_create()] for details.
11047*/
11048SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11049
11050/*
11051** CAPI3REF: Configure a Session Object
11052** METHOD: sqlite3_session
11053**
11054** This method is used to configure a session object after it has been
11055** created. At present the only valid values for the second parameter are
11056** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11057**
11058*/
11059SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11060
11061/*
11062** CAPI3REF: Options for sqlite3session_object_config
11063**
11064** The following values may passed as the the 2nd parameter to
11065** sqlite3session_object_config().
11066**
11067** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11068** This option is used to set, clear or query the flag that enables
11069** the [sqlite3session_changeset_size()] API. Because it imposes some
11070** computational overhead, this API is disabled by default. Argument
11071** pArg must point to a value of type (int). If the value is initially
11072** 0, then the sqlite3session_changeset_size() API is disabled. If it
11073** is greater than 0, then the same API is enabled. Or, if the initial
11074** value is less than zero, no change is made. In all cases the (int)
11075** variable is set to 1 if the sqlite3session_changeset_size() API is
11076** enabled following the current call, or 0 otherwise.
11077**
11078** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11079** the first table has been attached to the session object.
11080**
11081** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11082** This option is used to set, clear or query the flag that enables
11083** collection of data for tables with no explicit PRIMARY KEY.
11084**
11085** Normally, tables with no explicit PRIMARY KEY are simply ignored
11086** by the sessions module. However, if this flag is set, it behaves
11087** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11088** as their leftmost columns.
11089**
11090** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11091** the first table has been attached to the session object.
11092*/
11093#define SQLITE_SESSION_OBJCONFIG_SIZE 1
11094#define SQLITE_SESSION_OBJCONFIG_ROWID 2
11095
11096/*
11097** CAPI3REF: Enable Or Disable A Session Object
11098** METHOD: sqlite3_session
11099**
11100** Enable or disable the recording of changes by a session object. When
11101** enabled, a session object records changes made to the database. When
11102** disabled - it does not. A newly created session object is enabled.
11103** Refer to the documentation for [sqlite3session_changeset()] for further
11104** details regarding how enabling and disabling a session object affects
11105** the eventual changesets.
11106**
11107** Passing zero to this function disables the session. Passing a value
11108** greater than zero enables it. Passing a value less than zero is a
11109** no-op, and may be used to query the current state of the session.
11110**
11111** The return value indicates the final state of the session object: 0 if
11112** the session is disabled, or 1 if it is enabled.
11113*/
11114SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11115
11116/*
11117** CAPI3REF: Set Or Clear the Indirect Change Flag
11118** METHOD: sqlite3_session
11119**
11120** Each change recorded by a session object is marked as either direct or
11121** indirect. A change is marked as indirect if either:
11122**
11123** <ul>
11124** <li> The session object "indirect" flag is set when the change is
11125** made, or
11126** <li> The change is made by an SQL trigger or foreign key action
11127** instead of directly as a result of a users SQL statement.
11128** </ul>
11129**
11130** If a single row is affected by more than one operation within a session,
11131** then the change is considered indirect if all operations meet the criteria
11132** for an indirect change above, or direct otherwise.
11133**
11134** This function is used to set, clear or query the session object indirect
11135** flag. If the second argument passed to this function is zero, then the
11136** indirect flag is cleared. If it is greater than zero, the indirect flag
11137** is set. Passing a value less than zero does not modify the current value
11138** of the indirect flag, and may be used to query the current state of the
11139** indirect flag for the specified session object.
11140**
11141** The return value indicates the final state of the indirect flag: 0 if
11142** it is clear, or 1 if it is set.
11143*/
11144SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11145
11146/*
11147** CAPI3REF: Attach A Table To A Session Object
11148** METHOD: sqlite3_session
11149**
11150** If argument zTab is not NULL, then it is the name of a table to attach
11151** to the session object passed as the first argument. All subsequent changes
11152** made to the table while the session object is enabled will be recorded. See
11153** documentation for [sqlite3session_changeset()] for further details.
11154**
11155** Or, if argument zTab is NULL, then changes are recorded for all tables
11156** in the database. If additional tables are added to the database (by
11157** executing "CREATE TABLE" statements) after this call is made, changes for
11158** the new tables are also recorded.
11159**
11160** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11161** defined as part of their CREATE TABLE statement. It does not matter if the
11162** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11163** KEY may consist of a single column, or may be a composite key.
11164**
11165** It is not an error if the named table does not exist in the database. Nor
11166** is it an error if the named table does not have a PRIMARY KEY. However,
11167** no changes will be recorded in either of these scenarios.
11168**
11169** Changes are not recorded for individual rows that have NULL values stored
11170** in one or more of their PRIMARY KEY columns.
11171**
11172** SQLITE_OK is returned if the call completes without error. Or, if an error
11173** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11174**
11175** <h3>Special sqlite_stat1 Handling</h3>
11176**
11177** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11178** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11179** <pre>
11180** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11181** </pre>
11182**
11183** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11184** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11185** are recorded for rows for which (idx IS NULL) is true. However, for such
11186** rows a zero-length blob (SQL value X'') is stored in the changeset or
11187** patchset instead of a NULL value. This allows such changesets to be
11188** manipulated by legacy implementations of sqlite3changeset_invert(),
11189** concat() and similar.
11190**
11191** The sqlite3changeset_apply() function automatically converts the
11192** zero-length blob back to a NULL value when updating the sqlite_stat1
11193** table. However, if the application calls sqlite3changeset_new(),
11194** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11195** iterator directly (including on a changeset iterator passed to a
11196** conflict-handler callback) then the X'' value is returned. The application
11197** must translate X'' to NULL itself if required.
11198**
11199** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11200** changes made to the sqlite_stat1 table. Legacy versions of the
11201** sqlite3changeset_apply() function silently ignore any modifications to the
11202** sqlite_stat1 table that are part of a changeset or patchset.
11203*/
11204SQLITE_API int sqlite3session_attach(
11205 sqlite3_session *pSession, /* Session object */
11206 const char *zTab /* Table name */
11207);
11208
11209/*
11210** CAPI3REF: Set a table filter on a Session Object.
11211** METHOD: sqlite3_session
11212**
11213** The second argument (xFilter) is the "filter callback". For changes to rows
11214** in tables that are not attached to the Session object, the filter is called
11215** to determine whether changes to the table's rows should be tracked or not.
11216** If xFilter returns 0, changes are not tracked. Note that once a table is
11217** attached, xFilter will not be called again.
11218*/
11219SQLITE_API void sqlite3session_table_filter(
11220 sqlite3_session *pSession, /* Session object */
11221 int(*xFilter)(
11222 void *pCtx, /* Copy of third arg to _filter_table() */
11223 const char *zTab /* Table name */
11224 ),
11225 void *pCtx /* First argument passed to xFilter */
11226);
11227
11228/*
11229** CAPI3REF: Generate A Changeset From A Session Object
11230** METHOD: sqlite3_session
11231**
11232** Obtain a changeset containing changes to the tables attached to the
11233** session object passed as the first argument. If successful,
11234** set *ppChangeset to point to a buffer containing the changeset
11235** and *pnChangeset to the size of the changeset in bytes before returning
11236** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11237** zero and return an SQLite error code.
11238**
11239** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11240** each representing a change to a single row of an attached table. An INSERT
11241** change contains the values of each field of a new database row. A DELETE
11242** contains the original values of each field of a deleted database row. An
11243** UPDATE change contains the original values of each field of an updated
11244** database row along with the updated values for each updated non-primary-key
11245** column. It is not possible for an UPDATE change to represent a change that
11246** modifies the values of primary key columns. If such a change is made, it
11247** is represented in a changeset as a DELETE followed by an INSERT.
11248**
11249** Changes are not recorded for rows that have NULL values stored in one or
11250** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11251** no corresponding change is present in the changesets returned by this
11252** function. If an existing row with one or more NULL values stored in
11253** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11254** only an INSERT is appears in the changeset. Similarly, if an existing row
11255** with non-NULL PRIMARY KEY values is updated so that one or more of its
11256** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11257** DELETE change only.
11258**
11259** The contents of a changeset may be traversed using an iterator created
11260** using the [sqlite3changeset_start()] API. A changeset may be applied to
11261** a database with a compatible schema using the [sqlite3changeset_apply()]
11262** API.
11263**
11264** Within a changeset generated by this function, all changes related to a
11265** single table are grouped together. In other words, when iterating through
11266** a changeset or when applying a changeset to a database, all changes related
11267** to a single table are processed before moving on to the next table. Tables
11268** are sorted in the same order in which they were attached (or auto-attached)
11269** to the sqlite3_session object. The order in which the changes related to
11270** a single table are stored is undefined.
11271**
11272** Following a successful call to this function, it is the responsibility of
11273** the caller to eventually free the buffer that *ppChangeset points to using
11274** [sqlite3_free()].
11275**
11276** <h3>Changeset Generation</h3>
11277**
11278** Once a table has been attached to a session object, the session object
11279** records the primary key values of all new rows inserted into the table.
11280** It also records the original primary key and other column values of any
11281** deleted or updated rows. For each unique primary key value, data is only
11282** recorded once - the first time a row with said primary key is inserted,
11283** updated or deleted in the lifetime of the session.
11284**
11285** There is one exception to the previous paragraph: when a row is inserted,
11286** updated or deleted, if one or more of its primary key columns contain a
11287** NULL value, no record of the change is made.
11288**
11289** The session object therefore accumulates two types of records - those
11290** that consist of primary key values only (created when the user inserts
11291** a new record) and those that consist of the primary key values and the
11292** original values of other table columns (created when the users deletes
11293** or updates a record).
11294**
11295** When this function is called, the requested changeset is created using
11296** both the accumulated records and the current contents of the database
11297** file. Specifically:
11298**
11299** <ul>
11300** <li> For each record generated by an insert, the database is queried
11301** for a row with a matching primary key. If one is found, an INSERT
11302** change is added to the changeset. If no such row is found, no change
11303** is added to the changeset.
11304**
11305** <li> For each record generated by an update or delete, the database is
11306** queried for a row with a matching primary key. If such a row is
11307** found and one or more of the non-primary key fields have been
11308** modified from their original values, an UPDATE change is added to
11309** the changeset. Or, if no such row is found in the table, a DELETE
11310** change is added to the changeset. If there is a row with a matching
11311** primary key in the database, but all fields contain their original
11312** values, no change is added to the changeset.
11313** </ul>
11314**
11315** This means, amongst other things, that if a row is inserted and then later
11316** deleted while a session object is active, neither the insert nor the delete
11317** will be present in the changeset. Or if a row is deleted and then later a
11318** row with the same primary key values inserted while a session object is
11319** active, the resulting changeset will contain an UPDATE change instead of
11320** a DELETE and an INSERT.
11321**
11322** When a session object is disabled (see the [sqlite3session_enable()] API),
11323** it does not accumulate records when rows are inserted, updated or deleted.
11324** This may appear to have some counter-intuitive effects if a single row
11325** is written to more than once during a session. For example, if a row
11326** is inserted while a session object is enabled, then later deleted while
11327** the same session object is disabled, no INSERT record will appear in the
11328** changeset, even though the delete took place while the session was disabled.
