1/* 2** 2001-09-15 3** 4** The author disclaims copyright to this source code. In place of 5** a legal notice, here is a blessing: 6** 7** May you do good and not evil. 8** May you find forgiveness for yourself and forgive others. 9** May you share freely, never taking more than you give. 10** 11************************************************************************* 12** This header file defines the interface that the SQLite library 13** presents to client programs. If a C-function, structure, datatype, 14** or constant definition does not appear in this file, then it is 15** not a published API of SQLite, is subject to change without 16** notice, and should not be referenced by programs that use SQLite. 17** 18** Some of the definitions that are in this file are marked as 19** "experimental". Experimental interfaces are normally new 20** features recently added to SQLite. We do not anticipate changes 21** to experimental interfaces but reserve the right to make minor changes 22** if experience from use "in the wild" suggest such changes are prudent. 23** 24** The official C-language API documentation for SQLite is derived 25** from comments in this file. This file is the authoritative source 26** on how SQLite interfaces are supposed to operate. 27** 28** The name of this file under configuration management is "sqlite.h.in". 29** The makefile makes some minor changes to this file (such as inserting 30** the version number) and changes its name to "sqlite3.h" as 31** part of the build process. 32*/ 33#ifndef SQLITE3_H 34#define SQLITE3_H 35#include <stdarg.h> /* Needed for the definition of va_list */ 36 37/* 38** Make sure we can call this stuff from C++. 39*/ 40#ifdef __cplusplus 41extern "C" { 42#endif 43 44 45/* 46** Provide the ability to override linkage features of the interface. 47*/ 48#ifndef SQLITE_EXTERN 49# define SQLITE_EXTERN extern 50#endif 51#ifndef SQLITE_API 52# define SQLITE_API 53#endif 54#ifndef SQLITE_CDECL 55# define SQLITE_CDECL 56#endif 57#ifndef SQLITE_APICALL 58# define SQLITE_APICALL 59#endif 60#ifndef SQLITE_STDCALL 61# define SQLITE_STDCALL SQLITE_APICALL 62#endif 63#ifndef SQLITE_CALLBACK 64# define SQLITE_CALLBACK 65#endif 66#ifndef SQLITE_SYSAPI 67# define SQLITE_SYSAPI 68#endif 69 70/* 71** These no-op macros are used in front of interfaces to mark those 72** interfaces as either deprecated or experimental. New applications 73** should not use deprecated interfaces - they are supported for backwards 74** compatibility only. Application writers should be aware that 75** experimental interfaces are subject to change in point releases. 76** 77** These macros used to resolve to various kinds of compiler magic that 78** would generate warning messages when they were used. But that 79** compiler magic ended up generating such a flurry of bug reports 80** that we have taken it all out and gone back to using simple 81** noop macros. 82*/ 83#define SQLITE_DEPRECATED 84#define SQLITE_EXPERIMENTAL 85 86/* 87** Ensure these symbols were not defined by some previous header file. 88*/ 89#ifdef SQLITE_VERSION 90# undef SQLITE_VERSION 91#endif 92#ifdef SQLITE_VERSION_NUMBER 93# undef SQLITE_VERSION_NUMBER 94#endif 95 96/* 97** CAPI3REF: Compile-Time Library Version Numbers 98** 99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 100** evaluates to a string literal that is the SQLite version in the 101** format "X.Y.Z" where X is the major version number (always 3 for 102** SQLite3) and Y is the minor version number and Z is the release number.)^ 103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 105** numbers used in [SQLITE_VERSION].)^ 106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 107** be larger than the release from which it is derived. Either Y will 108** be held constant and Z will be incremented or else Y will be incremented 109** and Z will be reset to zero. 110** 111** Since [version 3.6.18] ([dateof:3.6.18]), 112** SQLite source code has been stored in the 113** <a href="http://www.fossil-scm.org/">Fossil configuration management 114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 115** a string which identifies a particular check-in of SQLite 116** within its configuration management system. ^The SQLITE_SOURCE_ID 117** string contains the date and time of the check-in (UTC) and a SHA1 118** or SHA3-256 hash of the entire source tree. If the source code has 119** been edited in any way since it was last checked in, then the last 120** four hexadecimal digits of the hash may be modified. 121** 122** See also: [sqlite3_libversion()], 123** [sqlite3_libversion_number()], [sqlite3_sourceid()], 124** [sqlite_version()] and [sqlite_source_id()]. 125*/ 126#define SQLITE_VERSION "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 129 130/* 131** CAPI3REF: Run-Time Library Version Numbers 132** KEYWORDS: sqlite3_version sqlite3_sourceid 133** 134** These interfaces provide the same information as the [SQLITE_VERSION], 135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 136** but are associated with the library instead of the header file. ^(Cautious 137** programmers might include assert() statements in their application to 138** verify that values returned by these interfaces match the macros in 139** the header, and thus ensure that the application is 140** compiled with matching library and header files. 141** 142** <blockquote><pre> 143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 ); 145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 146** </pre></blockquote>)^ 147** 148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 149** macro. ^The sqlite3_libversion() function returns a pointer to the 150** to the sqlite3_version[] string constant. The sqlite3_libversion() 151** function is provided for use in DLLs since DLL users usually do not have 152** direct access to string constants within the DLL. ^The 153** sqlite3_libversion_number() function returns an integer equal to 154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns 155** a pointer to a string constant whose value is the same as the 156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built 157** using an edited copy of [the amalgamation], then the last four characters 158** of the hash might be different from [SQLITE_SOURCE_ID].)^ 159** 160** See also: [sqlite_version()] and [sqlite_source_id()]. 161*/ 162SQLITE_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int sqlite3_libversion_number(void); 166 167/* 168** CAPI3REF: Run-Time Library Compilation Options Diagnostics 169** 170** ^The sqlite3_compileoption_used() function returns 0 or 1 171** indicating whether the specified option was defined at 172** compile time. ^The SQLITE_ prefix may be omitted from the 173** option name passed to sqlite3_compileoption_used(). 174** 175** ^The sqlite3_compileoption_get() function allows iterating 176** over the list of options that were defined at compile time by 177** returning the N-th compile time option string. ^If N is out of range, 178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 179** prefix is omitted from any strings returned by 180** sqlite3_compileoption_get(). 181** 182** ^Support for the diagnostic functions sqlite3_compileoption_used() 183** and sqlite3_compileoption_get() may be omitted by specifying the 184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 185** 186** See also: SQL functions [sqlite_compileoption_used()] and 187** [sqlite_compileoption_get()] and the [compile_options pragma]. 188*/ 189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#else 193# define sqlite3_compileoption_used(X) 0 194# define sqlite3_compileoption_get(X) ((void*)0) 195#endif 196 197/* 198** CAPI3REF: Test To See If The Library Is Threadsafe 199** 200** ^The sqlite3_threadsafe() function returns zero if and only if 201** SQLite was compiled with mutexing code omitted due to the 202** [SQLITE_THREADSAFE] compile-time option being set to 0. 203** 204** SQLite can be compiled with or without mutexes. When 205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206** are enabled and SQLite is threadsafe. When the 207** [SQLITE_THREADSAFE] macro is 0, 208** the mutexes are omitted. Without the mutexes, it is not safe 209** to use SQLite concurrently from more than one thread. 210** 211** Enabling mutexes incurs a measurable performance penalty. 212** So if speed is of utmost importance, it makes sense to disable 213** the mutexes. But for maximum safety, mutexes should be enabled. 214** ^The default behavior is for mutexes to be enabled. 215** 216** This interface can be used by an application to make sure that the 217** version of SQLite that it is linking against was compiled with 218** the desired setting of the [SQLITE_THREADSAFE] macro. 219** 220** This interface only reports on the compile-time mutex setting 221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223** can be fully or partially disabled using a call to [sqlite3_config()] 224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226** sqlite3_threadsafe() function shows only the compile-time setting of 227** thread safety, not any run-time changes to that setting made by 228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229** is unchanged by calls to sqlite3_config().)^ 230** 231** See the [threading mode] documentation for additional information. 232*/ 233int sqlite3_threadsafe(void); 234 235/* 236** CAPI3REF: Database Connection Handle 237** KEYWORDS: {database connection} {database connections} 238** 239** Each open SQLite database is represented by a pointer to an instance of 240** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243** and [sqlite3_close_v2()] are its destructors. There are many other 244** interfaces (such as 245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246** [sqlite3_busy_timeout()] to name but three) that are methods on an 247** sqlite3 object. 248*/ 249typedef struct sqlite3 sqlite3; 250 251/* 252** CAPI3REF: 64-Bit Integer Types 253** KEYWORDS: sqlite_int64 sqlite_uint64 254** 255** Because there is no cross-platform way to specify 64-bit integer types 256** SQLite includes typedefs for 64-bit signed and unsigned integers. 257** 258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260** compatibility only. 261** 262** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264** sqlite3_uint64 and sqlite_uint64 types can store integer values 265** between 0 and +18446744073709551615 inclusive. 266*/ 267#ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269# ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271# else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273# endif 274#elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277#else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280#endif 281typedef sqlite_int64 sqlite3_int64; 282typedef sqlite_uint64 sqlite3_uint64; 283 284/* 285** If compiling for a processor that lacks floating point support, 286** substitute integer for floating-point. 287*/ 288#ifdef SQLITE_OMIT_FLOATING_POINT 289# define double sqlite3_int64 290#endif 291 292/* 293** CAPI3REF: Closing A Database Connection 294** DESTRUCTOR: sqlite3 295** 296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297** for the [sqlite3] object. 298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299** the [sqlite3] object is successfully destroyed and all associated 300** resources are deallocated. 301** 302** ^If the database connection is associated with unfinalized prepared 303** statements or unfinished sqlite3_backup objects then sqlite3_close() 304** will leave the database connection open and return [SQLITE_BUSY]. 305** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306** and/or unfinished sqlite3_backups, then the database connection becomes 307** an unusable "zombie" which will automatically be deallocated when the 308** last prepared statement is finalized or the last sqlite3_backup is 309** finished. The sqlite3_close_v2() interface is intended for use with 310** host languages that are garbage collected, and where the order in which 311** destructors are called is arbitrary. 312** 313** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314** [sqlite3_blob_close | close] all [BLOB handles], and 315** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316** with the [sqlite3] object prior to attempting to close the object. ^If 317** sqlite3_close_v2() is called on a [database connection] that still has 318** outstanding [prepared statements], [BLOB handles], and/or 319** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320** of resources is deferred until all [prepared statements], [BLOB handles], 321** and [sqlite3_backup] objects are also destroyed. 322** 323** ^If an [sqlite3] object is destroyed while a transaction is open, 324** the transaction is automatically rolled back. 325** 326** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327** must be either a NULL 328** pointer or an [sqlite3] object pointer obtained 329** from [sqlite3_open()], [sqlite3_open16()], or 330** [sqlite3_open_v2()], and not previously closed. 331** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332** argument is a harmless no-op. 333*/ 334int sqlite3_close(sqlite3*); 335int sqlite3_close_v2(sqlite3*); 336 337/* 338** The type for a callback function. 339** This is legacy and deprecated. It is included for historical 340** compatibility and is not documented. 341*/ 342typedef int (*sqlite3_callback)(void*,int,char**, char**); 343 344/* 345** CAPI3REF: One-Step Query Execution Interface 346** METHOD: sqlite3 347** 348** The sqlite3_exec() interface is a convenience wrapper around 349** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350** that allows an application to run multiple statements of SQL 351** without having to use a lot of C code. 352** 353** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354** semicolon-separate SQL statements passed into its 2nd argument, 355** in the context of the [database connection] passed in as its 1st 356** argument. ^If the callback function of the 3rd argument to 357** sqlite3_exec() is not NULL, then it is invoked for each result row 358** coming out of the evaluated SQL statements. ^The 4th argument to 359** sqlite3_exec() is relayed through to the 1st argument of each 360** callback invocation. ^If the callback pointer to sqlite3_exec() 361** is NULL, then no callback is ever invoked and result rows are 362** ignored. 363** 364** ^If an error occurs while evaluating the SQL statements passed into 365** sqlite3_exec(), then execution of the current statement stops and 366** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367** is not NULL then any error message is written into memory obtained 368** from [sqlite3_malloc()] and passed back through the 5th parameter. 369** To avoid memory leaks, the application should invoke [sqlite3_free()] 370** on error message strings returned through the 5th parameter of 371** sqlite3_exec() after the error message string is no longer needed. 372** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374** NULL before returning. 375** 376** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377** routine returns SQLITE_ABORT without invoking the callback again and 378** without running any subsequent SQL statements. 379** 380** ^The 2nd argument to the sqlite3_exec() callback function is the 381** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382** callback is an array of pointers to strings obtained as if from 383** [sqlite3_column_text()], one for each column. ^If an element of a 384** result row is NULL then the corresponding string pointer for the 385** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386** sqlite3_exec() callback is an array of pointers to strings where each 387** entry represents the name of corresponding result column as obtained 388** from [sqlite3_column_name()]. 389** 390** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391** to an empty string, or a pointer that contains only whitespace and/or 392** SQL comments, then no SQL statements are evaluated and the database 393** is not changed. 394** 395** Restrictions: 396** 397** <ul> 398** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399** is a valid and open [database connection]. 400** <li> The application must not close the [database connection] specified by 401** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402** <li> The application must not modify the SQL statement text passed into 403** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404** </ul> 405*/ 406int sqlite3_exec( 407 sqlite3*, /* An open database */ 408 const char *sql, /* SQL to be evaluated */ 409 int (*callback)(void*,int,char**,char**), /* Callback function */ 410 void *, /* 1st argument to callback */ 411 char **errmsg /* Error msg written here */ 412); 413 414/* 415** CAPI3REF: Result Codes 416** KEYWORDS: {result code definitions} 417** 418** Many SQLite functions return an integer result code from the set shown 419** here in order to indicate success or failure. 420** 421** New error codes may be added in future versions of SQLite. 422** 423** See also: [extended result code definitions] 424*/ 425#define SQLITE_OK 0 /* Successful result */ 426/* beginning-of-error-codes */ 427#define SQLITE_ERROR 1 /* Generic error */ 428#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429#define SQLITE_PERM 3 /* Access permission denied */ 430#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431#define SQLITE_BUSY 5 /* The database file is locked */ 432#define SQLITE_LOCKED 6 /* A table in the database is locked */ 433#define SQLITE_NOMEM 7 /* A malloc() failed */ 434#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439#define SQLITE_FULL 13 /* Insertion failed because database is full */ 440#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442#define SQLITE_EMPTY 16 /* Internal use only */ 443#define SQLITE_SCHEMA 17 /* The database schema changed */ 444#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446#define SQLITE_MISMATCH 20 /* Data type mismatch */ 447#define SQLITE_MISUSE 21 /* Library used incorrectly */ 448#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449#define SQLITE_AUTH 23 /* Authorization denied */ 450#define SQLITE_FORMAT 24 /* Not used */ 451#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457/* end-of-error-codes */ 458 459/* 460** CAPI3REF: Extended Result Codes 461** KEYWORDS: {extended result code definitions} 462** 463** In its default configuration, SQLite API routines return one of 30 integer 464** [result codes]. However, experience has shown that many of 465** these result codes are too coarse-grained. They do not provide as 466** much information about problems as programmers might like. In an effort to 467** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468** and later) include 469** support for additional result codes that provide more detailed information 470** about errors. These [extended result codes] are enabled or disabled 471** on a per database connection basis using the 472** [sqlite3_extended_result_codes()] API. Or, the extended code for 473** the most recent error can be obtained using 474** [sqlite3_extended_errcode()]. 475*/ 476#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 520#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 521#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 522#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 529#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 530#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 531#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 532#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 533#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 534#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 535#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 536#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 537#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 538#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 539#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8)) 540#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 541#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 542#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 543#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 544#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 545#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 546 547/* 548** CAPI3REF: Flags For File Open Operations 549** 550** These bit values are intended for use in the 551** 3rd parameter to the [sqlite3_open_v2()] interface and 552** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 553*/ 554#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 557#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 558#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 559#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 560#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 561#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 562#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 563#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 564#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 565#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 566#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 567#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 568#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 569#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 570#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 571#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 572#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 573#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 574#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 575 576/* Reserved: 0x00F00000 */ 577 578/* 579** CAPI3REF: Device Characteristics 580** 581** The xDeviceCharacteristics method of the [sqlite3_io_methods] 582** object returns an integer which is a vector of these 583** bit values expressing I/O characteristics of the mass storage 584** device that holds the file that the [sqlite3_io_methods] 585** refers to. 586** 587** The SQLITE_IOCAP_ATOMIC property means that all writes of 588** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 589** mean that writes of blocks that are nnn bytes in size and 590** are aligned to an address which is an integer multiple of 591** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 592** that when data is appended to a file, the data is appended 593** first then the size of the file is extended, never the other 594** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 595** information is written to disk in the same order as calls 596** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 597** after reboot following a crash or power loss, the only bytes in a 598** file that were written at the application level might have changed 599** and that adjacent bytes, even bytes within the same sector are 600** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 601** flag indicates that a file cannot be deleted when open. The 602** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 603** read-only media and cannot be changed even by processes with 604** elevated privileges. 605** 606** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 607** filesystem supports doing multiple write operations atomically when those 608** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 609** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 610*/ 611#define SQLITE_IOCAP_ATOMIC 0x00000001 612#define SQLITE_IOCAP_ATOMIC512 0x00000002 613#define SQLITE_IOCAP_ATOMIC1K 0x00000004 614#define SQLITE_IOCAP_ATOMIC2K 0x00000008 615#define SQLITE_IOCAP_ATOMIC4K 0x00000010 616#define SQLITE_IOCAP_ATOMIC8K 0x00000020 617#define SQLITE_IOCAP_ATOMIC16K 0x00000040 618#define SQLITE_IOCAP_ATOMIC32K 0x00000080 619#define SQLITE_IOCAP_ATOMIC64K 0x00000100 620#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 621#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 622#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 623#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 624#define SQLITE_IOCAP_IMMUTABLE 0x00002000 625#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 626 627/* 628** CAPI3REF: File Locking Levels 629** 630** SQLite uses one of these integer values as the second 631** argument to calls it makes to the xLock() and xUnlock() methods 632** of an [sqlite3_io_methods] object. 633*/ 634#define SQLITE_LOCK_NONE 0 635#define SQLITE_LOCK_SHARED 1 636#define SQLITE_LOCK_RESERVED 2 637#define SQLITE_LOCK_PENDING 3 638#define SQLITE_LOCK_EXCLUSIVE 4 639 640/* 641** CAPI3REF: Synchronization Type Flags 642** 643** When SQLite invokes the xSync() method of an 644** [sqlite3_io_methods] object it uses a combination of 645** these integer values as the second argument. 646** 647** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 648** sync operation only needs to flush data to mass storage. Inode 649** information need not be flushed. If the lower four bits of the flag 650** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 651** If the lower four bits equal SQLITE_SYNC_FULL, that means 652** to use Mac OS X style fullsync instead of fsync(). 653** 654** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 655** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 656** settings. The [synchronous pragma] determines when calls to the 657** xSync VFS method occur and applies uniformly across all platforms. 658** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 659** energetic or rigorous or forceful the sync operations are and 660** only make a difference on Mac OSX for the default SQLite code. 661** (Third-party VFS implementations might also make the distinction 662** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 663** operating systems natively supported by SQLite, only Mac OSX 664** cares about the difference.) 665*/ 666#define SQLITE_SYNC_NORMAL 0x00002 667#define SQLITE_SYNC_FULL 0x00003 668#define SQLITE_SYNC_DATAONLY 0x00010 669 670/* 671** CAPI3REF: OS Interface Open File Handle 672** 673** An [sqlite3_file] object represents an open file in the 674** [sqlite3_vfs | OS interface layer]. Individual OS interface 675** implementations will 676** want to subclass this object by appending additional fields 677** for their own use. The pMethods entry is a pointer to an 678** [sqlite3_io_methods] object that defines methods for performing 679** I/O operations on the open file. 680*/ 681typedef struct sqlite3_file sqlite3_file; 682struct sqlite3_file { 683 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 684}; 685 686/* 687** CAPI3REF: OS Interface File Virtual Methods Object 688** 689** Every file opened by the [sqlite3_vfs.xOpen] method populates an 690** [sqlite3_file] object (or, more commonly, a subclass of the 691** [sqlite3_file] object) with a pointer to an instance of this object. 692** This object defines the methods used to perform various operations 693** against the open file represented by the [sqlite3_file] object. 694** 695** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 696** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 697** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 698** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 699** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 700** to NULL. 701** 702** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 703** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 704** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 705** flag may be ORed in to indicate that only the data of the file 706** and not its inode needs to be synced. 707** 708** The integer values to xLock() and xUnlock() are one of 709** <ul> 710** <li> [SQLITE_LOCK_NONE], 711** <li> [SQLITE_LOCK_SHARED], 712** <li> [SQLITE_LOCK_RESERVED], 713** <li> [SQLITE_LOCK_PENDING], or 714** <li> [SQLITE_LOCK_EXCLUSIVE]. 715** </ul> 716** xLock() increases the lock. xUnlock() decreases the lock. 717** The xCheckReservedLock() method checks whether any database connection, 718** either in this process or in some other process, is holding a RESERVED, 719** PENDING, or EXCLUSIVE lock on the file. It returns true 720** if such a lock exists and false otherwise. 721** 722** The xFileControl() method is a generic interface that allows custom 723** VFS implementations to directly control an open file using the 724** [sqlite3_file_control()] interface. The second "op" argument is an 725** integer opcode. The third argument is a generic pointer intended to 726** point to a structure that may contain arguments or space in which to 727** write return values. Potential uses for xFileControl() might be 728** functions to enable blocking locks with timeouts, to change the 729** locking strategy (for example to use dot-file locks), to inquire 730** about the status of a lock, or to break stale locks. The SQLite 731** core reserves all opcodes less than 100 for its own use. 732** A [file control opcodes | list of opcodes] less than 100 is available. 733** Applications that define a custom xFileControl method should use opcodes 734** greater than 100 to avoid conflicts. VFS implementations should 735** return [SQLITE_NOTFOUND] for file control opcodes that they do not 736** recognize. 737** 738** The xSectorSize() method returns the sector size of the 739** device that underlies the file. The sector size is the 740** minimum write that can be performed without disturbing 741** other bytes in the file. The xDeviceCharacteristics() 742** method returns a bit vector describing behaviors of the 743** underlying device: 744** 745** <ul> 746** <li> [SQLITE_IOCAP_ATOMIC] 747** <li> [SQLITE_IOCAP_ATOMIC512] 748** <li> [SQLITE_IOCAP_ATOMIC1K] 749** <li> [SQLITE_IOCAP_ATOMIC2K] 750** <li> [SQLITE_IOCAP_ATOMIC4K] 751** <li> [SQLITE_IOCAP_ATOMIC8K] 752** <li> [SQLITE_IOCAP_ATOMIC16K] 753** <li> [SQLITE_IOCAP_ATOMIC32K] 754** <li> [SQLITE_IOCAP_ATOMIC64K] 755** <li> [SQLITE_IOCAP_SAFE_APPEND] 756** <li> [SQLITE_IOCAP_SEQUENTIAL] 757** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 758** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 759** <li> [SQLITE_IOCAP_IMMUTABLE] 760** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 761** </ul> 762** 763** The SQLITE_IOCAP_ATOMIC property means that all writes of 764** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 765** mean that writes of blocks that are nnn bytes in size and 766** are aligned to an address which is an integer multiple of 767** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 768** that when data is appended to a file, the data is appended 769** first then the size of the file is extended, never the other 770** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 771** information is written to disk in the same order as calls 772** to xWrite(). 773** 774** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 775** in the unread portions of the buffer with zeros. A VFS that 776** fails to zero-fill short reads might seem to work. However, 777** failure to zero-fill short reads will eventually lead to 778** database corruption. 779*/ 780typedef struct sqlite3_io_methods sqlite3_io_methods; 781struct sqlite3_io_methods { 782 int iVersion; 783 int (*xClose)(sqlite3_file*); 784 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 785 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 786 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 787 int (*xSync)(sqlite3_file*, int flags); 788 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 789 int (*xLock)(sqlite3_file*, int); 790 int (*xUnlock)(sqlite3_file*, int); 791 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 792 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 793 int (*xSectorSize)(sqlite3_file*); 794 int (*xDeviceCharacteristics)(sqlite3_file*); 795 /* Methods above are valid for version 1 */ 796 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 797 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 798 void (*xShmBarrier)(sqlite3_file*); 799 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 800 /* Methods above are valid for version 2 */ 801 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 802 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 803 /* Methods above are valid for version 3 */ 804 /* Additional methods may be added in future releases */ 805}; 806 807/* 808** CAPI3REF: Standard File Control Opcodes 809** KEYWORDS: {file control opcodes} {file control opcode} 810** 811** These integer constants are opcodes for the xFileControl method 812** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 813** interface. 814** 815** <ul> 816** <li>[[SQLITE_FCNTL_LOCKSTATE]] 817** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 818** opcode causes the xFileControl method to write the current state of 819** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 820** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 821** into an integer that the pArg argument points to. This capability 822** is used during testing and is only available when the SQLITE_TEST 823** compile-time option is used. 824** 825** <li>[[SQLITE_FCNTL_SIZE_HINT]] 826** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 827** layer a hint of how large the database file will grow to be during the 828** current transaction. This hint is not guaranteed to be accurate but it 829** is often close. The underlying VFS might choose to preallocate database 830** file space based on this hint in order to help writes to the database 831** file run faster. 832** 833** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 834** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 835** implements [sqlite3_deserialize()] to set an upper bound on the size 836** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 837** If the integer pointed to is negative, then it is filled in with the 838** current limit. Otherwise the limit is set to the larger of the value 839** of the integer pointed to and the current database size. The integer 840** pointed to is set to the new limit. 841** 842** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 843** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 844** extends and truncates the database file in chunks of a size specified 845** by the user. The fourth argument to [sqlite3_file_control()] should 846** point to an integer (type int) containing the new chunk-size to use 847** for the nominated database. Allocating database file space in large 848** chunks (say 1MB at a time), may reduce file-system fragmentation and 849** improve performance on some systems. 850** 851** <li>[[SQLITE_FCNTL_FILE_POINTER]] 852** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 853** to the [sqlite3_file] object associated with a particular database 854** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 855** 856** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 857** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 858** to the [sqlite3_file] object associated with the journal file (either 859** the [rollback journal] or the [write-ahead log]) for a particular database 860** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 861** 862** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 863** No longer in use. 864** 865** <li>[[SQLITE_FCNTL_SYNC]] 866** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 867** sent to the VFS immediately before the xSync method is invoked on a 868** database file descriptor. Or, if the xSync method is not invoked 869** because the user has configured SQLite with 870** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 871** of the xSync method. In most cases, the pointer argument passed with 872** this file-control is NULL. However, if the database file is being synced 873** as part of a multi-database commit, the argument points to a nul-terminated 874** string containing the transactions master-journal file name. VFSes that 875** do not need this signal should silently ignore this opcode. Applications 876** should not call [sqlite3_file_control()] with this opcode as doing so may 877** disrupt the operation of the specialized VFSes that do require it. 878** 879** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 880** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 881** and sent to the VFS after a transaction has been committed immediately 882** but before the database is unlocked. VFSes that do not need this signal 883** should silently ignore this opcode. Applications should not call 884** [sqlite3_file_control()] with this opcode as doing so may disrupt the 885** operation of the specialized VFSes that do require it. 886** 887** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 888** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 889** retry counts and intervals for certain disk I/O operations for the 890** windows [VFS] in order to provide robustness in the presence of 891** anti-virus programs. By default, the windows VFS will retry file read, 892** file write, and file delete operations up to 10 times, with a delay 893** of 25 milliseconds before the first retry and with the delay increasing 894** by an additional 25 milliseconds with each subsequent retry. This 895** opcode allows these two values (10 retries and 25 milliseconds of delay) 896** to be adjusted. The values are changed for all database connections 897** within the same process. The argument is a pointer to an array of two 898** integers where the first integer is the new retry count and the second 899** integer is the delay. If either integer is negative, then the setting 900** is not changed but instead the prior value of that setting is written 901** into the array entry, allowing the current retry settings to be 902** interrogated. The zDbName parameter is ignored. 903** 904** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 905** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 906** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 907** write ahead log ([WAL file]) and shared memory 908** files used for transaction control 909** are automatically deleted when the latest connection to the database 910** closes. Setting persistent WAL mode causes those files to persist after 911** close. Persisting the files is useful when other processes that do not 912** have write permission on the directory containing the database file want 913** to read the database file, as the WAL and shared memory files must exist 914** in order for the database to be readable. The fourth parameter to 915** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 916** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 917** WAL mode. If the integer is -1, then it is overwritten with the current 918** WAL persistence setting. 919** 920** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 921** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 922** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 923** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 924** xDeviceCharacteristics methods. The fourth parameter to 925** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 926** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 927** mode. If the integer is -1, then it is overwritten with the current 928** zero-damage mode setting. 929** 930** <li>[[SQLITE_FCNTL_OVERWRITE]] 931** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 932** a write transaction to indicate that, unless it is rolled back for some 933** reason, the entire database file will be overwritten by the current 934** transaction. This is used by VACUUM operations. 935** 936** <li>[[SQLITE_FCNTL_VFSNAME]] 937** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 938** all [VFSes] in the VFS stack. The names are of all VFS shims and the 939** final bottom-level VFS are written into memory obtained from 940** [sqlite3_malloc()] and the result is stored in the char* variable 941** that the fourth parameter of [sqlite3_file_control()] points to. 942** The caller is responsible for freeing the memory when done. As with 943** all file-control actions, there is no guarantee that this will actually 944** do anything. Callers should initialize the char* variable to a NULL 945** pointer in case this file-control is not implemented. This file-control 946** is intended for diagnostic use only. 947** 948** <li>[[SQLITE_FCNTL_VFS_POINTER]] 949** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 950** [VFSes] currently in use. ^(The argument X in 951** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 952** of type "[sqlite3_vfs] **". This opcodes will set *X 953** to a pointer to the top-level VFS.)^ 954** ^When there are multiple VFS shims in the stack, this opcode finds the 955** upper-most shim only. 956** 957** <li>[[SQLITE_FCNTL_PRAGMA]] 958** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 959** file control is sent to the open [sqlite3_file] object corresponding 960** to the database file to which the pragma statement refers. ^The argument 961** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 962** pointers to strings (char**) in which the second element of the array 963** is the name of the pragma and the third element is the argument to the 964** pragma or NULL if the pragma has no argument. ^The handler for an 965** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 966** of the char** argument point to a string obtained from [sqlite3_mprintf()] 967** or the equivalent and that string will become the result of the pragma or 968** the error message if the pragma fails. ^If the 969** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 970** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 971** file control returns [SQLITE_OK], then the parser assumes that the 972** VFS has handled the PRAGMA itself and the parser generates a no-op 973** prepared statement if result string is NULL, or that returns a copy 974** of the result string if the string is non-NULL. 975** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 976** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 977** that the VFS encountered an error while handling the [PRAGMA] and the 978** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 979** file control occurs at the beginning of pragma statement analysis and so 980** it is able to override built-in [PRAGMA] statements. 981** 982** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 983** ^The [SQLITE_FCNTL_BUSYHANDLER] 984** file-control may be invoked by SQLite on the database file handle 985** shortly after it is opened in order to provide a custom VFS with access 986** to the connection's busy-handler callback. The argument is of type (void**) 987** - an array of two (void *) values. The first (void *) actually points 988** to a function of type (int (*)(void *)). In order to invoke the connection's 989** busy-handler, this function should be invoked with the second (void *) in 990** the array as the only argument. If it returns non-zero, then the operation 991** should be retried. If it returns zero, the custom VFS should abandon the 992** current operation. 993** 994** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 995** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 996** to have SQLite generate a 997** temporary filename using the same algorithm that is followed to generate 998** temporary filenames for TEMP tables and other internal uses. The 999** argument should be a char** which will be filled with the filename 1000** written into memory obtained from [sqlite3_malloc()]. The caller should 1001** invoke [sqlite3_free()] on the result to avoid a memory leak. 1002** 1003** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1004** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1005** maximum number of bytes that will be used for memory-mapped I/O. 1006** The argument is a pointer to a value of type sqlite3_int64 that 1007** is an advisory maximum number of bytes in the file to memory map. The 1008** pointer is overwritten with the old value. The limit is not changed if 1009** the value originally pointed to is negative, and so the current limit 1010** can be queried by passing in a pointer to a negative number. This 1011** file-control is used internally to implement [PRAGMA mmap_size]. 1012** 1013** <li>[[SQLITE_FCNTL_TRACE]] 1014** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1015** to the VFS about what the higher layers of the SQLite stack are doing. 1016** This file control is used by some VFS activity tracing [shims]. 1017** The argument is a zero-terminated string. Higher layers in the 1018** SQLite stack may generate instances of this file control if 1019** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1020** 1021** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1022** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1023** pointer to an integer and it writes a boolean into that integer depending 1024** on whether or not the file has been renamed, moved, or deleted since it 1025** was first opened. 1026** 1027** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1028** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1029** underlying native file handle associated with a file handle. This file 1030** control interprets its argument as a pointer to a native file handle and 1031** writes the resulting value there. 