11329** Or, if one field of a row is updated while a session is disabled, and
11330** another field of the same row is updated while the session is enabled, the
11331** resulting changeset will contain an UPDATE change that updates both fields.
11332*/
11333SQLITE_API int sqlite3session_changeset(
11334 sqlite3_session *pSession, /* Session object */
11335 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11336 void **ppChangeset /* OUT: Buffer containing changeset */
11337);
11338
11339/*
11340** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11341** METHOD: sqlite3_session
11342**
11343** By default, this function always returns 0. For it to return
11344** a useful result, the sqlite3_session object must have been configured
11345** to enable this API using sqlite3session_object_config() with the
11346** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11347**
11348** When enabled, this function returns an upper limit, in bytes, for the size
11349** of the changeset that might be produced if sqlite3session_changeset() were
11350** called. The final changeset size might be equal to or smaller than the
11351** size in bytes returned by this function.
11352*/
11353SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11354
11355/*
11356** CAPI3REF: Load The Difference Between Tables Into A Session
11357** METHOD: sqlite3_session
11358**
11359** If it is not already attached to the session object passed as the first
11360** argument, this function attaches table zTbl in the same manner as the
11361** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11362** does not have a primary key, this function is a no-op (but does not return
11363** an error).
11364**
11365** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11366** attached to the same database handle as the session object that contains
11367** a table compatible with the table attached to the session by this function.
11368** A table is considered compatible if it:
11369**
11370** <ul>
11371** <li> Has the same name,
11372** <li> Has the same set of columns declared in the same order, and
11373** <li> Has the same PRIMARY KEY definition.
11374** </ul>
11375**
11376** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11377** are compatible but do not have any PRIMARY KEY columns, it is not an error
11378** but no changes are added to the session object. As with other session
11379** APIs, tables without PRIMARY KEYs are simply ignored.
11380**
11381** This function adds a set of changes to the session object that could be
11382** used to update the table in database zFrom (call this the "from-table")
11383** so that its content is the same as the table attached to the session
11384** object (call this the "to-table"). Specifically:
11385**
11386** <ul>
11387** <li> For each row (primary key) that exists in the to-table but not in
11388** the from-table, an INSERT record is added to the session object.
11389**
11390** <li> For each row (primary key) that exists in the to-table but not in
11391** the from-table, a DELETE record is added to the session object.
11392**
11393** <li> For each row (primary key) that exists in both tables, but features
11394** different non-PK values in each, an UPDATE record is added to the
11395** session.
11396** </ul>
11397**
11398** To clarify, if this function is called and then a changeset constructed
11399** using [sqlite3session_changeset()], then after applying that changeset to
11400** database zFrom the contents of the two compatible tables would be
11401** identical.
11402**
11403** It an error if database zFrom does not exist or does not contain the
11404** required compatible table.
11405**
11406** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11407** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11408** may be set to point to a buffer containing an English language error
11409** message. It is the responsibility of the caller to free this buffer using
11410** sqlite3_free().
11411*/
11412SQLITE_API int sqlite3session_diff(
11413 sqlite3_session *pSession,
11414 const char *zFromDb,
11415 const char *zTbl,
11416 char **pzErrMsg
11417);
11418
11419
11420/*
11421** CAPI3REF: Generate A Patchset From A Session Object
11422** METHOD: sqlite3_session
11423**
11424** The differences between a patchset and a changeset are that:
11425**
11426** <ul>
11427** <li> DELETE records consist of the primary key fields only. The
11428** original values of other fields are omitted.
11429** <li> The original values of any modified fields are omitted from
11430** UPDATE records.
11431** </ul>
11432**
11433** A patchset blob may be used with up to date versions of all
11434** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11435** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11436** attempting to use a patchset blob with old versions of the
11437** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11438**
11439** Because the non-primary key "old.*" fields are omitted, no
11440** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11441** is passed to the sqlite3changeset_apply() API. Other conflict types work
11442** in the same way as for changesets.
11443**
11444** Changes within a patchset are ordered in the same way as for changesets
11445** generated by the sqlite3session_changeset() function (i.e. all changes for
11446** a single table are grouped together, tables appear in the order in which
11447** they were attached to the session object).
11448*/
11449SQLITE_API int sqlite3session_patchset(
11450 sqlite3_session *pSession, /* Session object */
11451 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11452 void **ppPatchset /* OUT: Buffer containing patchset */
11453);
11454
11455/*
11456** CAPI3REF: Test if a changeset has recorded any changes.
11457**
11458** Return non-zero if no changes to attached tables have been recorded by
11459** the session object passed as the first argument. Otherwise, if one or
11460** more changes have been recorded, return zero.
11461**
11462** Even if this function returns zero, it is possible that calling
11463** [sqlite3session_changeset()] on the session handle may still return a
11464** changeset that contains no changes. This can happen when a row in
11465** an attached table is modified and then later on the original values
11466** are restored. However, if this function returns non-zero, then it is
11467** guaranteed that a call to sqlite3session_changeset() will return a
11468** changeset containing zero changes.
11469*/
11470SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11471
11472/*
11473** CAPI3REF: Query for the amount of heap memory used by a session object.
11474**
11475** This API returns the total amount of heap memory in bytes currently
11476** used by the session object passed as the only argument.
11477*/
11478SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11479
11480/*
11481** CAPI3REF: Create An Iterator To Traverse A Changeset
11482** CONSTRUCTOR: sqlite3_changeset_iter
11483**
11484** Create an iterator used to iterate through the contents of a changeset.
11485** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11486** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11487** SQLite error code is returned.
11488**
11489** The following functions can be used to advance and query a changeset
11490** iterator created by this function:
11491**
11492** <ul>
11493** <li> [sqlite3changeset_next()]
11494** <li> [sqlite3changeset_op()]
11495** <li> [sqlite3changeset_new()]
11496** <li> [sqlite3changeset_old()]
11497** </ul>
11498**
11499** It is the responsibility of the caller to eventually destroy the iterator
11500** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11501** changeset (pChangeset) must remain valid until after the iterator is
11502** destroyed.
11503**
11504** Assuming the changeset blob was created by one of the
11505** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11506** [sqlite3changeset_invert()] functions, all changes within the changeset
11507** that apply to a single table are grouped together. This means that when
11508** an application iterates through a changeset using an iterator created by
11509** this function, all changes that relate to a single table are visited
11510** consecutively. There is no chance that the iterator will visit a change
11511** the applies to table X, then one for table Y, and then later on visit
11512** another change for table X.
11513**
11514** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11515** may be modified by passing a combination of
11516** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11517**
11518** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11519** and therefore subject to change.
11520*/
11521SQLITE_API int sqlite3changeset_start(
11522 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11523 int nChangeset, /* Size of changeset blob in bytes */
11524 void *pChangeset /* Pointer to blob containing changeset */
11525);
11526SQLITE_API int sqlite3changeset_start_v2(
11527 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11528 int nChangeset, /* Size of changeset blob in bytes */
11529 void *pChangeset, /* Pointer to blob containing changeset */
11530 int flags /* SESSION_CHANGESETSTART_* flags */
11531);
11532
11533/*
11534** CAPI3REF: Flags for sqlite3changeset_start_v2
11535**
11536** The following flags may passed via the 4th parameter to
11537** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11538**
11539** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11540** Invert the changeset while iterating through it. This is equivalent to
11541** inverting a changeset using sqlite3changeset_invert() before applying it.
11542** It is an error to specify this flag with a patchset.
11543*/
11544#define SQLITE_CHANGESETSTART_INVERT 0x0002
11545
11546
11547/*
11548** CAPI3REF: Advance A Changeset Iterator
11549** METHOD: sqlite3_changeset_iter
11550**
11551** This function may only be used with iterators created by the function
11552** [sqlite3changeset_start()]. If it is called on an iterator passed to
11553** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11554** is returned and the call has no effect.
11555**
11556** Immediately after an iterator is created by sqlite3changeset_start(), it
11557** does not point to any change in the changeset. Assuming the changeset
11558** is not empty, the first call to this function advances the iterator to
11559** point to the first change in the changeset. Each subsequent call advances
11560** the iterator to point to the next change in the changeset (if any). If
11561** no error occurs and the iterator points to a valid change after a call
11562** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11563** Otherwise, if all changes in the changeset have already been visited,
11564** SQLITE_DONE is returned.
11565**
11566** If an error occurs, an SQLite error code is returned. Possible error
11567** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11568** SQLITE_NOMEM.
11569*/
11570SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11571
11572/*
11573** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11574** METHOD: sqlite3_changeset_iter
11575**
11576** The pIter argument passed to this function may either be an iterator
11577** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11578** created by [sqlite3changeset_start()]. In the latter case, the most recent
11579** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11580** is not the case, this function returns [SQLITE_MISUSE].
11581**
11582** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11583** outputs are set through these pointers:
11584**
11585** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11586** depending on the type of change that the iterator currently points to;
11587**
11588** *pnCol is set to the number of columns in the table affected by the change; and
11589**
11590** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11591** the name of the table affected by the current change. The buffer remains
11592** valid until either sqlite3changeset_next() is called on the iterator
11593** or until the conflict-handler function returns.
11594**
11595** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11596** is an indirect change, or false (0) otherwise. See the documentation for
11597** [sqlite3session_indirect()] for a description of direct and indirect
11598** changes.
11599**
11600** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11601** SQLite error code is returned. The values of the output variables may not
11602** be trusted in this case.
11603*/
11604SQLITE_API int sqlite3changeset_op(
11605 sqlite3_changeset_iter *pIter, /* Iterator object */
11606 const char **pzTab, /* OUT: Pointer to table name */
11607 int *pnCol, /* OUT: Number of columns in table */
11608 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11609 int *pbIndirect /* OUT: True for an 'indirect' change */
11610);
11611
11612/*
11613** CAPI3REF: Obtain The Primary Key Definition Of A Table
11614** METHOD: sqlite3_changeset_iter
11615**
11616** For each modified table, a changeset includes the following:
11617**
11618** <ul>
11619** <li> The number of columns in the table, and
11620** <li> Which of those columns make up the tables PRIMARY KEY.
11621** </ul>
11622**
11623** This function is used to find which columns comprise the PRIMARY KEY of
11624** the table modified by the change that iterator pIter currently points to.
11625** If successful, *pabPK is set to point to an array of nCol entries, where
11626** nCol is the number of columns in the table. Elements of *pabPK are set to
11627** 0x01 if the corresponding column is part of the tables primary key, or
11628** 0x00 if it is not.
11629**
11630** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11631** in the table.
11632**
11633** If this function is called when the iterator does not point to a valid
11634** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11635** SQLITE_OK is returned and the output variables populated as described
11636** above.