1032** 1033** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1034** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1035** opcode causes the xFileControl method to swap the file handle with the one 1036** pointed to by the pArg argument. This capability is used during testing 1037** and only needs to be supported when SQLITE_TEST is defined. 1038** 1039** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1040** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1041** be advantageous to block on the next WAL lock if the lock is not immediately 1042** available. The WAL subsystem issues this signal during rare 1043** circumstances in order to fix a problem with priority inversion. 1044** Applications should <em>not</em> use this file-control. 1045** 1046** <li>[[SQLITE_FCNTL_ZIPVFS]] 1047** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1048** VFS should return SQLITE_NOTFOUND for this opcode. 1049** 1050** <li>[[SQLITE_FCNTL_RBU]] 1051** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1052** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1053** this opcode. 1054** 1055** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1056** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1057** the file descriptor is placed in "batch write mode", which 1058** means all subsequent write operations will be deferred and done 1059** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1060** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1061** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1062** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1063** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1064** no VFS interface calls on the same [sqlite3_file] file descriptor 1065** except for calls to the xWrite method and the xFileControl method 1066** with [SQLITE_FCNTL_SIZE_HINT]. 1067** 1068** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1069** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1070** operations since the previous successful call to 1071** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1072** This file control returns [SQLITE_OK] if and only if the writes were 1073** all performed successfully and have been committed to persistent storage. 1074** ^Regardless of whether or not it is successful, this file control takes 1075** the file descriptor out of batch write mode so that all subsequent 1076** write operations are independent. 1077** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1078** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1079** 1080** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1081** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1082** operations since the previous successful call to 1083** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1084** ^This file control takes the file descriptor out of batch write mode 1085** so that all subsequent write operations are independent. 1086** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1087** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1088** 1089** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1090** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1091** a file lock using the xLock or xShmLock methods of the VFS to wait 1092** for up to M milliseconds before failing, where M is the single 1093** unsigned integer parameter. 1094** 1095** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1096** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1097** a database file. The argument is a pointer to a 32-bit unsigned integer. 1098** The "data version" for the pager is written into the pointer. The 1099** "data version" changes whenever any change occurs to the corresponding 1100** database file, either through SQL statements on the same database 1101** connection or through transactions committed by separate database 1102** connections possibly in other processes. The [sqlite3_total_changes()] 1103** interface can be used to find if any database on the connection has changed, 1104** but that interface responds to changes on TEMP as well as MAIN and does 1105** not provide a mechanism to detect changes to MAIN only. Also, the 1106** [sqlite3_total_changes()] interface responds to internal changes only and 1107** omits changes made by other database connections. The 1108** [PRAGMA data_version] command provides a mechanism to detect changes to 1109** a single attached database that occur due to other database connections, 1110** but omits changes implemented by the database connection on which it is 1111** called. This file control is the only mechanism to detect changes that 1112** happen either internally or externally and that are associated with 1113** a particular attached database. 1114** </ul> 1115*/ 1116#define SQLITE_FCNTL_LOCKSTATE 1 1117#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1118#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1119#define SQLITE_FCNTL_LAST_ERRNO 4 1120#define SQLITE_FCNTL_SIZE_HINT 5 1121#define SQLITE_FCNTL_CHUNK_SIZE 6 1122#define SQLITE_FCNTL_FILE_POINTER 7 1123#define SQLITE_FCNTL_SYNC_OMITTED 8 1124#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1125#define SQLITE_FCNTL_PERSIST_WAL 10 1126#define SQLITE_FCNTL_OVERWRITE 11 1127#define SQLITE_FCNTL_VFSNAME 12 1128#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1129#define SQLITE_FCNTL_PRAGMA 14 1130#define SQLITE_FCNTL_BUSYHANDLER 15 1131#define SQLITE_FCNTL_TEMPFILENAME 16 1132#define SQLITE_FCNTL_MMAP_SIZE 18 1133#define SQLITE_FCNTL_TRACE 19 1134#define SQLITE_FCNTL_HAS_MOVED 20 1135#define SQLITE_FCNTL_SYNC 21 1136#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1137#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1138#define SQLITE_FCNTL_WAL_BLOCK 24 1139#define SQLITE_FCNTL_ZIPVFS 25 1140#define SQLITE_FCNTL_RBU 26 1141#define SQLITE_FCNTL_VFS_POINTER 27 1142#define SQLITE_FCNTL_JOURNAL_POINTER 28 1143#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1144#define SQLITE_FCNTL_PDB 30 1145#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1146#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1147#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1148#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1149#define SQLITE_FCNTL_DATA_VERSION 35 1150#define SQLITE_FCNTL_SIZE_LIMIT 36 1151 1152/* deprecated names */ 1153#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1154#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1155#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1156 1157 1158/* 1159** CAPI3REF: Mutex Handle 1160** 1161** The mutex module within SQLite defines [sqlite3_mutex] to be an 1162** abstract type for a mutex object. The SQLite core never looks 1163** at the internal representation of an [sqlite3_mutex]. It only 1164** deals with pointers to the [sqlite3_mutex] object. 1165** 1166** Mutexes are created using [sqlite3_mutex_alloc()]. 1167*/ 1168typedef struct sqlite3_mutex sqlite3_mutex; 1169 1170/* 1171** CAPI3REF: Loadable Extension Thunk 1172** 1173** A pointer to the opaque sqlite3_api_routines structure is passed as 1174** the third parameter to entry points of [loadable extensions]. This 1175** structure must be typedefed in order to work around compiler warnings 1176** on some platforms. 1177*/ 1178typedef struct sqlite3_api_routines sqlite3_api_routines; 1179 1180/* 1181** CAPI3REF: OS Interface Object 1182** 1183** An instance of the sqlite3_vfs object defines the interface between 1184** the SQLite core and the underlying operating system. The "vfs" 1185** in the name of the object stands for "virtual file system". See 1186** the [VFS | VFS documentation] for further information. 1187** 1188** The VFS interface is sometimes extended by adding new methods onto 1189** the end. Each time such an extension occurs, the iVersion field 1190** is incremented. The iVersion value started out as 1 in 1191** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1192** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1193** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1194** may be appended to the sqlite3_vfs object and the iVersion value 1195** may increase again in future versions of SQLite. 1196** Note that due to an oversight, the structure 1197** of the sqlite3_vfs object changed in the transition from 1198** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1199** and yet the iVersion field was not increased. 1200** 1201** The szOsFile field is the size of the subclassed [sqlite3_file] 1202** structure used by this VFS. mxPathname is the maximum length of 1203** a pathname in this VFS. 1204** 1205** Registered sqlite3_vfs objects are kept on a linked list formed by 1206** the pNext pointer. The [sqlite3_vfs_register()] 1207** and [sqlite3_vfs_unregister()] interfaces manage this list 1208** in a thread-safe way. The [sqlite3_vfs_find()] interface 1209** searches the list. Neither the application code nor the VFS 1210** implementation should use the pNext pointer. 1211** 1212** The pNext field is the only field in the sqlite3_vfs 1213** structure that SQLite will ever modify. SQLite will only access 1214** or modify this field while holding a particular static mutex. 1215** The application should never modify anything within the sqlite3_vfs 1216** object once the object has been registered. 1217** 1218** The zName field holds the name of the VFS module. The name must 1219** be unique across all VFS modules. 1220** 1221** [[sqlite3_vfs.xOpen]] 1222** ^SQLite guarantees that the zFilename parameter to xOpen 1223** is either a NULL pointer or string obtained 1224** from xFullPathname() with an optional suffix added. 1225** ^If a suffix is added to the zFilename parameter, it will 1226** consist of a single "-" character followed by no more than 1227** 11 alphanumeric and/or "-" characters. 1228** ^SQLite further guarantees that 1229** the string will be valid and unchanged until xClose() is 1230** called. Because of the previous sentence, 1231** the [sqlite3_file] can safely store a pointer to the 1232** filename if it needs to remember the filename for some reason. 1233** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1234** must invent its own temporary name for the file. ^Whenever the 1235** xFilename parameter is NULL it will also be the case that the 1236** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1237** 1238** The flags argument to xOpen() includes all bits set in 1239** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1240** or [sqlite3_open16()] is used, then flags includes at least 1241** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1242** If xOpen() opens a file read-only then it sets *pOutFlags to 1243** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1244** 1245** ^(SQLite will also add one of the following flags to the xOpen() 1246** call, depending on the object being opened: 1247** 1248** <ul> 1249** <li> [SQLITE_OPEN_MAIN_DB] 1250** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1251** <li> [SQLITE_OPEN_TEMP_DB] 1252** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1253** <li> [SQLITE_OPEN_TRANSIENT_DB] 1254** <li> [SQLITE_OPEN_SUBJOURNAL] 1255** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1256** <li> [SQLITE_OPEN_WAL] 1257** </ul>)^ 1258** 1259** The file I/O implementation can use the object type flags to 1260** change the way it deals with files. For example, an application 1261** that does not care about crash recovery or rollback might make 1262** the open of a journal file a no-op. Writes to this journal would 1263** also be no-ops, and any attempt to read the journal would return 1264** SQLITE_IOERR. Or the implementation might recognize that a database 1265** file will be doing page-aligned sector reads and writes in a random 1266** order and set up its I/O subsystem accordingly. 1267** 1268** SQLite might also add one of the following flags to the xOpen method: 1269** 1270** <ul> 1271** <li> [SQLITE_OPEN_DELETEONCLOSE] 1272** <li> [SQLITE_OPEN_EXCLUSIVE] 1273** </ul> 1274** 1275** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1276** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1277** will be set for TEMP databases and their journals, transient 1278** databases, and subjournals. 1279** 1280** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1281** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1282** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1283** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1284** SQLITE_OPEN_CREATE, is used to indicate that file should always 1285** be created, and that it is an error if it already exists. 1286** It is <i>not</i> used to indicate the file should be opened 1287** for exclusive access. 1288** 1289** ^At least szOsFile bytes of memory are allocated by SQLite 1290** to hold the [sqlite3_file] structure passed as the third 1291** argument to xOpen. The xOpen method does not have to 1292** allocate the structure; it should just fill it in. Note that 1293** the xOpen method must set the sqlite3_file.pMethods to either 1294** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1295** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1296** element will be valid after xOpen returns regardless of the success 1297** or failure of the xOpen call. 1298** 1299** [[sqlite3_vfs.xAccess]] 1300** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1301** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1302** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1303** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1304** flag is never actually used and is not implemented in the built-in 1305** VFSes of SQLite. The file is named by the second argument and can be a 1306** directory. The xAccess method returns [SQLITE_OK] on success or some 1307** non-zero error code if there is an I/O error or if the name of 1308** the file given in the second argument is illegal. If SQLITE_OK 1309** is returned, then non-zero or zero is written into *pResOut to indicate 1310** whether or not the file is accessible. 1311** 1312** ^SQLite will always allocate at least mxPathname+1 bytes for the 1313** output buffer xFullPathname. The exact size of the output buffer 1314** is also passed as a parameter to both methods. If the output buffer 1315** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1316** handled as a fatal error by SQLite, vfs implementations should endeavor 1317** to prevent this by setting mxPathname to a sufficiently large value. 1318** 1319** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1320** interfaces are not strictly a part of the filesystem, but they are 1321** included in the VFS structure for completeness. 1322** The xRandomness() function attempts to return nBytes bytes 1323** of good-quality randomness into zOut. The return value is 1324** the actual number of bytes of randomness obtained. 1325** The xSleep() method causes the calling thread to sleep for at 1326** least the number of microseconds given. ^The xCurrentTime() 1327** method returns a Julian Day Number for the current date and time as 1328** a floating point value. 1329** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1330** Day Number multiplied by 86400000 (the number of milliseconds in 1331** a 24-hour day). 1332** ^SQLite will use the xCurrentTimeInt64() method to get the current 1333** date and time if that method is available (if iVersion is 2 or 1334** greater and the function pointer is not NULL) and will fall back 1335** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1336** 1337** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1338** are not used by the SQLite core. These optional interfaces are provided 1339** by some VFSes to facilitate testing of the VFS code. By overriding 1340** system calls with functions under its control, a test program can 1341** simulate faults and error conditions that would otherwise be difficult 1342** or impossible to induce. The set of system calls that can be overridden 1343** varies from one VFS to another, and from one version of the same VFS to the 1344** next. Applications that use these interfaces must be prepared for any 1345** or all of these interfaces to be NULL or for their behavior to change 1346** from one release to the next. Applications must not attempt to access 1347** any of these methods if the iVersion of the VFS is less than 3. 1348*/ 1349typedef struct sqlite3_vfs sqlite3_vfs; 1350typedef void (*sqlite3_syscall_ptr)(void); 1351struct sqlite3_vfs { 1352 int iVersion; /* Structure version number (currently 3) */ 1353 int szOsFile; /* Size of subclassed sqlite3_file */ 1354 int mxPathname; /* Maximum file pathname length */ 1355 sqlite3_vfs *pNext; /* Next registered VFS */ 1356 const char *zName; /* Name of this virtual file system */ 1357 void *pAppData; /* Pointer to application-specific data */ 1358 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1359 int flags, int *pOutFlags); 1360 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1361 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1362 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1363 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1364 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1365 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1366 void (*xDlClose)(sqlite3_vfs*, void*); 1367 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1368 int (*xSleep)(sqlite3_vfs*, int microseconds); 1369 int (*xCurrentTime)(sqlite3_vfs*, double*); 1370 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1371 /* 1372 ** The methods above are in version 1 of the sqlite_vfs object 1373 ** definition. Those that follow are added in version 2 or later 1374 */ 1375 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1376 /* 1377 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1378 ** Those below are for version 3 and greater. 1379 */ 1380 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1381 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1382 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1383 /* 1384 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1385 ** New fields may be appended in future versions. The iVersion 1386 ** value will increment whenever this happens. 1387 */ 1388}; 1389 1390/* 1391** CAPI3REF: Flags for the xAccess VFS method 1392** 1393** These integer constants can be used as the third parameter to 1394** the xAccess method of an [sqlite3_vfs] object. They determine 1395** what kind of permissions the xAccess method is looking for. 1396** With SQLITE_ACCESS_EXISTS, the xAccess method 1397** simply checks whether the file exists. 1398** With SQLITE_ACCESS_READWRITE, the xAccess method 1399** checks whether the named directory is both readable and writable 1400** (in other words, if files can be added, removed, and renamed within 1401** the directory). 1402** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1403** [temp_store_directory pragma], though this could change in a future 1404** release of SQLite. 1405** With SQLITE_ACCESS_READ, the xAccess method 1406** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1407** currently unused, though it might be used in a future release of 1408** SQLite. 1409*/ 1410#define SQLITE_ACCESS_EXISTS 0 1411#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1412#define SQLITE_ACCESS_READ 2 /* Unused */ 1413 1414/* 1415** CAPI3REF: Flags for the xShmLock VFS method 1416** 1417** These integer constants define the various locking operations 1418** allowed by the xShmLock method of [sqlite3_io_methods]. The 1419** following are the only legal combinations of flags to the 1420** xShmLock method: 1421** 1422** <ul> 1423** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1424** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1425** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1426** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1427** </ul> 1428** 1429** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1430** was given on the corresponding lock. 1431** 1432** The xShmLock method can transition between unlocked and SHARED or 1433** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1434** and EXCLUSIVE. 1435*/ 1436#define SQLITE_SHM_UNLOCK 1 1437#define SQLITE_SHM_LOCK 2 1438#define SQLITE_SHM_SHARED 4 1439#define SQLITE_SHM_EXCLUSIVE 8 1440 1441/* 1442** CAPI3REF: Maximum xShmLock index 1443** 1444** The xShmLock method on [sqlite3_io_methods] may use values 1445** between 0 and this upper bound as its "offset" argument. 1446** The SQLite core will never attempt to acquire or release a 1447** lock outside of this range 1448*/ 1449#define SQLITE_SHM_NLOCK 8 1450 1451 1452/* 1453** CAPI3REF: Initialize The SQLite Library 1454** 1455** ^The sqlite3_initialize() routine initializes the 1456** SQLite library. ^The sqlite3_shutdown() routine 1457** deallocates any resources that were allocated by sqlite3_initialize(). 1458** These routines are designed to aid in process initialization and 1459** shutdown on embedded systems. Workstation applications using 1460** SQLite normally do not need to invoke either of these routines. 1461** 1462** A call to sqlite3_initialize() is an "effective" call if it is 1463** the first time sqlite3_initialize() is invoked during the lifetime of 1464** the process, or if it is the first time sqlite3_initialize() is invoked 1465** following a call to sqlite3_shutdown(). ^(Only an effective call 1466** of sqlite3_initialize() does any initialization. All other calls 1467** are harmless no-ops.)^ 1468** 1469** A call to sqlite3_shutdown() is an "effective" call if it is the first 1470** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1471** an effective call to sqlite3_shutdown() does any deinitialization. 1472** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1473** 1474** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1475** is not. The sqlite3_shutdown() interface must only be called from a 1476** single thread. All open [database connections] must be closed and all 1477** other SQLite resources must be deallocated prior to invoking 1478** sqlite3_shutdown(). 1479** 1480** Among other things, ^sqlite3_initialize() will invoke 1481** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1482** will invoke sqlite3_os_end(). 1483** 1484** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1485** ^If for some reason, sqlite3_initialize() is unable to initialize 1486** the library (perhaps it is unable to allocate a needed resource such 1487** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1488** 1489** ^The sqlite3_initialize() routine is called internally by many other 1490** SQLite interfaces so that an application usually does not need to 1491** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1492** calls sqlite3_initialize() so the SQLite library will be automatically 1493** initialized when [sqlite3_open()] is called if it has not be initialized 1494** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1495** compile-time option, then the automatic calls to sqlite3_initialize() 1496** are omitted and the application must call sqlite3_initialize() directly 1497** prior to using any other SQLite interface. For maximum portability, 1498** it is recommended that applications always invoke sqlite3_initialize() 1499** directly prior to using any other SQLite interface. Future releases 1500** of SQLite may require this. In other words, the behavior exhibited 1501** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1502** default behavior in some future release of SQLite. 1503** 1504** The sqlite3_os_init() routine does operating-system specific 1505** initialization of the SQLite library. The sqlite3_os_end() 1506** routine undoes the effect of sqlite3_os_init(). Typical tasks 1507** performed by these routines include allocation or deallocation 1508** of static resources, initialization of global variables, 1509** setting up a default [sqlite3_vfs] module, or setting up 1510** a default configuration using [sqlite3_config()]. 1511** 1512** The application should never invoke either sqlite3_os_init() 1513** or sqlite3_os_end() directly. The application should only invoke 1514** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1515** interface is called automatically by sqlite3_initialize() and 1516** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1517** implementations for sqlite3_os_init() and sqlite3_os_end() 1518** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1519** When [custom builds | built for other platforms] 1520** (using the [SQLITE_OS_OTHER=1] compile-time 1521** option) the application must supply a suitable implementation for 1522** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1523** implementation of sqlite3_os_init() or sqlite3_os_end() 1524** must return [SQLITE_OK] on success and some other [error code] upon 1525** failure. 1526*/ 1527int sqlite3_initialize(void); 1528int sqlite3_shutdown(void); 1529int sqlite3_os_init(void); 1530int sqlite3_os_end(void); 1531 1532/* 1533** CAPI3REF: Configuring The SQLite Library 1534** 1535** The sqlite3_config() interface is used to make global configuration 1536** changes to SQLite in order to tune SQLite to the specific needs of 1537** the application. The default configuration is recommended for most 1538** applications and so this routine is usually not necessary. It is 1539** provided to support rare applications with unusual needs. 1540** 1541** <b>The sqlite3_config() interface is not threadsafe. The application 1542** must ensure that no other SQLite interfaces are invoked by other 1543** threads while sqlite3_config() is running.</b> 1544** 1545** The sqlite3_config() interface 1546** may only be invoked prior to library initialization using 1547** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1548** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1549** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1550** Note, however, that ^sqlite3_config() can be called as part of the 1551** implementation of an application-defined [sqlite3_os_init()]. 1552** 1553** The first argument to sqlite3_config() is an integer 1554** [configuration option] that determines 1555** what property of SQLite is to be configured. Subsequent arguments 1556** vary depending on the [configuration option] 1557** in the first argument. 1558** 1559** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1560** ^If the option is unknown or SQLite is unable to set the option 1561** then this routine returns a non-zero [error code]. 1562*/ 1563int sqlite3_config(int, ...); 1564 1565/* 1566** CAPI3REF: Configure database connections 1567** METHOD: sqlite3 1568** 1569** The sqlite3_db_config() interface is used to make configuration 1570** changes to a [database connection]. The interface is similar to 1571** [sqlite3_config()] except that the changes apply to a single 1572** [database connection] (specified in the first argument). 1573** 1574** The second argument to sqlite3_db_config(D,V,...) is the 1575** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1576** that indicates what aspect of the [database connection] is being configured. 1577** Subsequent arguments vary depending on the configuration verb. 1578** 1579** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1580** the call is considered successful. 1581*/ 1582int sqlite3_db_config(sqlite3*, int op, ...); 1583 1584/* 1585** CAPI3REF: Memory Allocation Routines 1586** 1587** An instance of this object defines the interface between SQLite 1588** and low-level memory allocation routines. 1589** 1590** This object is used in only one place in the SQLite interface. 1591** A pointer to an instance of this object is the argument to 1592** [sqlite3_config()] when the configuration option is 1593** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1594** By creating an instance of this object 1595** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1596** during configuration, an application can specify an alternative 1597** memory allocation subsystem for SQLite to use for all of its 1598** dynamic memory needs. 1599** 1600** Note that SQLite comes with several [built-in memory allocators] 1601** that are perfectly adequate for the overwhelming majority of applications 1602** and that this object is only useful to a tiny minority of applications 1603** with specialized memory allocation requirements. This object is 1604** also used during testing of SQLite in order to specify an alternative 1605** memory allocator that simulates memory out-of-memory conditions in 1606** order to verify that SQLite recovers gracefully from such 1607** conditions. 1608** 1609** The xMalloc, xRealloc, and xFree methods must work like the 1610** malloc(), realloc() and free() functions from the standard C library. 1611** ^SQLite guarantees that the second argument to 1612** xRealloc is always a value returned by a prior call to xRoundup. 1613** 1614** xSize should return the allocated size of a memory allocation 1615** previously obtained from xMalloc or xRealloc. The allocated size 1616** is always at least as big as the requested size but may be larger. 1617** 1618** The xRoundup method returns what would be the allocated size of 1619** a memory allocation given a particular requested size. Most memory 1620** allocators round up memory allocations at least to the next multiple 1621** of 8. Some allocators round up to a larger multiple or to a power of 2. 1622** Every memory allocation request coming in through [sqlite3_malloc()] 1623** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1624** that causes the corresponding memory allocation to fail. 1625** 1626** The xInit method initializes the memory allocator. For example, 1627** it might allocate any required mutexes or initialize internal data 1628** structures. The xShutdown method is invoked (indirectly) by 1629** [sqlite3_shutdown()] and should deallocate any resources acquired 1630** by xInit. The pAppData pointer is used as the only parameter to 1631** xInit and xShutdown. 1632** 1633** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1634** the xInit method, so the xInit method need not be threadsafe. The 1635** xShutdown method is only called from [sqlite3_shutdown()] so it does 1636** not need to be threadsafe either. For all other methods, SQLite 1637** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1638** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1639** it is by default) and so the methods are automatically serialized. 1640** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1641** methods must be threadsafe or else make their own arrangements for 1642** serialization. 1643** 1644** SQLite will never invoke xInit() more than once without an intervening 1645** call to xShutdown(). 1646*/ 1647typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1648struct sqlite3_mem_methods { 1649 void *(*xMalloc)(int); /* Memory allocation function */ 1650 void (*xFree)(void*); /* Free a prior allocation */ 1651 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1652 int (*xSize)(void*); /* Return the size of an allocation */ 1653 int (*xRoundup)(int); /* Round up request size to allocation size */ 1654 int (*xInit)(void*); /* Initialize the memory allocator */ 1655 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1656 void *pAppData; /* Argument to xInit() and xShutdown() */ 1657}; 1658 1659/* 1660** CAPI3REF: Configuration Options 1661** KEYWORDS: {configuration option} 1662** 1663** These constants are the available integer configuration options that 1664** can be passed as the first argument to the [sqlite3_config()] interface. 1665** 1666** New configuration options may be added in future releases of SQLite. 1667** Existing configuration options might be discontinued. Applications 1668** should check the return code from [sqlite3_config()] to make sure that 1669** the call worked. The [sqlite3_config()] interface will return a 1670** non-zero [error code] if a discontinued or unsupported configuration option 1671** is invoked. 1672** 1673** <dl> 1674** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1675** <dd>There are no arguments to this option. ^This option sets the 1676** [threading mode] to Single-thread. In other words, it disables 1677** all mutexing and puts SQLite into a mode where it can only be used 1678** by a single thread. ^If SQLite is compiled with 1679** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1680** it is not possible to change the [threading mode] from its default 1681** value of Single-thread and so [sqlite3_config()] will return 1682** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1683** configuration option.</dd> 1684** 1685** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1686** <dd>There are no arguments to this option. ^This option sets the 1687** [threading mode] to Multi-thread. In other words, it disables 1688** mutexing on [database connection] and [prepared statement] objects. 1689** The application is responsible for serializing access to 1690** [database connections] and [prepared statements]. But other mutexes 1691** are enabled so that SQLite will be safe to use in a multi-threaded 1692** environment as long as no two threads attempt to use the same 1693** [database connection] at the same time. ^If SQLite is compiled with 1694** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1695** it is not possible to set the Multi-thread [threading mode] and 1696** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1697** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1698** 1699** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1700** <dd>There are no arguments to this option. ^This option sets the 1701** [threading mode] to Serialized. In other words, this option enables 1702** all mutexes including the recursive 1703** mutexes on [database connection] and [prepared statement] objects. 1704** In this mode (which is the default when SQLite is compiled with 1705** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1706** to [database connections] and [prepared statements] so that the 1707** application is free to use the same [database connection] or the 1708** same [prepared statement] in different threads at the same time. 1709** ^If SQLite is compiled with 1710** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1711** it is not possible to set the Serialized [threading mode] and 1712** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1713** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1714** 1715** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1716** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1717** a pointer to an instance of the [sqlite3_mem_methods] structure. 1718** The argument specifies 1719** alternative low-level memory allocation routines to be used in place of 1720** the memory allocation routines built into SQLite.)^ ^SQLite makes 1721** its own private copy of the content of the [sqlite3_mem_methods] structure 1722** before the [sqlite3_config()] call returns.</dd> 1723** 1724** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1725** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1726** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1727** The [sqlite3_mem_methods] 1728** structure is filled with the currently defined memory allocation routines.)^ 1729** This option can be used to overload the default memory allocation 1730** routines with a wrapper that simulations memory allocation failure or 1731** tracks memory usage, for example. </dd> 1732** 1733** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1734** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1735** type int, interpreted as a boolean, which if true provides a hint to 1736** SQLite that it should avoid large memory allocations if possible. 1737** SQLite will run faster if it is free to make large memory allocations, 1738** but some application might prefer to run slower in exchange for 1739** guarantees about memory fragmentation that are possible if large 1740** allocations are avoided. This hint is normally off. 1741** </dd> 1742** 1743** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1744** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1745** interpreted as a boolean, which enables or disables the collection of 1746** memory allocation statistics. ^(When memory allocation statistics are 1747** disabled, the following SQLite interfaces become non-operational: 1748** <ul> 1749** <li> [sqlite3_hard_heap_limit64()] 1750** <li> [sqlite3_memory_used()] 1751** <li> [sqlite3_memory_highwater()] 1752** <li> [sqlite3_soft_heap_limit64()] 1753** <li> [sqlite3_status64()] 1754** </ul>)^ 1755** ^Memory allocation statistics are enabled by default unless SQLite is 1756** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1757** allocation statistics are disabled by default. 1758** </dd> 1759** 1760** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1761** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1762** </dd> 1763** 1764** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1765** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1766** that SQLite can use for the database page cache with the default page 1767** cache implementation. 1768** This configuration option is a no-op if an application-defined page 1769** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1770** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1771** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1772** and the number of cache lines (N). 1773** The sz argument should be the size of the largest database page 1774** (a power of two between 512 and 65536) plus some extra bytes for each 1775** page header. ^The number of extra bytes needed by the page header 1776** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1777** ^It is harmless, apart from the wasted memory, 1778** for the sz parameter to be larger than necessary. The pMem 1779** argument must be either a NULL pointer or a pointer to an 8-byte 1780** aligned block of memory of at least sz*N bytes, otherwise 1781** subsequent behavior is undefined. 1782** ^When pMem is not NULL, SQLite will strive to use the memory provided 1783** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1784** a page cache line is larger than sz bytes or if all of the pMem buffer 1785** is exhausted. 1786** ^If pMem is NULL and N is non-zero, then each database connection 1787** does an initial bulk allocation for page cache memory 1788** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1789** of -1024*N bytes if N is negative, . ^If additional 1790** page cache memory is needed beyond what is provided by the initial 1791** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1792** additional cache line. </dd> 1793** 1794** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1795** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1796** that SQLite will use for all of its dynamic memory allocation needs 1797** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1798** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1799** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1800** [SQLITE_ERROR] if invoked otherwise. 1801** ^There are three arguments to SQLITE_CONFIG_HEAP: 1802** An 8-byte aligned pointer to the memory, 1803** the number of bytes in the memory buffer, and the minimum allocation size. 1804** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1805** to using its default memory allocator (the system malloc() implementation), 1806** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1807** memory pointer is not NULL then the alternative memory 1808** allocator is engaged to handle all of SQLites memory allocation needs. 1809** The first pointer (the memory pointer) must be aligned to an 8-byte 1810** boundary or subsequent behavior of SQLite will be undefined. 1811** The minimum allocation size is capped at 2**12. Reasonable values 1812** for the minimum allocation size are 2**5 through 2**8.</dd> 1813** 1814** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1815** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1816** pointer to an instance of the [sqlite3_mutex_methods] structure. 1817** The argument specifies alternative low-level mutex routines to be used 1818** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1819** the content of the [sqlite3_mutex_methods] structure before the call to 1820** [sqlite3_config()] returns. ^If SQLite is compiled with 1821** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1822** the entire mutexing subsystem is omitted from the build and hence calls to 1823** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1824** return [SQLITE_ERROR].</dd> 1825** 1826** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1827** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1828** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1829** [sqlite3_mutex_methods] 1830** structure is filled with the currently defined mutex routines.)^ 1831** This option can be used to overload the default mutex allocation 1832** routines with a wrapper used to track mutex usage for performance 1833** profiling or testing, for example. ^If SQLite is compiled with 1834** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1835** the entire mutexing subsystem is omitted from the build and hence calls to 1836** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1837** return [SQLITE_ERROR].</dd> 1838** 1839** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1840** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1841** the default size of lookaside memory on each [database connection]. 1842** The first argument is the 1843** size of each lookaside buffer slot and the second is the number of 1844** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1845** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1846** option to [sqlite3_db_config()] can be used to change the lookaside 1847** configuration on individual connections.)^ </dd> 1848** 1849** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1850** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1851** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1852** the interface to a custom page cache implementation.)^ 1853** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1854** 1855** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1856** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1857** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1858** the current page cache implementation into that object.)^ </dd> 1859** 1860** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1861** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1862** global [error log]. 1863** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1864** function with a call signature of void(*)(void*,int,const char*), 1865** and a pointer to void. ^If the function pointer is not NULL, it is 1866** invoked by [sqlite3_log()] to process each logging event. ^If the 1867** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1868** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1869** passed through as the first parameter to the application-defined logger 1870** function whenever that function is invoked. ^The second parameter to 1871** the logger function is a copy of the first parameter to the corresponding 1872** [sqlite3_log()] call and is intended to be a [result code] or an 1873** [extended result code]. ^The third parameter passed to the logger is 1874** log message after formatting via [sqlite3_snprintf()]. 1875** The SQLite logging interface is not reentrant; the logger function 1876** supplied by the application must not invoke any SQLite interface. 1877** In a multi-threaded application, the application-defined logger 1878** function must be threadsafe. </dd> 1879** 1880** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1881** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1882** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1883** then URI handling is globally disabled.)^ ^If URI handling is globally 1884** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1885** [sqlite3_open16()] or 1886** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1887** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1888** connection is opened. ^If it is globally disabled, filenames are 1889** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1890** database connection is opened. ^(By default, URI handling is globally 1891** disabled. The default value may be changed by compiling with the 1892** [SQLITE_USE_URI] symbol defined.)^ 1893** 1894** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1895** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1896** argument which is interpreted as a boolean in order to enable or disable 1897** the use of covering indices for full table scans in the query optimizer. 1898** ^The default setting is determined 1899** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1900** if that compile-time option is omitted. 1901** The ability to disable the use of covering indices for full table scans 1902** is because some incorrectly coded legacy applications might malfunction 1903** when the optimization is enabled. Providing the ability to 1904** disable the optimization allows the older, buggy application code to work 1905** without change even with newer versions of SQLite. 