11637*/
11638SQLITE_API int sqlite3changeset_pk(
11639 sqlite3_changeset_iter *pIter, /* Iterator object */
11640 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11641 int *pnCol /* OUT: Number of entries in output array */
11642);
11643
11644/*
11645** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11646** METHOD: sqlite3_changeset_iter
11647**
11648** The pIter argument passed to this function may either be an iterator
11649** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11650** created by [sqlite3changeset_start()]. In the latter case, the most recent
11651** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11652** Furthermore, it may only be called if the type of change that the iterator
11653** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11654** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11655**
11656** Argument iVal must be greater than or equal to 0, and less than the number
11657** of columns in the table affected by the current change. Otherwise,
11658** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11659**
11660** If successful, this function sets *ppValue to point to a protected
11661** sqlite3_value object containing the iVal'th value from the vector of
11662** original row values stored as part of the UPDATE or DELETE change and
11663** returns SQLITE_OK. The name of the function comes from the fact that this
11664** is similar to the "old.*" columns available to update or delete triggers.
11665**
11666** If some other error occurs (e.g. an OOM condition), an SQLite error code
11667** is returned and *ppValue is set to NULL.
11668*/
11669SQLITE_API int sqlite3changeset_old(
11670 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11671 int iVal, /* Column number */
11672 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11673);
11674
11675/*
11676** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11677** METHOD: sqlite3_changeset_iter
11678**
11679** The pIter argument passed to this function may either be an iterator
11680** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11681** created by [sqlite3changeset_start()]. In the latter case, the most recent
11682** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11683** Furthermore, it may only be called if the type of change that the iterator
11684** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11685** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11686**
11687** Argument iVal must be greater than or equal to 0, and less than the number
11688** of columns in the table affected by the current change. Otherwise,
11689** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11690**
11691** If successful, this function sets *ppValue to point to a protected
11692** sqlite3_value object containing the iVal'th value from the vector of
11693** new row values stored as part of the UPDATE or INSERT change and
11694** returns SQLITE_OK. If the change is an UPDATE and does not include
11695** a new value for the requested column, *ppValue is set to NULL and
11696** SQLITE_OK returned. The name of the function comes from the fact that
11697** this is similar to the "new.*" columns available to update or delete
11698** triggers.
11699**
11700** If some other error occurs (e.g. an OOM condition), an SQLite error code
11701** is returned and *ppValue is set to NULL.
11702*/
11703SQLITE_API int sqlite3changeset_new(
11704 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11705 int iVal, /* Column number */
11706 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11707);
11708
11709/*
11710** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11711** METHOD: sqlite3_changeset_iter
11712**
11713** This function should only be used with iterator objects passed to a
11714** conflict-handler callback by [sqlite3changeset_apply()] with either
11715** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11716** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11717** is set to NULL.
11718**
11719** Argument iVal must be greater than or equal to 0, and less than the number
11720** of columns in the table affected by the current change. Otherwise,
11721** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11722**
11723** If successful, this function sets *ppValue to point to a protected
11724** sqlite3_value object containing the iVal'th value from the
11725** "conflicting row" associated with the current conflict-handler callback
11726** and returns SQLITE_OK.
11727**
11728** If some other error occurs (e.g. an OOM condition), an SQLite error code
11729** is returned and *ppValue is set to NULL.
11730*/
11731SQLITE_API int sqlite3changeset_conflict(
11732 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11733 int iVal, /* Column number */
11734 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11735);
11736
11737/*
11738** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11739** METHOD: sqlite3_changeset_iter
11740**
11741** This function may only be called with an iterator passed to an
11742** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11743** it sets the output variable to the total number of known foreign key
11744** violations in the destination database and returns SQLITE_OK.
11745**
11746** In all other cases this function returns SQLITE_MISUSE.
11747*/
11748SQLITE_API int sqlite3changeset_fk_conflicts(
11749 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11750 int *pnOut /* OUT: Number of FK violations */
11751);
11752
11753
11754/*
11755** CAPI3REF: Finalize A Changeset Iterator
11756** METHOD: sqlite3_changeset_iter
11757**
11758** This function is used to finalize an iterator allocated with
11759** [sqlite3changeset_start()].
11760**
11761** This function should only be called on iterators created using the
11762** [sqlite3changeset_start()] function. If an application calls this
11763** function with an iterator passed to a conflict-handler by
11764** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11765** call has no effect.
11766**
11767** If an error was encountered within a call to an sqlite3changeset_xxx()
11768** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11769** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11770** to that error is returned by this function. Otherwise, SQLITE_OK is
11771** returned. This is to allow the following pattern (pseudo-code):
11772**
11773** <pre>
11774** sqlite3changeset_start();
11775** while( SQLITE_ROW==sqlite3changeset_next() ){
11776** // Do something with change.
11777** }
11778** rc = sqlite3changeset_finalize();
11779** if( rc!=SQLITE_OK ){
11780** // An error has occurred
11781** }
11782** </pre>
11783*/
11784SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11785
11786/*
11787** CAPI3REF: Invert A Changeset
11788**
11789** This function is used to "invert" a changeset object. Applying an inverted
11790** changeset to a database reverses the effects of applying the uninverted
11791** changeset. Specifically:
11792**
11793** <ul>
11794** <li> Each DELETE change is changed to an INSERT, and
11795** <li> Each INSERT change is changed to a DELETE, and
11796** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11797** </ul>
11798**
11799** This function does not change the order in which changes appear within
11800** the changeset. It merely reverses the sense of each individual change.
11801**
11802** If successful, a pointer to a buffer containing the inverted changeset
11803** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11804** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11805** zeroed and an SQLite error code returned.
11806**
11807** It is the responsibility of the caller to eventually call sqlite3_free()
11808** on the *ppOut pointer to free the buffer allocation following a successful
11809** call to this function.
11810**
11811** WARNING/TODO: This function currently assumes that the input is a valid
11812** changeset. If it is not, the results are undefined.
11813*/
11814SQLITE_API int sqlite3changeset_invert(
11815 int nIn, const void *pIn, /* Input changeset */
11816 int *pnOut, void **ppOut /* OUT: Inverse of input */
11817);
11818
11819/*
11820** CAPI3REF: Concatenate Two Changeset Objects
11821**
11822** This function is used to concatenate two changesets, A and B, into a
11823** single changeset. The result is a changeset equivalent to applying
11824** changeset A followed by changeset B.
11825**
11826** This function combines the two input changesets using an
11827** sqlite3_changegroup object. Calling it produces similar results as the
11828** following code fragment:
11829**
11830** <pre>
11831** sqlite3_changegroup *pGrp;
11832** rc = sqlite3_changegroup_new(&pGrp);
11833** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11834** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11835** if( rc==SQLITE_OK ){
11836** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11837** }else{
11838** *ppOut = 0;
11839** *pnOut = 0;
11840** }
11841** </pre>
11842**
11843** Refer to the sqlite3_changegroup documentation below for details.
11844*/
11845SQLITE_API int sqlite3changeset_concat(
11846 int nA, /* Number of bytes in buffer pA */
11847 void *pA, /* Pointer to buffer containing changeset A */
11848 int nB, /* Number of bytes in buffer pB */
11849 void *pB, /* Pointer to buffer containing changeset B */
11850 int *pnOut, /* OUT: Number of bytes in output changeset */
11851 void **ppOut /* OUT: Buffer containing output changeset */
11852);
11853
11854
11855/*
11856** CAPI3REF: Upgrade the Schema of a Changeset/Patchset
11857*/
11858SQLITE_API int sqlite3changeset_upgrade(
11859 sqlite3 *db,
11860 const char *zDb,
11861 int nIn, const void *pIn, /* Input changeset */
11862 int *pnOut, void **ppOut /* OUT: Inverse of input */
11863);
11864
11865
11866
11867/*
11868** CAPI3REF: Changegroup Handle
11869**
11870** A changegroup is an object used to combine two or more
11871** [changesets] or [patchsets]
11872*/
11873typedef struct sqlite3_changegroup sqlite3_changegroup;
11874
11875/*
11876** CAPI3REF: Create A New Changegroup Object
11877** CONSTRUCTOR: sqlite3_changegroup
11878**
11879** An sqlite3_changegroup object is used to combine two or more changesets
11880** (or patchsets) into a single changeset (or patchset). A single changegroup
11881** object may combine changesets or patchsets, but not both. The output is
11882** always in the same format as the input.
11883**
11884** If successful, this function returns SQLITE_OK and populates (*pp) with
11885** a pointer to a new sqlite3_changegroup object before returning. The caller
11886** should eventually free the returned object using a call to
11887** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11888** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11889**
11890** The usual usage pattern for an sqlite3_changegroup object is as follows:
11891**
11892** <ul>
11893** <li> It is created using a call to sqlite3changegroup_new().
11894**
11895** <li> Zero or more changesets (or patchsets) are added to the object
11896** by calling sqlite3changegroup_add().
11897**
11898** <li> The result of combining all input changesets together is obtained
11899** by the application via a call to sqlite3changegroup_output().
11900**
11901** <li> The object is deleted using a call to sqlite3changegroup_delete().
11902** </ul>
11903**
11904** Any number of calls to add() and output() may be made between the calls to
11905** new() and delete(), and in any order.
11906**
11907** As well as the regular sqlite3changegroup_add() and
11908** sqlite3changegroup_output() functions, also available are the streaming
11909** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11910*/
11911SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11912
11913/*
11914** CAPI3REF: Add a Schema to a Changegroup
11915** METHOD: sqlite3_changegroup_schema
11916**
11917** This method may be used to optionally enforce the rule that the changesets
11918** added to the changegroup handle must match the schema of database zDb
11919** ("main", "temp", or the name of an attached database). If
11920** sqlite3changegroup_add() is called to add a changeset that is not compatible
11921** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
11922** object is left in an undefined state.
11923**
11924** A changeset schema is considered compatible with the database schema in
11925** the same way as for sqlite3changeset_apply(). Specifically, for each
11926** table in the changeset, there exists a database table with:
11927**
11928** <ul>
11929** <li> The name identified by the changeset, and
11930** <li> at least as many columns as recorded in the changeset, and
11931** <li> the primary key columns in the same position as recorded in
11932** the changeset.
11933** </ul>
11934**
11935** The output of the changegroup object always has the same schema as the
11936** database nominated using this function. In cases where changesets passed
11937** to sqlite3changegroup_add() have fewer columns than the corresponding table
11938** in the database schema, these are filled in using the default column
11939** values from the database schema. This makes it possible to combined
11940** changesets that have different numbers of columns for a single table
11941** within a changegroup, provided that they are otherwise compatible.
11942*/
11943SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
11944
11945/*
11946** CAPI3REF: Add A Changeset To A Changegroup
11947** METHOD: sqlite3_changegroup
11948**
11949** Add all changes within the changeset (or patchset) in buffer pData (size
11950** nData bytes) to the changegroup.
11951**
11952** If the buffer contains a patchset, then all prior calls to this function
11953** on the same changegroup object must also have specified patchsets. Or, if
11954** the buffer contains a changeset, so must have the earlier calls to this
11955** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11956** to the changegroup.
11957**
11958** Rows within the changeset and changegroup are identified by the values in
11959** their PRIMARY KEY columns. A change in the changeset is considered to
11960** apply to the same row as a change already present in the changegroup if
11961** the two rows have the same primary key.