1906** 1907** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1908** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1909** <dd> These options are obsolete and should not be used by new code. 1910** They are retained for backwards compatibility but are now no-ops. 1911** </dd> 1912** 1913** [[SQLITE_CONFIG_SQLLOG]] 1914** <dt>SQLITE_CONFIG_SQLLOG 1915** <dd>This option is only available if sqlite is compiled with the 1916** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1917** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1918** The second should be of type (void*). The callback is invoked by the library 1919** in three separate circumstances, identified by the value passed as the 1920** fourth parameter. If the fourth parameter is 0, then the database connection 1921** passed as the second argument has just been opened. The third argument 1922** points to a buffer containing the name of the main database file. If the 1923** fourth parameter is 1, then the SQL statement that the third parameter 1924** points to has just been executed. Or, if the fourth parameter is 2, then 1925** the connection being passed as the second parameter is being closed. The 1926** third parameter is passed NULL In this case. An example of using this 1927** configuration option can be seen in the "test_sqllog.c" source file in 1928** the canonical SQLite source tree.</dd> 1929** 1930** [[SQLITE_CONFIG_MMAP_SIZE]] 1931** <dt>SQLITE_CONFIG_MMAP_SIZE 1932** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1933** that are the default mmap size limit (the default setting for 1934** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1935** ^The default setting can be overridden by each database connection using 1936** either the [PRAGMA mmap_size] command, or by using the 1937** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1938** will be silently truncated if necessary so that it does not exceed the 1939** compile-time maximum mmap size set by the 1940** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1941** ^If either argument to this option is negative, then that argument is 1942** changed to its compile-time default. 1943** 1944** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1945** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1946** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1947** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1948** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1949** that specifies the maximum size of the created heap. 1950** 1951** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1952** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1953** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1954** is a pointer to an integer and writes into that integer the number of extra 1955** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1956** The amount of extra space required can change depending on the compiler, 1957** target platform, and SQLite version. 1958** 1959** [[SQLITE_CONFIG_PMASZ]] 1960** <dt>SQLITE_CONFIG_PMASZ 1961** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1962** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1963** sorter to that integer. The default minimum PMA Size is set by the 1964** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1965** to help with sort operations when multithreaded sorting 1966** is enabled (using the [PRAGMA threads] command) and the amount of content 1967** to be sorted exceeds the page size times the minimum of the 1968** [PRAGMA cache_size] setting and this value. 1969** 1970** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1971** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1972** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1973** becomes the [statement journal] spill-to-disk threshold. 1974** [Statement journals] are held in memory until their size (in bytes) 1975** exceeds this threshold, at which point they are written to disk. 1976** Or if the threshold is -1, statement journals are always held 1977** exclusively in memory. 1978** Since many statement journals never become large, setting the spill 1979** threshold to a value such as 64KiB can greatly reduce the amount of 1980** I/O required to support statement rollback. 1981** The default value for this setting is controlled by the 1982** [SQLITE_STMTJRNL_SPILL] compile-time option. 1983** 1984** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1985** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1986** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1987** of type (int) - the new value of the sorter-reference size threshold. 1988** Usually, when SQLite uses an external sort to order records according 1989** to an ORDER BY clause, all fields required by the caller are present in the 1990** sorted records. However, if SQLite determines based on the declared type 1991** of a table column that its values are likely to be very large - larger 1992** than the configured sorter-reference size threshold - then a reference 1993** is stored in each sorted record and the required column values loaded 1994** from the database as records are returned in sorted order. The default 1995** value for this option is to never use this optimization. Specifying a 1996** negative value for this option restores the default behaviour. 1997** This option is only available if SQLite is compiled with the 1998** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1999** 2000** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2001** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2002** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2003** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2004** database created using [sqlite3_deserialize()]. This default maximum 2005** size can be adjusted up or down for individual databases using the 2006** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2007** configuration setting is never used, then the default maximum is determined 2008** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2009** compile-time option is not set, then the default maximum is 1073741824. 2010** </dl> 2011*/ 2012#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2013#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2014#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2015#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2016#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2017#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2018#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2019#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2020#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2021#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2022#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2023/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2024#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2025#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2026#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2027#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2028#define SQLITE_CONFIG_URI 17 /* int */ 2029#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2030#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2031#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2032#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2033#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2034#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2035#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2036#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2037#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2038#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2039#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2040#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2041 2042/* 2043** CAPI3REF: Database Connection Configuration Options 2044** 2045** These constants are the available integer configuration options that 2046** can be passed as the second argument to the [sqlite3_db_config()] interface. 2047** 2048** New configuration options may be added in future releases of SQLite. 2049** Existing configuration options might be discontinued. Applications 2050** should check the return code from [sqlite3_db_config()] to make sure that 2051** the call worked. ^The [sqlite3_db_config()] interface will return a 2052** non-zero [error code] if a discontinued or unsupported configuration option 2053** is invoked. 2054** 2055** <dl> 2056** [[SQLITE_DBCONFIG_LOOKASIDE]] 2057** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2058** <dd> ^This option takes three additional arguments that determine the 2059** [lookaside memory allocator] configuration for the [database connection]. 2060** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2061** pointer to a memory buffer to use for lookaside memory. 2062** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2063** may be NULL in which case SQLite will allocate the 2064** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2065** size of each lookaside buffer slot. ^The third argument is the number of 2066** slots. The size of the buffer in the first argument must be greater than 2067** or equal to the product of the second and third arguments. The buffer 2068** must be aligned to an 8-byte boundary. ^If the second argument to 2069** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2070** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2071** configuration for a database connection can only be changed when that 2072** connection is not currently using lookaside memory, or in other words 2073** when the "current value" returned by 2074** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2075** Any attempt to change the lookaside memory configuration when lookaside 2076** memory is in use leaves the configuration unchanged and returns 2077** [SQLITE_BUSY].)^</dd> 2078** 2079** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2080** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2081** <dd> ^This option is used to enable or disable the enforcement of 2082** [foreign key constraints]. There should be two additional arguments. 2083** The first argument is an integer which is 0 to disable FK enforcement, 2084** positive to enable FK enforcement or negative to leave FK enforcement 2085** unchanged. The second parameter is a pointer to an integer into which 2086** is written 0 or 1 to indicate whether FK enforcement is off or on 2087** following this call. The second parameter may be a NULL pointer, in 2088** which case the FK enforcement setting is not reported back. </dd> 2089** 2090** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2091** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2092** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2093** There should be two additional arguments. 2094** The first argument is an integer which is 0 to disable triggers, 2095** positive to enable triggers or negative to leave the setting unchanged. 2096** The second parameter is a pointer to an integer into which 2097** is written 0 or 1 to indicate whether triggers are disabled or enabled 2098** following this call. The second parameter may be a NULL pointer, in 2099** which case the trigger setting is not reported back. </dd> 2100** 2101** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2102** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2103** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2104** There should be two additional arguments. 2105** The first argument is an integer which is 0 to disable views, 2106** positive to enable views or negative to leave the setting unchanged. 2107** The second parameter is a pointer to an integer into which 2108** is written 0 or 1 to indicate whether views are disabled or enabled 2109** following this call. The second parameter may be a NULL pointer, in 2110** which case the view setting is not reported back. </dd> 2111** 2112** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2113** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2114** <dd> ^This option is used to enable or disable the 2115** [fts3_tokenizer()] function which is part of the 2116** [FTS3] full-text search engine extension. 2117** There should be two additional arguments. 2118** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2119** positive to enable fts3_tokenizer() or negative to leave the setting 2120** unchanged. 2121** The second parameter is a pointer to an integer into which 2122** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2123** following this call. The second parameter may be a NULL pointer, in 2124** which case the new setting is not reported back. </dd> 2125** 2126** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2127** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2128** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2129** interface independently of the [load_extension()] SQL function. 2130** The [sqlite3_enable_load_extension()] API enables or disables both the 2131** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2132** There should be two additional arguments. 2133** When the first argument to this interface is 1, then only the C-API is 2134** enabled and the SQL function remains disabled. If the first argument to 2135** this interface is 0, then both the C-API and the SQL function are disabled. 2136** If the first argument is -1, then no changes are made to state of either the 2137** C-API or the SQL function. 2138** The second parameter is a pointer to an integer into which 2139** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2140** is disabled or enabled following this call. The second parameter may 2141** be a NULL pointer, in which case the new setting is not reported back. 2142** </dd> 2143** 2144** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2145** <dd> ^This option is used to change the name of the "main" database 2146** schema. ^The sole argument is a pointer to a constant UTF8 string 2147** which will become the new schema name in place of "main". ^SQLite 2148** does not make a copy of the new main schema name string, so the application 2149** must ensure that the argument passed into this DBCONFIG option is unchanged 2150** until after the database connection closes. 2151** </dd> 2152** 2153** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2154** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2155** <dd> Usually, when a database in wal mode is closed or detached from a 2156** database handle, SQLite checks if this will mean that there are now no 2157** connections at all to the database. If so, it performs a checkpoint 2158** operation before closing the connection. This option may be used to 2159** override this behaviour. The first parameter passed to this operation 2160** is an integer - positive to disable checkpoints-on-close, or zero (the 2161** default) to enable them, and negative to leave the setting unchanged. 2162** The second parameter is a pointer to an integer 2163** into which is written 0 or 1 to indicate whether checkpoints-on-close 2164** have been disabled - 0 if they are not disabled, 1 if they are. 2165** </dd> 2166** 2167** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2168** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2169** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2170** a single SQL query statement will always use the same algorithm regardless 2171** of values of [bound parameters].)^ The QPSG disables some query optimizations 2172** that look at the values of bound parameters, which can make some queries 2173** slower. But the QPSG has the advantage of more predictable behavior. With 2174** the QPSG active, SQLite will always use the same query plan in the field as 2175** was used during testing in the lab. 2176** The first argument to this setting is an integer which is 0 to disable 2177** the QPSG, positive to enable QPSG, or negative to leave the setting 2178** unchanged. The second parameter is a pointer to an integer into which 2179** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2180** following this call. 2181** </dd> 2182** 2183** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2184** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2185** include output for any operations performed by trigger programs. This 2186** option is used to set or clear (the default) a flag that governs this 2187** behavior. The first parameter passed to this operation is an integer - 2188** positive to enable output for trigger programs, or zero to disable it, 2189** or negative to leave the setting unchanged. 2190** The second parameter is a pointer to an integer into which is written 2191** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2192** it is not disabled, 1 if it is. 2193** </dd> 2194** 2195** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2196** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2197** [VACUUM] in order to reset a database back to an empty database 2198** with no schema and no content. The following process works even for 2199** a badly corrupted database file: 2200** <ol> 2201** <li> If the database connection is newly opened, make sure it has read the 2202** database schema by preparing then discarding some query against the 2203** database, or calling sqlite3_table_column_metadata(), ignoring any 2204** errors. This step is only necessary if the application desires to keep 2205** the database in WAL mode after the reset if it was in WAL mode before 2206** the reset. 2207** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2208** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2209** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2210** </ol> 2211** Because resetting a database is destructive and irreversible, the 2212** process requires the use of this obscure API and multiple steps to help 2213** ensure that it does not happen by accident. 2214** 2215** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2216** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2217** "defensive" flag for a database connection. When the defensive 2218** flag is enabled, language features that allow ordinary SQL to 2219** deliberately corrupt the database file are disabled. The disabled 2220** features include but are not limited to the following: 2221** <ul> 2222** <li> The [PRAGMA writable_schema=ON] statement. 2223** <li> The [PRAGMA journal_mode=OFF] statement. 2224** <li> Writes to the [sqlite_dbpage] virtual table. 2225** <li> Direct writes to [shadow tables]. 2226** </ul> 2227** </dd> 2228** 2229** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2230** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2231** "writable_schema" flag. This has the same effect and is logically equivalent 2232** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2233** The first argument to this setting is an integer which is 0 to disable 2234** the writable_schema, positive to enable writable_schema, or negative to 2235** leave the setting unchanged. The second parameter is a pointer to an 2236** integer into which is written 0 or 1 to indicate whether the writable_schema 2237** is enabled or disabled following this call. 2238** </dd> 2239** 2240** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2241** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2242** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2243** the legacy behavior of the [ALTER TABLE RENAME] command such it 2244** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2245** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2246** additional information. This feature can also be turned on and off 2247** using the [PRAGMA legacy_alter_table] statement. 2248** </dd> 2249** 2250** [[SQLITE_DBCONFIG_DQS_DML]] 2251** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2252** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2253** the legacy [double-quoted string literal] misfeature for DML statements 2254** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2255** default value of this setting is determined by the [-DSQLITE_DQS] 2256** compile-time option. 2257** </dd> 2258** 2259** [[SQLITE_DBCONFIG_DQS_DDL]] 2260** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2261** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2262** the legacy [double-quoted string literal] misfeature for DDL statements, 2263** such as CREATE TABLE and CREATE INDEX. The 2264** default value of this setting is determined by the [-DSQLITE_DQS] 2265** compile-time option. 2266** </dd> 2267** 2268** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]] 2269** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td> 2270** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells the SQLite to 2271** assume that database schemas are untainted by malicious content. 2272** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite 2273** takes additional defensive steps to protect the application from harm 2274** including, but not limited to, the following: 2275** <ul> 2276** <li> Prohibit the use of SQL functions inside triggers, views, 2277** CHECK constraints, DEFAULT clauses, expression indexes, 2278** partial indexes, or generated columns 2279** unless those functions are tagged with [SQLITE_INNOCUOUS]. 2280** <li> Pohibit the use of virtual tables inside of triggers or views 2281** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS]. 2282** </ul> 2283** This setting defaults to "on" for legacy compatibility, however 2284** all applications are advised to turn it off if possible. 2285** </dd> 2286** 2287** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2288** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2289** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2290** the legacy file format flag. When activated, this flag causes all newly 2291** created database file to have a schema format version number (the 4-byte 2292** integer found at offset 44 into the database header) of 1. This in turn 2293** means that the resulting database file will be readable and writable by 2294** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2295** newly created databases are generally not understandable by SQLite versions 2296** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2297** is now scarcely any need to generated database files that are compatible 2298** all the way back to version 3.0.0, and so this setting is of little 2299** practical use, but is provided so that SQLite can continue to claim the 2300** ability to generate new database files that are compatible with version 2301** 3.0.0. 2302** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2303** the [VACUUM] command will fail with an obscure error when attempting to 2304** process a table with generated columns and a descending index. This is 2305** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2306** either generated columns or decending indexes. 2307** </dd> 2308** </dl> 2309*/ 2310#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2311#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2312#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2313#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2314#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2315#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2316#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2317#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2318#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2319#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2320#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2321#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2322#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2323#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2324#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2325#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2326#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2327#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */ 2328#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */ 2329 2330/* 2331** CAPI3REF: Enable Or Disable Extended Result Codes 2332** METHOD: sqlite3 2333** 2334** ^The sqlite3_extended_result_codes() routine enables or disables the 2335** [extended result codes] feature of SQLite. ^The extended result 2336** codes are disabled by default for historical compatibility. 2337*/ 2338int sqlite3_extended_result_codes(sqlite3*, int onoff); 2339 2340/* 2341** CAPI3REF: Last Insert Rowid 2342** METHOD: sqlite3 2343** 2344** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2345** has a unique 64-bit signed 2346** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2347** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2348** names are not also used by explicitly declared columns. ^If 2349** the table has a column of type [INTEGER PRIMARY KEY] then that column 2350** is another alias for the rowid. 2351** 2352** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2353** the most recent successful [INSERT] into a rowid table or [virtual table] 2354** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2355** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2356** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2357** zero. 2358** 2359** As well as being set automatically as rows are inserted into database 2360** tables, the value returned by this function may be set explicitly by 2361** [sqlite3_set_last_insert_rowid()] 2362** 2363** Some virtual table implementations may INSERT rows into rowid tables as 2364** part of committing a transaction (e.g. to flush data accumulated in memory 2365** to disk). In this case subsequent calls to this function return the rowid 2366** associated with these internal INSERT operations, which leads to 2367** unintuitive results. Virtual table implementations that do write to rowid 2368** tables in this way can avoid this problem by restoring the original 2369** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2370** control to the user. 2371** 2372** ^(If an [INSERT] occurs within a trigger then this routine will 2373** return the [rowid] of the inserted row as long as the trigger is 2374** running. Once the trigger program ends, the value returned 2375** by this routine reverts to what it was before the trigger was fired.)^ 2376** 2377** ^An [INSERT] that fails due to a constraint violation is not a 2378** successful [INSERT] and does not change the value returned by this 2379** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2380** and INSERT OR ABORT make no changes to the return value of this 2381** routine when their insertion fails. ^(When INSERT OR REPLACE 2382** encounters a constraint violation, it does not fail. The 2383** INSERT continues to completion after deleting rows that caused 2384** the constraint problem so INSERT OR REPLACE will always change 2385** the return value of this interface.)^ 2386** 2387** ^For the purposes of this routine, an [INSERT] is considered to 2388** be successful even if it is subsequently rolled back. 2389** 2390** This function is accessible to SQL statements via the 2391** [last_insert_rowid() SQL function]. 2392** 2393** If a separate thread performs a new [INSERT] on the same 2394** database connection while the [sqlite3_last_insert_rowid()] 2395** function is running and thus changes the last insert [rowid], 2396** then the value returned by [sqlite3_last_insert_rowid()] is 2397** unpredictable and might not equal either the old or the new 2398** last insert [rowid]. 2399*/ 2400sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2401 2402/* 2403** CAPI3REF: Set the Last Insert Rowid value. 2404** METHOD: sqlite3 2405** 2406** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2407** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2408** without inserting a row into the database. 2409*/ 2410void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2411 2412/* 2413** CAPI3REF: Count The Number Of Rows Modified 2414** METHOD: sqlite3 2415** 2416** ^This function returns the number of rows modified, inserted or 2417** deleted by the most recently completed INSERT, UPDATE or DELETE 2418** statement on the database connection specified by the only parameter. 2419** ^Executing any other type of SQL statement does not modify the value 2420** returned by this function. 2421** 2422** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2423** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2424** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2425** 2426** Changes to a view that are intercepted by 2427** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2428** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2429** DELETE statement run on a view is always zero. Only changes made to real 2430** tables are counted. 2431** 2432** Things are more complicated if the sqlite3_changes() function is 2433** executed while a trigger program is running. This may happen if the 2434** program uses the [changes() SQL function], or if some other callback 2435** function invokes sqlite3_changes() directly. Essentially: 2436** 2437** <ul> 2438** <li> ^(Before entering a trigger program the value returned by 2439** sqlite3_changes() function is saved. After the trigger program 2440** has finished, the original value is restored.)^ 2441** 2442** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2443** statement sets the value returned by sqlite3_changes() 2444** upon completion as normal. Of course, this value will not include 2445** any changes performed by sub-triggers, as the sqlite3_changes() 2446** value will be saved and restored after each sub-trigger has run.)^ 2447** </ul> 2448** 2449** ^This means that if the changes() SQL function (or similar) is used 2450** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2451** returns the value as set when the calling statement began executing. 2452** ^If it is used by the second or subsequent such statement within a trigger 2453** program, the value returned reflects the number of rows modified by the 2454** previous INSERT, UPDATE or DELETE statement within the same trigger. 2455** 2456** If a separate thread makes changes on the same database connection 2457** while [sqlite3_changes()] is running then the value returned 2458** is unpredictable and not meaningful. 2459** 2460** See also: 2461** <ul> 2462** <li> the [sqlite3_total_changes()] interface 2463** <li> the [count_changes pragma] 2464** <li> the [changes() SQL function] 2465** <li> the [data_version pragma] 2466** </ul> 2467*/ 2468int sqlite3_changes(sqlite3*); 2469 2470/* 2471** CAPI3REF: Total Number Of Rows Modified 2472** METHOD: sqlite3 2473** 2474** ^This function returns the total number of rows inserted, modified or 2475** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2476** since the database connection was opened, including those executed as 2477** part of trigger programs. ^Executing any other type of SQL statement 2478** does not affect the value returned by sqlite3_total_changes(). 2479** 2480** ^Changes made as part of [foreign key actions] are included in the 2481** count, but those made as part of REPLACE constraint resolution are 2482** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2483** are not counted. 2484** 2485** The [sqlite3_total_changes(D)] interface only reports the number 2486** of rows that changed due to SQL statement run against database 2487** connection D. Any changes by other database connections are ignored. 2488** To detect changes against a database file from other database 2489** connections use the [PRAGMA data_version] command or the 2490** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2491** 2492** If a separate thread makes changes on the same database connection 2493** while [sqlite3_total_changes()] is running then the value 2494** returned is unpredictable and not meaningful. 2495** 2496** See also: 2497** <ul> 2498** <li> the [sqlite3_changes()] interface 2499** <li> the [count_changes pragma] 2500** <li> the [changes() SQL function] 2501** <li> the [data_version pragma] 2502** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2503** </ul> 2504*/ 2505int sqlite3_total_changes(sqlite3*); 2506 2507/* 2508** CAPI3REF: Interrupt A Long-Running Query 2509** METHOD: sqlite3 2510** 2511** ^This function causes any pending database operation to abort and 2512** return at its earliest opportunity. This routine is typically 2513** called in response to a user action such as pressing "Cancel" 2514** or Ctrl-C where the user wants a long query operation to halt 2515** immediately. 2516** 2517** ^It is safe to call this routine from a thread different from the 2518** thread that is currently running the database operation. But it 2519** is not safe to call this routine with a [database connection] that 2520** is closed or might close before sqlite3_interrupt() returns. 2521** 2522** ^If an SQL operation is very nearly finished at the time when 2523** sqlite3_interrupt() is called, then it might not have an opportunity 2524** to be interrupted and might continue to completion. 2525** 2526** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2527** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2528** that is inside an explicit transaction, then the entire transaction 2529** will be rolled back automatically. 2530** 2531** ^The sqlite3_interrupt(D) call is in effect until all currently running 2532** SQL statements on [database connection] D complete. ^Any new SQL statements 2533** that are started after the sqlite3_interrupt() call and before the 2534** running statement count reaches zero are interrupted as if they had been 2535** running prior to the sqlite3_interrupt() call. ^New SQL statements 2536** that are started after the running statement count reaches zero are 2537** not effected by the sqlite3_interrupt(). 2538** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2539** SQL statements is a no-op and has no effect on SQL statements 2540** that are started after the sqlite3_interrupt() call returns. 2541*/ 2542void sqlite3_interrupt(sqlite3*); 2543 2544/* 2545** CAPI3REF: Determine If An SQL Statement Is Complete 2546** 2547** These routines are useful during command-line input to determine if the 2548** currently entered text seems to form a complete SQL statement or 2549** if additional input is needed before sending the text into 2550** SQLite for parsing. ^These routines return 1 if the input string 2551** appears to be a complete SQL statement. ^A statement is judged to be 2552** complete if it ends with a semicolon token and is not a prefix of a 2553** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2554** string literals or quoted identifier names or comments are not 2555** independent tokens (they are part of the token in which they are 2556** embedded) and thus do not count as a statement terminator. ^Whitespace 2557** and comments that follow the final semicolon are ignored. 2558** 2559** ^These routines return 0 if the statement is incomplete. ^If a 2560** memory allocation fails, then SQLITE_NOMEM is returned. 2561** 2562** ^These routines do not parse the SQL statements thus 2563** will not detect syntactically incorrect SQL. 2564** 2565** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2566** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2567** automatically by sqlite3_complete16(). If that initialization fails, 2568** then the return value from sqlite3_complete16() will be non-zero 2569** regardless of whether or not the input SQL is complete.)^ 2570** 2571** The input to [sqlite3_complete()] must be a zero-terminated 2572** UTF-8 string. 2573** 2574** The input to [sqlite3_complete16()] must be a zero-terminated 2575** UTF-16 string in native byte order. 2576*/ 2577int sqlite3_complete(const char *sql); 2578int sqlite3_complete16(const void *sql); 2579 2580/* 2581** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2582** KEYWORDS: {busy-handler callback} {busy handler} 2583** METHOD: sqlite3 2584** 2585** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2586** that might be invoked with argument P whenever 2587** an attempt is made to access a database table associated with 2588** [database connection] D when another thread 2589** or process has the table locked. 2590** The sqlite3_busy_handler() interface is used to implement 2591** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2592** 2593** ^If the busy callback is NULL, then [SQLITE_BUSY] 2594** is returned immediately upon encountering the lock. ^If the busy callback 2595** is not NULL, then the callback might be invoked with two arguments. 2596** 2597** ^The first argument to the busy handler is a copy of the void* pointer which 2598** is the third argument to sqlite3_busy_handler(). ^The second argument to 2599** the busy handler callback is the number of times that the busy handler has 2600** been invoked previously for the same locking event. ^If the 2601** busy callback returns 0, then no additional attempts are made to 2602** access the database and [SQLITE_BUSY] is returned 2603** to the application. 2604** ^If the callback returns non-zero, then another attempt 2605** is made to access the database and the cycle repeats. 2606** 2607** The presence of a busy handler does not guarantee that it will be invoked 2608** when there is lock contention. ^If SQLite determines that invoking the busy 2609** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2610** to the application instead of invoking the 2611** busy handler. 2612** Consider a scenario where one process is holding a read lock that 2613** it is trying to promote to a reserved lock and 2614** a second process is holding a reserved lock that it is trying 2615** to promote to an exclusive lock. The first process cannot proceed 2616** because it is blocked by the second and the second process cannot 2617** proceed because it is blocked by the first. If both processes 2618** invoke the busy handlers, neither will make any progress. Therefore, 2619** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2620** will induce the first process to release its read lock and allow 2621** the second process to proceed. 2622** 2623** ^The default busy callback is NULL. 2624** 2625** ^(There can only be a single busy handler defined for each 2626** [database connection]. Setting a new busy handler clears any 2627** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2628** or evaluating [PRAGMA busy_timeout=N] will change the 2629** busy handler and thus clear any previously set busy handler. 2630** 2631** The busy callback should not take any actions which modify the 2632** database connection that invoked the busy handler. In other words, 2633** the busy handler is not reentrant. Any such actions 2634** result in undefined behavior. 2635** 2636** A busy handler must not close the database connection 2637** or [prepared statement] that invoked the busy handler. 2638*/ 2639int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2640 2641/* 2642** CAPI3REF: Set A Busy Timeout 2643** METHOD: sqlite3 2644** 2645** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2646** for a specified amount of time when a table is locked. ^The handler 2647** will sleep multiple times until at least "ms" milliseconds of sleeping 2648** have accumulated. ^After at least "ms" milliseconds of sleeping, 2649** the handler returns 0 which causes [sqlite3_step()] to return 2650** [SQLITE_BUSY]. 2651** 2652** ^Calling this routine with an argument less than or equal to zero 2653** turns off all busy handlers. 2654** 2655** ^(There can only be a single busy handler for a particular 2656** [database connection] at any given moment. If another busy handler 2657** was defined (using [sqlite3_busy_handler()]) prior to calling 2658** this routine, that other busy handler is cleared.)^ 2659** 2660** See also: [PRAGMA busy_timeout] 2661*/ 2662int sqlite3_busy_timeout(sqlite3*, int ms); 2663 2664/* 2665** CAPI3REF: Convenience Routines For Running Queries 2666** METHOD: sqlite3 2667** 2668** This is a legacy interface that is preserved for backwards compatibility. 2669** Use of this interface is not recommended. 2670** 2671** Definition: A <b>result table</b> is memory data structure created by the 2672** [sqlite3_get_table()] interface. A result table records the 2673** complete query results from one or more queries. 2674** 2675** The table conceptually has a number of rows and columns. But 2676** these numbers are not part of the result table itself. These 2677** numbers are obtained separately. Let N be the number of rows 2678** and M be the number of columns. 2679** 2680** A result table is an array of pointers to zero-terminated UTF-8 strings. 2681** There are (N+1)*M elements in the array. The first M pointers point 2682** to zero-terminated strings that contain the names of the columns. 2683** The remaining entries all point to query results. NULL values result 2684** in NULL pointers. All other values are in their UTF-8 zero-terminated 2685** string representation as returned by [sqlite3_column_text()]. 2686** 2687** A result table might consist of one or more memory allocations. 2688** It is not safe to pass a result table directly to [sqlite3_free()]. 2689** A result table should be deallocated using [sqlite3_free_table()]. 2690** 2691** ^(As an example of the result table format, suppose a query result 2692** is as follows: 2693** 2694** <blockquote><pre> 2695** Name | Age 2696** ----------------------- 2697** Alice | 43 2698** Bob | 28 2699** Cindy | 21 2700** </pre></blockquote> 2701** 2702** There are two columns (M==2) and three rows (N==3). Thus the 2703** result table has 8 entries. Suppose the result table is stored 2704** in an array named azResult. Then azResult holds this content: 2705** 2706** <blockquote><pre> 2707** azResult[0] = "Name"; 2708** azResult[1] = "Age"; 2709** azResult[2] = "Alice"; 2710** azResult[3] = "43"; 2711** azResult[4] = "Bob"; 2712** azResult[5] = "28"; 2713** azResult[6] = "Cindy"; 2714** azResult[7] = "21"; 2715** </pre></blockquote>)^ 2716** 2717** ^The sqlite3_get_table() function evaluates one or more 2718** semicolon-separated SQL statements in the zero-terminated UTF-8 2719** string of its 2nd parameter and returns a result table to the 2720** pointer given in its 3rd parameter. 2721** 2722** After the application has finished with the result from sqlite3_get_table(), 2723** it must pass the result table pointer to sqlite3_free_table() in order to 2724** release the memory that was malloced. Because of the way the 2725** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2726** function must not try to call [sqlite3_free()] directly. Only 2727** [sqlite3_free_table()] is able to release the memory properly and safely. 2728** 2729** The sqlite3_get_table() interface is implemented as a wrapper around 2730** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2731** to any internal data structures of SQLite. It uses only the public 2732** interface defined here. As a consequence, errors that occur in the 2733** wrapper layer outside of the internal [sqlite3_exec()] call are not 2734** reflected in subsequent calls to [sqlite3_errcode()] or 2735** [sqlite3_errmsg()]. 2736*/ 2737int sqlite3_get_table( 2738 sqlite3 *db, /* An open database */ 2739 const char *zSql, /* SQL to be evaluated */ 2740 char ***pazResult, /* Results of the query */ 2741 int *pnRow, /* Number of result rows written here */ 2742 int *pnColumn, /* Number of result columns written here */ 2743 char **pzErrmsg /* Error msg written here */ 2744); 2745void sqlite3_free_table(char **result); 2746 2747/* 2748** CAPI3REF: Formatted String Printing Functions 2749** 2750** These routines are work-alikes of the "printf()" family of functions 2751** from the standard C library. 2752** These routines understand most of the common formatting options from 2753** the standard library printf() 2754** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2755** See the [built-in printf()] documentation for details. 2756** 2757** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2758** results into memory obtained from [sqlite3_malloc64()]. 2759** The strings returned by these two routines should be 2760** released by [sqlite3_free()]. ^Both routines return a 2761** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2762** memory to hold the resulting string. 2763** 2764** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2765** the standard C library. The result is written into the 2766** buffer supplied as the second parameter whose size is given by 2767** the first parameter. Note that the order of the 2768** first two parameters is reversed from snprintf().)^ This is an 2769** historical accident that cannot be fixed without breaking 2770** backwards compatibility. ^(Note also that sqlite3_snprintf() 2771** returns a pointer to its buffer instead of the number of 2772** characters actually written into the buffer.)^ We admit that 2773** the number of characters written would be a more useful return 2774** value but we cannot change the implementation of sqlite3_snprintf() 2775** now without breaking compatibility. 2776** 2777** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2778** guarantees that the buffer is always zero-terminated. ^The first 2779** parameter "n" is the total size of the buffer, including space for 2780** the zero terminator. So the longest string that can be completely 2781** written will be n-1 characters. 2782** 2783** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2784** 2785** See also: [built-in printf()], [printf() SQL function] 2786*/ 2787char *sqlite3_mprintf(const char*,...); 2788char *sqlite3_vmprintf(const char*, va_list); 2789char *sqlite3_snprintf(int,char*,const char*, ...); 2790char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2791 2792/* 2793** CAPI3REF: Memory Allocation Subsystem 2794** 2795** The SQLite core uses these three routines for all of its own 2796** internal memory allocation needs. "Core" in the previous sentence 2797** does not include operating-system specific [VFS] implementation. The 2798** Windows VFS uses native malloc() and free() for some operations. 2799** 2800** ^The sqlite3_malloc() routine returns a pointer to a block 2801** of memory at least N bytes in length, where N is the parameter. 2802** ^If sqlite3_malloc() is unable to obtain sufficient free 2803** memory, it returns a NULL pointer. ^If the parameter N to 2804** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2805** a NULL pointer. 2806** 2807** ^The sqlite3_malloc64(N) routine works just like 2808** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2809** of a signed 32-bit integer. 2810** 2811** ^Calling sqlite3_free() with a pointer previously returned 2812** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2813** that it might be reused. ^The sqlite3_free() routine is 2814** a no-op if is called with a NULL pointer. Passing a NULL pointer 2815** to sqlite3_free() is harmless. After being freed, memory 2816** should neither be read nor written. Even reading previously freed 2817** memory might result in a segmentation fault or other severe error. 2818** Memory corruption, a segmentation fault, or other severe error 2819** might result if sqlite3_free() is called with a non-NULL pointer that 2820** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2821** 2822** ^The sqlite3_realloc(X,N) interface attempts to resize a 2823** prior memory allocation X to be at least N bytes. 2824** ^If the X parameter to sqlite3_realloc(X,N) 2825** is a NULL pointer then its behavior is identical to calling 2826** sqlite3_malloc(N). 2827** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2828** negative then the behavior is exactly the same as calling 2829** sqlite3_free(X). 2830** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2831** of at least N bytes in size or NULL if insufficient memory is available. 2832** ^If M is the size of the prior allocation, then min(N,M) bytes 2833** of the prior allocation are copied into the beginning of buffer returned 2834** by sqlite3_realloc(X,N) and the prior allocation is freed. 2835** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2836** prior allocation is not freed. 2837** 2838** ^The sqlite3_realloc64(X,N) interfaces works the same as 2839** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2840** of a 32-bit signed integer. 2841** 2842** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2843** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2844** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2845** ^The value returned by sqlite3_msize(X) might be larger than the number 2846** of bytes requested when X was allocated. ^If X is a NULL pointer then 2847** sqlite3_msize(X) returns zero. If X points to something that is not 2848** the beginning of memory allocation, or if it points to a formerly 2849** valid memory allocation that has now been freed, then the behavior 2850** of sqlite3_msize(X) is undefined and possibly harmful. 2851** 2852** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2853** sqlite3_malloc64(), and sqlite3_realloc64() 2854** is always aligned to at least an 8 byte boundary, or to a 2855** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2856** option is used. 2857** 2858** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2859** must be either NULL or else pointers obtained from a prior 2860** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2861** not yet been released. 2862** 2863** The application must not read or write any part of 2864** a block of memory after it has been released using 2865** [sqlite3_free()] or [sqlite3_realloc()]. 2866*/ 2867void *sqlite3_malloc(int); 2868void *sqlite3_malloc64(sqlite3_uint64); 2869void *sqlite3_realloc(void*, int); 2870void *sqlite3_realloc64(void*, sqlite3_uint64); 2871void sqlite3_free(void*); 2872sqlite3_uint64 sqlite3_msize(void*); 2873 2874/* 2875** CAPI3REF: Memory Allocator Statistics 2876** 2877** SQLite provides these two interfaces for reporting on the status 2878** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2879** routines, which form the built-in memory allocation subsystem. 2880** 2881** ^The [sqlite3_memory_used()] routine returns the number of bytes 2882** of memory currently outstanding (malloced but not freed). 2883** ^The [sqlite3_memory_highwater()] routine returns the maximum 2884** value of [sqlite3_memory_used()] since the high-water mark 2885** was last reset. ^The values returned by [sqlite3_memory_used()] and 2886** [sqlite3_memory_highwater()] include any overhead 2887** added by SQLite in its implementation of [sqlite3_malloc()], 2888** but not overhead added by the any underlying system library 2889** routines that [sqlite3_malloc()] may call. 2890** 2891** ^The memory high-water mark is reset to the current value of 2892** [sqlite3_memory_used()] if and only if the parameter to 2893** [sqlite3_memory_highwater()] is true. ^The value returned 2894** by [sqlite3_memory_highwater(1)] is the high-water mark 2895** prior to the reset. 2896*/ 2897sqlite3_int64 sqlite3_memory_used(void); 2898sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2899 2900/* 2901** CAPI3REF: Pseudo-Random Number Generator 2902** 2903** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2904** select random [ROWID | ROWIDs] when inserting new records into a table that 2905** already uses the largest possible [ROWID]. The PRNG is also used for 2906** the built-in random() and randomblob() SQL functions. This interface allows 2907** applications to access the same PRNG for other purposes. 2908** 2909** ^A call to this routine stores N bytes of randomness into buffer P. 2910** ^The P parameter can be a NULL pointer. 2911** 2912** ^If this routine has not been previously called or if the previous 2913** call had N less than one or a NULL pointer for P, then the PRNG is 2914** seeded using randomness obtained from the xRandomness method of 2915** the default [sqlite3_vfs] object. 2916** ^If the previous call to this routine had an N of 1 or more and a 2917** non-NULL P then the pseudo-randomness is generated 2918** internally and without recourse to the [sqlite3_vfs] xRandomness 2919** method. 2920*/ 2921void sqlite3_randomness(int N, void *P); 2922 2923/* 2924** CAPI3REF: Compile-Time Authorization Callbacks 2925** METHOD: sqlite3 2926** KEYWORDS: {authorizer callback} 2927** 2928** ^This routine registers an authorizer callback with a particular 2929** [database connection], supplied in the first argument. 2930** ^The authorizer callback is invoked as SQL statements are being compiled 2931** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2932** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2933** and [sqlite3_prepare16_v3()]. ^At various 2934** points during the compilation process, as logic is being created 2935** to perform various actions, the authorizer callback is invoked to 2936** see if those actions are allowed. ^The authorizer callback should 2937** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2938** specific action but allow the SQL statement to continue to be 2939** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2940** rejected with an error. ^If the authorizer callback returns 2941** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2942** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2943** the authorizer will fail with an error message. 2944** 2945** When the callback returns [SQLITE_OK], that means the operation 2946** requested is ok. ^When the callback returns [SQLITE_DENY], the 2947** [sqlite3_prepare_v2()] or equivalent call that triggered the 2948** authorizer will fail with an error message explaining that 2949** access is denied. 2950** 2951** ^The first parameter to the authorizer callback is a copy of the third 2952** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2953** to the callback is an integer [SQLITE_COPY | action code] that specifies 2954** the particular action to be authorized. ^The third through sixth parameters 2955** to the callback are either NULL pointers or zero-terminated strings 2956** that contain additional details about the action to be authorized. 2957** Applications must always be prepared to encounter a NULL pointer in any 2958** of the third through the sixth parameters of the authorization callback. 2959** 2960** ^If the action code is [SQLITE_READ] 2961** and the callback returns [SQLITE_IGNORE] then the 2962** [prepared statement] statement is constructed to substitute 2963** a NULL value in place of the table column that would have 2964** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2965** return can be used to deny an untrusted user access to individual 2966** columns of a table. 2967** ^When a table is referenced by a [SELECT] but no column values are 2968** extracted from that table (for example in a query like 2969** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2970** is invoked once for that table with a column name that is an empty string. 2971** ^If the action code is [SQLITE_DELETE] and the callback returns 2972** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2973** [truncate optimization] is disabled and all rows are deleted individually. 2974** 2975** An authorizer is used when [sqlite3_prepare | preparing] 2976** SQL statements from an untrusted source, to ensure that the SQL statements 2977** do not try to access data they are not allowed to see, or that they do not 2978** try to execute malicious statements that damage the database. For 2979** example, an application may allow a user to enter arbitrary 2980** SQL queries for evaluation by a database. But the application does 2981** not want the user to be able to make arbitrary changes to the 2982** database. An authorizer could then be put in place while the 2983** user-entered SQL is being [sqlite3_prepare | prepared] that 2984** disallows everything except [SELECT] statements. 2985** 2986** Applications that need to process SQL from untrusted sources 2987** might also consider lowering resource limits using [sqlite3_limit()] 2988** and limiting database size using the [max_page_count] [PRAGMA] 2989** in addition to using an authorizer. 2990** 2991** ^(Only a single authorizer can be in place on a database connection 2992** at a time. Each call to sqlite3_set_authorizer overrides the 2993** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2994** The authorizer is disabled by default. 2995** 2996** The authorizer callback must not do anything that will modify 2997** the database connection that invoked the authorizer callback. 2998** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2999** database connections for the meaning of "modify" in this paragraph. 3000** 3001** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 3002** statement might be re-prepared during [sqlite3_step()] due to a 3003** schema change. Hence, the application should ensure that the 3004** correct authorizer callback remains in place during the [sqlite3_step()]. 3005** 3006** ^Note that the authorizer callback is invoked only during 3007** [sqlite3_prepare()] or its variants. Authorization is not 3008** performed during statement evaluation in [sqlite3_step()], unless 3009** as stated in the previous paragraph, sqlite3_step() invokes 3010** sqlite3_prepare_v2() to reprepare a statement after a schema change. 3011*/ 3012int sqlite3_set_authorizer( 3013 sqlite3*, 3014 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 3015 void *pUserData 3016); 3017 3018/* 3019** CAPI3REF: Authorizer Return Codes 3020** 3021** The [sqlite3_set_authorizer | authorizer callback function] must 3022** return either [SQLITE_OK] or one of these two constants in order 3023** to signal SQLite whether or not the action is permitted. See the 3024** [sqlite3_set_authorizer | authorizer documentation] for additional 3025** information. 3026** 3027** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3028** returned from the [sqlite3_vtab_on_conflict()] interface. 3029*/ 3030#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3031#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3032 3033/* 3034** CAPI3REF: Authorizer Action Codes 3035** 3036** The [sqlite3_set_authorizer()] interface registers a callback function 3037** that is invoked to authorize certain SQL statement actions. The 3038** second parameter to the callback is an integer code that specifies 3039** what action is being authorized. These are the integer action codes that 3040** the authorizer callback may be passed. 3041** 3042** These action code values signify what kind of operation is to be 3043** authorized. The 3rd and 4th parameters to the authorization 3044** callback function will be parameters or NULL depending on which of these 3045** codes is used as the second parameter. ^(The 5th parameter to the 3046** authorizer callback is the name of the database ("main", "temp", 3047** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3048** is the name of the inner-most trigger or view that is responsible for 3049** the access attempt or NULL if this access attempt is directly from 3050** top-level SQL code. 3051*/ 3052/******************************************* 3rd ************ 4th ***********/ 3053#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3054#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3055#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3056#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3057#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3058#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3059#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3060#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3061#define SQLITE_DELETE 9 /* Table Name NULL */ 3062#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3063#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3064#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3065#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3066#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3067#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3068#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3069#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3070#define SQLITE_INSERT 18 /* Table Name NULL */ 3071#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3072#define SQLITE_READ 20 /* Table Name Column Name */ 3073#define SQLITE_SELECT 21 /* NULL NULL */ 3074#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3075#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3076#define SQLITE_ATTACH 24 /* Filename NULL */ 3077#define SQLITE_DETACH 25 /* Database Name NULL */ 3078#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3079#define SQLITE_REINDEX 27 /* Index Name NULL */ 3080#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3081#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3082#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3083#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3084#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3085#define SQLITE_COPY 0 /* No longer used */ 3086#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3087 3088/* 3089** CAPI3REF: Tracing And Profiling Functions 3090** METHOD: sqlite3 3091** 3092** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3093** instead of the routines described here. 3094** 3095** These routines register callback functions that can be used for 3096** tracing and profiling the execution of SQL statements. 3097** 3098** ^The callback function registered by sqlite3_trace() is invoked at 3099** various times when an SQL statement is being run by [sqlite3_step()]. 3100** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3101** SQL statement text as the statement first begins executing. 3102** ^(Additional sqlite3_trace() callbacks might occur 3103** as each triggered subprogram is entered. The callbacks for triggers 3104** contain a UTF-8 SQL comment that identifies the trigger.)^ 3105** 3106** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3107** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3108** 3109** ^The callback function registered by sqlite3_profile() is invoked 3110** as each SQL statement finishes. ^The profile callback contains 3111** the original statement text and an estimate of wall-clock time 3112** of how long that statement took to run. ^The profile callback 3113** time is in units of nanoseconds, however the current implementation 3114** is only capable of millisecond resolution so the six least significant 3115** digits in the time are meaningless. Future versions of SQLite 3116** might provide greater resolution on the profiler callback. Invoking 3117** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3118** profile callback. 3119*/ 3120SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3121 void(*xTrace)(void*,const char*), void*); 3122SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3123 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3124 3125/* 3126** CAPI3REF: SQL Trace Event Codes 3127** KEYWORDS: SQLITE_TRACE 3128** 3129** These constants identify classes of events that can be monitored 3130** using the [sqlite3_trace_v2()] tracing logic. The M argument 3131** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3132** the following constants. ^The first argument to the trace callback 3133** is one of the following constants. 3134** 3135** New tracing constants may be added in future releases. 3136** 3137** ^A trace callback has four arguments: xCallback(T,C,P,X). 3138** ^The T argument is one of the integer type codes above. 3139** ^The C argument is a copy of the context pointer passed in as the 3140** fourth argument to [sqlite3_trace_v2()]. 3141** The P and X arguments are pointers whose meanings depend on T. 3142** 3143** <dl> 3144** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3145** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3146** first begins running and possibly at other times during the 3147** execution of the prepared statement, such as at the start of each 3148** trigger subprogram. ^The P argument is a pointer to the 3149** [prepared statement]. ^The X argument is a pointer to a string which 3150** is the unexpanded SQL text of the prepared statement or an SQL comment 3151** that indicates the invocation of a trigger. ^The callback can compute 3152** the same text that would have been returned by the legacy [sqlite3_trace()] 3153** interface by using the X argument when X begins with "--" and invoking 3154** [sqlite3_expanded_sql(P)] otherwise. 3155** 3156** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3157** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3158** information as is provided by the [sqlite3_profile()] callback. 3159** ^The P argument is a pointer to the [prepared statement] and the 3160** X argument points to a 64-bit integer which is the estimated of 3161** the number of nanosecond that the prepared statement took to run. 3162** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3163** 3164** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3165** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3166** statement generates a single row of result. 3167** ^The P argument is a pointer to the [prepared statement] and the 3168** X argument is unused. 3169** 3170** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3171** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3172** connection closes. 3173** ^The P argument is a pointer to the [database connection] object 3174** and the X argument is unused. 3175** </dl> 3176*/ 3177#define SQLITE_TRACE_STMT 0x01 3178#define SQLITE_TRACE_PROFILE 0x02 3179#define SQLITE_TRACE_ROW 0x04 3180#define SQLITE_TRACE_CLOSE 0x08 3181 3182/* 3183** CAPI3REF: SQL Trace Hook 3184** METHOD: sqlite3 3185** 3186** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3187** function X against [database connection] D, using property mask M 3188** and context pointer P. ^If the X callback is 3189** NULL or if the M mask is zero, then tracing is disabled. The 3190** M argument should be the bitwise OR-ed combination of 3191** zero or more [SQLITE_TRACE] constants. 3192** 3193** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3194** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3195** 3196** ^The X callback is invoked whenever any of the events identified by 3197** mask M occur. ^The integer return value from the callback is currently 3198** ignored, though this may change in future releases. Callback 3199** implementations should return zero to ensure future compatibility. 3200** 3201** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3202** ^The T argument is one of the [SQLITE_TRACE] 3203** constants to indicate why the callback was invoked. 3204** ^The C argument is a copy of the context pointer. 3205** The P and X arguments are pointers whose meanings depend on T. 3206** 3207** The sqlite3_trace_v2() interface is intended to replace the legacy 3208** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3209** are deprecated. 3210*/ 3211int sqlite3_trace_v2( 3212 sqlite3*, 3213 unsigned uMask, 3214 int(*xCallback)(unsigned,void*,void*,void*), 3215 void *pCtx 3216); 3217 3218/* 3219** CAPI3REF: Query Progress Callbacks 3220** METHOD: sqlite3 3221** 3222** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3223** function X to be invoked periodically during long running calls to 3224** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3225** database connection D. An example use for this 3226** interface is to keep a GUI updated during a large query. 3227** 3228** ^The parameter P is passed through as the only parameter to the 3229** callback function X. ^The parameter N is the approximate number of 3230** [virtual machine instructions] that are evaluated between successive 3231** invocations of the callback X. ^If N is less than one then the progress 3232** handler is disabled. 3233** 3234** ^Only a single progress handler may be defined at one time per 3235** [database connection]; setting a new progress handler cancels the 3236** old one. ^Setting parameter X to NULL disables the progress handler. 3237** ^The progress handler is also disabled by setting N to a value less 3238** than 1. 3239** 3240** ^If the progress callback returns non-zero, the operation is 3241** interrupted. This feature can be used to implement a 3242** "Cancel" button on a GUI progress dialog box. 3243** 3244** The progress handler callback must not do anything that will modify 3245** the database connection that invoked the progress handler. 3246** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3247** database connections for the meaning of "modify" in this paragraph. 3248** 3249*/ 3250void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3251 3252/* 3253** CAPI3REF: Opening A New Database Connection 3254** CONSTRUCTOR: sqlite3 3255** 3256** ^These routines open an SQLite database file as specified by the 3257** filename argument. ^The filename argument is interpreted as UTF-8 for 3258** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3259** order for sqlite3_open16(). ^(A [database connection] handle is usually 3260** returned in *ppDb, even if an error occurs. The only exception is that 3261** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3262** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3263** object.)^ ^(If the database is opened (and/or created) successfully, then 3264** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3265** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3266** an English language description of the error following a failure of any 3267** of the sqlite3_open() routines. 3268** 3269** ^The default encoding will be UTF-8 for databases created using 3270** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3271** created using sqlite3_open16() will be UTF-16 in the native byte order. 3272** 3273** Whether or not an error occurs when it is opened, resources 3274** associated with the [database connection] handle should be released by 3275** passing it to [sqlite3_close()] when it is no longer required. 3276** 3277** The sqlite3_open_v2() interface works like sqlite3_open() 3278** except that it accepts two additional parameters for additional control 3279** over the new database connection. ^(The flags parameter to 3280** sqlite3_open_v2() can take one of 3281** the following three values, optionally combined with the 3282** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3283** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3284** 3285** <dl> 3286** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3287** <dd>The database is opened in read-only mode. If the database does not 3288** already exist, an error is returned.</dd>)^ 3289** 3290** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3291** <dd>The database is opened for reading and writing if possible, or reading 3292** only if the file is write protected by the operating system. In either 3293** case the database must already exist, otherwise an error is returned.</dd>)^ 3294** 3295** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3296** <dd>The database is opened for reading and writing, and is created if 3297** it does not already exist. This is the behavior that is always used for 3298** sqlite3_open() and sqlite3_open16().</dd>)^ 3299** </dl> 3300** 3301** If the 3rd parameter to sqlite3_open_v2() is not one of the 3302** combinations shown above optionally combined with other 3303** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3304** then the behavior is undefined. 3305** 3306** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3307** opens in the multi-thread [threading mode] as long as the single-thread 3308** mode has not been set at compile-time or start-time. ^If the 3309** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3310** in the serialized [threading mode] unless single-thread was 3311** previously selected at compile-time or start-time. 3312** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3313** eligible to use [shared cache mode], regardless of whether or not shared 3314** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3315** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3316** participate in [shared cache mode] even if it is enabled. 3317** 3318** ^The fourth parameter to sqlite3_open_v2() is the name of the 3319** [sqlite3_vfs] object that defines the operating system interface that 3320** the new database connection should use. ^If the fourth parameter is 3321** a NULL pointer then the default [sqlite3_vfs] object is used. 3322** 3323** ^If the filename is ":memory:", then a private, temporary in-memory database 3324** is created for the connection. ^This in-memory database will vanish when 3325** the database connection is closed. Future versions of SQLite might 3326** make use of additional special filenames that begin with the ":" character. 3327** It is recommended that when a database filename actually does begin with 3328** a ":" character you should prefix the filename with a pathname such as 3329** "./" to avoid ambiguity. 3330** 3331** ^If the filename is an empty string, then a private, temporary 3332** on-disk database will be created. ^This private database will be 3333** automatically deleted as soon as the database connection is closed. 3334** 3335** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3336** 3337** ^If [URI filename] interpretation is enabled, and the filename argument 3338** begins with "file:", then the filename is interpreted as a URI. ^URI 3339** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3340** set in the third argument to sqlite3_open_v2(), or if it has 3341** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3342** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3343** URI filename interpretation is turned off 3344** by default, but future releases of SQLite might enable URI filename 3345** interpretation by default. See "[URI filenames]" for additional 3346** information. 3347** 3348** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3349** authority, then it must be either an empty string or the string 3350** "localhost". ^If the authority is not an empty string or "localhost", an 3351** error is returned to the caller. ^The fragment component of a URI, if 3352** present, is ignored. 3353** 3354** ^SQLite uses the path component of the URI as the name of the disk file 3355** which contains the database. ^If the path begins with a '/' character, 3356** then it is interpreted as an absolute path. ^If the path does not begin 3357** with a '/' (meaning that the authority section is omitted from the URI) 3358** then the path is interpreted as a relative path. 3359** ^(On windows, the first component of an absolute path 3360** is a drive specification (e.g. "C:").)^ 3361** 3362** [[core URI query parameters]] 3363** The query component of a URI may contain parameters that are interpreted 3364** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3365** SQLite and its built-in [VFSes] interpret the 3366** following query parameters: 3367** 3368** <ul> 3369** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3370** a VFS object that provides the operating system interface that should 3371** be used to access the database file on disk. ^If this option is set to 3372** an empty string the default VFS object is used. ^Specifying an unknown 3373** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3374** present, then the VFS specified by the option takes precedence over 3375** the value passed as the fourth parameter to sqlite3_open_v2(). 3376** 3377** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3378** "rwc", or "memory". Attempting to set it to any other value is 3379** an error)^. 3380** ^If "ro" is specified, then the database is opened for read-only 3381** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3382** third argument to sqlite3_open_v2(). ^If the mode option is set to 3383** "rw", then the database is opened for read-write (but not create) 3384** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3385** been set. ^Value "rwc" is equivalent to setting both 3386** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3387** set to "memory" then a pure [in-memory database] that never reads 3388** or writes from disk is used. ^It is an error to specify a value for 3389** the mode parameter that is less restrictive than that specified by 3390** the flags passed in the third parameter to sqlite3_open_v2(). 3391** 3392** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3393** "private". ^Setting it to "shared" is equivalent to setting the 3394** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3395** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3396** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3397** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3398** a URI filename, its value overrides any behavior requested by setting 3399** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3400** 3401** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3402** [powersafe overwrite] property does or does not apply to the 3403** storage media on which the database file resides. 3404** 3405** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3406** which if set disables file locking in rollback journal modes. This 3407** is useful for accessing a database on a filesystem that does not 3408** support locking. Caution: Database corruption might result if two 3409** or more processes write to the same database and any one of those 3410** processes uses nolock=1. 3411** 3412** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3413** parameter that indicates that the database file is stored on 3414** read-only media. ^When immutable is set, SQLite assumes that the 3415** database file cannot be changed, even by a process with higher 3416** privilege, and so the database is opened read-only and all locking 3417** and change detection is disabled. Caution: Setting the immutable 3418** property on a database file that does in fact change can result 3419** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3420** See also: [SQLITE_IOCAP_IMMUTABLE]. 3421** 3422** </ul> 3423** 3424** ^Specifying an unknown parameter in the query component of a URI is not an 3425** error. Future versions of SQLite might understand additional query 3426** parameters. See "[query parameters with special meaning to SQLite]" for 3427** additional information. 3428** 3429** [[URI filename examples]] <h3>URI filename examples</h3> 3430** 3431** <table border="1" align=center cellpadding=5> 3432** <tr><th> URI filenames <th> Results 3433** <tr><td> file:data.db <td> 3434** Open the file "data.db" in the current directory. 3435** <tr><td> file:/home/fred/data.db<br> 3436** file:///home/fred/data.db <br> 3437** file://localhost/home/fred/data.db <br> <td> 3438** Open the database file "/home/fred/data.db". 3439** <tr><td> file://darkstar/home/fred/data.db <td> 3440** An error. "darkstar" is not a recognized authority. 3441** <tr><td style="white-space:nowrap"> 3442** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3443** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3444** C:. Note that the %20 escaping in this example is not strictly 3445** necessary - space characters can be used literally 3446** in URI filenames. 3447** <tr><td> file:data.db?mode=ro&cache=private <td> 3448** Open file "data.db" in the current directory for read-only access. 3449** Regardless of whether or not shared-cache mode is enabled by 3450** default, use a private cache. 3451** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3452** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3453** that uses dot-files in place of posix advisory locking. 3454** <tr><td> file:data.db?mode=readonly <td> 3455** An error. "readonly" is not a valid option for the "mode" parameter. 3456** </table> 3457** 3458** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3459** query components of a URI. A hexadecimal escape sequence consists of a 3460** percent sign - "%" - followed by exactly two hexadecimal digits 3461** specifying an octet value. ^Before the path or query components of a 3462** URI filename are interpreted, they are encoded using UTF-8 and all 3463** hexadecimal escape sequences replaced by a single byte containing the 3464** corresponding octet. If this process generates an invalid UTF-8 encoding, 3465** the results are undefined. 3466** 3467** <b>Note to Windows users:</b> The encoding used for the filename argument 3468** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3469** codepage is currently defined. Filenames containing international 3470** characters must be converted to UTF-8 prior to passing them into 3471** sqlite3_open() or sqlite3_open_v2(). 3472** 3473** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3474** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3475** features that require the use of temporary files may fail. 3476** 3477** See also: [sqlite3_temp_directory] 3478*/ 3479int sqlite3_open( 3480 const char *filename, /* Database filename (UTF-8) */ 3481 sqlite3 **ppDb /* OUT: SQLite db handle */ 3482); 3483int sqlite3_open16( 3484 const void *filename, /* Database filename (UTF-16) */ 3485 sqlite3 **ppDb /* OUT: SQLite db handle */ 3486); 3487int sqlite3_open_v2( 3488 const char *filename, /* Database filename (UTF-8) */ 3489 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3490 int flags, /* Flags */ 3491 const char *zVfs /* Name of VFS module to use */ 3492); 3493 3494/* 3495** CAPI3REF: Obtain Values For URI Parameters 3496** 3497** These are utility routines, useful to [VFS|custom VFS implementations], 3498** that check if a database file was a URI that contained a specific query 3499** parameter, and if so obtains the value of that query parameter. 3500** 3501** If F is the database filename pointer passed into the xOpen() method of 3502** a VFS implementation or it is the return value of [sqlite3_db_filename()] 3503** and if P is the name of the query parameter, then 3504** sqlite3_uri_parameter(F,P) returns the value of the P 3505** parameter if it exists or a NULL pointer if P does not appear as a 3506** query parameter on F. If P is a query parameter of F and it 3507** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3508** a pointer to an empty string. 3509** 3510** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3511** parameter and returns true (1) or false (0) according to the value 3512** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3513** value of query parameter P is one of "yes", "true", or "on" in any 3514** case or if the value begins with a non-zero number. The 3515** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3516** query parameter P is one of "no", "false", or "off" in any case or 3517** if the value begins with a numeric zero. If P is not a query 3518** parameter on F or if the value of P does not match any of the 3519** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3520** 3521** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3522** 64-bit signed integer and returns that integer, or D if P does not 3523** exist. If the value of P is something other than an integer, then 3524** zero is returned. 3525** 3526** The sqlite3_uri_key(F,N) returns a pointer to the name (not 3527** the value) of the N-th query parameter for filename F, or a NULL 3528** pointer if N is less than zero or greater than the number of query 3529** parameters minus 1. The N value is zero-based so N should be 0 to obtain 3530** the name of the first query parameter, 1 for the second parameter, and 3531** so forth. 3532** 3533** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3534** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3535** is not a database file pathname pointer that the SQLite core passed 3536** into the xOpen VFS method, then the behavior of this routine is undefined 3537** and probably undesirable. 3538** 3539** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F 3540** parameter can also be the name of a rollback journal file or WAL file 3541** in addition to the main database file. Prior to version 3.31.0, these 3542** routines would only work if F was the name of the main database file. 3543** When the F parameter is the name of the rollback journal or WAL file, 3544** it has access to all the same query parameters as were found on the 3545** main database file. 3546** 3547** See the [URI filename] documentation for additional information. 3548*/ 3549const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3550int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3551sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3552const char *sqlite3_uri_key(const char *zFilename, int N); 3553 3554/* 3555** CAPI3REF: Translate filenames 3556** 3557** These routines are available to [VFS|custom VFS implementations] for 3558** translating filenames between the main database file, the journal file, 3559** and the WAL file. 3560** 3561** If F is the name of an sqlite database file, journal file, or WAL file 3562** passed by the SQLite core into the VFS, then sqlite3_filename_database(F) 3563** returns the name of the corresponding database file. 3564** 3565** If F is the name of an sqlite database file, journal file, or WAL file 3566** passed by the SQLite core into the VFS, or if F is a database filename 3567** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F) 3568** returns the name of the corresponding rollback journal file. 3569** 3570** If F is the name of an sqlite database file, journal file, or WAL file 3571** that was passed by the SQLite core into the VFS, or if F is a database 3572** filename obtained from [sqlite3_db_filename()], then 3573** sqlite3_filename_wal(F) returns the name of the corresponding 3574** WAL file. 3575** 3576** In all of the above, if F is not the name of a database, journal or WAL 3577** filename passed into the VFS from the SQLite core and F is not the 3578** return value from [sqlite3_db_filename()], then the result is 3579** undefined and is likely a memory access violation. 3580*/ 3581const char *sqlite3_filename_database(const char*); 3582const char *sqlite3_filename_journal(const char*); 3583const char *sqlite3_filename_wal(const char*); 3584 3585 3586/* 3587** CAPI3REF: Error Codes And Messages 3588** METHOD: sqlite3 3589** 3590** ^If the most recent sqlite3_* API call associated with 3591** [database connection] D failed, then the sqlite3_errcode(D) interface 3592** returns the numeric [result code] or [extended result code] for that 3593** API call. 3594** ^The sqlite3_extended_errcode() 3595** interface is the same except that it always returns the 3596** [extended result code] even when extended result codes are 3597** disabled. 3598** 3599** The values returned by sqlite3_errcode() and/or 3600** sqlite3_extended_errcode() might change with each API call. 3601** Except, there are some interfaces that are guaranteed to never 3602** change the value of the error code. The error-code preserving 3603** interfaces are: 3604** 3605** <ul> 3606** <li> sqlite3_errcode() 3607** <li> sqlite3_extended_errcode() 3608** <li> sqlite3_errmsg() 3609** <li> sqlite3_errmsg16() 3610** </ul> 3611** 3612** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3613** text that describes the error, as either UTF-8 or UTF-16 respectively. 3614** ^(Memory to hold the error message string is managed internally. 3615** The application does not need to worry about freeing the result. 3616** However, the error string might be overwritten or deallocated by 3617** subsequent calls to other SQLite interface functions.)^ 3618** 3619** ^The sqlite3_errstr() interface returns the English-language text 3620** that describes the [result code], as UTF-8. 3621** ^(Memory to hold the error message string is managed internally 3622** and must not be freed by the application)^. 3623** 3624** When the serialized [threading mode] is in use, it might be the 3625** case that a second error occurs on a separate thread in between 3626** the time of the first error and the call to these interfaces. 3627** When that happens, the second error will be reported since these 3628** interfaces always report the most recent result. To avoid 3629** this, each thread can obtain exclusive use of the [database connection] D 3630** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3631** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3632** all calls to the interfaces listed here are completed. 3633** 3634** If an interface fails with SQLITE_MISUSE, that means the interface 3635** was invoked incorrectly by the application. In that case, the 3636** error code and message may or may not be set. 3637*/ 3638int sqlite3_errcode(sqlite3 *db); 3639int sqlite3_extended_errcode(sqlite3 *db); 3640const char *sqlite3_errmsg(sqlite3*); 3641const void *sqlite3_errmsg16(sqlite3*); 3642const char *sqlite3_errstr(int); 3643 3644/* 3645** CAPI3REF: Prepared Statement Object 3646** KEYWORDS: {prepared statement} {prepared statements} 3647** 3648** An instance of this object represents a single SQL statement that 3649** has been compiled into binary form and is ready to be evaluated. 3650** 3651** Think of each SQL statement as a separate computer program. The 3652** original SQL text is source code. A prepared statement object 3653** is the compiled object code. All SQL must be converted into a 3654** prepared statement before it can be run. 3655** 3656** The life-cycle of a prepared statement object usually goes like this: 3657** 3658** <ol> 3659** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3660** <li> Bind values to [parameters] using the sqlite3_bind_*() 3661** interfaces. 3662** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3663** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3664** to step 2. Do this zero or more times. 3665** <li> Destroy the object using [sqlite3_finalize()]. 3666** </ol> 3667*/ 3668typedef struct sqlite3_stmt sqlite3_stmt; 3669 3670/* 3671** CAPI3REF: Run-time Limits 3672** METHOD: sqlite3 3673** 3674** ^(This interface allows the size of various constructs to be limited 3675** on a connection by connection basis. The first parameter is the 3676** [database connection] whose limit is to be set or queried. The 3677** second parameter is one of the [limit categories] that define a 3678** class of constructs to be size limited. The third parameter is the 3679** new limit for that construct.)^ 3680** 3681** ^If the new limit is a negative number, the limit is unchanged. 3682** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3683** [limits | hard upper bound] 3684** set at compile-time by a C preprocessor macro called 3685** [limits | SQLITE_MAX_<i>NAME</i>]. 