11962**
11963** Changes to rows that do not already appear in the changegroup are
11964** simply copied into it. Or, if both the new changeset and the changegroup
11965** contain changes that apply to a single row, the final contents of the
11966** changegroup depends on the type of each change, as follows:
11967**
11968** <table border=1 style="margin-left:8ex;margin-right:8ex">
11969** <tr><th style="white-space:pre">Existing Change </th>
11970** <th style="white-space:pre">New Change </th>
11971** <th>Output Change
11972** <tr><td>INSERT <td>INSERT <td>
11973** The new change is ignored. This case does not occur if the new
11974** changeset was recorded immediately after the changesets already
11975** added to the changegroup.
11976** <tr><td>INSERT <td>UPDATE <td>
11977** The INSERT change remains in the changegroup. The values in the
11978** INSERT change are modified as if the row was inserted by the
11979** existing change and then updated according to the new change.
11980** <tr><td>INSERT <td>DELETE <td>
11981** The existing INSERT is removed from the changegroup. The DELETE is
11982** not added.
11983** <tr><td>UPDATE <td>INSERT <td>
11984** The new change is ignored. This case does not occur if the new
11985** changeset was recorded immediately after the changesets already
11986** added to the changegroup.
11987** <tr><td>UPDATE <td>UPDATE <td>
11988** The existing UPDATE remains within the changegroup. It is amended
11989** so that the accompanying values are as if the row was updated once
11990** by the existing change and then again by the new change.
11991** <tr><td>UPDATE <td>DELETE <td>
11992** The existing UPDATE is replaced by the new DELETE within the
11993** changegroup.
11994** <tr><td>DELETE <td>INSERT <td>
11995** If one or more of the column values in the row inserted by the
11996** new change differ from those in the row deleted by the existing
11997** change, the existing DELETE is replaced by an UPDATE within the
11998** changegroup. Otherwise, if the inserted row is exactly the same
11999** as the deleted row, the existing DELETE is simply discarded.
12000** <tr><td>DELETE <td>UPDATE <td>
12001** The new change is ignored. This case does not occur if the new
12002** changeset was recorded immediately after the changesets already
12003** added to the changegroup.
12004** <tr><td>DELETE <td>DELETE <td>
12005** The new change is ignored. This case does not occur if the new
12006** changeset was recorded immediately after the changesets already
12007** added to the changegroup.
12008** </table>
12009**
12010** If the new changeset contains changes to a table that is already present
12011** in the changegroup, then the number of columns and the position of the
12012** primary key columns for the table must be consistent. If this is not the
12013** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12014** object has been configured with a database schema using the
12015** sqlite3changegroup_schema() API, then it is possible to combine changesets
12016** with different numbers of columns for a single table, provided that
12017** they are otherwise compatible.
12018**
12019** If the input changeset appears to be corrupt and the corruption is
12020** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12021** occurs during processing, this function returns SQLITE_NOMEM.
12022**
12023** In all cases, if an error occurs the state of the final contents of the
12024** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12025*/
12026SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12027
12028/*
12029** CAPI3REF: Add A Single Change To A Changegroup
12030** METHOD: sqlite3_changegroup
12031**
12032** This function adds the single change currently indicated by the iterator
12033** passed as the second argument to the changegroup object. The rules for
12034** adding the change are just as described for [sqlite3changegroup_add()].
12035**
12036** If the change is successfully added to the changegroup, SQLITE_OK is
12037** returned. Otherwise, an SQLite error code is returned.
12038**
12039** The iterator must point to a valid entry when this function is called.
12040** If it does not, SQLITE_ERROR is returned and no change is added to the
12041** changegroup. Additionally, the iterator must not have been opened with
12042** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12043** returned.
12044*/
12045SQLITE_API int sqlite3changegroup_add_change(
12046 sqlite3_changegroup*,
12047 sqlite3_changeset_iter*
12048);
12049
12050
12051
12052/*
12053** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12054** METHOD: sqlite3_changegroup
12055**
12056** Obtain a buffer containing a changeset (or patchset) representing the
12057** current contents of the changegroup. If the inputs to the changegroup
12058** were themselves changesets, the output is a changeset. Or, if the
12059** inputs were patchsets, the output is also a patchset.
12060**
12061** As with the output of the sqlite3session_changeset() and
12062** sqlite3session_patchset() functions, all changes related to a single
12063** table are grouped together in the output of this function. Tables appear
12064** in the same order as for the very first changeset added to the changegroup.
12065** If the second or subsequent changesets added to the changegroup contain
12066** changes for tables that do not appear in the first changeset, they are
12067** appended onto the end of the output changeset, again in the order in
12068** which they are first encountered.
12069**
12070** If an error occurs, an SQLite error code is returned and the output
12071** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12072** is returned and the output variables are set to the size of and a
12073** pointer to the output buffer, respectively. In this case it is the
12074** responsibility of the caller to eventually free the buffer using a
12075** call to sqlite3_free().
12076*/
12077SQLITE_API int sqlite3changegroup_output(
12078 sqlite3_changegroup*,
12079 int *pnData, /* OUT: Size of output buffer in bytes */
12080 void **ppData /* OUT: Pointer to output buffer */
12081);
12082
12083/*
12084** CAPI3REF: Delete A Changegroup Object
12085** DESTRUCTOR: sqlite3_changegroup
12086*/
12087SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12088
12089/*
12090** CAPI3REF: Apply A Changeset To A Database
12091**
12092** Apply a changeset or patchset to a database. These functions attempt to
12093** update the "main" database attached to handle db with the changes found in
12094** the changeset passed via the second and third arguments.
12095**
12096** The fourth argument (xFilter) passed to these functions is the "filter
12097** callback". If it is not NULL, then for each table affected by at least one
12098** change in the changeset, the filter callback is invoked with
12099** the table name as the second argument, and a copy of the context pointer
12100** passed as the sixth argument as the first. If the "filter callback"
12101** returns zero, then no attempt is made to apply any changes to the table.
12102** Otherwise, if the return value is non-zero or the xFilter argument to
12103** is NULL, all changes related to the table are attempted.
12104**
12105** For each table that is not excluded by the filter callback, this function
12106** tests that the target database contains a compatible table. A table is
12107** considered compatible if all of the following are true:
12108**
12109** <ul>
12110** <li> The table has the same name as the name recorded in the
12111** changeset, and
12112** <li> The table has at least as many columns as recorded in the
12113** changeset, and
12114** <li> The table has primary key columns in the same position as
12115** recorded in the changeset.
12116** </ul>
12117**
12118** If there is no compatible table, it is not an error, but none of the
12119** changes associated with the table are applied. A warning message is issued
12120** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12121** one such warning is issued for each table in the changeset.
12122**
12123** For each change for which there is a compatible table, an attempt is made
12124** to modify the table contents according to the UPDATE, INSERT or DELETE
12125** change. If a change cannot be applied cleanly, the conflict handler
12126** function passed as the fifth argument to sqlite3changeset_apply() may be
12127** invoked. A description of exactly when the conflict handler is invoked for
12128** each type of change is below.
12129**
12130** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12131** of passing anything other than a valid function pointer as the xConflict
12132** argument are undefined.
12133**
12134** Each time the conflict handler function is invoked, it must return one
12135** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12136** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12137** if the second argument passed to the conflict handler is either
12138** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12139** returns an illegal value, any changes already made are rolled back and
12140** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12141** actions are taken by sqlite3changeset_apply() depending on the value
12142** returned by each invocation of the conflict-handler function. Refer to
12143** the documentation for the three
12144** [SQLITE_CHANGESET_OMIT|available return values] for details.
12145**
12146** <dl>
12147** <dt>DELETE Changes<dd>
12148** For each DELETE change, the function checks if the target database
12149** contains a row with the same primary key value (or values) as the
12150** original row values stored in the changeset. If it does, and the values
12151** stored in all non-primary key columns also match the values stored in
12152** the changeset the row is deleted from the target database.
12153**
12154** If a row with matching primary key values is found, but one or more of
12155** the non-primary key fields contains a value different from the original
12156** row value stored in the changeset, the conflict-handler function is
12157** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12158** database table has more columns than are recorded in the changeset,
12159** only the values of those non-primary key fields are compared against
12160** the current database contents - any trailing database table columns
12161** are ignored.
12162**
12163** If no row with matching primary key values is found in the database,
12164** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12165** passed as the second argument.
12166**
12167** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12168** (which can only happen if a foreign key constraint is violated), the
12169** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12170** passed as the second argument. This includes the case where the DELETE
12171** operation is attempted because an earlier call to the conflict handler
12172** function returned [SQLITE_CHANGESET_REPLACE].
12173**
12174** <dt>INSERT Changes<dd>
12175** For each INSERT change, an attempt is made to insert the new row into
12176** the database. If the changeset row contains fewer fields than the
12177** database table, the trailing fields are populated with their default
12178** values.
12179**
12180** If the attempt to insert the row fails because the database already
12181** contains a row with the same primary key values, the conflict handler
12182** function is invoked with the second argument set to
12183** [SQLITE_CHANGESET_CONFLICT].
12184**
12185** If the attempt to insert the row fails because of some other constraint
12186** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12187** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12188** This includes the case where the INSERT operation is re-attempted because
12189** an earlier call to the conflict handler function returned
12190** [SQLITE_CHANGESET_REPLACE].
12191**
12192** <dt>UPDATE Changes<dd>
12193** For each UPDATE change, the function checks if the target database
12194** contains a row with the same primary key value (or values) as the
12195** original row values stored in the changeset. If it does, and the values
12196** stored in all modified non-primary key columns also match the values
12197** stored in the changeset the row is updated within the target database.
12198**
12199** If a row with matching primary key values is found, but one or more of
12200** the modified non-primary key fields contains a value different from an
12201** original row value stored in the changeset, the conflict-handler function
12202** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12203** UPDATE changes only contain values for non-primary key fields that are
12204** to be modified, only those fields need to match the original values to
12205** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12206**
12207** If no row with matching primary key values is found in the database,
12208** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12209** passed as the second argument.
12210**
12211** If the UPDATE operation is attempted, but SQLite returns
12212** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12213** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12214** This includes the case where the UPDATE operation is attempted after
12215** an earlier call to the conflict handler function returned
12216** [SQLITE_CHANGESET_REPLACE].
12217** </dl>
12218**
12219** It is safe to execute SQL statements, including those that write to the
12220** table that the callback related to, from within the xConflict callback.
12221** This can be used to further customize the application's conflict
12222** resolution strategy.
12223**
12224** All changes made by these functions are enclosed in a savepoint transaction.
12225** If any other error (aside from a constraint failure when attempting to
12226** write to the target database) occurs, then the savepoint transaction is
12227** rolled back, restoring the target database to its original state, and an
12228** SQLite error code returned.
12229**
12230** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12231** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12232** may set (*ppRebase) to point to a "rebase" that may be used with the
12233** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12234** is set to the size of the buffer in bytes. It is the responsibility of the
12235** caller to eventually free any such buffer using sqlite3_free(). The buffer
12236** is only allocated and populated if one or more conflicts were encountered
12237** while applying the patchset. See comments surrounding the sqlite3_rebaser
12238** APIs for further details.
12239**
12240** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12241** may be modified by passing a combination of
12242** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12243**
12244** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12245** and therefore subject to change.
12246*/
12247SQLITE_API int sqlite3changeset_apply(
12248 sqlite3 *db, /* Apply change to "main" db of this handle */
12249 int nChangeset, /* Size of changeset in bytes */
12250 void *pChangeset, /* Changeset blob */
12251 int(*xFilter)(
12252 void *pCtx, /* Copy of sixth arg to _apply() */
12253 const char *zTab /* Table name */
12254 ),
12255 int(*xConflict)(
12256 void *pCtx, /* Copy of sixth arg to _apply() */
12257 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12258 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12259 ),
12260 void *pCtx /* First argument passed to xConflict */
12261);
12262SQLITE_API int sqlite3changeset_apply_v2(
12263 sqlite3 *db, /* Apply change to "main" db of this handle */
12264 int nChangeset, /* Size of changeset in bytes */
12265 void *pChangeset, /* Changeset blob */
12266 int(*xFilter)(
12267 void *pCtx, /* Copy of sixth arg to _apply() */
12268 const char *zTab /* Table name */
12269 ),
12270 int(*xConflict)(
12271 void *pCtx, /* Copy of sixth arg to _apply() */
12272 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12273 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12274 ),
12275 void *pCtx, /* First argument passed to xConflict */
12276 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12277 int flags /* SESSION_CHANGESETAPPLY_* flags */
12278);
12279
12280/*
12281** CAPI3REF: Flags for sqlite3changeset_apply_v2
12282**
12283** The following flags may passed via the 9th parameter to
12284** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12285**
12286** <dl>
12287** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12288** Usually, the sessions module encloses all operations performed by
12289** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12290** SAVEPOINT is committed if the changeset or patchset is successfully
12291** applied, or rolled back if an error occurs. Specifying this flag
12292** causes the sessions module to omit this savepoint. In this case, if the
12293** caller has an open transaction or savepoint when apply_v2() is called,
12294** it may revert the partially applied changeset by rolling it back.
12295**
12296** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12297** Invert the changeset before applying it. This is equivalent to inverting
12298** a changeset using sqlite3changeset_invert() before applying it. It is
12299** an error to specify this flag with a patchset.
12300**
12301** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12302** Do not invoke the conflict handler callback for any changes that
12303** would not actually modify the database even if they were applied.
12304** Specifically, this means that the conflict handler is not invoked
12305** for:
12306** <ul>
12307** <li>a delete change if the row being deleted cannot be found,
12308** <li>an update change if the modified fields are already set to
12309** their new values in the conflicting row, or
12310** <li>an insert change if all fields of the conflicting row match
12311** the row being inserted.
12312** </ul>
12313**
12314** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12315** If this flag it set, then all foreign key constraints in the target
12316** database behave as if they were declared with "ON UPDATE NO ACTION ON
12317** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12318** or SET DEFAULT.
12319*/
12320#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12321#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12322#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12323#define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12324
12325/*
12326** CAPI3REF: Constants Passed To The Conflict Handler
12327**
12328** Values that may be passed as the second argument to a conflict-handler.
12329**
12330** <dl>
12331** <dt>SQLITE_CHANGESET_DATA<dd>
12332** The conflict handler is invoked with CHANGESET_DATA as the second argument
12333** when processing a DELETE or UPDATE change if a row with the required
12334** PRIMARY KEY fields is present in the database, but one or more other
12335** (non primary-key) fields modified by the update do not contain the
12336** expected "before" values.
12337**
12338** The conflicting row, in this case, is the database row with the matching
12339** primary key.
12340**
12341** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12342** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12343** argument when processing a DELETE or UPDATE change if a row with the
12344** required PRIMARY KEY fields is not present in the database.
12345**
12346** There is no conflicting row in this case. The results of invoking the
12347** sqlite3changeset_conflict() API are undefined.
12348**
12349** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12350** CHANGESET_CONFLICT is passed as the second argument to the conflict
12351** handler while processing an INSERT change if the operation would result
12352** in duplicate primary key values.
12353**
12354** The conflicting row in this case is the database row with the matching
12355** primary key.
12356**
12357** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12358** If foreign key handling is enabled, and applying a changeset leaves the
12359** database in a state containing foreign key violations, the conflict
12360** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12361** exactly once before the changeset is committed. If the conflict handler
12362** returns CHANGESET_OMIT, the changes, including those that caused the
12363** foreign key constraint violation, are committed. Or, if it returns
12364** CHANGESET_ABORT, the changeset is rolled back.
12365**
12366** No current or conflicting row information is provided. The only function
12367** it is possible to call on the supplied sqlite3_changeset_iter handle
12368** is sqlite3changeset_fk_conflicts().
12369**
12370** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12371** If any other constraint violation occurs while applying a change (i.e.
12372** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12373** invoked with CHANGESET_CONSTRAINT as the second argument.
12374**
12375** There is no conflicting row in this case. The results of invoking the
12376** sqlite3changeset_conflict() API are undefined.
12377**
12378** </dl>
12379*/
12380#define SQLITE_CHANGESET_DATA 1
12381#define SQLITE_CHANGESET_NOTFOUND 2
12382#define SQLITE_CHANGESET_CONFLICT 3
12383#define SQLITE_CHANGESET_CONSTRAINT 4
12384#define SQLITE_CHANGESET_FOREIGN_KEY 5
12385
12386/*
12387** CAPI3REF: Constants Returned By The Conflict Handler
12388**
12389** A conflict handler callback must return one of the following three values.
12390**
12391** <dl>
12392** <dt>SQLITE_CHANGESET_OMIT<dd>
12393** If a conflict handler returns this value no special action is taken. The
12394** change that caused the conflict is not applied. The session module
12395** continues to the next change in the changeset.
12396**
12397** <dt>SQLITE_CHANGESET_REPLACE<dd>
12398** This value may only be returned if the second argument to the conflict
12399** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12400** is not the case, any changes applied so far are rolled back and the
12401** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12402**
12403** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12404** handler, then the conflicting row is either updated or deleted, depending
12405** on the type of change.
12406**
12407** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12408** handler, then the conflicting row is removed from the database and a
12409** second attempt to apply the change is made. If this second attempt fails,
12410** the original row is restored to the database before continuing.
12411**
12412** <dt>SQLITE_CHANGESET_ABORT<dd>
12413** If this value is returned, any changes applied so far are rolled back
12414** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12415** </dl>
12416*/
12417#define SQLITE_CHANGESET_OMIT 0
12418#define SQLITE_CHANGESET_REPLACE 1
12419#define SQLITE_CHANGESET_ABORT 2
12420
12421/*
12422** CAPI3REF: Rebasing changesets
12423** EXPERIMENTAL
12424**
12425** Suppose there is a site hosting a database in state S0. And that
12426** modifications are made that move that database to state S1 and a
12427** changeset recorded (the "local" changeset). Then, a changeset based
12428** on S0 is received from another site (the "remote" changeset) and
12429** applied to the database. The database is then in state
12430** (S1+"remote"), where the exact state depends on any conflict
12431** resolution decisions (OMIT or REPLACE) made while applying "remote".
12432** Rebasing a changeset is to update it to take those conflict
12433** resolution decisions into account, so that the same conflicts
12434** do not have to be resolved elsewhere in the network.
12435**
12436** For example, if both the local and remote changesets contain an
12437** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12438**
12439** local: INSERT INTO t1 VALUES(1, 'v1');
12440** remote: INSERT INTO t1 VALUES(1, 'v2');
12441**
12442** and the conflict resolution is REPLACE, then the INSERT change is
12443** removed from the local changeset (it was overridden). Or, if the
12444** conflict resolution was "OMIT", then the local changeset is modified
12445** to instead contain:
12446**
12447** UPDATE t1 SET b = 'v2' WHERE a=1;
12448**
12449** Changes within the local changeset are rebased as follows:
12450**
12451** <dl>
12452** <dt>Local INSERT<dd>
12453** This may only conflict with a remote INSERT. If the conflict
12454** resolution was OMIT, then add an UPDATE change to the rebased
12455** changeset. Or, if the conflict resolution was REPLACE, add
12456** nothing to the rebased changeset.
12457**
12458** <dt>Local DELETE<dd>
12459** This may conflict with a remote UPDATE or DELETE. In both cases the
12460** only possible resolution is OMIT. If the remote operation was a
12461** DELETE, then add no change to the rebased changeset. If the remote
12462** operation was an UPDATE, then the old.* fields of change are updated
12463** to reflect the new.* values in the UPDATE.
12464**
12465** <dt>Local UPDATE<dd>
12466** This may conflict with a remote UPDATE or DELETE. If it conflicts
12467** with a DELETE, and the conflict resolution was OMIT, then the update
12468** is changed into an INSERT. Any undefined values in the new.* record
12469** from the update change are filled in using the old.* values from
12470** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12471** the UPDATE change is simply omitted from the rebased changeset.
12472**
12473** If conflict is with a remote UPDATE and the resolution is OMIT, then
12474** the old.* values are rebased using the new.* values in the remote
12475** change. Or, if the resolution is REPLACE, then the change is copied
12476** into the rebased changeset with updates to columns also updated by
12477** the conflicting remote UPDATE removed. If this means no columns would
12478** be updated, the change is omitted.
12479** </dl>
12480**
12481** A local change may be rebased against multiple remote changes
12482** simultaneously. If a single key is modified by multiple remote
12483** changesets, they are combined as follows before the local changeset
12484** is rebased:
12485**
12486** <ul>
12487** <li> If there has been one or more REPLACE resolutions on a
12488** key, it is rebased according to a REPLACE.
12489**
12490** <li> If there have been no REPLACE resolutions on a key, then
12491** the local changeset is rebased according to the most recent
12492** of the OMIT resolutions.
12493** </ul>
12494**
12495** Note that conflict resolutions from multiple remote changesets are
12496** combined on a per-field basis, not per-row. This means that in the
12497** case of multiple remote UPDATE operations, some fields of a single
12498** local change may be rebased for REPLACE while others are rebased for
12499** OMIT.
12500**
12501** In order to rebase a local changeset, the remote changeset must first
12502** be applied to the local database using sqlite3changeset_apply_v2() and
12503** the buffer of rebase information captured. Then:
12504**
12505** <ol>
12506** <li> An sqlite3_rebaser object is created by calling
12507** sqlite3rebaser_create().
12508** <li> The new object is configured with the rebase buffer obtained from
12509** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12510** If the local changeset is to be rebased against multiple remote
12511** changesets, then sqlite3rebaser_configure() should be called
12512** multiple times, in the same order that the multiple
12513** sqlite3changeset_apply_v2() calls were made.
12514** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12515** <li> The sqlite3_rebaser object is deleted by calling
12516** sqlite3rebaser_delete().
12517** </ol>
12518*/
12519typedef struct sqlite3_rebaser sqlite3_rebaser;
12520
12521/*
12522** CAPI3REF: Create a changeset rebaser object.
12523** EXPERIMENTAL
12524**
12525** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12526** point to the new object and return SQLITE_OK. Otherwise, if an error
12527** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12528** to NULL.