3686** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3687** ^Attempts to increase a limit above its hard upper bound are 3688** silently truncated to the hard upper bound. 3689** 3690** ^Regardless of whether or not the limit was changed, the 3691** [sqlite3_limit()] interface returns the prior value of the limit. 3692** ^Hence, to find the current value of a limit without changing it, 3693** simply invoke this interface with the third parameter set to -1. 3694** 3695** Run-time limits are intended for use in applications that manage 3696** both their own internal database and also databases that are controlled 3697** by untrusted external sources. An example application might be a 3698** web browser that has its own databases for storing history and 3699** separate databases controlled by JavaScript applications downloaded 3700** off the Internet. The internal databases can be given the 3701** large, default limits. Databases managed by external sources can 3702** be given much smaller limits designed to prevent a denial of service 3703** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3704** interface to further control untrusted SQL. The size of the database 3705** created by an untrusted script can be contained using the 3706** [max_page_count] [PRAGMA]. 3707** 3708** New run-time limit categories may be added in future releases. 3709*/ 3710int sqlite3_limit(sqlite3*, int id, int newVal); 3711 3712/* 3713** CAPI3REF: Run-Time Limit Categories 3714** KEYWORDS: {limit category} {*limit categories} 3715** 3716** These constants define various performance limits 3717** that can be lowered at run-time using [sqlite3_limit()]. 3718** The synopsis of the meanings of the various limits is shown below. 3719** Additional information is available at [limits | Limits in SQLite]. 3720** 3721** <dl> 3722** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3723** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3724** 3725** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3726** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3727** 3728** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3729** <dd>The maximum number of columns in a table definition or in the 3730** result set of a [SELECT] or the maximum number of columns in an index 3731** or in an ORDER BY or GROUP BY clause.</dd>)^ 3732** 3733** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3734** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3735** 3736** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3737** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3738** 3739** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3740** <dd>The maximum number of instructions in a virtual machine program 3741** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3742** the equivalent tries to allocate space for more than this many opcodes 3743** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3744** 3745** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3746** <dd>The maximum number of arguments on a function.</dd>)^ 3747** 3748** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3749** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3750** 3751** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3752** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3753** <dd>The maximum length of the pattern argument to the [LIKE] or 3754** [GLOB] operators.</dd>)^ 3755** 3756** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3757** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3758** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3759** 3760** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3761** <dd>The maximum depth of recursion for triggers.</dd>)^ 3762** 3763** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3764** <dd>The maximum number of auxiliary worker threads that a single 3765** [prepared statement] may start.</dd>)^ 3766** </dl> 3767*/ 3768#define SQLITE_LIMIT_LENGTH 0 3769#define SQLITE_LIMIT_SQL_LENGTH 1 3770#define SQLITE_LIMIT_COLUMN 2 3771#define SQLITE_LIMIT_EXPR_DEPTH 3 3772#define SQLITE_LIMIT_COMPOUND_SELECT 4 3773#define SQLITE_LIMIT_VDBE_OP 5 3774#define SQLITE_LIMIT_FUNCTION_ARG 6 3775#define SQLITE_LIMIT_ATTACHED 7 3776#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3777#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3778#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3779#define SQLITE_LIMIT_WORKER_THREADS 11 3780 3781/* 3782** CAPI3REF: Prepare Flags 3783** 3784** These constants define various flags that can be passed into 3785** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3786** [sqlite3_prepare16_v3()] interfaces. 3787** 3788** New flags may be added in future releases of SQLite. 3789** 3790** <dl> 3791** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3792** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3793** that the prepared statement will be retained for a long time and 3794** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3795** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3796** be used just once or at most a few times and then destroyed using 3797** [sqlite3_finalize()] relatively soon. The current implementation acts 3798** on this hint by avoiding the use of [lookaside memory] so as not to 3799** deplete the limited store of lookaside memory. Future versions of 3800** SQLite may act on this hint differently. 3801** 3802** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3803** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3804** to be required for any prepared statement that wanted to use the 3805** [sqlite3_normalized_sql()] interface. However, the 3806** [sqlite3_normalized_sql()] interface is now available to all 3807** prepared statements, regardless of whether or not they use this 3808** flag. 3809** 3810** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3811** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3812** to return an error (error code SQLITE_ERROR) if the statement uses 3813** any virtual tables. 3814** </dl> 3815*/ 3816#define SQLITE_PREPARE_PERSISTENT 0x01 3817#define SQLITE_PREPARE_NORMALIZE 0x02 3818#define SQLITE_PREPARE_NO_VTAB 0x04 3819 3820/* 3821** CAPI3REF: Compiling An SQL Statement 3822** KEYWORDS: {SQL statement compiler} 3823** METHOD: sqlite3 3824** CONSTRUCTOR: sqlite3_stmt 3825** 3826** To execute an SQL statement, it must first be compiled into a byte-code 3827** program using one of these routines. Or, in other words, these routines 3828** are constructors for the [prepared statement] object. 3829** 3830** The preferred routine to use is [sqlite3_prepare_v2()]. The 3831** [sqlite3_prepare()] interface is legacy and should be avoided. 3832** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3833** for special purposes. 3834** 3835** The use of the UTF-8 interfaces is preferred, as SQLite currently 3836** does all parsing using UTF-8. The UTF-16 interfaces are provided 3837** as a convenience. The UTF-16 interfaces work by converting the 3838** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3839** 3840** The first argument, "db", is a [database connection] obtained from a 3841** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3842** [sqlite3_open16()]. The database connection must not have been closed. 3843** 3844** The second argument, "zSql", is the statement to be compiled, encoded 3845** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3846** and sqlite3_prepare_v3() 3847** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3848** and sqlite3_prepare16_v3() use UTF-16. 3849** 3850** ^If the nByte argument is negative, then zSql is read up to the 3851** first zero terminator. ^If nByte is positive, then it is the 3852** number of bytes read from zSql. ^If nByte is zero, then no prepared 3853** statement is generated. 3854** If the caller knows that the supplied string is nul-terminated, then 3855** there is a small performance advantage to passing an nByte parameter that 3856** is the number of bytes in the input string <i>including</i> 3857** the nul-terminator. 3858** 3859** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3860** past the end of the first SQL statement in zSql. These routines only 3861** compile the first statement in zSql, so *pzTail is left pointing to 3862** what remains uncompiled. 3863** 3864** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3865** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3866** to NULL. ^If the input text contains no SQL (if the input is an empty 3867** string or a comment) then *ppStmt is set to NULL. 3868** The calling procedure is responsible for deleting the compiled 3869** SQL statement using [sqlite3_finalize()] after it has finished with it. 3870** ppStmt may not be NULL. 3871** 3872** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3873** otherwise an [error code] is returned. 3874** 3875** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3876** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3877** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3878** are retained for backwards compatibility, but their use is discouraged. 3879** ^In the "vX" interfaces, the prepared statement 3880** that is returned (the [sqlite3_stmt] object) contains a copy of the 3881** original SQL text. This causes the [sqlite3_step()] interface to 3882** behave differently in three ways: 3883** 3884** <ol> 3885** <li> 3886** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3887** always used to do, [sqlite3_step()] will automatically recompile the SQL 3888** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3889** retries will occur before sqlite3_step() gives up and returns an error. 3890** </li> 3891** 3892** <li> 3893** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3894** [error codes] or [extended error codes]. ^The legacy behavior was that 3895** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3896** and the application would have to make a second call to [sqlite3_reset()] 3897** in order to find the underlying cause of the problem. With the "v2" prepare 3898** interfaces, the underlying reason for the error is returned immediately. 3899** </li> 3900** 3901** <li> 3902** ^If the specific value bound to a [parameter | host parameter] in the 3903** WHERE clause might influence the choice of query plan for a statement, 3904** then the statement will be automatically recompiled, as if there had been 3905** a schema change, on the first [sqlite3_step()] call following any change 3906** to the [sqlite3_bind_text | bindings] of that [parameter]. 3907** ^The specific value of a WHERE-clause [parameter] might influence the 3908** choice of query plan if the parameter is the left-hand side of a [LIKE] 3909** or [GLOB] operator or if the parameter is compared to an indexed column 3910** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3911** </li> 3912** </ol> 3913** 3914** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3915** the extra prepFlags parameter, which is a bit array consisting of zero or 3916** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3917** sqlite3_prepare_v2() interface works exactly the same as 3918** sqlite3_prepare_v3() with a zero prepFlags parameter. 3919*/ 3920int sqlite3_prepare( 3921 sqlite3 *db, /* Database handle */ 3922 const char *zSql, /* SQL statement, UTF-8 encoded */ 3923 int nByte, /* Maximum length of zSql in bytes. */ 3924 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3925 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3926); 3927int sqlite3_prepare_v2( 3928 sqlite3 *db, /* Database handle */ 3929 const char *zSql, /* SQL statement, UTF-8 encoded */ 3930 int nByte, /* Maximum length of zSql in bytes. */ 3931 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3932 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3933); 3934int sqlite3_prepare_v3( 3935 sqlite3 *db, /* Database handle */ 3936 const char *zSql, /* SQL statement, UTF-8 encoded */ 3937 int nByte, /* Maximum length of zSql in bytes. */ 3938 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3939 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3940 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3941); 3942int sqlite3_prepare16( 3943 sqlite3 *db, /* Database handle */ 3944 const void *zSql, /* SQL statement, UTF-16 encoded */ 3945 int nByte, /* Maximum length of zSql in bytes. */ 3946 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3947 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3948); 3949int sqlite3_prepare16_v2( 3950 sqlite3 *db, /* Database handle */ 3951 const void *zSql, /* SQL statement, UTF-16 encoded */ 3952 int nByte, /* Maximum length of zSql in bytes. */ 3953 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3954 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3955); 3956int sqlite3_prepare16_v3( 3957 sqlite3 *db, /* Database handle */ 3958 const void *zSql, /* SQL statement, UTF-16 encoded */ 3959 int nByte, /* Maximum length of zSql in bytes. */ 3960 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3961 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3962 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3963); 3964 3965/* 3966** CAPI3REF: Retrieving Statement SQL 3967** METHOD: sqlite3_stmt 3968** 3969** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3970** SQL text used to create [prepared statement] P if P was 3971** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3972** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3973** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3974** string containing the SQL text of prepared statement P with 3975** [bound parameters] expanded. 3976** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3977** string containing the normalized SQL text of prepared statement P. The 3978** semantics used to normalize a SQL statement are unspecified and subject 3979** to change. At a minimum, literal values will be replaced with suitable 3980** placeholders. 3981** 3982** ^(For example, if a prepared statement is created using the SQL 3983** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3984** and parameter :xyz is unbound, then sqlite3_sql() will return 3985** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3986** will return "SELECT 2345,NULL".)^ 3987** 3988** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3989** is available to hold the result, or if the result would exceed the 3990** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3991** 3992** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3993** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3994** option causes sqlite3_expanded_sql() to always return NULL. 3995** 3996** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3997** are managed by SQLite and are automatically freed when the prepared 3998** statement is finalized. 3999** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 4000** is obtained from [sqlite3_malloc()] and must be free by the application 4001** by passing it to [sqlite3_free()]. 4002*/ 4003const char *sqlite3_sql(sqlite3_stmt *pStmt); 4004char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 4005const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 4006 4007/* 4008** CAPI3REF: Determine If An SQL Statement Writes The Database 4009** METHOD: sqlite3_stmt 4010** 4011** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 4012** and only if the [prepared statement] X makes no direct changes to 4013** the content of the database file. 4014** 4015** Note that [application-defined SQL functions] or 4016** [virtual tables] might change the database indirectly as a side effect. 4017** ^(For example, if an application defines a function "eval()" that 4018** calls [sqlite3_exec()], then the following SQL statement would 4019** change the database file through side-effects: 4020** 4021** <blockquote><pre> 4022** SELECT eval('DELETE FROM t1') FROM t2; 4023** </pre></blockquote> 4024** 4025** But because the [SELECT] statement does not change the database file 4026** directly, sqlite3_stmt_readonly() would still return true.)^ 4027** 4028** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 4029** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 4030** since the statements themselves do not actually modify the database but 4031** rather they control the timing of when other statements modify the 4032** database. ^The [ATTACH] and [DETACH] statements also cause 4033** sqlite3_stmt_readonly() to return true since, while those statements 4034** change the configuration of a database connection, they do not make 4035** changes to the content of the database files on disk. 4036** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 4037** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 4038** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 4039** sqlite3_stmt_readonly() returns false for those commands. 4040*/ 4041int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 4042 4043/* 4044** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 4045** METHOD: sqlite3_stmt 4046** 4047** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 4048** prepared statement S is an EXPLAIN statement, or 2 if the 4049** statement S is an EXPLAIN QUERY PLAN. 4050** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 4051** an ordinary statement or a NULL pointer. 4052*/ 4053int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 4054 4055/* 4056** CAPI3REF: Determine If A Prepared Statement Has Been Reset 4057** METHOD: sqlite3_stmt 4058** 4059** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 4060** [prepared statement] S has been stepped at least once using 4061** [sqlite3_step(S)] but has neither run to completion (returned 4062** [SQLITE_DONE] from [sqlite3_step(S)]) nor 4063** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 4064** interface returns false if S is a NULL pointer. If S is not a 4065** NULL pointer and is not a pointer to a valid [prepared statement] 4066** object, then the behavior is undefined and probably undesirable. 4067** 4068** This interface can be used in combination [sqlite3_next_stmt()] 4069** to locate all prepared statements associated with a database 4070** connection that are in need of being reset. This can be used, 4071** for example, in diagnostic routines to search for prepared 4072** statements that are holding a transaction open. 4073*/ 4074int sqlite3_stmt_busy(sqlite3_stmt*); 4075 4076/* 4077** CAPI3REF: Dynamically Typed Value Object 4078** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4079** 4080** SQLite uses the sqlite3_value object to represent all values 4081** that can be stored in a database table. SQLite uses dynamic typing 4082** for the values it stores. ^Values stored in sqlite3_value objects 4083** can be integers, floating point values, strings, BLOBs, or NULL. 4084** 4085** An sqlite3_value object may be either "protected" or "unprotected". 4086** Some interfaces require a protected sqlite3_value. Other interfaces 4087** will accept either a protected or an unprotected sqlite3_value. 4088** Every interface that accepts sqlite3_value arguments specifies 4089** whether or not it requires a protected sqlite3_value. The 4090** [sqlite3_value_dup()] interface can be used to construct a new 4091** protected sqlite3_value from an unprotected sqlite3_value. 4092** 4093** The terms "protected" and "unprotected" refer to whether or not 4094** a mutex is held. An internal mutex is held for a protected 4095** sqlite3_value object but no mutex is held for an unprotected 4096** sqlite3_value object. If SQLite is compiled to be single-threaded 4097** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4098** or if SQLite is run in one of reduced mutex modes 4099** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4100** then there is no distinction between protected and unprotected 4101** sqlite3_value objects and they can be used interchangeably. However, 4102** for maximum code portability it is recommended that applications 4103** still make the distinction between protected and unprotected 4104** sqlite3_value objects even when not strictly required. 4105** 4106** ^The sqlite3_value objects that are passed as parameters into the 4107** implementation of [application-defined SQL functions] are protected. 4108** ^The sqlite3_value object returned by 4109** [sqlite3_column_value()] is unprotected. 4110** Unprotected sqlite3_value objects may only be used as arguments 4111** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4112** [sqlite3_value_dup()]. 4113** The [sqlite3_value_blob | sqlite3_value_type()] family of 4114** interfaces require protected sqlite3_value objects. 4115*/ 4116typedef struct sqlite3_value sqlite3_value; 4117 4118/* 4119** CAPI3REF: SQL Function Context Object 4120** 4121** The context in which an SQL function executes is stored in an 4122** sqlite3_context object. ^A pointer to an sqlite3_context object 4123** is always first parameter to [application-defined SQL functions]. 4124** The application-defined SQL function implementation will pass this 4125** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4126** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4127** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4128** and/or [sqlite3_set_auxdata()]. 4129*/ 4130typedef struct sqlite3_context sqlite3_context; 4131 4132/* 4133** CAPI3REF: Binding Values To Prepared Statements 4134** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4135** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4136** METHOD: sqlite3_stmt 4137** 4138** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4139** literals may be replaced by a [parameter] that matches one of following 4140** templates: 4141** 4142** <ul> 4143** <li> ? 4144** <li> ?NNN 4145** <li> :VVV 4146** <li> @VVV 4147** <li> $VVV 4148** </ul> 4149** 4150** In the templates above, NNN represents an integer literal, 4151** and VVV represents an alphanumeric identifier.)^ ^The values of these 4152** parameters (also called "host parameter names" or "SQL parameters") 4153** can be set using the sqlite3_bind_*() routines defined here. 4154** 4155** ^The first argument to the sqlite3_bind_*() routines is always 4156** a pointer to the [sqlite3_stmt] object returned from 4157** [sqlite3_prepare_v2()] or its variants. 4158** 4159** ^The second argument is the index of the SQL parameter to be set. 4160** ^The leftmost SQL parameter has an index of 1. ^When the same named 4161** SQL parameter is used more than once, second and subsequent 4162** occurrences have the same index as the first occurrence. 4163** ^The index for named parameters can be looked up using the 4164** [sqlite3_bind_parameter_index()] API if desired. ^The index 4165** for "?NNN" parameters is the value of NNN. 4166** ^The NNN value must be between 1 and the [sqlite3_limit()] 4167** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4168** 4169** ^The third argument is the value to bind to the parameter. 4170** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4171** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4172** is ignored and the end result is the same as sqlite3_bind_null(). 4173** 4174** ^(In those routines that have a fourth argument, its value is the 4175** number of bytes in the parameter. To be clear: the value is the 4176** number of <u>bytes</u> in the value, not the number of characters.)^ 4177** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4178** is negative, then the length of the string is 4179** the number of bytes up to the first zero terminator. 4180** If the fourth parameter to sqlite3_bind_blob() is negative, then 4181** the behavior is undefined. 4182** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4183** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4184** that parameter must be the byte offset 4185** where the NUL terminator would occur assuming the string were NUL 4186** terminated. If any NUL characters occur at byte offsets less than 4187** the value of the fourth parameter then the resulting string value will 4188** contain embedded NULs. The result of expressions involving strings 4189** with embedded NULs is undefined. 4190** 4191** ^The fifth argument to the BLOB and string binding interfaces 4192** is a destructor used to dispose of the BLOB or 4193** string after SQLite has finished with it. ^The destructor is called 4194** to dispose of the BLOB or string even if the call to the bind API fails, 4195** except the destructor is not called if the third parameter is a NULL 4196** pointer or the fourth parameter is negative. 4197** ^If the fifth argument is 4198** the special value [SQLITE_STATIC], then SQLite assumes that the 4199** information is in static, unmanaged space and does not need to be freed. 4200** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4201** SQLite makes its own private copy of the data immediately, before 4202** the sqlite3_bind_*() routine returns. 4203** 4204** ^The sixth argument to sqlite3_bind_text64() must be one of 4205** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4206** to specify the encoding of the text in the third parameter. If 4207** the sixth argument to sqlite3_bind_text64() is not one of the 4208** allowed values shown above, or if the text encoding is different 4209** from the encoding specified by the sixth parameter, then the behavior 4210** is undefined. 4211** 4212** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4213** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4214** (just an integer to hold its size) while it is being processed. 4215** Zeroblobs are intended to serve as placeholders for BLOBs whose 4216** content is later written using 4217** [sqlite3_blob_open | incremental BLOB I/O] routines. 4218** ^A negative value for the zeroblob results in a zero-length BLOB. 4219** 4220** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4221** [prepared statement] S to have an SQL value of NULL, but to also be 4222** associated with the pointer P of type T. ^D is either a NULL pointer or 4223** a pointer to a destructor function for P. ^SQLite will invoke the 4224** destructor D with a single argument of P when it is finished using 4225** P. The T parameter should be a static string, preferably a string 4226** literal. The sqlite3_bind_pointer() routine is part of the 4227** [pointer passing interface] added for SQLite 3.20.0. 4228** 4229** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4230** for the [prepared statement] or with a prepared statement for which 4231** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4232** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4233** routine is passed a [prepared statement] that has been finalized, the 4234** result is undefined and probably harmful. 4235** 4236** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4237** ^Unbound parameters are interpreted as NULL. 4238** 4239** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4240** [error code] if anything goes wrong. 4241** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4242** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4243** [SQLITE_MAX_LENGTH]. 4244** ^[SQLITE_RANGE] is returned if the parameter 4245** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4246** 4247** See also: [sqlite3_bind_parameter_count()], 4248** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4249*/ 4250int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4251int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4252 void(*)(void*)); 4253int sqlite3_bind_double(sqlite3_stmt*, int, double); 4254int sqlite3_bind_int(sqlite3_stmt*, int, int); 4255int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4256int sqlite3_bind_null(sqlite3_stmt*, int); 4257int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4258int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4259int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4260 void(*)(void*), unsigned char encoding); 4261int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4262int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4263int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4264int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4265 4266/* 4267** CAPI3REF: Number Of SQL Parameters 4268** METHOD: sqlite3_stmt 4269** 4270** ^This routine can be used to find the number of [SQL parameters] 4271** in a [prepared statement]. SQL parameters are tokens of the 4272** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4273** placeholders for values that are [sqlite3_bind_blob | bound] 4274** to the parameters at a later time. 4275** 4276** ^(This routine actually returns the index of the largest (rightmost) 4277** parameter. For all forms except ?NNN, this will correspond to the 4278** number of unique parameters. If parameters of the ?NNN form are used, 4279** there may be gaps in the list.)^ 4280** 4281** See also: [sqlite3_bind_blob|sqlite3_bind()], 4282** [sqlite3_bind_parameter_name()], and 4283** [sqlite3_bind_parameter_index()]. 4284*/ 4285int sqlite3_bind_parameter_count(sqlite3_stmt*); 4286 4287/* 4288** CAPI3REF: Name Of A Host Parameter 4289** METHOD: sqlite3_stmt 4290** 4291** ^The sqlite3_bind_parameter_name(P,N) interface returns 4292** the name of the N-th [SQL parameter] in the [prepared statement] P. 4293** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4294** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4295** respectively. 4296** In other words, the initial ":" or "$" or "@" or "?" 4297** is included as part of the name.)^ 4298** ^Parameters of the form "?" without a following integer have no name 4299** and are referred to as "nameless" or "anonymous parameters". 4300** 4301** ^The first host parameter has an index of 1, not 0. 4302** 4303** ^If the value N is out of range or if the N-th parameter is 4304** nameless, then NULL is returned. ^The returned string is 4305** always in UTF-8 encoding even if the named parameter was 4306** originally specified as UTF-16 in [sqlite3_prepare16()], 4307** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4308** 4309** See also: [sqlite3_bind_blob|sqlite3_bind()], 4310** [sqlite3_bind_parameter_count()], and 4311** [sqlite3_bind_parameter_index()]. 4312*/ 4313const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4314 4315/* 4316** CAPI3REF: Index Of A Parameter With A Given Name 4317** METHOD: sqlite3_stmt 4318** 4319** ^Return the index of an SQL parameter given its name. ^The 4320** index value returned is suitable for use as the second 4321** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4322** is returned if no matching parameter is found. ^The parameter 4323** name must be given in UTF-8 even if the original statement 4324** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4325** [sqlite3_prepare16_v3()]. 4326** 4327** See also: [sqlite3_bind_blob|sqlite3_bind()], 4328** [sqlite3_bind_parameter_count()], and 4329** [sqlite3_bind_parameter_name()]. 4330*/ 4331int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4332 4333/* 4334** CAPI3REF: Reset All Bindings On A Prepared Statement 4335** METHOD: sqlite3_stmt 4336** 4337** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4338** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4339** ^Use this routine to reset all host parameters to NULL. 4340*/ 4341int sqlite3_clear_bindings(sqlite3_stmt*); 4342 4343/* 4344** CAPI3REF: Number Of Columns In A Result Set 4345** METHOD: sqlite3_stmt 4346** 4347** ^Return the number of columns in the result set returned by the 4348** [prepared statement]. ^If this routine returns 0, that means the 4349** [prepared statement] returns no data (for example an [UPDATE]). 4350** ^However, just because this routine returns a positive number does not 4351** mean that one or more rows of data will be returned. ^A SELECT statement 4352** will always have a positive sqlite3_column_count() but depending on the 4353** WHERE clause constraints and the table content, it might return no rows. 4354** 4355** See also: [sqlite3_data_count()] 4356*/ 4357int sqlite3_column_count(sqlite3_stmt *pStmt); 4358 4359/* 4360** CAPI3REF: Column Names In A Result Set 4361** METHOD: sqlite3_stmt 4362** 4363** ^These routines return the name assigned to a particular column 4364** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4365** interface returns a pointer to a zero-terminated UTF-8 string 4366** and sqlite3_column_name16() returns a pointer to a zero-terminated 4367** UTF-16 string. ^The first parameter is the [prepared statement] 4368** that implements the [SELECT] statement. ^The second parameter is the 4369** column number. ^The leftmost column is number 0. 4370** 4371** ^The returned string pointer is valid until either the [prepared statement] 4372** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4373** reprepared by the first call to [sqlite3_step()] for a particular run 4374** or until the next call to 4375** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4376** 4377** ^If sqlite3_malloc() fails during the processing of either routine 4378** (for example during a conversion from UTF-8 to UTF-16) then a 4379** NULL pointer is returned. 4380** 4381** ^The name of a result column is the value of the "AS" clause for 4382** that column, if there is an AS clause. If there is no AS clause 4383** then the name of the column is unspecified and may change from 4384** one release of SQLite to the next. 4385*/ 4386const char *sqlite3_column_name(sqlite3_stmt*, int N); 4387const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4388 4389/* 4390** CAPI3REF: Source Of Data In A Query Result 4391** METHOD: sqlite3_stmt 4392** 4393** ^These routines provide a means to determine the database, table, and 4394** table column that is the origin of a particular result column in 4395** [SELECT] statement. 4396** ^The name of the database or table or column can be returned as 4397** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4398** the database name, the _table_ routines return the table name, and 4399** the origin_ routines return the column name. 4400** ^The returned string is valid until the [prepared statement] is destroyed 4401** using [sqlite3_finalize()] or until the statement is automatically 4402** reprepared by the first call to [sqlite3_step()] for a particular run 4403** or until the same information is requested 4404** again in a different encoding. 4405** 4406** ^The names returned are the original un-aliased names of the 4407** database, table, and column. 4408** 4409** ^The first argument to these interfaces is a [prepared statement]. 4410** ^These functions return information about the Nth result column returned by 4411** the statement, where N is the second function argument. 4412** ^The left-most column is column 0 for these routines. 4413** 4414** ^If the Nth column returned by the statement is an expression or 4415** subquery and is not a column value, then all of these functions return 4416** NULL. ^These routines might also return NULL if a memory allocation error 4417** occurs. ^Otherwise, they return the name of the attached database, table, 4418** or column that query result column was extracted from. 4419** 4420** ^As with all other SQLite APIs, those whose names end with "16" return 4421** UTF-16 encoded strings and the other functions return UTF-8. 4422** 4423** ^These APIs are only available if the library was compiled with the 4424** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4425** 4426** If two or more threads call one or more 4427** [sqlite3_column_database_name | column metadata interfaces] 4428** for the same [prepared statement] and result column 4429** at the same time then the results are undefined. 4430*/ 4431const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4432const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4433const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4434const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4435const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4436const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4437 4438/* 4439** CAPI3REF: Declared Datatype Of A Query Result 4440** METHOD: sqlite3_stmt 4441** 4442** ^(The first parameter is a [prepared statement]. 4443** If this statement is a [SELECT] statement and the Nth column of the 4444** returned result set of that [SELECT] is a table column (not an 4445** expression or subquery) then the declared type of the table 4446** column is returned.)^ ^If the Nth column of the result set is an 4447** expression or subquery, then a NULL pointer is returned. 4448** ^The returned string is always UTF-8 encoded. 4449** 4450** ^(For example, given the database schema: 4451** 4452** CREATE TABLE t1(c1 VARIANT); 4453** 4454** and the following statement to be compiled: 4455** 4456** SELECT c1 + 1, c1 FROM t1; 4457** 4458** this routine would return the string "VARIANT" for the second result 4459** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4460** 4461** ^SQLite uses dynamic run-time typing. ^So just because a column 4462** is declared to contain a particular type does not mean that the 4463** data stored in that column is of the declared type. SQLite is 4464** strongly typed, but the typing is dynamic not static. ^Type 4465** is associated with individual values, not with the containers 4466** used to hold those values. 4467*/ 4468const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4469const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4470 4471/* 4472** CAPI3REF: Evaluate An SQL Statement 4473** METHOD: sqlite3_stmt 4474** 4475** After a [prepared statement] has been prepared using any of 4476** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4477** or [sqlite3_prepare16_v3()] or one of the legacy 4478** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4479** must be called one or more times to evaluate the statement. 4480** 4481** The details of the behavior of the sqlite3_step() interface depend 4482** on whether the statement was prepared using the newer "vX" interfaces 4483** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4484** [sqlite3_prepare16_v2()] or the older legacy 4485** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4486** new "vX" interface is recommended for new applications but the legacy 4487** interface will continue to be supported. 4488** 4489** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4490** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4491** ^With the "v2" interface, any of the other [result codes] or 4492** [extended result codes] might be returned as well. 4493** 4494** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4495** database locks it needs to do its job. ^If the statement is a [COMMIT] 4496** or occurs outside of an explicit transaction, then you can retry the 4497** statement. If the statement is not a [COMMIT] and occurs within an 4498** explicit transaction then you should rollback the transaction before 4499** continuing. 4500** 4501** ^[SQLITE_DONE] means that the statement has finished executing 4502** successfully. sqlite3_step() should not be called again on this virtual 4503** machine without first calling [sqlite3_reset()] to reset the virtual 4504** machine back to its initial state. 4505** 4506** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4507** is returned each time a new row of data is ready for processing by the 4508** caller. The values may be accessed using the [column access functions]. 4509** sqlite3_step() is called again to retrieve the next row of data. 4510** 4511** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4512** violation) has occurred. sqlite3_step() should not be called again on 4513** the VM. More information may be found by calling [sqlite3_errmsg()]. 4514** ^With the legacy interface, a more specific error code (for example, 4515** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4516** can be obtained by calling [sqlite3_reset()] on the 4517** [prepared statement]. ^In the "v2" interface, 4518** the more specific error code is returned directly by sqlite3_step(). 4519** 4520** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4521** Perhaps it was called on a [prepared statement] that has 4522** already been [sqlite3_finalize | finalized] or on one that had 4523** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4524** be the case that the same database connection is being used by two or 4525** more threads at the same moment in time. 4526** 4527** For all versions of SQLite up to and including 3.6.23.1, a call to 4528** [sqlite3_reset()] was required after sqlite3_step() returned anything 4529** other than [SQLITE_ROW] before any subsequent invocation of 4530** sqlite3_step(). Failure to reset the prepared statement using 4531** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4532** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4533** sqlite3_step() began 4534** calling [sqlite3_reset()] automatically in this circumstance rather 4535** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4536** break because any application that ever receives an SQLITE_MISUSE error 4537** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4538** can be used to restore the legacy behavior. 4539** 4540** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4541** API always returns a generic error code, [SQLITE_ERROR], following any 4542** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4543** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4544** specific [error codes] that better describes the error. 4545** We admit that this is a goofy design. The problem has been fixed 4546** with the "v2" interface. If you prepare all of your SQL statements 4547** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4548** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4549** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4550** then the more specific [error codes] are returned directly 4551** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4552*/ 4553int sqlite3_step(sqlite3_stmt*); 4554 4555/* 4556** CAPI3REF: Number of columns in a result set 4557** METHOD: sqlite3_stmt 4558** 4559** ^The sqlite3_data_count(P) interface returns the number of columns in the 4560** current row of the result set of [prepared statement] P. 4561** ^If prepared statement P does not have results ready to return 4562** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4563** interfaces) then sqlite3_data_count(P) returns 0. 4564** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4565** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4566** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4567** will return non-zero if previous call to [sqlite3_step](P) returned 4568** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4569** where it always returns zero since each step of that multi-step 4570** pragma returns 0 columns of data. 4571** 4572** See also: [sqlite3_column_count()] 4573*/ 4574int sqlite3_data_count(sqlite3_stmt *pStmt); 4575 4576/* 4577** CAPI3REF: Fundamental Datatypes 4578** KEYWORDS: SQLITE_TEXT 4579** 4580** ^(Every value in SQLite has one of five fundamental datatypes: 4581** 4582** <ul> 4583** <li> 64-bit signed integer 4584** <li> 64-bit IEEE floating point number 4585** <li> string 4586** <li> BLOB 4587** <li> NULL 4588** </ul>)^ 4589** 4590** These constants are codes for each of those types. 4591** 4592** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4593** for a completely different meaning. Software that links against both 4594** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4595** SQLITE_TEXT. 4596*/ 4597#define SQLITE_INTEGER 1 4598#define SQLITE_FLOAT 2 4599#define SQLITE_BLOB 4 4600#define SQLITE_NULL 5 4601#ifdef SQLITE_TEXT 4602# undef SQLITE_TEXT 4603#else 4604# define SQLITE_TEXT 3 4605#endif 4606#define SQLITE3_TEXT 3 4607 4608/* 4609** CAPI3REF: Result Values From A Query 4610** KEYWORDS: {column access functions} 4611** METHOD: sqlite3_stmt 4612** 4613** <b>Summary:</b> 4614** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4615** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4616** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4617** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4618** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4619** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4620** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4621** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4622** [sqlite3_value|unprotected sqlite3_value] object. 4623** <tr><td> <td> <td> 4624** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4625** or a UTF-8 TEXT result in bytes 4626** <tr><td><b>sqlite3_column_bytes16 </b> 4627** <td>→ <td>Size of UTF-16 4628** TEXT in bytes 4629** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4630** datatype of the result 4631** </table></blockquote> 4632** 4633** <b>Details:</b> 4634** 4635** ^These routines return information about a single column of the current 4636** result row of a query. ^In every case the first argument is a pointer 4637** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4638** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4639** and the second argument is the index of the column for which information 4640** should be returned. ^The leftmost column of the result set has the index 0. 4641** ^The number of columns in the result can be determined using 4642** [sqlite3_column_count()]. 