12529*/
12530SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12531
12532/*
12533** CAPI3REF: Configure a changeset rebaser object.
12534** EXPERIMENTAL
12535**
12536** Configure the changeset rebaser object to rebase changesets according
12537** to the conflict resolutions described by buffer pRebase (size nRebase
12538** bytes), which must have been obtained from a previous call to
12539** sqlite3changeset_apply_v2().
12540*/
12541SQLITE_API int sqlite3rebaser_configure(
12542 sqlite3_rebaser*,
12543 int nRebase, const void *pRebase
12544);
12545
12546/*
12547** CAPI3REF: Rebase a changeset
12548** EXPERIMENTAL
12549**
12550** Argument pIn must point to a buffer containing a changeset nIn bytes
12551** in size. This function allocates and populates a buffer with a copy
12552** of the changeset rebased according to the configuration of the
12553** rebaser object passed as the first argument. If successful, (*ppOut)
12554** is set to point to the new buffer containing the rebased changeset and
12555** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12556** responsibility of the caller to eventually free the new buffer using
12557** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12558** are set to zero and an SQLite error code returned.
12559*/
12560SQLITE_API int sqlite3rebaser_rebase(
12561 sqlite3_rebaser*,
12562 int nIn, const void *pIn,
12563 int *pnOut, void **ppOut
12564);
12565
12566/*
12567** CAPI3REF: Delete a changeset rebaser object.
12568** EXPERIMENTAL
12569**
12570** Delete the changeset rebaser object and all associated resources. There
12571** should be one call to this function for each successful invocation
12572** of sqlite3rebaser_create().
12573*/
12574SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12575
12576/*
12577** CAPI3REF: Streaming Versions of API functions.
12578**
12579** The six streaming API xxx_strm() functions serve similar purposes to the
12580** corresponding non-streaming API functions:
12581**
12582** <table border=1 style="margin-left:8ex;margin-right:8ex">
12583** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12584** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12585** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12586** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12587** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12588** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12589** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12590** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12591** </table>
12592**
12593** Non-streaming functions that accept changesets (or patchsets) as input
12594** require that the entire changeset be stored in a single buffer in memory.
12595** Similarly, those that return a changeset or patchset do so by returning
12596** a pointer to a single large buffer allocated using sqlite3_malloc().
12597** Normally this is convenient. However, if an application running in a
12598** low-memory environment is required to handle very large changesets, the
12599** large contiguous memory allocations required can become onerous.
12600**
12601** In order to avoid this problem, instead of a single large buffer, input
12602** is passed to a streaming API functions by way of a callback function that
12603** the sessions module invokes to incrementally request input data as it is
12604** required. In all cases, a pair of API function parameters such as
12605**
12606** <pre>
12607** &nbsp; int nChangeset,
12608** &nbsp; void *pChangeset,
12609** </pre>
12610**
12611** Is replaced by:
12612**
12613** <pre>
12614** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
12615** &nbsp; void *pIn,
12616** </pre>
12617**
12618** Each time the xInput callback is invoked by the sessions module, the first
12619** argument passed is a copy of the supplied pIn context pointer. The second
12620** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12621** error occurs the xInput method should copy up to (*pnData) bytes of data
12622** into the buffer and set (*pnData) to the actual number of bytes copied
12623** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12624** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12625** error code should be returned. In all cases, if an xInput callback returns
12626** an error, all processing is abandoned and the streaming API function
12627** returns a copy of the error code to the caller.
12628**
12629** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12630** invoked by the sessions module at any point during the lifetime of the
12631** iterator. If such an xInput callback returns an error, the iterator enters
12632** an error state, whereby all subsequent calls to iterator functions
12633** immediately fail with the same error code as returned by xInput.
12634**
12635** Similarly, streaming API functions that return changesets (or patchsets)
12636** return them in chunks by way of a callback function instead of via a
12637** pointer to a single large buffer. In this case, a pair of parameters such
12638** as:
12639**
12640** <pre>
12641** &nbsp; int *pnChangeset,
12642** &nbsp; void **ppChangeset,
12643** </pre>
12644**
12645** Is replaced by:
12646**
12647** <pre>
12648** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
12649** &nbsp; void *pOut
12650** </pre>
12651**
12652** The xOutput callback is invoked zero or more times to return data to
12653** the application. The first parameter passed to each call is a copy of the
12654** pOut pointer supplied by the application. The second parameter, pData,
12655** points to a buffer nData bytes in size containing the chunk of output
12656** data being returned. If the xOutput callback successfully processes the
12657** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12658** it should return some other SQLite error code. In this case processing
12659** is immediately abandoned and the streaming API function returns a copy
12660** of the xOutput error code to the application.
12661**
12662** The sessions module never invokes an xOutput callback with the third
12663** parameter set to a value less than or equal to zero. Other than this,
12664** no guarantees are made as to the size of the chunks of data returned.
12665*/
12666SQLITE_API int sqlite3changeset_apply_strm(
12667 sqlite3 *db, /* Apply change to "main" db of this handle */
12668 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12669 void *pIn, /* First arg for xInput */
12670 int(*xFilter)(
12671 void *pCtx, /* Copy of sixth arg to _apply() */
12672 const char *zTab /* Table name */
12673 ),
12674 int(*xConflict)(
12675 void *pCtx, /* Copy of sixth arg to _apply() */
12676 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12677 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12678 ),
12679 void *pCtx /* First argument passed to xConflict */
12680);
12681SQLITE_API int sqlite3changeset_apply_v2_strm(
12682 sqlite3 *db, /* Apply change to "main" db of this handle */
12683 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12684 void *pIn, /* First arg for xInput */
12685 int(*xFilter)(
12686 void *pCtx, /* Copy of sixth arg to _apply() */
12687 const char *zTab /* Table name */
12688 ),
12689 int(*xConflict)(
12690 void *pCtx, /* Copy of sixth arg to _apply() */
12691 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12692 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12693 ),
12694 void *pCtx, /* First argument passed to xConflict */
12695 void **ppRebase, int *pnRebase,
12696 int flags
12697);
12698SQLITE_API int sqlite3changeset_concat_strm(
12699 int (*xInputA)(void *pIn, void *pData, int *pnData),
12700 void *pInA,
12701 int (*xInputB)(void *pIn, void *pData, int *pnData),
12702 void *pInB,
12703 int (*xOutput)(void *pOut, const void *pData, int nData),
12704 void *pOut
12705);
12706SQLITE_API int sqlite3changeset_invert_strm(
12707 int (*xInput)(void *pIn, void *pData, int *pnData),
12708 void *pIn,
12709 int (*xOutput)(void *pOut, const void *pData, int nData),
12710 void *pOut
12711);
12712SQLITE_API int sqlite3changeset_start_strm(
12713 sqlite3_changeset_iter **pp,
12714 int (*xInput)(void *pIn, void *pData, int *pnData),
12715 void *pIn
12716);
12717SQLITE_API int sqlite3changeset_start_v2_strm(
12718 sqlite3_changeset_iter **pp,
12719 int (*xInput)(void *pIn, void *pData, int *pnData),
12720 void *pIn,
12721 int flags
12722);
12723SQLITE_API int sqlite3session_changeset_strm(
12724 sqlite3_session *pSession,
12725 int (*xOutput)(void *pOut, const void *pData, int nData),
12726 void *pOut
12727);
12728SQLITE_API int sqlite3session_patchset_strm(
12729 sqlite3_session *pSession,
12730 int (*xOutput)(void *pOut, const void *pData, int nData),
12731 void *pOut
12732);
12733SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12734 int (*xInput)(void *pIn, void *pData, int *pnData),
12735 void *pIn
12736);
12737SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12738 int (*xOutput)(void *pOut, const void *pData, int nData),
12739 void *pOut
12740);
12741SQLITE_API int sqlite3rebaser_rebase_strm(
12742 sqlite3_rebaser *pRebaser,
12743 int (*xInput)(void *pIn, void *pData, int *pnData),
12744 void *pIn,
12745 int (*xOutput)(void *pOut, const void *pData, int nData),
12746 void *pOut
12747);
12748
12749/*
12750** CAPI3REF: Configure global parameters
12751**
12752** The sqlite3session_config() interface is used to make global configuration
12753** changes to the sessions module in order to tune it to the specific needs
12754** of the application.
12755**
12756** The sqlite3session_config() interface is not threadsafe. If it is invoked
12757** while any other thread is inside any other sessions method then the
12758** results are undefined. Furthermore, if it is invoked after any sessions
12759** related objects have been created, the results are also undefined.
12760**
12761** The first argument to the sqlite3session_config() function must be one
12762** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12763** interpretation of the (void*) value passed as the second parameter and
12764** the effect of calling this function depends on the value of the first
12765** parameter.
12766**
12767** <dl>
12768** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12769** By default, the sessions module streaming interfaces attempt to input
12770** and output data in approximately 1 KiB chunks. This operand may be used
12771** to set and query the value of this configuration setting. The pointer
12772** passed as the second argument must point to a value of type (int).
12773** If this value is greater than 0, it is used as the new streaming data
12774** chunk size for both input and output. Before returning, the (int) value
12775** pointed to by pArg is set to the final value of the streaming interface
12776** chunk size.
12777** </dl>
12778**
12779** This function returns SQLITE_OK if successful, or an SQLite error code
12780** otherwise.
12781*/
12782SQLITE_API int sqlite3session_config(int op, void *pArg);
12783
12784/*
12785** CAPI3REF: Values for sqlite3session_config().
12786*/
12787#define SQLITE_SESSION_CONFIG_STRMSIZE 1
12788
12789/*
12790** Make sure we can call this stuff from C++.
12791*/
12792#ifdef __cplusplus
12793}
12794#endif
12795
12796#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12797
12798/******** End of sqlite3session.h *********/
12799/******** Begin file fts5.h *********/
12800/*
12801** 2014 May 31
12802**
12803** The author disclaims copyright to this source code. In place of
12804** a legal notice, here is a blessing:
12805**
12806** May you do good and not evil.
12807** May you find forgiveness for yourself and forgive others.
12808** May you share freely, never taking more than you give.
12809**
12810******************************************************************************
12811**
12812** Interfaces to extend FTS5. Using the interfaces defined in this file,
12813** FTS5 may be extended with:
12814**
12815** * custom tokenizers, and
12816** * custom auxiliary functions.
12817*/
12818
12819
12820#ifndef _FTS5_H
12821#define _FTS5_H
12822
12823
12824#ifdef __cplusplus
12825extern "C" {
12826#endif
12827
12828/*************************************************************************
12829** CUSTOM AUXILIARY FUNCTIONS
12830**
12831** Virtual table implementations may overload SQL functions by implementing
12832** the sqlite3_module.xFindFunction() method.
12833*/
12834
12835typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12836typedef struct Fts5Context Fts5Context;
12837typedef struct Fts5PhraseIter Fts5PhraseIter;
12838
12839typedef void (*fts5_extension_function)(
12840 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12841 Fts5Context *pFts, /* First arg to pass to pApi functions */
12842 sqlite3_context *pCtx, /* Context for returning result/error */
12843 int nVal, /* Number of values in apVal[] array */
12844 sqlite3_value **apVal /* Array of trailing arguments */
12845);
12846
12847struct Fts5PhraseIter {
12848 const unsigned char *a;
12849 const unsigned char *b;
12850};
12851
12852/*
12853** EXTENSION API FUNCTIONS
12854**
12855** xUserData(pFts):
12856** Return a copy of the pUserData pointer passed to the xCreateFunction()
12857** API when the extension function was registered.
12858**
12859** xColumnTotalSize(pFts, iCol, pnToken):
12860** If parameter iCol is less than zero, set output variable *pnToken
12861** to the total number of tokens in the FTS5 table. Or, if iCol is
12862** non-negative but less than the number of columns in the table, return
12863** the total number of tokens in column iCol, considering all rows in
12864** the FTS5 table.
12865**
12866** If parameter iCol is greater than or equal to the number of columns
12867** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12868** an OOM condition or IO error), an appropriate SQLite error code is
12869** returned.
12870**
12871** xColumnCount(pFts):
12872** Return the number of columns in the table.
12873**
12874** xColumnSize(pFts, iCol, pnToken):
12875** If parameter iCol is less than zero, set output variable *pnToken
12876** to the total number of tokens in the current row. Or, if iCol is
12877** non-negative but less than the number of columns in the table, set
12878** *pnToken to the number of tokens in column iCol of the current row.
12879**
12880** If parameter iCol is greater than or equal to the number of columns
12881** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12882** an OOM condition or IO error), an appropriate SQLite error code is
12883** returned.
12884**
12885** This function may be quite inefficient if used with an FTS5 table
12886** created with the "columnsize=0" option.
12887**
12888** xColumnText:
12889** If parameter iCol is less than zero, or greater than or equal to the
12890** number of columns in the table, SQLITE_RANGE is returned.
12891**
12892** Otherwise, this function attempts to retrieve the text of column iCol of
12893** the current document. If successful, (*pz) is set to point to a buffer
12894** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12895** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12896** if an error occurs, an SQLite error code is returned and the final values
12897** of (*pz) and (*pn) are undefined.
12898**
12899** xPhraseCount:
12900** Returns the number of phrases in the current query expression.
12901**
12902** xPhraseSize:
12903** If parameter iCol is less than zero, or greater than or equal to the
12904** number of phrases in the current query, as returned by xPhraseCount,
12905** 0 is returned. Otherwise, this function returns the number of tokens in
12906** phrase iPhrase of the query. Phrases are numbered starting from zero.
12907**
12908** xInstCount:
12909** Set *pnInst to the total number of occurrences of all phrases within
12910** the query within the current row. Return SQLITE_OK if successful, or
12911** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12912**
12913** This API can be quite slow if used with an FTS5 table created with the
12914** "detail=none" or "detail=column" option. If the FTS5 table is created
12915** with either "detail=none" or "detail=column" and "content=" option
12916** (i.e. if it is a contentless table), then this API always returns 0.
12917**
12918** xInst:
12919** Query for the details of phrase match iIdx within the current row.
12920** Phrase matches are numbered starting from zero, so the iIdx argument
12921** should be greater than or equal to zero and smaller than the value
12922** output by xInstCount(). If iIdx is less than zero or greater than
12923** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
12924**
12925** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
12926** to the column in which it occurs and *piOff the token offset of the
12927** first token of the phrase. SQLITE_OK is returned if successful, or an
12928** error code (i.e. SQLITE_NOMEM) if an error occurs.
12929**
12930** This API can be quite slow if used with an FTS5 table created with the
12931** "detail=none" or "detail=column" option.
12932**
12933** xRowid:
12934** Returns the rowid of the current row.
12935**
12936** xTokenize:
12937** Tokenize text using the tokenizer belonging to the FTS5 table.
12938**
12939** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12940** This API function is used to query the FTS table for phrase iPhrase
12941** of the current query. Specifically, a query equivalent to:
12942**
12943** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12944**
12945** with $p set to a phrase equivalent to the phrase iPhrase of the
12946** current query is executed. Any column filter that applies to
12947** phrase iPhrase of the current query is included in $p. For each
12948** row visited, the callback function passed as the fourth argument
12949** is invoked. The context and API objects passed to the callback
12950** function may be used to access the properties of each matched row.
12951** Invoking Api.xUserData() returns a copy of the pointer passed as
12952** the third argument to pUserData.
12953**
12954** If parameter iPhrase is less than zero, or greater than or equal to
12955** the number of phrases in the query, as returned by xPhraseCount(),
12956** this function returns SQLITE_RANGE.
12957**
12958** If the callback function returns any value other than SQLITE_OK, the
12959** query is abandoned and the xQueryPhrase function returns immediately.
12960** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12961** Otherwise, the error code is propagated upwards.
12962**
12963** If the query runs to completion without incident, SQLITE_OK is returned.
12964** Or, if some error occurs before the query completes or is aborted by
12965** the callback, an SQLite error code is returned.
12966**
12967**
12968** xSetAuxdata(pFts5, pAux, xDelete)
12969**
12970** Save the pointer passed as the second argument as the extension function's
12971** "auxiliary data". The pointer may then be retrieved by the current or any
12972** future invocation of the same fts5 extension function made as part of
12973** the same MATCH query using the xGetAuxdata() API.
12974**
12975** Each extension function is allocated a single auxiliary data slot for
12976** each FTS query (MATCH expression). If the extension function is invoked
12977** more than once for a single FTS query, then all invocations share a
12978** single auxiliary data context.
12979**
12980** If there is already an auxiliary data pointer when this function is
12981** invoked, then it is replaced by the new pointer. If an xDelete callback
12982** was specified along with the original pointer, it is invoked at this
12983** point.
12984**
12985** The xDelete callback, if one is specified, is also invoked on the
12986** auxiliary data pointer after the FTS5 query has finished.
12987**
12988** If an error (e.g. an OOM condition) occurs within this function,
12989** the auxiliary data is set to NULL and an error code returned. If the
12990** xDelete parameter was not NULL, it is invoked on the auxiliary data
12991** pointer before returning.
12992**
12993**
12994** xGetAuxdata(pFts5, bClear)
12995**
12996** Returns the current auxiliary data pointer for the fts5 extension
12997** function. See the xSetAuxdata() method for details.
12998**
12999** If the bClear argument is non-zero, then the auxiliary data is cleared
13000** (set to NULL) before this function returns. In this case the xDelete,
13001** if any, is not invoked.
13002**
13003**
13004** xRowCount(pFts5, pnRow)
13005**
13006** This function is used to retrieve the total number of rows in the table.
13007** In other words, the same value that would be returned by:
13008**
13009** SELECT count(*) FROM ftstable;
13010**
13011** xPhraseFirst()
13012** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13013** method, to iterate through all instances of a single query phrase within
13014** the current row. This is the same information as is accessible via the
13015** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13016** to use, this API may be faster under some circumstances. To iterate
13017** through instances of phrase iPhrase, use the following code:
13018**
13019** Fts5PhraseIter iter;
13020** int iCol, iOff;
13021** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13022** iCol>=0;
13023** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13024** ){
13025** // An instance of phrase iPhrase at offset iOff of column iCol
13026** }
13027**
13028** The Fts5PhraseIter structure is defined above. Applications should not
13029** modify this structure directly - it should only be used as shown above
13030** with the xPhraseFirst() and xPhraseNext() API methods (and by
13031** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13032**
13033** This API can be quite slow if used with an FTS5 table created with the
13034** "detail=none" or "detail=column" option. If the FTS5 table is created
13035** with either "detail=none" or "detail=column" and "content=" option
13036** (i.e. if it is a contentless table), then this API always iterates
13037** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13038**
13039** xPhraseNext()
13040** See xPhraseFirst above.
13041**
13042** xPhraseFirstColumn()
13043** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13044** and xPhraseNext() APIs described above. The difference is that instead
13045** of iterating through all instances of a phrase in the current row, these
13046** APIs are used to iterate through the set of columns in the current row
13047** that contain one or more instances of a specified phrase. For example:
13048**
13049** Fts5PhraseIter iter;
13050** int iCol;
13051** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13052** iCol>=0;
13053** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13054** ){
13055** // Column iCol contains at least one instance of phrase iPhrase
13056** }
13057**
13058** This API can be quite slow if used with an FTS5 table created with the
13059** "detail=none" option. If the FTS5 table is created with either
13060** "detail=none" "content=" option (i.e. if it is a contentless table),
13061** then this API always iterates through an empty set (all calls to
13062** xPhraseFirstColumn() set iCol to -1).
13063**
13064** The information accessed using this API and its companion
13065** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13066** (or xInst/xInstCount). The chief advantage of this API is that it is
13067** significantly more efficient than those alternatives when used with
13068** "detail=column" tables.
13069**
13070** xPhraseNextColumn()
13071** See xPhraseFirstColumn above.
13072**
13073** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13074** This is used to access token iToken of phrase iPhrase of the current
13075** query. Before returning, output parameter *ppToken is set to point
13076** to a buffer containing the requested token, and *pnToken to the
13077** size of this buffer in bytes.
13078**
13079** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13080** or equal to the number of phrases in the query as reported by
13081** xPhraseCount(), or if iToken is equal to or greater than the number of
13082** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13083 are both zeroed.
13084**
13085** The output text is not a copy of the query text that specified the
13086** token. It is the output of the tokenizer module. For tokendata=1
13087** tables, this includes any embedded 0x00 and trailing data.
13088**
13089** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13090** This is used to access token iToken of phrase hit iIdx within the
13091** current row. If iIdx is less than zero or greater than or equal to the
13092** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13093** output variable (*ppToken) is set to point to a buffer containing the
13094** matching document token, and (*pnToken) to the size of that buffer in
13095** bytes. This API is not available if the specified token matches a
13096** prefix query term. In that case both output variables are always set
13097** to 0.
13098**
13099** The output text is not a copy of the document text that was tokenized.
13100** It is the output of the tokenizer module. For tokendata=1 tables, this
13101** includes any embedded 0x00 and trailing data.
13102**
13103** This API can be quite slow if used with an FTS5 table created with the
13104** "detail=none" or "detail=column" option.
13105*/
13106struct Fts5ExtensionApi {
13107 int iVersion; /* Currently always set to 3 */
13108
13109 void *(*xUserData)(Fts5Context*);
13110
13111 int (*xColumnCount)(Fts5Context*);
13112 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13113 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13114
13115 int (*xTokenize)(Fts5Context*,
13116 const char *pText, int nText, /* Text to tokenize */
13117 void *pCtx, /* Context passed to xToken() */
13118 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13119 );
13120
13121 int (*xPhraseCount)(Fts5Context*);
13122 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13123
13124 int (*xInstCount)(Fts5Context*, int *pnInst);
13125 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13126
13127 sqlite3_int64 (*xRowid)(Fts5Context*);
13128 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13129 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13130
13131 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13132 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13133 );
13134 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13135 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13136
13137 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13138 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13139
13140 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13141 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13142
13143 /* Below this point are iVersion>=3 only */
13144 int (*xQueryToken)(Fts5Context*,
13145 int iPhrase, int iToken,
13146 const char **ppToken, int *pnToken
13147 );
13148 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13149};
13150
13151/*
13152** CUSTOM AUXILIARY FUNCTIONS
13153*************************************************************************/
13154
13155/*************************************************************************
13156** CUSTOM TOKENIZERS
13157**
13158** Applications may also register custom tokenizer types. A tokenizer
13159** is registered by providing fts5 with a populated instance of the
13160** following structure. All structure methods must be defined, setting
13161** any member of the fts5_tokenizer struct to NULL leads to undefined
13162** behaviour. The structure methods are expected to function as follows:
13163**
13164** xCreate:
13165** This function is used to allocate and initialize a tokenizer instance.