4643** 4644** If the SQL statement does not currently point to a valid row, or if the 4645** column index is out of range, the result is undefined. 4646** These routines may only be called when the most recent call to 4647** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4648** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4649** If any of these routines are called after [sqlite3_reset()] or 4650** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4651** something other than [SQLITE_ROW], the results are undefined. 4652** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4653** are called from a different thread while any of these routines 4654** are pending, then the results are undefined. 4655** 4656** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4657** each return the value of a result column in a specific data format. If 4658** the result column is not initially in the requested format (for example, 4659** if the query returns an integer but the sqlite3_column_text() interface 4660** is used to extract the value) then an automatic type conversion is performed. 4661** 4662** ^The sqlite3_column_type() routine returns the 4663** [SQLITE_INTEGER | datatype code] for the initial data type 4664** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4665** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4666** The return value of sqlite3_column_type() can be used to decide which 4667** of the first six interface should be used to extract the column value. 4668** The value returned by sqlite3_column_type() is only meaningful if no 4669** automatic type conversions have occurred for the value in question. 4670** After a type conversion, the result of calling sqlite3_column_type() 4671** is undefined, though harmless. Future 4672** versions of SQLite may change the behavior of sqlite3_column_type() 4673** following a type conversion. 4674** 4675** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4676** or sqlite3_column_bytes16() interfaces can be used to determine the size 4677** of that BLOB or string. 4678** 4679** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4680** routine returns the number of bytes in that BLOB or string. 4681** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4682** the string to UTF-8 and then returns the number of bytes. 4683** ^If the result is a numeric value then sqlite3_column_bytes() uses 4684** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4685** the number of bytes in that string. 4686** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4687** 4688** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4689** routine returns the number of bytes in that BLOB or string. 4690** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4691** the string to UTF-16 and then returns the number of bytes. 4692** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4693** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4694** the number of bytes in that string. 4695** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4696** 4697** ^The values returned by [sqlite3_column_bytes()] and 4698** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4699** of the string. ^For clarity: the values returned by 4700** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4701** bytes in the string, not the number of characters. 4702** 4703** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4704** even empty strings, are always zero-terminated. ^The return 4705** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4706** 4707** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4708** [unprotected sqlite3_value] object. In a multithreaded environment, 4709** an unprotected sqlite3_value object may only be used safely with 4710** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4711** If the [unprotected sqlite3_value] object returned by 4712** [sqlite3_column_value()] is used in any other way, including calls 4713** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4714** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4715** Hence, the sqlite3_column_value() interface 4716** is normally only useful within the implementation of 4717** [application-defined SQL functions] or [virtual tables], not within 4718** top-level application code. 4719** 4720** The these routines may attempt to convert the datatype of the result. 4721** ^For example, if the internal representation is FLOAT and a text result 4722** is requested, [sqlite3_snprintf()] is used internally to perform the 4723** conversion automatically. ^(The following table details the conversions 4724** that are applied: 4725** 4726** <blockquote> 4727** <table border="1"> 4728** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4729** 4730** <tr><td> NULL <td> INTEGER <td> Result is 0 4731** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4732** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4733** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4734** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4735** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4736** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4737** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4738** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4739** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4740** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4741** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4742** <tr><td> TEXT <td> BLOB <td> No change 4743** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4744** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4745** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4746** </table> 4747** </blockquote>)^ 4748** 4749** Note that when type conversions occur, pointers returned by prior 4750** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4751** sqlite3_column_text16() may be invalidated. 4752** Type conversions and pointer invalidations might occur 4753** in the following cases: 4754** 4755** <ul> 4756** <li> The initial content is a BLOB and sqlite3_column_text() or 4757** sqlite3_column_text16() is called. A zero-terminator might 4758** need to be added to the string.</li> 4759** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4760** sqlite3_column_text16() is called. The content must be converted 4761** to UTF-16.</li> 4762** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4763** sqlite3_column_text() is called. The content must be converted 4764** to UTF-8.</li> 4765** </ul> 4766** 4767** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4768** not invalidate a prior pointer, though of course the content of the buffer 4769** that the prior pointer references will have been modified. Other kinds 4770** of conversion are done in place when it is possible, but sometimes they 4771** are not possible and in those cases prior pointers are invalidated. 4772** 4773** The safest policy is to invoke these routines 4774** in one of the following ways: 4775** 4776** <ul> 4777** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4778** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4779** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4780** </ul> 4781** 4782** In other words, you should call sqlite3_column_text(), 4783** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4784** into the desired format, then invoke sqlite3_column_bytes() or 4785** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4786** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4787** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4788** with calls to sqlite3_column_bytes(). 4789** 4790** ^The pointers returned are valid until a type conversion occurs as 4791** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4792** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4793** and BLOBs is freed automatically. Do not pass the pointers returned 4794** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4795** [sqlite3_free()]. 4796** 4797** As long as the input parameters are correct, these routines will only 4798** fail if an out-of-memory error occurs during a format conversion. 4799** Only the following subset of interfaces are subject to out-of-memory 4800** errors: 4801** 4802** <ul> 4803** <li> sqlite3_column_blob() 4804** <li> sqlite3_column_text() 4805** <li> sqlite3_column_text16() 4806** <li> sqlite3_column_bytes() 4807** <li> sqlite3_column_bytes16() 4808** </ul> 4809** 4810** If an out-of-memory error occurs, then the return value from these 4811** routines is the same as if the column had contained an SQL NULL value. 4812** Valid SQL NULL returns can be distinguished from out-of-memory errors 4813** by invoking the [sqlite3_errcode()] immediately after the suspect 4814** return value is obtained and before any 4815** other SQLite interface is called on the same [database connection]. 4816*/ 4817const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4818double sqlite3_column_double(sqlite3_stmt*, int iCol); 4819int sqlite3_column_int(sqlite3_stmt*, int iCol); 4820sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4821const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4822const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4823sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4824int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4825int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4826int sqlite3_column_type(sqlite3_stmt*, int iCol); 4827 4828/* 4829** CAPI3REF: Destroy A Prepared Statement Object 4830** DESTRUCTOR: sqlite3_stmt 4831** 4832** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4833** ^If the most recent evaluation of the statement encountered no errors 4834** or if the statement is never been evaluated, then sqlite3_finalize() returns 4835** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4836** sqlite3_finalize(S) returns the appropriate [error code] or 4837** [extended error code]. 4838** 4839** ^The sqlite3_finalize(S) routine can be called at any point during 4840** the life cycle of [prepared statement] S: 4841** before statement S is ever evaluated, after 4842** one or more calls to [sqlite3_reset()], or after any call 4843** to [sqlite3_step()] regardless of whether or not the statement has 4844** completed execution. 4845** 4846** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4847** 4848** The application must finalize every [prepared statement] in order to avoid 4849** resource leaks. It is a grievous error for the application to try to use 4850** a prepared statement after it has been finalized. Any use of a prepared 4851** statement after it has been finalized can result in undefined and 4852** undesirable behavior such as segfaults and heap corruption. 4853*/ 4854int sqlite3_finalize(sqlite3_stmt *pStmt); 4855 4856/* 4857** CAPI3REF: Reset A Prepared Statement Object 4858** METHOD: sqlite3_stmt 4859** 4860** The sqlite3_reset() function is called to reset a [prepared statement] 4861** object back to its initial state, ready to be re-executed. 4862** ^Any SQL statement variables that had values bound to them using 4863** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4864** Use [sqlite3_clear_bindings()] to reset the bindings. 4865** 4866** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4867** back to the beginning of its program. 4868** 4869** ^If the most recent call to [sqlite3_step(S)] for the 4870** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4871** or if [sqlite3_step(S)] has never before been called on S, 4872** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4873** 4874** ^If the most recent call to [sqlite3_step(S)] for the 4875** [prepared statement] S indicated an error, then 4876** [sqlite3_reset(S)] returns an appropriate [error code]. 4877** 4878** ^The [sqlite3_reset(S)] interface does not change the values 4879** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4880*/ 4881int sqlite3_reset(sqlite3_stmt *pStmt); 4882 4883/* 4884** CAPI3REF: Create Or Redefine SQL Functions 4885** KEYWORDS: {function creation routines} 4886** KEYWORDS: {application-defined SQL function} 4887** KEYWORDS: {application-defined SQL functions} 4888** METHOD: sqlite3 4889** 4890** ^These functions (collectively known as "function creation routines") 4891** are used to add SQL functions or aggregates or to redefine the behavior 4892** of existing SQL functions or aggregates. The only differences between 4893** the three "sqlite3_create_function*" routines are the text encoding 4894** expected for the second parameter (the name of the function being 4895** created) and the presence or absence of a destructor callback for 4896** the application data pointer. Function sqlite3_create_window_function() 4897** is similar, but allows the user to supply the extra callback functions 4898** needed by [aggregate window functions]. 4899** 4900** ^The first parameter is the [database connection] to which the SQL 4901** function is to be added. ^If an application uses more than one database 4902** connection then application-defined SQL functions must be added 4903** to each database connection separately. 4904** 4905** ^The second parameter is the name of the SQL function to be created or 4906** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4907** representation, exclusive of the zero-terminator. ^Note that the name 4908** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4909** ^Any attempt to create a function with a longer name 4910** will result in [SQLITE_MISUSE] being returned. 4911** 4912** ^The third parameter (nArg) 4913** is the number of arguments that the SQL function or 4914** aggregate takes. ^If this parameter is -1, then the SQL function or 4915** aggregate may take any number of arguments between 0 and the limit 4916** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4917** parameter is less than -1 or greater than 127 then the behavior is 4918** undefined. 4919** 4920** ^The fourth parameter, eTextRep, specifies what 4921** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4922** its parameters. The application should set this parameter to 4923** [SQLITE_UTF16LE] if the function implementation invokes 4924** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4925** implementation invokes [sqlite3_value_text16be()] on an input, or 4926** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4927** otherwise. ^The same SQL function may be registered multiple times using 4928** different preferred text encodings, with different implementations for 4929** each encoding. 4930** ^When multiple implementations of the same function are available, SQLite 4931** will pick the one that involves the least amount of data conversion. 4932** 4933** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4934** to signal that the function will always return the same result given 4935** the same inputs within a single SQL statement. Most SQL functions are 4936** deterministic. The built-in [random()] SQL function is an example of a 4937** function that is not deterministic. The SQLite query planner is able to 4938** perform additional optimizations on deterministic functions, so use 4939** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4940** 4941** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4942** flag, which if present prevents the function from being invoked from 4943** within VIEWs or TRIGGERs. For security reasons, the [SQLITE_DIRECTONLY] 4944** flag is recommended for any application-defined SQL function that has 4945** side-effects. 4946** 4947** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4948** function can gain access to this pointer using [sqlite3_user_data()].)^ 4949** 4950** ^The sixth, seventh and eighth parameters passed to the three 4951** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4952** pointers to C-language functions that implement the SQL function or 4953** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4954** callback only; NULL pointers must be passed as the xStep and xFinal 4955** parameters. ^An aggregate SQL function requires an implementation of xStep 4956** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4957** SQL function or aggregate, pass NULL pointers for all three function 4958** callbacks. 4959** 4960** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4961** and xInverse) passed to sqlite3_create_window_function are pointers to 4962** C-language callbacks that implement the new function. xStep and xFinal 4963** must both be non-NULL. xValue and xInverse may either both be NULL, in 4964** which case a regular aggregate function is created, or must both be 4965** non-NULL, in which case the new function may be used as either an aggregate 4966** or aggregate window function. More details regarding the implementation 4967** of aggregate window functions are 4968** [user-defined window functions|available here]. 4969** 4970** ^(If the final parameter to sqlite3_create_function_v2() or 4971** sqlite3_create_window_function() is not NULL, then it is destructor for 4972** the application data pointer. The destructor is invoked when the function 4973** is deleted, either by being overloaded or when the database connection 4974** closes.)^ ^The destructor is also invoked if the call to 4975** sqlite3_create_function_v2() fails. ^When the destructor callback is 4976** invoked, it is passed a single argument which is a copy of the application 4977** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4978** 4979** ^It is permitted to register multiple implementations of the same 4980** functions with the same name but with either differing numbers of 4981** arguments or differing preferred text encodings. ^SQLite will use 4982** the implementation that most closely matches the way in which the 4983** SQL function is used. ^A function implementation with a non-negative 4984** nArg parameter is a better match than a function implementation with 4985** a negative nArg. ^A function where the preferred text encoding 4986** matches the database encoding is a better 4987** match than a function where the encoding is different. 4988** ^A function where the encoding difference is between UTF16le and UTF16be 4989** is a closer match than a function where the encoding difference is 4990** between UTF8 and UTF16. 4991** 4992** ^Built-in functions may be overloaded by new application-defined functions. 4993** 4994** ^An application-defined function is permitted to call other 4995** SQLite interfaces. However, such calls must not 4996** close the database connection nor finalize or reset the prepared 4997** statement in which the function is running. 4998*/ 4999int sqlite3_create_function( 5000 sqlite3 *db, 5001 const char *zFunctionName, 5002 int nArg, 5003 int eTextRep, 5004 void *pApp, 5005 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5006 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5007 void (*xFinal)(sqlite3_context*) 5008); 5009int sqlite3_create_function16( 5010 sqlite3 *db, 5011 const void *zFunctionName, 5012 int nArg, 5013 int eTextRep, 5014 void *pApp, 5015 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5016 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5017 void (*xFinal)(sqlite3_context*) 5018); 5019int sqlite3_create_function_v2( 5020 sqlite3 *db, 5021 const char *zFunctionName, 5022 int nArg, 5023 int eTextRep, 5024 void *pApp, 5025 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 5026 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5027 void (*xFinal)(sqlite3_context*), 5028 void(*xDestroy)(void*) 5029); 5030int sqlite3_create_window_function( 5031 sqlite3 *db, 5032 const char *zFunctionName, 5033 int nArg, 5034 int eTextRep, 5035 void *pApp, 5036 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 5037 void (*xFinal)(sqlite3_context*), 5038 void (*xValue)(sqlite3_context*), 5039 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 5040 void(*xDestroy)(void*) 5041); 5042 5043/* 5044** CAPI3REF: Text Encodings 5045** 5046** These constant define integer codes that represent the various 5047** text encodings supported by SQLite. 5048*/ 5049#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 5050#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 5051#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 5052#define SQLITE_UTF16 4 /* Use native byte order */ 5053#define SQLITE_ANY 5 /* Deprecated */ 5054#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 5055 5056/* 5057** CAPI3REF: Function Flags 5058** 5059** These constants may be ORed together with the 5060** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 5061** to [sqlite3_create_function()], [sqlite3_create_function16()], or 5062** [sqlite3_create_function_v2()]. 5063** 5064** <dl> 5065** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd> 5066** The SQLITE_DETERMINISTIC flag means that the new function always gives 5067** the same output when the input parameters are the same. 5068** The [abs|abs() function] is deterministic, for example, but 5069** [randomblob|randomblob()] is not. Functions must 5070** be deterministic in order to be used in certain contexts such as 5071** [CHECK constraints] or [generated columns]. SQLite might also optimize 5072** deterministic functions by factoring them out of inner loops. 5073** </dd> 5074** 5075** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd> 5076** The SQLITE_INNOCUOUS flag means that the new function is unlikely 5077** to cause problems even if misused. An innocuous function should have 5078** no side effects and consume few resources. The [abs|abs() function] 5079** is an example of an innocuous function. 5080** The [load_extension() SQL function] is not innocuous because of its 5081** side effects. Some heightened security settings 5082** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF]) 5083** disable the use of SQL functions inside views and triggers and in 5084** schema structures such as [CHECK constraints], [DEFAULT clauses], 5085** [expression indexes], [partial indexes], and [generated columns] unless 5086** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions 5087** are innocuous. Developers are advised to avoid using the 5088** SQLITE_INNOCUOUS flag for application-defined functions unless the 5089** function has been carefully audited and found to be free of potentially 5090** security-adverse side-effects and information-leaks. 5091** </dd> 5092** 5093** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd> 5094** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5095** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in 5096** schema structures such as [CHECK constraints], [DEFAULT clauses], 5097** [expression indexes], [partial indexes], or [generated columns]. This is 5098** a security feature which is recommended for all 5099** [application-defined SQL functions] that have side-effects or that 5100** could potentially leak sensitive information. 5101** </dd> 5102** 5103** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd> 5104** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5105** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5106** Specifying this flag makes no difference for scalar or aggregate user 5107** functions. However, if it is not specified for a user-defined window 5108** function, then any sub-types belonging to arguments passed to the window 5109** function may be discarded before the window function is called (i.e. 5110** sqlite3_value_subtype() will always return 0). 5111** </dd> 5112** </dl> 5113*/ 5114#define SQLITE_DETERMINISTIC 0x000000800 5115#define SQLITE_DIRECTONLY 0x000080000 5116#define SQLITE_SUBTYPE 0x000100000 5117#define SQLITE_INNOCUOUS 0x000200000 5118 5119/* 5120** CAPI3REF: Deprecated Functions 5121** DEPRECATED 5122** 5123** These functions are [deprecated]. In order to maintain 5124** backwards compatibility with older code, these functions continue 5125** to be supported. However, new applications should avoid 5126** the use of these functions. To encourage programmers to avoid 5127** these functions, we will not explain what they do. 5128*/ 5129#ifndef SQLITE_OMIT_DEPRECATED 5130SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5131SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5132SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5133SQLITE_DEPRECATED int sqlite3_global_recover(void); 5134SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5135SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5136 void*,sqlite3_int64); 5137#endif 5138 5139/* 5140** CAPI3REF: Obtaining SQL Values 5141** METHOD: sqlite3_value 5142** 5143** <b>Summary:</b> 5144** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5145** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5146** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5147** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5148** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5149** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5150** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5151** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5152** the native byteorder 5153** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5154** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5155** <tr><td> <td> <td> 5156** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5157** or a UTF-8 TEXT in bytes 5158** <tr><td><b>sqlite3_value_bytes16 </b> 5159** <td>→ <td>Size of UTF-16 5160** TEXT in bytes 5161** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5162** datatype of the value 5163** <tr><td><b>sqlite3_value_numeric_type </b> 5164** <td>→ <td>Best numeric datatype of the value 5165** <tr><td><b>sqlite3_value_nochange </b> 5166** <td>→ <td>True if the column is unchanged in an UPDATE 5167** against a virtual table. 5168** <tr><td><b>sqlite3_value_frombind </b> 5169** <td>→ <td>True if value originated from a [bound parameter] 5170** </table></blockquote> 5171** 5172** <b>Details:</b> 5173** 5174** These routines extract type, size, and content information from 5175** [protected sqlite3_value] objects. Protected sqlite3_value objects 5176** are used to pass parameter information into the functions that 5177** implement [application-defined SQL functions] and [virtual tables]. 5178** 5179** These routines work only with [protected sqlite3_value] objects. 5180** Any attempt to use these routines on an [unprotected sqlite3_value] 5181** is not threadsafe. 5182** 5183** ^These routines work just like the corresponding [column access functions] 5184** except that these routines take a single [protected sqlite3_value] object 5185** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5186** 5187** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5188** in the native byte-order of the host machine. ^The 5189** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5190** extract UTF-16 strings as big-endian and little-endian respectively. 5191** 5192** ^If [sqlite3_value] object V was initialized 5193** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5194** and if X and Y are strings that compare equal according to strcmp(X,Y), 5195** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5196** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5197** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5198** 5199** ^(The sqlite3_value_type(V) interface returns the 5200** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5201** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5202** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5203** Other interfaces might change the datatype for an sqlite3_value object. 5204** For example, if the datatype is initially SQLITE_INTEGER and 5205** sqlite3_value_text(V) is called to extract a text value for that 5206** integer, then subsequent calls to sqlite3_value_type(V) might return 5207** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5208** occurs is undefined and may change from one release of SQLite to the next. 5209** 5210** ^(The sqlite3_value_numeric_type() interface attempts to apply 5211** numeric affinity to the value. This means that an attempt is 5212** made to convert the value to an integer or floating point. If 5213** such a conversion is possible without loss of information (in other 5214** words, if the value is a string that looks like a number) 5215** then the conversion is performed. Otherwise no conversion occurs. 5216** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5217** 5218** ^Within the [xUpdate] method of a [virtual table], the 5219** sqlite3_value_nochange(X) interface returns true if and only if 5220** the column corresponding to X is unchanged by the UPDATE operation 5221** that the xUpdate method call was invoked to implement and if 5222** and the prior [xColumn] method call that was invoked to extracted 5223** the value for that column returned without setting a result (probably 5224** because it queried [sqlite3_vtab_nochange()] and found that the column 5225** was unchanging). ^Within an [xUpdate] method, any value for which 5226** sqlite3_value_nochange(X) is true will in all other respects appear 5227** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5228** than within an [xUpdate] method call for an UPDATE statement, then 5229** the return value is arbitrary and meaningless. 5230** 5231** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5232** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5233** interfaces. ^If X comes from an SQL literal value, or a table column, 5234** or an expression, then sqlite3_value_frombind(X) returns zero. 5235** 5236** Please pay particular attention to the fact that the pointer returned 5237** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5238** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5239** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5240** or [sqlite3_value_text16()]. 5241** 5242** These routines must be called from the same thread as 5243** the SQL function that supplied the [sqlite3_value*] parameters. 5244** 5245** As long as the input parameter is correct, these routines can only 5246** fail if an out-of-memory error occurs during a format conversion. 5247** Only the following subset of interfaces are subject to out-of-memory 5248** errors: 5249** 5250** <ul> 5251** <li> sqlite3_value_blob() 5252** <li> sqlite3_value_text() 5253** <li> sqlite3_value_text16() 5254** <li> sqlite3_value_text16le() 5255** <li> sqlite3_value_text16be() 5256** <li> sqlite3_value_bytes() 5257** <li> sqlite3_value_bytes16() 5258** </ul> 5259** 5260** If an out-of-memory error occurs, then the return value from these 5261** routines is the same as if the column had contained an SQL NULL value. 5262** Valid SQL NULL returns can be distinguished from out-of-memory errors 5263** by invoking the [sqlite3_errcode()] immediately after the suspect 5264** return value is obtained and before any 5265** other SQLite interface is called on the same [database connection]. 5266*/ 5267const void *sqlite3_value_blob(sqlite3_value*); 5268double sqlite3_value_double(sqlite3_value*); 5269int sqlite3_value_int(sqlite3_value*); 5270sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5271void *sqlite3_value_pointer(sqlite3_value*, const char*); 5272const unsigned char *sqlite3_value_text(sqlite3_value*); 5273const void *sqlite3_value_text16(sqlite3_value*); 5274const void *sqlite3_value_text16le(sqlite3_value*); 5275const void *sqlite3_value_text16be(sqlite3_value*); 5276int sqlite3_value_bytes(sqlite3_value*); 5277int sqlite3_value_bytes16(sqlite3_value*); 5278int sqlite3_value_type(sqlite3_value*); 5279int sqlite3_value_numeric_type(sqlite3_value*); 5280int sqlite3_value_nochange(sqlite3_value*); 5281int sqlite3_value_frombind(sqlite3_value*); 5282 5283/* 5284** CAPI3REF: Finding The Subtype Of SQL Values 5285** METHOD: sqlite3_value 5286** 5287** The sqlite3_value_subtype(V) function returns the subtype for 5288** an [application-defined SQL function] argument V. The subtype 5289** information can be used to pass a limited amount of context from 5290** one SQL function to another. Use the [sqlite3_result_subtype()] 5291** routine to set the subtype for the return value of an SQL function. 5292*/ 5293unsigned int sqlite3_value_subtype(sqlite3_value*); 5294 5295/* 5296** CAPI3REF: Copy And Free SQL Values 5297** METHOD: sqlite3_value 5298** 5299** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5300** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5301** is a [protected sqlite3_value] object even if the input is not. 5302** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5303** memory allocation fails. 5304** 5305** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5306** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5307** then sqlite3_value_free(V) is a harmless no-op. 5308*/ 5309sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5310void sqlite3_value_free(sqlite3_value*); 5311 5312/* 5313** CAPI3REF: Obtain Aggregate Function Context 5314** METHOD: sqlite3_context 5315** 5316** Implementations of aggregate SQL functions use this 5317** routine to allocate memory for storing their state. 5318** 5319** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5320** for a particular aggregate function, SQLite allocates 5321** N bytes of memory, zeroes out that memory, and returns a pointer 5322** to the new memory. ^On second and subsequent calls to 5323** sqlite3_aggregate_context() for the same aggregate function instance, 5324** the same buffer is returned. Sqlite3_aggregate_context() is normally 5325** called once for each invocation of the xStep callback and then one 5326** last time when the xFinal callback is invoked. ^(When no rows match 5327** an aggregate query, the xStep() callback of the aggregate function 5328** implementation is never called and xFinal() is called exactly once. 5329** In those cases, sqlite3_aggregate_context() might be called for the 5330** first time from within xFinal().)^ 5331** 5332** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5333** when first called if N is less than or equal to zero or if a memory 5334** allocate error occurs. 5335** 5336** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5337** determined by the N parameter on first successful call. Changing the 5338** value of N in any subsequents call to sqlite3_aggregate_context() within 5339** the same aggregate function instance will not resize the memory 5340** allocation.)^ Within the xFinal callback, it is customary to set 5341** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5342** pointless memory allocations occur. 5343** 5344** ^SQLite automatically frees the memory allocated by 5345** sqlite3_aggregate_context() when the aggregate query concludes. 5346** 5347** The first parameter must be a copy of the 5348** [sqlite3_context | SQL function context] that is the first parameter 5349** to the xStep or xFinal callback routine that implements the aggregate 5350** function. 5351** 5352** This routine must be called from the same thread in which 5353** the aggregate SQL function is running. 5354*/ 5355void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5356 5357/* 5358** CAPI3REF: User Data For Functions 5359** METHOD: sqlite3_context 5360** 5361** ^The sqlite3_user_data() interface returns a copy of 5362** the pointer that was the pUserData parameter (the 5th parameter) 5363** of the [sqlite3_create_function()] 5364** and [sqlite3_create_function16()] routines that originally 5365** registered the application defined function. 5366** 5367** This routine must be called from the same thread in which 5368** the application-defined function is running. 5369*/ 5370void *sqlite3_user_data(sqlite3_context*); 5371 5372/* 5373** CAPI3REF: Database Connection For Functions 5374** METHOD: sqlite3_context 5375** 5376** ^The sqlite3_context_db_handle() interface returns a copy of 5377** the pointer to the [database connection] (the 1st parameter) 5378** of the [sqlite3_create_function()] 5379** and [sqlite3_create_function16()] routines that originally 5380** registered the application defined function. 5381*/ 5382sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5383 5384/* 5385** CAPI3REF: Function Auxiliary Data 5386** METHOD: sqlite3_context 5387** 5388** These functions may be used by (non-aggregate) SQL functions to 5389** associate metadata with argument values. If the same value is passed to 5390** multiple invocations of the same SQL function during query execution, under 5391** some circumstances the associated metadata may be preserved. An example 5392** of where this might be useful is in a regular-expression matching 5393** function. The compiled version of the regular expression can be stored as 5394** metadata associated with the pattern string. 5395** Then as long as the pattern string remains the same, 5396** the compiled regular expression can be reused on multiple 5397** invocations of the same function. 5398** 5399** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5400** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5401** value to the application-defined function. ^N is zero for the left-most 5402** function argument. ^If there is no metadata 5403** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5404** returns a NULL pointer. 5405** 5406** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5407** argument of the application-defined function. ^Subsequent 5408** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5409** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5410** NULL if the metadata has been discarded. 5411** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5412** SQLite will invoke the destructor function X with parameter P exactly 5413** once, when the metadata is discarded. 5414** SQLite is free to discard the metadata at any time, including: <ul> 5415** <li> ^(when the corresponding function parameter changes)^, or 5416** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5417** SQL statement)^, or 5418** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5419** parameter)^, or 5420** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5421** allocation error occurs.)^ </ul> 5422** 5423** Note the last bullet in particular. The destructor X in 5424** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5425** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5426** should be called near the end of the function implementation and the 5427** function implementation should not make any use of P after 5428** sqlite3_set_auxdata() has been called. 5429** 5430** ^(In practice, metadata is preserved between function calls for 5431** function parameters that are compile-time constants, including literal 5432** values and [parameters] and expressions composed from the same.)^ 5433** 5434** The value of the N parameter to these interfaces should be non-negative. 5435** Future enhancements may make use of negative N values to define new 5436** kinds of function caching behavior. 5437** 5438** These routines must be called from the same thread in which 5439** the SQL function is running. 5440*/ 5441void *sqlite3_get_auxdata(sqlite3_context*, int N); 5442void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5443 5444 5445/* 5446** CAPI3REF: Constants Defining Special Destructor Behavior 5447** 5448** These are special values for the destructor that is passed in as the 5449** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5450** argument is SQLITE_STATIC, it means that the content pointer is constant 5451** and will never change. It does not need to be destroyed. ^The 5452** SQLITE_TRANSIENT value means that the content will likely change in 5453** the near future and that SQLite should make its own private copy of 5454** the content before returning. 5455** 5456** The typedef is necessary to work around problems in certain 5457** C++ compilers. 5458*/ 5459typedef void (*sqlite3_destructor_type)(void*); 5460#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5461#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5462 5463/* 5464** CAPI3REF: Setting The Result Of An SQL Function 5465** METHOD: sqlite3_context 5466** 5467** These routines are used by the xFunc or xFinal callbacks that 5468** implement SQL functions and aggregates. See 5469** [sqlite3_create_function()] and [sqlite3_create_function16()] 5470** for additional information. 5471** 5472** These functions work very much like the [parameter binding] family of 5473** functions used to bind values to host parameters in prepared statements. 5474** Refer to the [SQL parameter] documentation for additional information. 5475** 5476** ^The sqlite3_result_blob() interface sets the result from 5477** an application-defined function to be the BLOB whose content is pointed 5478** to by the second parameter and which is N bytes long where N is the 5479** third parameter. 5480** 5481** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5482** interfaces set the result of the application-defined function to be 5483** a BLOB containing all zero bytes and N bytes in size. 5484** 5485** ^The sqlite3_result_double() interface sets the result from 5486** an application-defined function to be a floating point value specified 5487** by its 2nd argument. 5488** 5489** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5490** cause the implemented SQL function to throw an exception. 5491** ^SQLite uses the string pointed to by the 5492** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5493** as the text of an error message. ^SQLite interprets the error 5494** message string from sqlite3_result_error() as UTF-8. ^SQLite 5495** interprets the string from sqlite3_result_error16() as UTF-16 in native 5496** byte order. ^If the third parameter to sqlite3_result_error() 5497** or sqlite3_result_error16() is negative then SQLite takes as the error 5498** message all text up through the first zero character. 5499** ^If the third parameter to sqlite3_result_error() or 5500** sqlite3_result_error16() is non-negative then SQLite takes that many 5501** bytes (not characters) from the 2nd parameter as the error message. 5502** ^The sqlite3_result_error() and sqlite3_result_error16() 5503** routines make a private copy of the error message text before 5504** they return. Hence, the calling function can deallocate or 5505** modify the text after they return without harm. 5506** ^The sqlite3_result_error_code() function changes the error code 5507** returned by SQLite as a result of an error in a function. ^By default, 5508** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5509** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5510** 5511** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5512** error indicating that a string or BLOB is too long to represent. 5513** 5514** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5515** error indicating that a memory allocation failed. 5516** 5517** ^The sqlite3_result_int() interface sets the return value 5518** of the application-defined function to be the 32-bit signed integer 5519** value given in the 2nd argument. 5520** ^The sqlite3_result_int64() interface sets the return value 5521** of the application-defined function to be the 64-bit signed integer 5522** value given in the 2nd argument. 5523** 5524** ^The sqlite3_result_null() interface sets the return value 5525** of the application-defined function to be NULL. 5526** 5527** ^The sqlite3_result_text(), sqlite3_result_text16(), 5528** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5529** set the return value of the application-defined function to be 5530** a text string which is represented as UTF-8, UTF-16 native byte order, 5531** UTF-16 little endian, or UTF-16 big endian, respectively. 5532** ^The sqlite3_result_text64() interface sets the return value of an 5533** application-defined function to be a text string in an encoding 5534** specified by the fifth (and last) parameter, which must be one 5535** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5536** ^SQLite takes the text result from the application from 5537** the 2nd parameter of the sqlite3_result_text* interfaces. 5538** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5539** is negative, then SQLite takes result text from the 2nd parameter 5540** through the first zero character. 5541** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5542** is non-negative, then as many bytes (not characters) of the text 5543** pointed to by the 2nd parameter are taken as the application-defined 5544** function result. If the 3rd parameter is non-negative, then it 5545** must be the byte offset into the string where the NUL terminator would 5546** appear if the string where NUL terminated. If any NUL characters occur 5547** in the string at a byte offset that is less than the value of the 3rd 5548** parameter, then the resulting string will contain embedded NULs and the 5549** result of expressions operating on strings with embedded NULs is undefined. 5550** ^If the 4th parameter to the sqlite3_result_text* interfaces 5551** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5552** function as the destructor on the text or BLOB result when it has 5553** finished using that result. 5554** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5555** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5556** assumes that the text or BLOB result is in constant space and does not 5557** copy the content of the parameter nor call a destructor on the content 5558** when it has finished using that result. 