13166** A tokenizer instance is required to actually tokenize text.
13167**
13168** The first argument passed to this function is a copy of the (void*)
13169** pointer provided by the application when the fts5_tokenizer object
13170** was registered with FTS5 (the third argument to xCreateTokenizer()).
13171** The second and third arguments are an array of nul-terminated strings
13172** containing the tokenizer arguments, if any, specified following the
13173** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13174** to create the FTS5 table.
13175**
13176** The final argument is an output variable. If successful, (*ppOut)
13177** should be set to point to the new tokenizer handle and SQLITE_OK
13178** returned. If an error occurs, some value other than SQLITE_OK should
13179** be returned. In this case, fts5 assumes that the final value of *ppOut
13180** is undefined.
13181**
13182** xDelete:
13183** This function is invoked to delete a tokenizer handle previously
13184** allocated using xCreate(). Fts5 guarantees that this function will
13185** be invoked exactly once for each successful call to xCreate().
13186**
13187** xTokenize:
13188** This function is expected to tokenize the nText byte string indicated
13189** by argument pText. pText may or may not be nul-terminated. The first
13190** argument passed to this function is a pointer to an Fts5Tokenizer object
13191** returned by an earlier call to xCreate().
13192**
13193** The second argument indicates the reason that FTS5 is requesting
13194** tokenization of the supplied text. This is always one of the following
13195** four values:
13196**
13197** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13198** or removed from the FTS table. The tokenizer is being invoked to
13199** determine the set of tokens to add to (or delete from) the
13200** FTS index.
13201**
13202** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13203** against the FTS index. The tokenizer is being called to tokenize
13204** a bareword or quoted string specified as part of the query.
13205**
13206** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13207** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13208** followed by a "*" character, indicating that the last token
13209** returned by the tokenizer will be treated as a token prefix.
13210**
13211** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13212** satisfy an fts5_api.xTokenize() request made by an auxiliary
13213** function. Or an fts5_api.xColumnSize() request made by the same
13214** on a columnsize=0 database.
13215** </ul>
13216**
13217** For each token in the input string, the supplied callback xToken() must
13218** be invoked. The first argument to it should be a copy of the pointer
13219** passed as the second argument to xTokenize(). The third and fourth
13220** arguments are a pointer to a buffer containing the token text, and the
13221** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13222** of the first byte of and first byte immediately following the text from
13223** which the token is derived within the input.
13224**
13225** The second argument passed to the xToken() callback ("tflags") should
13226** normally be set to 0. The exception is if the tokenizer supports
13227** synonyms. In this case see the discussion below for details.
13228**
13229** FTS5 assumes the xToken() callback is invoked for each token in the
13230** order that they occur within the input text.
13231**
13232** If an xToken() callback returns any value other than SQLITE_OK, then
13233** the tokenization should be abandoned and the xTokenize() method should
13234** immediately return a copy of the xToken() return value. Or, if the
13235** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13236** if an error occurs with the xTokenize() implementation itself, it
13237** may abandon the tokenization and return any error code other than
13238** SQLITE_OK or SQLITE_DONE.
13239**
13240** SYNONYM SUPPORT
13241**
13242** Custom tokenizers may also support synonyms. Consider a case in which a
13243** user wishes to query for a phrase such as "first place". Using the
13244** built-in tokenizers, the FTS5 query 'first + place' will match instances
13245** of "first place" within the document set, but not alternative forms
13246** such as "1st place". In some applications, it would be better to match
13247** all instances of "first place" or "1st place" regardless of which form
13248** the user specified in the MATCH query text.
13249**
13250** There are several ways to approach this in FTS5:
13251**
13252** <ol><li> By mapping all synonyms to a single token. In this case, using
13253** the above example, this means that the tokenizer returns the
13254** same token for inputs "first" and "1st". Say that token is in
13255** fact "first", so that when the user inserts the document "I won
13256** 1st place" entries are added to the index for tokens "i", "won",
13257** "first" and "place". If the user then queries for '1st + place',
13258** the tokenizer substitutes "first" for "1st" and the query works
13259** as expected.
13260**
13261** <li> By querying the index for all synonyms of each query term
13262** separately. In this case, when tokenizing query text, the
13263** tokenizer may provide multiple synonyms for a single term
13264** within the document. FTS5 then queries the index for each
13265** synonym individually. For example, faced with the query:
13266**
13267** <codeblock>
13268** ... MATCH 'first place'</codeblock>
13269**
13270** the tokenizer offers both "1st" and "first" as synonyms for the
13271** first token in the MATCH query and FTS5 effectively runs a query
13272** similar to:
13273**
13274** <codeblock>
13275** ... MATCH '(first OR 1st) place'</codeblock>
13276**
13277** except that, for the purposes of auxiliary functions, the query
13278** still appears to contain just two phrases - "(first OR 1st)"
13279** being treated as a single phrase.
13280**
13281** <li> By adding multiple synonyms for a single term to the FTS index.
13282** Using this method, when tokenizing document text, the tokenizer
13283** provides multiple synonyms for each token. So that when a
13284** document such as "I won first place" is tokenized, entries are
13285** added to the FTS index for "i", "won", "first", "1st" and
13286** "place".
13287**
13288** This way, even if the tokenizer does not provide synonyms
13289** when tokenizing query text (it should not - to do so would be
13290** inefficient), it doesn't matter if the user queries for
13291** 'first + place' or '1st + place', as there are entries in the
13292** FTS index corresponding to both forms of the first token.
13293** </ol>
13294**
13295** Whether it is parsing document or query text, any call to xToken that
13296** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13297** is considered to supply a synonym for the previous token. For example,
13298** when parsing the document "I won first place", a tokenizer that supports
13299** synonyms would call xToken() 5 times, as follows:
13300**
13301** <codeblock>
13302** xToken(pCtx, 0, "i", 1, 0, 1);
13303** xToken(pCtx, 0, "won", 3, 2, 5);
13304** xToken(pCtx, 0, "first", 5, 6, 11);
13305** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13306** xToken(pCtx, 0, "place", 5, 12, 17);
13307**</codeblock>
13308**
13309** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13310** xToken() is called. Multiple synonyms may be specified for a single token
13311** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13312** There is no limit to the number of synonyms that may be provided for a
13313** single token.
13314**
13315** In many cases, method (1) above is the best approach. It does not add
13316** extra data to the FTS index or require FTS5 to query for multiple terms,
13317** so it is efficient in terms of disk space and query speed. However, it
13318** does not support prefix queries very well. If, as suggested above, the
13319** token "first" is substituted for "1st" by the tokenizer, then the query:
13320**
13321** <codeblock>
13322** ... MATCH '1s*'</codeblock>
13323**
13324** will not match documents that contain the token "1st" (as the tokenizer
13325** will probably not map "1s" to any prefix of "first").
13326**
13327** For full prefix support, method (3) may be preferred. In this case,
13328** because the index contains entries for both "first" and "1st", prefix
13329** queries such as 'fi*' or '1s*' will match correctly. However, because
13330** extra entries are added to the FTS index, this method uses more space
13331** within the database.
13332**
13333** Method (2) offers a midpoint between (1) and (3). Using this method,
13334** a query such as '1s*' will match documents that contain the literal
13335** token "1st", but not "first" (assuming the tokenizer is not able to
13336** provide synonyms for prefixes). However, a non-prefix query like '1st'
13337** will match against "1st" and "first". This method does not require
13338** extra disk space, as no extra entries are added to the FTS index.
13339** On the other hand, it may require more CPU cycles to run MATCH queries,
13340** as separate queries of the FTS index are required for each synonym.
13341**
13342** When using methods (2) or (3), it is important that the tokenizer only
13343** provide synonyms when tokenizing document text (method (3)) or query
13344** text (method (2)), not both. Doing so will not cause any errors, but is
13345** inefficient.
13346*/
13347typedef struct Fts5Tokenizer Fts5Tokenizer;
13348typedef struct fts5_tokenizer fts5_tokenizer;
13349struct fts5_tokenizer {
13350 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13351 void (*xDelete)(Fts5Tokenizer*);
13352 int (*xTokenize)(Fts5Tokenizer*,
13353 void *pCtx,
13354 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13355 const char *pText, int nText,
13356 int (*xToken)(
13357 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13358 int tflags, /* Mask of FTS5_TOKEN_* flags */
13359 const char *pToken, /* Pointer to buffer containing token */
13360 int nToken, /* Size of token in bytes */
13361 int iStart, /* Byte offset of token within input text */
13362 int iEnd /* Byte offset of end of token within input text */
13363 )
13364 );
13365};
13366
13367/* Flags that may be passed as the third argument to xTokenize() */
13368#define FTS5_TOKENIZE_QUERY 0x0001
13369#define FTS5_TOKENIZE_PREFIX 0x0002
13370#define FTS5_TOKENIZE_DOCUMENT 0x0004
13371#define FTS5_TOKENIZE_AUX 0x0008
13372
13373/* Flags that may be passed by the tokenizer implementation back to FTS5
13374** as the third argument to the supplied xToken callback. */
13375#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13376
13377/*
13378** END OF CUSTOM TOKENIZERS
13379*************************************************************************/
13380
13381/*************************************************************************
13382** FTS5 EXTENSION REGISTRATION API
13383*/
13384typedef struct fts5_api fts5_api;
13385struct fts5_api {
13386 int iVersion; /* Currently always set to 2 */
13387
13388 /* Create a new tokenizer */
13389 int (*xCreateTokenizer)(
13390 fts5_api *pApi,
13391 const char *zName,
13392 void *pUserData,
13393 fts5_tokenizer *pTokenizer,
13394 void (*xDestroy)(void*)
13395 );
13396
13397 /* Find an existing tokenizer */
13398 int (*xFindTokenizer)(
13399 fts5_api *pApi,
13400 const char *zName,
13401 void **ppUserData,
13402 fts5_tokenizer *pTokenizer
13403 );
13404
13405 /* Create a new auxiliary function */
13406 int (*xCreateFunction)(
13407 fts5_api *pApi,
13408 const char *zName,
13409 void *pUserData,
13410 fts5_extension_function xFunction,
13411 void (*xDestroy)(void*)
13412 );
13413};
13414
13415/*
13416** END OF REGISTRATION API
13417*************************************************************************/
13418
13419#ifdef __cplusplus
13420} /* end of the 'extern "C"' block */
13421#endif
13422
13423#endif /* _FTS5_H */
13424
13425/******** End of fts5.h *********/
13426