5559** ^If the 4th parameter to the sqlite3_result_text* interfaces 5560** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5561** then SQLite makes a copy of the result into space obtained 5562** from [sqlite3_malloc()] before it returns. 5563** 5564** ^The sqlite3_result_value() interface sets the result of 5565** the application-defined function to be a copy of the 5566** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5567** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5568** so that the [sqlite3_value] specified in the parameter may change or 5569** be deallocated after sqlite3_result_value() returns without harm. 5570** ^A [protected sqlite3_value] object may always be used where an 5571** [unprotected sqlite3_value] object is required, so either 5572** kind of [sqlite3_value] object can be used with this interface. 5573** 5574** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5575** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5576** also associates the host-language pointer P or type T with that 5577** NULL value such that the pointer can be retrieved within an 5578** [application-defined SQL function] using [sqlite3_value_pointer()]. 5579** ^If the D parameter is not NULL, then it is a pointer to a destructor 5580** for the P parameter. ^SQLite invokes D with P as its only argument 5581** when SQLite is finished with P. The T parameter should be a static 5582** string and preferably a string literal. The sqlite3_result_pointer() 5583** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5584** 5585** If these routines are called from within the different thread 5586** than the one containing the application-defined function that received 5587** the [sqlite3_context] pointer, the results are undefined. 5588*/ 5589void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5590void sqlite3_result_blob64(sqlite3_context*,const void*, 5591 sqlite3_uint64,void(*)(void*)); 5592void sqlite3_result_double(sqlite3_context*, double); 5593void sqlite3_result_error(sqlite3_context*, const char*, int); 5594void sqlite3_result_error16(sqlite3_context*, const void*, int); 5595void sqlite3_result_error_toobig(sqlite3_context*); 5596void sqlite3_result_error_nomem(sqlite3_context*); 5597void sqlite3_result_error_code(sqlite3_context*, int); 5598void sqlite3_result_int(sqlite3_context*, int); 5599void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5600void sqlite3_result_null(sqlite3_context*); 5601void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5602void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5603 void(*)(void*), unsigned char encoding); 5604void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5605void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5606void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5607void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5608void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5609void sqlite3_result_zeroblob(sqlite3_context*, int n); 5610int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5611 5612 5613/* 5614** CAPI3REF: Setting The Subtype Of An SQL Function 5615** METHOD: sqlite3_context 5616** 5617** The sqlite3_result_subtype(C,T) function causes the subtype of 5618** the result from the [application-defined SQL function] with 5619** [sqlite3_context] C to be the value T. Only the lower 8 bits 5620** of the subtype T are preserved in current versions of SQLite; 5621** higher order bits are discarded. 5622** The number of subtype bytes preserved by SQLite might increase 5623** in future releases of SQLite. 5624*/ 5625void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5626 5627/* 5628** CAPI3REF: Define New Collating Sequences 5629** METHOD: sqlite3 5630** 5631** ^These functions add, remove, or modify a [collation] associated 5632** with the [database connection] specified as the first argument. 5633** 5634** ^The name of the collation is a UTF-8 string 5635** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5636** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5637** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5638** considered to be the same name. 5639** 5640** ^(The third argument (eTextRep) must be one of the constants: 5641** <ul> 5642** <li> [SQLITE_UTF8], 5643** <li> [SQLITE_UTF16LE], 5644** <li> [SQLITE_UTF16BE], 5645** <li> [SQLITE_UTF16], or 5646** <li> [SQLITE_UTF16_ALIGNED]. 5647** </ul>)^ 5648** ^The eTextRep argument determines the encoding of strings passed 5649** to the collating function callback, xCompare. 5650** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5651** force strings to be UTF16 with native byte order. 5652** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5653** on an even byte address. 5654** 5655** ^The fourth argument, pArg, is an application data pointer that is passed 5656** through as the first argument to the collating function callback. 5657** 5658** ^The fifth argument, xCompare, is a pointer to the collating function. 5659** ^Multiple collating functions can be registered using the same name but 5660** with different eTextRep parameters and SQLite will use whichever 5661** function requires the least amount of data transformation. 5662** ^If the xCompare argument is NULL then the collating function is 5663** deleted. ^When all collating functions having the same name are deleted, 5664** that collation is no longer usable. 5665** 5666** ^The collating function callback is invoked with a copy of the pArg 5667** application data pointer and with two strings in the encoding specified 5668** by the eTextRep argument. The two integer parameters to the collating 5669** function callback are the length of the two strings, in bytes. The collating 5670** function must return an integer that is negative, zero, or positive 5671** if the first string is less than, equal to, or greater than the second, 5672** respectively. A collating function must always return the same answer 5673** given the same inputs. If two or more collating functions are registered 5674** to the same collation name (using different eTextRep values) then all 5675** must give an equivalent answer when invoked with equivalent strings. 5676** The collating function must obey the following properties for all 5677** strings A, B, and C: 5678** 5679** <ol> 5680** <li> If A==B then B==A. 5681** <li> If A==B and B==C then A==C. 5682** <li> If A<B THEN B>A. 5683** <li> If A<B and B<C then A<C. 5684** </ol> 5685** 5686** If a collating function fails any of the above constraints and that 5687** collating function is registered and used, then the behavior of SQLite 5688** is undefined. 5689** 5690** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5691** with the addition that the xDestroy callback is invoked on pArg when 5692** the collating function is deleted. 5693** ^Collating functions are deleted when they are overridden by later 5694** calls to the collation creation functions or when the 5695** [database connection] is closed using [sqlite3_close()]. 5696** 5697** ^The xDestroy callback is <u>not</u> called if the 5698** sqlite3_create_collation_v2() function fails. Applications that invoke 5699** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5700** check the return code and dispose of the application data pointer 5701** themselves rather than expecting SQLite to deal with it for them. 5702** This is different from every other SQLite interface. The inconsistency 5703** is unfortunate but cannot be changed without breaking backwards 5704** compatibility. 5705** 5706** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5707*/ 5708int sqlite3_create_collation( 5709 sqlite3*, 5710 const char *zName, 5711 int eTextRep, 5712 void *pArg, 5713 int(*xCompare)(void*,int,const void*,int,const void*) 5714); 5715int sqlite3_create_collation_v2( 5716 sqlite3*, 5717 const char *zName, 5718 int eTextRep, 5719 void *pArg, 5720 int(*xCompare)(void*,int,const void*,int,const void*), 5721 void(*xDestroy)(void*) 5722); 5723int sqlite3_create_collation16( 5724 sqlite3*, 5725 const void *zName, 5726 int eTextRep, 5727 void *pArg, 5728 int(*xCompare)(void*,int,const void*,int,const void*) 5729); 5730 5731/* 5732** CAPI3REF: Collation Needed Callbacks 5733** METHOD: sqlite3 5734** 5735** ^To avoid having to register all collation sequences before a database 5736** can be used, a single callback function may be registered with the 5737** [database connection] to be invoked whenever an undefined collation 5738** sequence is required. 5739** 5740** ^If the function is registered using the sqlite3_collation_needed() API, 5741** then it is passed the names of undefined collation sequences as strings 5742** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5743** the names are passed as UTF-16 in machine native byte order. 5744** ^A call to either function replaces the existing collation-needed callback. 5745** 5746** ^(When the callback is invoked, the first argument passed is a copy 5747** of the second argument to sqlite3_collation_needed() or 5748** sqlite3_collation_needed16(). The second argument is the database 5749** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5750** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5751** sequence function required. The fourth parameter is the name of the 5752** required collation sequence.)^ 5753** 5754** The callback function should register the desired collation using 5755** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5756** [sqlite3_create_collation_v2()]. 5757*/ 5758int sqlite3_collation_needed( 5759 sqlite3*, 5760 void*, 5761 void(*)(void*,sqlite3*,int eTextRep,const char*) 5762); 5763int sqlite3_collation_needed16( 5764 sqlite3*, 5765 void*, 5766 void(*)(void*,sqlite3*,int eTextRep,const void*) 5767); 5768 5769#ifdef SQLITE_HAS_CODEC 5770/* 5771** Specify the key for an encrypted database. This routine should be 5772** called right after sqlite3_open(). 5773** 5774** The code to implement this API is not available in the public release 5775** of SQLite. 5776*/ 5777int sqlite3_key( 5778 sqlite3 *db, /* Database to be rekeyed */ 5779 const void *pKey, int nKey /* The key */ 5780); 5781int sqlite3_key_v2( 5782 sqlite3 *db, /* Database to be rekeyed */ 5783 const char *zDbName, /* Name of the database */ 5784 const void *pKey, int nKey /* The key */ 5785); 5786 5787/* 5788** Change the key on an open database. If the current database is not 5789** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5790** database is decrypted. 5791** 5792** The code to implement this API is not available in the public release 5793** of SQLite. 5794*/ 5795int sqlite3_rekey( 5796 sqlite3 *db, /* Database to be rekeyed */ 5797 const void *pKey, int nKey /* The new key */ 5798); 5799int sqlite3_rekey_v2( 5800 sqlite3 *db, /* Database to be rekeyed */ 5801 const char *zDbName, /* Name of the database */ 5802 const void *pKey, int nKey /* The new key */ 5803); 5804 5805/* 5806** Specify the activation key for a SEE database. Unless 5807** activated, none of the SEE routines will work. 5808*/ 5809void sqlite3_activate_see( 5810 const char *zPassPhrase /* Activation phrase */ 5811); 5812#endif 5813 5814#ifdef SQLITE_ENABLE_CEROD 5815/* 5816** Specify the activation key for a CEROD database. Unless 5817** activated, none of the CEROD routines will work. 5818*/ 5819void sqlite3_activate_cerod( 5820 const char *zPassPhrase /* Activation phrase */ 5821); 5822#endif 5823 5824/* 5825** CAPI3REF: Suspend Execution For A Short Time 5826** 5827** The sqlite3_sleep() function causes the current thread to suspend execution 5828** for at least a number of milliseconds specified in its parameter. 5829** 5830** If the operating system does not support sleep requests with 5831** millisecond time resolution, then the time will be rounded up to 5832** the nearest second. The number of milliseconds of sleep actually 5833** requested from the operating system is returned. 5834** 5835** ^SQLite implements this interface by calling the xSleep() 5836** method of the default [sqlite3_vfs] object. If the xSleep() method 5837** of the default VFS is not implemented correctly, or not implemented at 5838** all, then the behavior of sqlite3_sleep() may deviate from the description 5839** in the previous paragraphs. 5840*/ 5841int sqlite3_sleep(int); 5842 5843/* 5844** CAPI3REF: Name Of The Folder Holding Temporary Files 5845** 5846** ^(If this global variable is made to point to a string which is 5847** the name of a folder (a.k.a. directory), then all temporary files 5848** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5849** will be placed in that directory.)^ ^If this variable 5850** is a NULL pointer, then SQLite performs a search for an appropriate 5851** temporary file directory. 5852** 5853** Applications are strongly discouraged from using this global variable. 5854** It is required to set a temporary folder on Windows Runtime (WinRT). 5855** But for all other platforms, it is highly recommended that applications 5856** neither read nor write this variable. This global variable is a relic 5857** that exists for backwards compatibility of legacy applications and should 5858** be avoided in new projects. 5859** 5860** It is not safe to read or modify this variable in more than one 5861** thread at a time. It is not safe to read or modify this variable 5862** if a [database connection] is being used at the same time in a separate 5863** thread. 5864** It is intended that this variable be set once 5865** as part of process initialization and before any SQLite interface 5866** routines have been called and that this variable remain unchanged 5867** thereafter. 5868** 5869** ^The [temp_store_directory pragma] may modify this variable and cause 5870** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5871** the [temp_store_directory pragma] always assumes that any string 5872** that this variable points to is held in memory obtained from 5873** [sqlite3_malloc] and the pragma may attempt to free that memory 5874** using [sqlite3_free]. 5875** Hence, if this variable is modified directly, either it should be 5876** made NULL or made to point to memory obtained from [sqlite3_malloc] 5877** or else the use of the [temp_store_directory pragma] should be avoided. 5878** Except when requested by the [temp_store_directory pragma], SQLite 5879** does not free the memory that sqlite3_temp_directory points to. If 5880** the application wants that memory to be freed, it must do 5881** so itself, taking care to only do so after all [database connection] 5882** objects have been destroyed. 5883** 5884** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5885** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5886** features that require the use of temporary files may fail. Here is an 5887** example of how to do this using C++ with the Windows Runtime: 5888** 5889** <blockquote><pre> 5890** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5891** TemporaryFolder->Path->Data(); 5892** char zPathBuf[MAX_PATH + 1]; 5893** memset(zPathBuf, 0, sizeof(zPathBuf)); 5894** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5895** NULL, NULL); 5896** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5897** </pre></blockquote> 5898*/ 5899SQLITE_EXTERN char *sqlite3_temp_directory; 5900 5901/* 5902** CAPI3REF: Name Of The Folder Holding Database Files 5903** 5904** ^(If this global variable is made to point to a string which is 5905** the name of a folder (a.k.a. directory), then all database files 5906** specified with a relative pathname and created or accessed by 5907** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5908** to be relative to that directory.)^ ^If this variable is a NULL 5909** pointer, then SQLite assumes that all database files specified 5910** with a relative pathname are relative to the current directory 5911** for the process. Only the windows VFS makes use of this global 5912** variable; it is ignored by the unix VFS. 5913** 5914** Changing the value of this variable while a database connection is 5915** open can result in a corrupt database. 5916** 5917** It is not safe to read or modify this variable in more than one 5918** thread at a time. It is not safe to read or modify this variable 5919** if a [database connection] is being used at the same time in a separate 5920** thread. 5921** It is intended that this variable be set once 5922** as part of process initialization and before any SQLite interface 5923** routines have been called and that this variable remain unchanged 5924** thereafter. 5925** 5926** ^The [data_store_directory pragma] may modify this variable and cause 5927** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5928** the [data_store_directory pragma] always assumes that any string 5929** that this variable points to is held in memory obtained from 5930** [sqlite3_malloc] and the pragma may attempt to free that memory 5931** using [sqlite3_free]. 5932** Hence, if this variable is modified directly, either it should be 5933** made NULL or made to point to memory obtained from [sqlite3_malloc] 5934** or else the use of the [data_store_directory pragma] should be avoided. 5935*/ 5936SQLITE_EXTERN char *sqlite3_data_directory; 5937 5938/* 5939** CAPI3REF: Win32 Specific Interface 5940** 5941** These interfaces are available only on Windows. The 5942** [sqlite3_win32_set_directory] interface is used to set the value associated 5943** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5944** zValue, depending on the value of the type parameter. The zValue parameter 5945** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5946** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5947** prior to being used. The [sqlite3_win32_set_directory] interface returns 5948** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5949** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5950** [sqlite3_data_directory] variable is intended to act as a replacement for 5951** the current directory on the sub-platforms of Win32 where that concept is 5952** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5953** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5954** sqlite3_win32_set_directory interface except the string parameter must be 5955** UTF-8 or UTF-16, respectively. 5956*/ 5957int sqlite3_win32_set_directory( 5958 unsigned long type, /* Identifier for directory being set or reset */ 5959 void *zValue /* New value for directory being set or reset */ 5960); 5961int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5962int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5963 5964/* 5965** CAPI3REF: Win32 Directory Types 5966** 5967** These macros are only available on Windows. They define the allowed values 5968** for the type argument to the [sqlite3_win32_set_directory] interface. 5969*/ 5970#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5971#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5972 5973/* 5974** CAPI3REF: Test For Auto-Commit Mode 5975** KEYWORDS: {autocommit mode} 5976** METHOD: sqlite3 5977** 5978** ^The sqlite3_get_autocommit() interface returns non-zero or 5979** zero if the given database connection is or is not in autocommit mode, 5980** respectively. ^Autocommit mode is on by default. 5981** ^Autocommit mode is disabled by a [BEGIN] statement. 5982** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5983** 5984** If certain kinds of errors occur on a statement within a multi-statement 5985** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5986** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5987** transaction might be rolled back automatically. The only way to 5988** find out whether SQLite automatically rolled back the transaction after 5989** an error is to use this function. 5990** 5991** If another thread changes the autocommit status of the database 5992** connection while this routine is running, then the return value 5993** is undefined. 5994*/ 5995int sqlite3_get_autocommit(sqlite3*); 5996 5997/* 5998** CAPI3REF: Find The Database Handle Of A Prepared Statement 5999** METHOD: sqlite3_stmt 6000** 6001** ^The sqlite3_db_handle interface returns the [database connection] handle 6002** to which a [prepared statement] belongs. ^The [database connection] 6003** returned by sqlite3_db_handle is the same [database connection] 6004** that was the first argument 6005** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 6006** create the statement in the first place. 6007*/ 6008sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 6009 6010/* 6011** CAPI3REF: Return The Filename For A Database Connection 6012** METHOD: sqlite3 6013** 6014** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 6015** associated with database N of connection D. 6016** ^If there is no attached database N on the database 6017** connection D, or if database N is a temporary or in-memory database, then 6018** this function will return either a NULL pointer or an empty string. 6019** 6020** ^The string value returned by this routine is owned and managed by 6021** the database connection. ^The value will be valid until the database N 6022** is [DETACH]-ed or until the database connection closes. 6023** 6024** ^The filename returned by this function is the output of the 6025** xFullPathname method of the [VFS]. ^In other words, the filename 6026** will be an absolute pathname, even if the filename used 6027** to open the database originally was a URI or relative pathname. 6028** 6029** If the filename pointer returned by this routine is not NULL, then it 6030** can be used as the filename input parameter to these routines: 6031** <ul> 6032** <li> [sqlite3_uri_parameter()] 6033** <li> [sqlite3_uri_boolean()] 6034** <li> [sqlite3_uri_int64()] 6035** <li> [sqlite3_filename_database()] 6036** <li> [sqlite3_filename_journal()] 6037** <li> [sqlite3_filename_wal()] 6038** </ul> 6039*/ 6040const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 6041 6042/* 6043** CAPI3REF: Determine if a database is read-only 6044** METHOD: sqlite3 6045** 6046** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 6047** of connection D is read-only, 0 if it is read/write, or -1 if N is not 6048** the name of a database on connection D. 6049*/ 6050int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 6051 6052/* 6053** CAPI3REF: Find the next prepared statement 6054** METHOD: sqlite3 6055** 6056** ^This interface returns a pointer to the next [prepared statement] after 6057** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 6058** then this interface returns a pointer to the first prepared statement 6059** associated with the database connection pDb. ^If no prepared statement 6060** satisfies the conditions of this routine, it returns NULL. 6061** 6062** The [database connection] pointer D in a call to 6063** [sqlite3_next_stmt(D,S)] must refer to an open database 6064** connection and in particular must not be a NULL pointer. 6065*/ 6066sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 6067 6068/* 6069** CAPI3REF: Commit And Rollback Notification Callbacks 6070** METHOD: sqlite3 6071** 6072** ^The sqlite3_commit_hook() interface registers a callback 6073** function to be invoked whenever a transaction is [COMMIT | committed]. 6074** ^Any callback set by a previous call to sqlite3_commit_hook() 6075** for the same database connection is overridden. 6076** ^The sqlite3_rollback_hook() interface registers a callback 6077** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 6078** ^Any callback set by a previous call to sqlite3_rollback_hook() 6079** for the same database connection is overridden. 6080** ^The pArg argument is passed through to the callback. 6081** ^If the callback on a commit hook function returns non-zero, 6082** then the commit is converted into a rollback. 6083** 6084** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 6085** return the P argument from the previous call of the same function 6086** on the same [database connection] D, or NULL for 6087** the first call for each function on D. 6088** 6089** The commit and rollback hook callbacks are not reentrant. 6090** The callback implementation must not do anything that will modify 6091** the database connection that invoked the callback. Any actions 6092** to modify the database connection must be deferred until after the 6093** completion of the [sqlite3_step()] call that triggered the commit 6094** or rollback hook in the first place. 6095** Note that running any other SQL statements, including SELECT statements, 6096** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 6097** the database connections for the meaning of "modify" in this paragraph. 6098** 6099** ^Registering a NULL function disables the callback. 6100** 6101** ^When the commit hook callback routine returns zero, the [COMMIT] 6102** operation is allowed to continue normally. ^If the commit hook 6103** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 6104** ^The rollback hook is invoked on a rollback that results from a commit 6105** hook returning non-zero, just as it would be with any other rollback. 6106** 6107** ^For the purposes of this API, a transaction is said to have been 6108** rolled back if an explicit "ROLLBACK" statement is executed, or 6109** an error or constraint causes an implicit rollback to occur. 6110** ^The rollback callback is not invoked if a transaction is 6111** automatically rolled back because the database connection is closed. 6112** 6113** See also the [sqlite3_update_hook()] interface. 6114*/ 6115void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6116void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6117 6118/* 6119** CAPI3REF: Data Change Notification Callbacks 6120** METHOD: sqlite3 6121** 6122** ^The sqlite3_update_hook() interface registers a callback function 6123** with the [database connection] identified by the first argument 6124** to be invoked whenever a row is updated, inserted or deleted in 6125** a [rowid table]. 6126** ^Any callback set by a previous call to this function 6127** for the same database connection is overridden. 6128** 6129** ^The second argument is a pointer to the function to invoke when a 6130** row is updated, inserted or deleted in a rowid table. 6131** ^The first argument to the callback is a copy of the third argument 6132** to sqlite3_update_hook(). 6133** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6134** or [SQLITE_UPDATE], depending on the operation that caused the callback 6135** to be invoked. 6136** ^The third and fourth arguments to the callback contain pointers to the 6137** database and table name containing the affected row. 6138** ^The final callback parameter is the [rowid] of the row. 6139** ^In the case of an update, this is the [rowid] after the update takes place. 6140** 6141** ^(The update hook is not invoked when internal system tables are 6142** modified (i.e. sqlite_master and sqlite_sequence).)^ 6143** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6144** 6145** ^In the current implementation, the update hook 6146** is not invoked when conflicting rows are deleted because of an 6147** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6148** invoked when rows are deleted using the [truncate optimization]. 6149** The exceptions defined in this paragraph might change in a future 6150** release of SQLite. 6151** 6152** The update hook implementation must not do anything that will modify 6153** the database connection that invoked the update hook. Any actions 6154** to modify the database connection must be deferred until after the 6155** completion of the [sqlite3_step()] call that triggered the update hook. 6156** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6157** database connections for the meaning of "modify" in this paragraph. 6158** 6159** ^The sqlite3_update_hook(D,C,P) function 6160** returns the P argument from the previous call 6161** on the same [database connection] D, or NULL for 6162** the first call on D. 6163** 6164** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6165** and [sqlite3_preupdate_hook()] interfaces. 6166*/ 6167void *sqlite3_update_hook( 6168 sqlite3*, 6169 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6170 void* 6171); 6172 6173/* 6174** CAPI3REF: Enable Or Disable Shared Pager Cache 6175** 6176** ^(This routine enables or disables the sharing of the database cache 6177** and schema data structures between [database connection | connections] 6178** to the same database. Sharing is enabled if the argument is true 6179** and disabled if the argument is false.)^ 6180** 6181** ^Cache sharing is enabled and disabled for an entire process. 6182** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6183** In prior versions of SQLite, 6184** sharing was enabled or disabled for each thread separately. 6185** 6186** ^(The cache sharing mode set by this interface effects all subsequent 6187** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6188** Existing database connections continue to use the sharing mode 6189** that was in effect at the time they were opened.)^ 6190** 6191** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6192** successfully. An [error code] is returned otherwise.)^ 6193** 6194** ^Shared cache is disabled by default. It is recommended that it stay 6195** that way. In other words, do not use this routine. This interface 6196** continues to be provided for historical compatibility, but its use is 6197** discouraged. Any use of shared cache is discouraged. If shared cache 6198** must be used, it is recommended that shared cache only be enabled for 6199** individual database connections using the [sqlite3_open_v2()] interface 6200** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6201** 6202** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6203** and will always return SQLITE_MISUSE. On those systems, 6204** shared cache mode should be enabled per-database connection via 6205** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6206** 6207** This interface is threadsafe on processors where writing a 6208** 32-bit integer is atomic. 6209** 6210** See Also: [SQLite Shared-Cache Mode] 6211*/ 6212int sqlite3_enable_shared_cache(int); 6213 6214/* 6215** CAPI3REF: Attempt To Free Heap Memory 6216** 6217** ^The sqlite3_release_memory() interface attempts to free N bytes 6218** of heap memory by deallocating non-essential memory allocations 6219** held by the database library. Memory used to cache database 6220** pages to improve performance is an example of non-essential memory. 6221** ^sqlite3_release_memory() returns the number of bytes actually freed, 6222** which might be more or less than the amount requested. 6223** ^The sqlite3_release_memory() routine is a no-op returning zero 6224** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6225** 6226** See also: [sqlite3_db_release_memory()] 6227*/ 6228int sqlite3_release_memory(int); 6229 6230/* 6231** CAPI3REF: Free Memory Used By A Database Connection 6232** METHOD: sqlite3 6233** 6234** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6235** memory as possible from database connection D. Unlike the 6236** [sqlite3_release_memory()] interface, this interface is in effect even 6237** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6238** omitted. 6239** 6240** See also: [sqlite3_release_memory()] 6241*/ 6242int sqlite3_db_release_memory(sqlite3*); 6243 6244/* 6245** CAPI3REF: Impose A Limit On Heap Size 6246** 6247** These interfaces impose limits on the amount of heap memory that will be 6248** by all database connections within a single process. 6249** 6250** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6251** soft limit on the amount of heap memory that may be allocated by SQLite. 6252** ^SQLite strives to keep heap memory utilization below the soft heap 6253** limit by reducing the number of pages held in the page cache 6254** as heap memory usages approaches the limit. 6255** ^The soft heap limit is "soft" because even though SQLite strives to stay 6256** below the limit, it will exceed the limit rather than generate 6257** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6258** is advisory only. 6259** 6260** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6261** N bytes on the amount of memory that will be allocated. ^The 6262** sqlite3_hard_heap_limit64(N) interface is similar to 6263** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6264** when the hard heap limit is reached. 6265** 6266** ^The return value from both sqlite3_soft_heap_limit64() and 6267** sqlite3_hard_heap_limit64() is the size of 6268** the heap limit prior to the call, or negative in the case of an 6269** error. ^If the argument N is negative 6270** then no change is made to the heap limit. Hence, the current 6271** size of heap limits can be determined by invoking 6272** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6273** 6274** ^Setting the heap limits to zero disables the heap limiter mechanism. 6275** 6276** ^The soft heap limit may not be greater than the hard heap limit. 6277** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6278** is invoked with a value of N that is greater than the hard heap limit, 6279** the the soft heap limit is set to the value of the hard heap limit. 6280** ^The soft heap limit is automatically enabled whenever the hard heap 6281** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6282** the soft heap limit is outside the range of 1..N, then the soft heap 6283** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6284** hard heap limit is enabled makes the soft heap limit equal to the 6285** hard heap limit. 6286** 6287** The memory allocation limits can also be adjusted using 6288** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6289** 6290** ^(The heap limits are not enforced in the current implementation 6291** if one or more of following conditions are true: 6292** 6293** <ul> 6294** <li> The limit value is set to zero. 6295** <li> Memory accounting is disabled using a combination of the 6296** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6297** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6298** <li> An alternative page cache implementation is specified using 6299** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6300** <li> The page cache allocates from its own memory pool supplied 6301** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6302** from the heap. 6303** </ul>)^ 6304** 6305** The circumstances under which SQLite will enforce the heap limits may 6306** changes in future releases of SQLite. 6307*/ 6308sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6309sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6310 6311/* 6312** CAPI3REF: Deprecated Soft Heap Limit Interface 6313** DEPRECATED 6314** 6315** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6316** interface. This routine is provided for historical compatibility 6317** only. All new applications should use the 6318** [sqlite3_soft_heap_limit64()] interface rather than this one. 6319*/ 6320SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6321 6322 6323/* 6324** CAPI3REF: Extract Metadata About A Column Of A Table 6325** METHOD: sqlite3 6326** 6327** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6328** information about column C of table T in database D 6329** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6330** interface returns SQLITE_OK and fills in the non-NULL pointers in 6331** the final five arguments with appropriate values if the specified 6332** column exists. ^The sqlite3_table_column_metadata() interface returns 6333** SQLITE_ERROR if the specified column does not exist. 6334** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6335** NULL pointer, then this routine simply checks for the existence of the 6336** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6337** does not. If the table name parameter T in a call to 6338** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6339** undefined behavior. 6340** 6341** ^The column is identified by the second, third and fourth parameters to 6342** this function. ^(The second parameter is either the name of the database 6343** (i.e. "main", "temp", or an attached database) containing the specified 6344** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6345** for the table using the same algorithm used by the database engine to 6346** resolve unqualified table references. 6347** 6348** ^The third and fourth parameters to this function are the table and column 6349** name of the desired column, respectively. 6350** 6351** ^Metadata is returned by writing to the memory locations passed as the 5th 6352** and subsequent parameters to this function. ^Any of these arguments may be 6353** NULL, in which case the corresponding element of metadata is omitted. 6354** 6355** ^(<blockquote> 6356** <table border="1"> 6357** <tr><th> Parameter <th> Output<br>Type <th> Description 6358** 6359** <tr><td> 5th <td> const char* <td> Data type 6360** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6361** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6362** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6363** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6364** </table> 6365** </blockquote>)^ 6366** 6367** ^The memory pointed to by the character pointers returned for the 6368** declaration type and collation sequence is valid until the next 6369** call to any SQLite API function. 6370** 6371** ^If the specified table is actually a view, an [error code] is returned. 6372** 6373** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6374** is not a [WITHOUT ROWID] table and an 6375** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6376** parameters are set for the explicitly declared column. ^(If there is no 6377** [INTEGER PRIMARY KEY] column, then the outputs 6378** for the [rowid] are set as follows: 6379** 6380** <pre> 6381** data type: "INTEGER" 6382** collation sequence: "BINARY" 6383** not null: 0 6384** primary key: 1 6385** auto increment: 0 6386** </pre>)^ 6387** 6388** ^This function causes all database schemas to be read from disk and 6389** parsed, if that has not already been done, and returns an error if 6390** any errors are encountered while loading the schema. 6391*/ 6392int sqlite3_table_column_metadata( 6393 sqlite3 *db, /* Connection handle */ 6394 const char *zDbName, /* Database name or NULL */ 6395 const char *zTableName, /* Table name */ 6396 const char *zColumnName, /* Column name */ 6397 char const **pzDataType, /* OUTPUT: Declared data type */ 6398 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6399 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6400 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6401 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6402); 6403 6404/* 6405** CAPI3REF: Load An Extension 6406** METHOD: sqlite3 6407** 6408** ^This interface loads an SQLite extension library from the named file. 6409** 6410** ^The sqlite3_load_extension() interface attempts to load an 6411** [SQLite extension] library contained in the file zFile. If 6412** the file cannot be loaded directly, attempts are made to load 6413** with various operating-system specific extensions added. 6414** So for example, if "samplelib" cannot be loaded, then names like 6415** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6416** be tried also. 6417** 6418** ^The entry point is zProc. 6419** ^(zProc may be 0, in which case SQLite will try to come up with an 6420** entry point name on its own. It first tries "sqlite3_extension_init". 6421** If that does not work, it constructs a name "sqlite3_X_init" where the 6422** X is consists of the lower-case equivalent of all ASCII alphabetic 6423** characters in the filename from the last "/" to the first following 6424** "." and omitting any initial "lib".)^ 6425** ^The sqlite3_load_extension() interface returns 6426** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6427** ^If an error occurs and pzErrMsg is not 0, then the 6428** [sqlite3_load_extension()] interface shall attempt to 6429** fill *pzErrMsg with error message text stored in memory 6430** obtained from [sqlite3_malloc()]. The calling function 6431** should free this memory by calling [sqlite3_free()]. 6432** 6433** ^Extension loading must be enabled using 6434** [sqlite3_enable_load_extension()] or 6435** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6436** prior to calling this API, 6437** otherwise an error will be returned. 6438** 6439** <b>Security warning:</b> It is recommended that the 6440** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6441** interface. The use of the [sqlite3_enable_load_extension()] interface 6442** should be avoided. This will keep the SQL function [load_extension()] 6443** disabled and prevent SQL injections from giving attackers 6444** access to extension loading capabilities. 6445** 6446** See also the [load_extension() SQL function]. 6447*/ 6448int sqlite3_load_extension( 6449 sqlite3 *db, /* Load the extension into this database connection */ 6450 const char *zFile, /* Name of the shared library containing extension */ 6451 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6452 char **pzErrMsg /* Put error message here if not 0 */ 6453); 6454 6455/* 6456** CAPI3REF: Enable Or Disable Extension Loading 6457** METHOD: sqlite3 6458** 6459** ^So as not to open security holes in older applications that are 6460** unprepared to deal with [extension loading], and as a means of disabling 6461** [extension loading] while evaluating user-entered SQL, the following API 6462** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6463** 6464** ^Extension loading is off by default. 6465** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6466** to turn extension loading on and call it with onoff==0 to turn 6467** it back off again. 6468** 6469** ^This interface enables or disables both the C-API 6470** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6471** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6472** to enable or disable only the C-API.)^ 6473** 6474** <b>Security warning:</b> It is recommended that extension loading 6475** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6476** rather than this interface, so the [load_extension()] SQL function 6477** remains disabled. This will prevent SQL injections from giving attackers 6478** access to extension loading capabilities. 6479*/ 6480int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6481 6482/* 6483** CAPI3REF: Automatically Load Statically Linked Extensions 6484** 6485** ^This interface causes the xEntryPoint() function to be invoked for 6486** each new [database connection] that is created. The idea here is that 6487** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6488** that is to be automatically loaded into all new database connections. 6489** 6490** ^(Even though the function prototype shows that xEntryPoint() takes 6491** no arguments and returns void, SQLite invokes xEntryPoint() with three 6492** arguments and expects an integer result as if the signature of the 6493** entry point where as follows: 6494** 6495** <blockquote><pre> 6496** int xEntryPoint( 6497** sqlite3 *db, 6498** const char **pzErrMsg, 6499** const struct sqlite3_api_routines *pThunk 6500** ); 6501** </pre></blockquote>)^ 6502** 6503** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6504** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6505** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6506** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6507** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6508** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6509** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6510** 6511** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6512** on the list of automatic extensions is a harmless no-op. ^No entry point 6513** will be called more than once for each database connection that is opened. 6514** 6515** See also: [sqlite3_reset_auto_extension()] 6516** and [sqlite3_cancel_auto_extension()] 6517*/ 6518int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6519 6520/* 6521** CAPI3REF: Cancel Automatic Extension Loading 6522** 6523** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6524** initialization routine X that was registered using a prior call to 6525** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6526** routine returns 1 if initialization routine X was successfully 6527** unregistered and it returns 0 if X was not on the list of initialization 6528** routines. 6529*/ 6530int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6531 6532/* 6533** CAPI3REF: Reset Automatic Extension Loading 6534** 6535** ^This interface disables all automatic extensions previously 6536** registered using [sqlite3_auto_extension()]. 6537*/ 6538void sqlite3_reset_auto_extension(void); 6539 6540/* 6541** The interface to the virtual-table mechanism is currently considered 6542** to be experimental. The interface might change in incompatible ways. 6543** If this is a problem for you, do not use the interface at this time. 6544** 6545** When the virtual-table mechanism stabilizes, we will declare the 6546** interface fixed, support it indefinitely, and remove this comment. 6547*/ 6548 6549/* 6550** Structures used by the virtual table interface 6551*/ 6552typedef struct sqlite3_vtab sqlite3_vtab; 6553typedef struct sqlite3_index_info sqlite3_index_info; 6554typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6555typedef struct sqlite3_module sqlite3_module; 6556 6557/* 6558** CAPI3REF: Virtual Table Object 6559** KEYWORDS: sqlite3_module {virtual table module} 6560** 6561** This structure, sometimes called a "virtual table module", 6562** defines the implementation of a [virtual table]. 6563** This structure consists mostly of methods for the module. 6564** 6565** ^A virtual table module is created by filling in a persistent 6566** instance of this structure and passing a pointer to that instance 6567** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6568** ^The registration remains valid until it is replaced by a different 6569** module or until the [database connection] closes. The content 6570** of this structure must not change while it is registered with 6571** any database connection. 6572*/ 6573struct sqlite3_module { 6574 int iVersion; 6575 int (*xCreate)(sqlite3*, void *pAux, 6576 int argc, const char *const*argv, 6577 sqlite3_vtab **ppVTab, char**); 6578 int (*xConnect)(sqlite3*, void *pAux, 6579 int argc, const char *const*argv, 6580 sqlite3_vtab **ppVTab, char**); 6581 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6582 int (*xDisconnect)(sqlite3_vtab *pVTab); 6583 int (*xDestroy)(sqlite3_vtab *pVTab); 6584 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6585 int (*xClose)(sqlite3_vtab_cursor*); 6586 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6587 int argc, sqlite3_value **argv); 6588 int (*xNext)(sqlite3_vtab_cursor*); 6589 int (*xEof)(sqlite3_vtab_cursor*); 6590 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6591 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6592 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6593 int (*xBegin)(sqlite3_vtab *pVTab); 6594 int (*xSync)(sqlite3_vtab *pVTab); 6595 int (*xCommit)(sqlite3_vtab *pVTab); 6596 int (*xRollback)(sqlite3_vtab *pVTab); 6597 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6598 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6599 void **ppArg); 6600 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6601 /* The methods above are in version 1 of the sqlite_module object. Those 6602 ** below are for version 2 and greater. */ 6603 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6604 int (*xRelease)(sqlite3_vtab *pVTab, int); 6605 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6606 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6607 ** Those below are for version 3 and greater. */ 6608 int (*xShadowName)(const char*); 6609}; 6610 6611/* 6612** CAPI3REF: Virtual Table Indexing Information 6613** KEYWORDS: sqlite3_index_info 6614** 6615** The sqlite3_index_info structure and its substructures is used as part 6616** of the [virtual table] interface to 6617** pass information into and receive the reply from the [xBestIndex] 6618** method of a [virtual table module]. The fields under **Inputs** are the 6619** inputs to xBestIndex and are read-only. xBestIndex inserts its 6620** results into the **Outputs** fields. 6621** 6622** ^(The aConstraint[] array records WHERE clause constraints of the form: 6623** 6624** <blockquote>column OP expr</blockquote> 6625** 6626** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6627** stored in aConstraint[].op using one of the 6628** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6629** ^(The index of the column is stored in 6630** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6631** expr on the right-hand side can be evaluated (and thus the constraint 6632** is usable) and false if it cannot.)^ 6633** 6634** ^The optimizer automatically inverts terms of the form "expr OP column" 6635** and makes other simplifications to the WHERE clause in an attempt to 6636** get as many WHERE clause terms into the form shown above as possible. 6637** ^The aConstraint[] array only reports WHERE clause terms that are 6638** relevant to the particular virtual table being queried. 6639** 6640** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6641** ^Each term of aOrderBy records a column of the ORDER BY clause. 6642** 6643** The colUsed field indicates which columns of the virtual table may be 6644** required by the current scan. Virtual table columns are numbered from 6645** zero in the order in which they appear within the CREATE TABLE statement 6646** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6647** the corresponding bit is set within the colUsed mask if the column may be 6648** required by SQLite. If the table has at least 64 columns and any column 6649** to the right of the first 63 is required, then bit 63 of colUsed is also 6650** set. In other words, column iCol may be required if the expression 6651** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6652** non-zero. 6653** 6654** The [xBestIndex] method must fill aConstraintUsage[] with information 6655** about what parameters to pass to xFilter. ^If argvIndex>0 then 6656** the right-hand side of the corresponding aConstraint[] is evaluated 6657** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6658** is true, then the constraint is assumed to be fully handled by the 6659** virtual table and might not be checked again by the byte code.)^ ^(The 6660** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6661** is left in its default setting of false, the constraint will always be 6662** checked separately in byte code. If the omit flag is change to true, then 6663** the constraint may or may not be checked in byte code. In other words, 6664** when the omit flag is true there is no guarantee that the constraint will 6665** not be checked again using byte code.)^ 6666** 6667** ^The idxNum and idxPtr values are recorded and passed into the 6668** [xFilter] method. 6669** ^[sqlite3_free()] is used to free idxPtr if and only if 6670** needToFreeIdxPtr is true. 6671** 6672** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6673** the correct order to satisfy the ORDER BY clause so that no separate 6674** sorting step is required. 6675** 6676** ^The estimatedCost value is an estimate of the cost of a particular 6677** strategy. A cost of N indicates that the cost of the strategy is similar 6678** to a linear scan of an SQLite table with N rows. A cost of log(N) 6679** indicates that the expense of the operation is similar to that of a 6680** binary search on a unique indexed field of an SQLite table with N rows. 6681** 6682** ^The estimatedRows value is an estimate of the number of rows that 6683** will be returned by the strategy. 6684** 6685** The xBestIndex method may optionally populate the idxFlags field with a 6686** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6687** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6688** assumes that the strategy may visit at most one row. 6689** 6690** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6691** SQLite also assumes that if a call to the xUpdate() method is made as 6692** part of the same statement to delete or update a virtual table row and the 6693** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6694** any database changes. In other words, if the xUpdate() returns 6695** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6696** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6697** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6698** the xUpdate method are automatically rolled back by SQLite. 6699** 6700** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6701** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6702** If a virtual table extension is 6703** used with an SQLite version earlier than 3.8.2, the results of attempting 6704** to read or write the estimatedRows field are undefined (but are likely 6705** to include crashing the application). The estimatedRows field should 6706** therefore only be used if [sqlite3_libversion_number()] returns a 6707** value greater than or equal to 3008002. Similarly, the idxFlags field 6708** was added for [version 3.9.0] ([dateof:3.9.0]). 6709** It may therefore only be used if 6710** sqlite3_libversion_number() returns a value greater than or equal to 6711** 3009000. 6712*/ 6713struct sqlite3_index_info { 6714 /* Inputs */ 6715 int nConstraint; /* Number of entries in aConstraint */ 6716 struct sqlite3_index_constraint { 6717 int iColumn; /* Column constrained. -1 for ROWID */ 6718 unsigned char op; /* Constraint operator */ 6719 unsigned char usable; /* True if this constraint is usable */ 6720 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6721 } *aConstraint; /* Table of WHERE clause constraints */ 6722 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6723 struct sqlite3_index_orderby { 6724 int iColumn; /* Column number */ 6725 unsigned char desc; /* True for DESC. False for ASC. */ 6726 } *aOrderBy; /* The ORDER BY clause */ 6727 /* Outputs */ 6728 struct sqlite3_index_constraint_usage { 6729 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6730 unsigned char omit; /* Do not code a test for this constraint */ 6731 } *aConstraintUsage; 6732 int idxNum; /* Number used to identify the index */ 6733 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6734 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6735 int orderByConsumed; /* True if output is already ordered */ 6736 double estimatedCost; /* Estimated cost of using this index */ 6737 /* Fields below are only available in SQLite 3.8.2 and later */ 6738 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6739 /* Fields below are only available in SQLite 3.9.0 and later */ 6740 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6741 /* Fields below are only available in SQLite 3.10.0 and later */ 6742 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6743}; 6744 6745/* 6746** CAPI3REF: Virtual Table Scan Flags 6747** 6748** Virtual table implementations are allowed to set the 6749** [sqlite3_index_info].idxFlags field to some combination of 6750** these bits. 6751*/ 6752#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6753 6754/* 6755** CAPI3REF: Virtual Table Constraint Operator Codes 6756** 6757** These macros define the allowed values for the 6758** [sqlite3_index_info].aConstraint[].op field. Each value represents 6759** an operator that is part of a constraint term in the wHERE clause of 6760** a query that uses a [virtual table]. 6761*/ 6762#define SQLITE_INDEX_CONSTRAINT_EQ 2 6763#define SQLITE_INDEX_CONSTRAINT_GT 4 6764#define SQLITE_INDEX_CONSTRAINT_LE 8 6765#define SQLITE_INDEX_CONSTRAINT_LT 16 6766#define SQLITE_INDEX_CONSTRAINT_GE 32 6767#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6768#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6769#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6770#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6771#define SQLITE_INDEX_CONSTRAINT_NE 68 6772#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6773#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6774#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6775#define SQLITE_INDEX_CONSTRAINT_IS 72 6776#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6777 6778/* 6779** CAPI3REF: Register A Virtual Table Implementation 6780** METHOD: sqlite3 6781** 6782** ^These routines are used to register a new [virtual table module] name. 6783** ^Module names must be registered before 6784** creating a new [virtual table] using the module and before using a 6785** preexisting [virtual table] for the module. 6786** 6787** ^The module name is registered on the [database connection] specified 6788** by the first parameter. ^The name of the module is given by the 6789** second parameter. ^The third parameter is a pointer to 6790** the implementation of the [virtual table module]. ^The fourth 6791** parameter is an arbitrary client data pointer that is passed through 6792** into the [xCreate] and [xConnect] methods of the virtual table module 6793** when a new virtual table is be being created or reinitialized. 6794** 6795** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6796** is a pointer to a destructor for the pClientData. ^SQLite will 6797** invoke the destructor function (if it is not NULL) when SQLite 6798** no longer needs the pClientData pointer. ^The destructor will also 6799** be invoked if the call to sqlite3_create_module_v2() fails. 6800** ^The sqlite3_create_module() 6801** interface is equivalent to sqlite3_create_module_v2() with a NULL 6802** destructor. 6803** 6804** ^If the third parameter (the pointer to the sqlite3_module object) is 6805** NULL then no new module is create and any existing modules with the 6806** same name are dropped. 6807** 6808** See also: [sqlite3_drop_modules()] 6809*/ 6810int sqlite3_create_module( 6811 sqlite3 *db, /* SQLite connection to register module with */ 6812 const char *zName, /* Name of the module */ 6813 const sqlite3_module *p, /* Methods for the module */ 6814 void *pClientData /* Client data for xCreate/xConnect */ 6815); 6816int sqlite3_create_module_v2( 6817 sqlite3 *db, /* SQLite connection to register module with */ 6818 const char *zName, /* Name of the module */ 6819 const sqlite3_module *p, /* Methods for the module */ 6820 void *pClientData, /* Client data for xCreate/xConnect */ 6821 void(*xDestroy)(void*) /* Module destructor function */ 6822); 6823 6824/* 6825** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6826** METHOD: sqlite3 6827** 6828** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6829** table modules from database connection D except those named on list L. 6830** The L parameter must be either NULL or a pointer to an array of pointers 6831** to strings where the array is terminated by a single NULL pointer. 6832** ^If the L parameter is NULL, then all virtual table modules are removed. 6833** 6834** See also: [sqlite3_create_module()] 6835*/ 6836int sqlite3_drop_modules( 6837 sqlite3 *db, /* Remove modules from this connection */ 6838 const char **azKeep /* Except, do not remove the ones named here */ 6839); 6840 6841/* 6842** CAPI3REF: Virtual Table Instance Object 6843** KEYWORDS: sqlite3_vtab 6844** 6845** Every [virtual table module] implementation uses a subclass 6846** of this object to describe a particular instance 6847** of the [virtual table]. Each subclass will 6848** be tailored to the specific needs of the module implementation. 6849** The purpose of this superclass is to define certain fields that are 6850** common to all module implementations. 6851** 6852** ^Virtual tables methods can set an error message by assigning a 6853** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6854** take care that any prior string is freed by a call to [sqlite3_free()] 6855** prior to assigning a new string to zErrMsg. ^After the error message 6856** is delivered up to the client application, the string will be automatically 6857** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6858*/ 6859struct sqlite3_vtab { 6860 const sqlite3_module *pModule; /* The module for this virtual table */ 6861 int nRef; /* Number of open cursors */ 6862 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6863 /* Virtual table implementations will typically add additional fields */ 6864}; 6865 6866/* 6867** CAPI3REF: Virtual Table Cursor Object 6868** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6869** 6870** Every [virtual table module] implementation uses a subclass of the 6871** following structure to describe cursors that point into the 6872** [virtual table] and are used 6873** to loop through the virtual table. Cursors are created using the 6874** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6875** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6876** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6877** of the module. Each module implementation will define 6878** the content of a cursor structure to suit its own needs. 6879** 6880** This superclass exists in order to define fields of the cursor that 6881** are common to all implementations. 6882*/ 6883struct sqlite3_vtab_cursor { 6884 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6885 /* Virtual table implementations will typically add additional fields */ 6886}; 6887 6888/* 6889** CAPI3REF: Declare The Schema Of A Virtual Table 6890** 6891** ^The [xCreate] and [xConnect] methods of a 6892** [virtual table module] call this interface 6893** to declare the format (the names and datatypes of the columns) of 6894** the virtual tables they implement. 6895*/ 6896int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6897 6898/* 6899** CAPI3REF: Overload A Function For A Virtual Table 6900** METHOD: sqlite3 6901** 6902** ^(Virtual tables can provide alternative implementations of functions 6903** using the [xFindFunction] method of the [virtual table module]. 6904** But global versions of those functions 6905** must exist in order to be overloaded.)^ 6906** 6907** ^(This API makes sure a global version of a function with a particular 6908** name and number of parameters exists. If no such function exists 6909** before this API is called, a new function is created.)^ ^The implementation 6910** of the new function always causes an exception to be thrown. So 6911** the new function is not good for anything by itself. Its only 6912** purpose is to be a placeholder function that can be overloaded 6913** by a [virtual table]. 6914*/ 6915int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6916 6917/* 6918** The interface to the virtual-table mechanism defined above (back up 6919** to a comment remarkably similar to this one) is currently considered 6920** to be experimental. The interface might change in incompatible ways. 6921** If this is a problem for you, do not use the interface at this time. 6922** 6923** When the virtual-table mechanism stabilizes, we will declare the 6924** interface fixed, support it indefinitely, and remove this comment. 6925*/ 6926 6927/* 6928** CAPI3REF: A Handle To An Open BLOB 6929** KEYWORDS: {BLOB handle} {BLOB handles} 6930** 6931** An instance of this object represents an open BLOB on which 6932** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6933** ^Objects of this type are created by [sqlite3_blob_open()] 6934** and destroyed by [sqlite3_blob_close()]. 6935** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6936** can be used to read or write small subsections of the BLOB. 6937** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6938*/ 6939typedef struct sqlite3_blob sqlite3_blob; 6940 6941/* 6942** CAPI3REF: Open A BLOB For Incremental I/O 6943** METHOD: sqlite3 6944** CONSTRUCTOR: sqlite3_blob 6945** 6946** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6947** in row iRow, column zColumn, table zTable in database zDb; 6948** in other words, the same BLOB that would be selected by: 6949** 6950** <pre> 6951** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6952** </pre>)^ 6953** 6954** ^(Parameter zDb is not the filename that contains the database, but 6955** rather the symbolic name of the database. For attached databases, this is 6956** the name that appears after the AS keyword in the [ATTACH] statement. 6957** For the main database file, the database name is "main". For TEMP 6958** tables, the database name is "temp".)^ 6959** 6960** ^If the flags parameter is non-zero, then the BLOB is opened for read 6961** and write access. ^If the flags parameter is zero, the BLOB is opened for 6962** read-only access. 6963** 6964** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6965** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6966** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6967** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6968** on *ppBlob after this function it returns. 6969** 6970** This function fails with SQLITE_ERROR if any of the following are true: 6971** <ul> 6972** <li> ^(Database zDb does not exist)^, 6973** <li> ^(Table zTable does not exist within database zDb)^, 6974** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6975** <li> ^(Column zColumn does not exist)^, 6976** <li> ^(Row iRow is not present in the table)^, 6977** <li> ^(The specified column of row iRow contains a value that is not 6978** a TEXT or BLOB value)^, 6979** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6980** constraint and the blob is being opened for read/write access)^, 6981** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6982** column zColumn is part of a [child key] definition and the blob is 6983** being opened for read/write access)^. 6984** </ul> 6985** 6986** ^Unless it returns SQLITE_MISUSE, this function sets the 6987** [database connection] error code and message accessible via 6988** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6989** 6990** A BLOB referenced by sqlite3_blob_open() may be read using the 6991** [sqlite3_blob_read()] interface and modified by using 6992** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6993** different row of the same table using the [sqlite3_blob_reopen()] 6994** interface. However, the column, table, or database of a [BLOB handle] 6995** cannot be changed after the [BLOB handle] is opened. 6996** 6997** ^(If the row that a BLOB handle points to is modified by an 6998** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6999** then the BLOB handle is marked as "expired". 7000** This is true if any column of the row is changed, even a column 7001** other than the one the BLOB handle is open on.)^ 7002** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 7003** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 7004** ^(Changes written into a BLOB prior to the BLOB expiring are not 7005** rolled back by the expiration of the BLOB. Such changes will eventually 7006** commit if the transaction continues to completion.)^ 7007** 7008** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 7009** the opened blob. ^The size of a blob may not be changed by this 7010** interface. Use the [UPDATE] SQL command to change the size of a 7011** blob. 7012** 7013** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 7014** and the built-in [zeroblob] SQL function may be used to create a 7015** zero-filled blob to read or write using the incremental-blob interface. 7016** 7017** To avoid a resource leak, every open [BLOB handle] should eventually 7018** be released by a call to [sqlite3_blob_close()]. 7019** 7020** See also: [sqlite3_blob_close()], 7021** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 7022** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 7023*/ 7024int sqlite3_blob_open( 7025 sqlite3*, 7026 const char *zDb, 7027 const char *zTable, 7028 const char *zColumn, 7029 sqlite3_int64 iRow, 7030 int flags, 7031 sqlite3_blob **ppBlob 7032); 7033 7034/* 7035** CAPI3REF: Move a BLOB Handle to a New Row 7036** METHOD: sqlite3_blob 7037** 7038** ^This function is used to move an existing [BLOB handle] so that it points 7039** to a different row of the same database table. ^The new row is identified 7040** by the rowid value passed as the second argument. Only the row can be 7041** changed. ^The database, table and column on which the blob handle is open 7042** remain the same. Moving an existing [BLOB handle] to a new row is 7043** faster than closing the existing handle and opening a new one. 7044** 7045** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 7046** it must exist and there must be either a blob or text value stored in 7047** the nominated column.)^ ^If the new row is not present in the table, or if 7048** it does not contain a blob or text value, or if another error occurs, an 7049** SQLite error code is returned and the blob handle is considered aborted. 7050** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 7051** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 7052** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 7053** always returns zero. 7054** 7055** ^This function sets the database handle error code and message. 7056*/ 7057int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 7058 7059/* 7060** CAPI3REF: Close A BLOB Handle 7061** DESTRUCTOR: sqlite3_blob 7062** 7063** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 7064** unconditionally. Even if this routine returns an error code, the 7065** handle is still closed.)^ 7066** 7067** ^If the blob handle being closed was opened for read-write access, and if 7068** the database is in auto-commit mode and there are no other open read-write 7069** blob handles or active write statements, the current transaction is 7070** committed. ^If an error occurs while committing the transaction, an error 7071** code is returned and the transaction rolled back. 7072** 7073** Calling this function with an argument that is not a NULL pointer or an 7074** open blob handle results in undefined behaviour. ^Calling this routine 7075** with a null pointer (such as would be returned by a failed call to 7076** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 7077** is passed a valid open blob handle, the values returned by the 7078** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 7079*/ 7080int sqlite3_blob_close(sqlite3_blob *); 7081 7082/* 7083** CAPI3REF: Return The Size Of An Open BLOB 7084** METHOD: sqlite3_blob 7085** 7086** ^Returns the size in bytes of the BLOB accessible via the 7087** successfully opened [BLOB handle] in its only argument. ^The 7088** incremental blob I/O routines can only read or overwriting existing 7089** blob content; they cannot change the size of a blob. 7090** 7091** This routine only works on a [BLOB handle] which has been created 7092** by a prior successful call to [sqlite3_blob_open()] and which has not 7093** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7094** to this routine results in undefined and probably undesirable behavior. 7095*/ 7096int sqlite3_blob_bytes(sqlite3_blob *); 7097 7098/* 7099** CAPI3REF: Read Data From A BLOB Incrementally 7100** METHOD: sqlite3_blob 7101** 7102** ^(This function is used to read data from an open [BLOB handle] into a 7103** caller-supplied buffer. N bytes of data are copied into buffer Z 7104** from the open BLOB, starting at offset iOffset.)^ 7105** 7106** ^If offset iOffset is less than N bytes from the end of the BLOB, 7107** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7108** less than zero, [SQLITE_ERROR] is returned and no data is read. 7109** ^The size of the blob (and hence the maximum value of N+iOffset) 7110** can be determined using the [sqlite3_blob_bytes()] interface. 7111** 7112** ^An attempt to read from an expired [BLOB handle] fails with an 7113** error code of [SQLITE_ABORT]. 7114** 7115** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7116** Otherwise, an [error code] or an [extended error code] is returned.)^ 7117** 7118** This routine only works on a [BLOB handle] which has been created 7119** by a prior successful call to [sqlite3_blob_open()] and which has not 7120** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7121** to this routine results in undefined and probably undesirable behavior. 7122** 7123** See also: [sqlite3_blob_write()]. 7124*/ 7125int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7126 7127/* 7128** CAPI3REF: Write Data Into A BLOB Incrementally 7129** METHOD: sqlite3_blob 7130** 7131** ^(This function is used to write data into an open [BLOB handle] from a 7132** caller-supplied buffer. N bytes of data are copied from the buffer Z 7133** into the open BLOB, starting at offset iOffset.)^ 7134** 7135** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7136** Otherwise, an [error code] or an [extended error code] is returned.)^ 7137** ^Unless SQLITE_MISUSE is returned, this function sets the 7138** [database connection] error code and message accessible via 7139** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7140** 7141** ^If the [BLOB handle] passed as the first argument was not opened for 7142** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7143** this function returns [SQLITE_READONLY]. 7144** 7145** This function may only modify the contents of the BLOB; it is 7146** not possible to increase the size of a BLOB using this API. 7147** ^If offset iOffset is less than N bytes from the end of the BLOB, 7148** [SQLITE_ERROR] is returned and no data is written. The size of the 7149** BLOB (and hence the maximum value of N+iOffset) can be determined 7150** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7151** than zero [SQLITE_ERROR] is returned and no data is written. 7152** 7153** ^An attempt to write to an expired [BLOB handle] fails with an 7154** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7155** before the [BLOB handle] expired are not rolled back by the 7156** expiration of the handle, though of course those changes might 7157** have been overwritten by the statement that expired the BLOB handle 7158** or by other independent statements. 7159** 7160** This routine only works on a [BLOB handle] which has been created 7161** by a prior successful call to [sqlite3_blob_open()] and which has not 7162** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7163** to this routine results in undefined and probably undesirable behavior. 7164** 7165** See also: [sqlite3_blob_read()]. 7166*/ 7167int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7168 7169/* 7170** CAPI3REF: Virtual File System Objects 7171** 7172** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7173** that SQLite uses to interact 7174** with the underlying operating system. Most SQLite builds come with a 7175** single default VFS that is appropriate for the host computer. 7176** New VFSes can be registered and existing VFSes can be unregistered. 7177** The following interfaces are provided. 7178** 7179** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7180** ^Names are case sensitive. 7181** ^Names are zero-terminated UTF-8 strings. 7182** ^If there is no match, a NULL pointer is returned. 7183** ^If zVfsName is NULL then the default VFS is returned. 7184** 7185** ^New VFSes are registered with sqlite3_vfs_register(). 7186** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7187** ^The same VFS can be registered multiple times without injury. 7188** ^To make an existing VFS into the default VFS, register it again 7189** with the makeDflt flag set. If two different VFSes with the 7190** same name are registered, the behavior is undefined. If a 7191** VFS is registered with a name that is NULL or an empty string, 7192** then the behavior is undefined. 7193** 7194** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7195** ^(If the default VFS is unregistered, another VFS is chosen as 7196** the default. The choice for the new VFS is arbitrary.)^ 7197*/ 7198sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7199int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7200int sqlite3_vfs_unregister(sqlite3_vfs*); 7201 7202/* 7203** CAPI3REF: Mutexes 7204** 7205** The SQLite core uses these routines for thread 7206** synchronization. Though they are intended for internal 7207** use by SQLite, code that links against SQLite is 7208** permitted to use any of these routines. 7209** 7210** The SQLite source code contains multiple implementations 7211** of these mutex routines. An appropriate implementation 7212** is selected automatically at compile-time. The following 7213** implementations are available in the SQLite core: 7214** 7215** <ul> 7216** <li> SQLITE_MUTEX_PTHREADS 7217** <li> SQLITE_MUTEX_W32 7218** <li> SQLITE_MUTEX_NOOP 7219** </ul> 7220** 7221** The SQLITE_MUTEX_NOOP implementation is a set of routines 7222** that does no real locking and is appropriate for use in 7223** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7224** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7225** and Windows. 7226** 7227** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7228** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7229** implementation is included with the library. In this case the 7230** application must supply a custom mutex implementation using the 7231** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7232** before calling sqlite3_initialize() or any other public sqlite3_ 7233** function that calls sqlite3_initialize(). 7234** 7235** ^The sqlite3_mutex_alloc() routine allocates a new 7236** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7237** routine returns NULL if it is unable to allocate the requested 7238** mutex. The argument to sqlite3_mutex_alloc() must one of these 7239** integer constants: 7240** 7241** <ul> 7242** <li> SQLITE_MUTEX_FAST 7243** <li> SQLITE_MUTEX_RECURSIVE 7244** <li> SQLITE_MUTEX_STATIC_MASTER 7245** <li> SQLITE_MUTEX_STATIC_MEM 7246** <li> SQLITE_MUTEX_STATIC_OPEN 7247** <li> SQLITE_MUTEX_STATIC_PRNG 7248** <li> SQLITE_MUTEX_STATIC_LRU 7249** <li> SQLITE_MUTEX_STATIC_PMEM 7250** <li> SQLITE_MUTEX_STATIC_APP1 7251** <li> SQLITE_MUTEX_STATIC_APP2 7252** <li> SQLITE_MUTEX_STATIC_APP3 7253** <li> SQLITE_MUTEX_STATIC_VFS1 7254** <li> SQLITE_MUTEX_STATIC_VFS2 7255** <li> SQLITE_MUTEX_STATIC_VFS3 7256** </ul> 7257** 7258** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7259** cause sqlite3_mutex_alloc() to create 7260** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7261** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7262** The mutex implementation does not need to make a distinction 7263** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7264** not want to. SQLite will only request a recursive mutex in 7265** cases where it really needs one. If a faster non-recursive mutex 7266** implementation is available on the host platform, the mutex subsystem 7267** might return such a mutex in response to SQLITE_MUTEX_FAST. 7268** 7269** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7270** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7271** a pointer to a static preexisting mutex. ^Nine static mutexes are 7272** used by the current version of SQLite. Future versions of SQLite 7273** may add additional static mutexes. Static mutexes are for internal 7274** use by SQLite only. Applications that use SQLite mutexes should 7275** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7276** SQLITE_MUTEX_RECURSIVE. 7277** 7278** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7279** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7280** returns a different mutex on every call. ^For the static 7281** mutex types, the same mutex is returned on every call that has 7282** the same type number. 7283** 7284** ^The sqlite3_mutex_free() routine deallocates a previously 7285** allocated dynamic mutex. Attempting to deallocate a static 7286** mutex results in undefined behavior. 7287** 7288** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7289** to enter a mutex. ^If another thread is already within the mutex, 7290** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7291** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7292** upon successful entry. ^(Mutexes created using 7293** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7294** In such cases, the 7295** mutex must be exited an equal number of times before another thread 7296** can enter.)^ If the same thread tries to enter any mutex other 7297** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7298** 7299** ^(Some systems (for example, Windows 95) do not support the operation 7300** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7301** will always return SQLITE_BUSY. The SQLite core only ever uses 7302** sqlite3_mutex_try() as an optimization so this is acceptable 7303** behavior.)^ 7304** 7305** ^The sqlite3_mutex_leave() routine exits a mutex that was 7306** previously entered by the same thread. The behavior 7307** is undefined if the mutex is not currently entered by the 7308** calling thread or is not currently allocated. 7309** 7310** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7311** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7312** behave as no-ops. 7313** 7314** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7315*/ 7316sqlite3_mutex *sqlite3_mutex_alloc(int); 7317void sqlite3_mutex_free(sqlite3_mutex*); 7318void sqlite3_mutex_enter(sqlite3_mutex*); 7319int sqlite3_mutex_try(sqlite3_mutex*); 7320void sqlite3_mutex_leave(sqlite3_mutex*); 7321 7322/* 7323** CAPI3REF: Mutex Methods Object 7324** 7325** An instance of this structure defines the low-level routines 7326** used to allocate and use mutexes. 7327** 7328** Usually, the default mutex implementations provided by SQLite are 7329** sufficient, however the application has the option of substituting a custom 7330** implementation for specialized deployments or systems for which SQLite 7331** does not provide a suitable implementation. In this case, the application 7332** creates and populates an instance of this structure to pass 7333** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7334** Additionally, an instance of this structure can be used as an 7335** output variable when querying the system for the current mutex 7336** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7337** 7338** ^The xMutexInit method defined by this structure is invoked as 7339** part of system initialization by the sqlite3_initialize() function. 7340** ^The xMutexInit routine is called by SQLite exactly once for each 7341** effective call to [sqlite3_initialize()]. 7342** 7343** ^The xMutexEnd method defined by this structure is invoked as 7344** part of system shutdown by the sqlite3_shutdown() function. The 7345** implementation of this method is expected to release all outstanding 7346** resources obtained by the mutex methods implementation, especially 7347** those obtained by the xMutexInit method. ^The xMutexEnd() 7348** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7349** 7350** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7351** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7352** xMutexNotheld) implement the following interfaces (respectively): 7353** 7354** <ul> 7355** <li> [sqlite3_mutex_alloc()] </li> 7356** <li> [sqlite3_mutex_free()] </li> 7357** <li> [sqlite3_mutex_enter()] </li> 7358** <li> [sqlite3_mutex_try()] </li> 7359** <li> [sqlite3_mutex_leave()] </li> 7360** <li> [sqlite3_mutex_held()] </li> 7361** <li> [sqlite3_mutex_notheld()] </li> 7362** </ul>)^ 7363** 7364** The only difference is that the public sqlite3_XXX functions enumerated 7365** above silently ignore any invocations that pass a NULL pointer instead 7366** of a valid mutex handle. The implementations of the methods defined 7367** by this structure are not required to handle this case. The results 7368** of passing a NULL pointer instead of a valid mutex handle are undefined 7369** (i.e. it is acceptable to provide an implementation that segfaults if 7370** it is passed a NULL pointer). 7371** 7372** The xMutexInit() method must be threadsafe. It must be harmless to 7373** invoke xMutexInit() multiple times within the same process and without 7374** intervening calls to xMutexEnd(). Second and subsequent calls to 7375** xMutexInit() must be no-ops. 7376** 7377** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7378** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7379** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7380** memory allocation for a fast or recursive mutex. 7381** 7382** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7383** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7384** If xMutexInit fails in any way, it is expected to clean up after itself 7385** prior to returning. 7386*/ 7387typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7388struct sqlite3_mutex_methods { 7389 int (*xMutexInit)(void); 7390 int (*xMutexEnd)(void); 7391 sqlite3_mutex *(*xMutexAlloc)(int); 7392 void (*xMutexFree)(sqlite3_mutex *); 7393 void (*xMutexEnter)(sqlite3_mutex *); 7394 int (*xMutexTry)(sqlite3_mutex *); 7395 void (*xMutexLeave)(sqlite3_mutex *); 7396 int (*xMutexHeld)(sqlite3_mutex *); 7397 int (*xMutexNotheld)(sqlite3_mutex *); 7398}; 7399 7400/* 7401** CAPI3REF: Mutex Verification Routines 7402** 7403** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7404** are intended for use inside assert() statements. The SQLite core 7405** never uses these routines except inside an assert() and applications 7406** are advised to follow the lead of the core. The SQLite core only 7407** provides implementations for these routines when it is compiled 7408** with the SQLITE_DEBUG flag. External mutex implementations 7409** are only required to provide these routines if SQLITE_DEBUG is 7410** defined and if NDEBUG is not defined. 7411** 7412** These routines should return true if the mutex in their argument 7413** is held or not held, respectively, by the calling thread. 7414** 7415** The implementation is not required to provide versions of these 7416** routines that actually work. If the implementation does not provide working 7417** versions of these routines, it should at least provide stubs that always 7418** return true so that one does not get spurious assertion failures. 7419** 7420** If the argument to sqlite3_mutex_held() is a NULL pointer then 7421** the routine should return 1. This seems counter-intuitive since 7422** clearly the mutex cannot be held if it does not exist. But 7423** the reason the mutex does not exist is because the build is not 7424** using mutexes. And we do not want the assert() containing the 7425** call to sqlite3_mutex_held() to fail, so a non-zero return is 7426** the appropriate thing to do. The sqlite3_mutex_notheld() 7427** interface should also return 1 when given a NULL pointer. 7428*/ 7429#ifndef NDEBUG 7430int sqlite3_mutex_held(sqlite3_mutex*); 7431int sqlite3_mutex_notheld(sqlite3_mutex*); 7432#endif 7433 7434/* 7435** CAPI3REF: Mutex Types 7436** 7437** The [sqlite3_mutex_alloc()] interface takes a single argument 7438** which is one of these integer constants. 7439** 7440** The set of static mutexes may change from one SQLite release to the 7441** next. Applications that override the built-in mutex logic must be 7442** prepared to accommodate additional static mutexes. 7443*/ 7444#define SQLITE_MUTEX_FAST 0 7445#define SQLITE_MUTEX_RECURSIVE 1 7446#define SQLITE_MUTEX_STATIC_MASTER 2 7447#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7448#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7449#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7450#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7451#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7452#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7453#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7454#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7455#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7456#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7457#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7458#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7459#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7460 7461/* 7462** CAPI3REF: Retrieve the mutex for a database connection 7463** METHOD: sqlite3 7464** 7465** ^This interface returns a pointer the [sqlite3_mutex] object that 7466** serializes access to the [database connection] given in the argument 7467** when the [threading mode] is Serialized. 7468** ^If the [threading mode] is Single-thread or Multi-thread then this 7469** routine returns a NULL pointer. 7470*/ 7471sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7472 7473/* 7474** CAPI3REF: Low-Level Control Of Database Files 7475** METHOD: sqlite3 7476** KEYWORDS: {file control} 7477** 7478** ^The [sqlite3_file_control()] interface makes a direct call to the 7479** xFileControl method for the [sqlite3_io_methods] object associated 7480** with a particular database identified by the second argument. ^The 7481** name of the database is "main" for the main database or "temp" for the 7482** TEMP database, or the name that appears after the AS keyword for 7483** databases that are added using the [ATTACH] SQL command. 7484** ^A NULL pointer can be used in place of "main" to refer to the 7485** main database file. 7486** ^The third and fourth parameters to this routine 7487** are passed directly through to the second and third parameters of 7488** the xFileControl method. ^The return value of the xFileControl 7489** method becomes the return value of this routine. 7490** 7491** A few opcodes for [sqlite3_file_control()] are handled directly 7492** by the SQLite core and never invoke the 7493** sqlite3_io_methods.xFileControl method. 7494** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7495** a pointer to the underlying [sqlite3_file] object to be written into 7496** the space pointed to by the 4th parameter. The 7497** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7498** the [sqlite3_file] object associated with the journal file instead of 7499** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7500** a pointer to the underlying [sqlite3_vfs] object for the file. 7501** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7502** from the pager. 7503** 7504** ^If the second parameter (zDbName) does not match the name of any 7505** open database file, then SQLITE_ERROR is returned. ^This error 7506** code is not remembered and will not be recalled by [sqlite3_errcode()] 7507** or [sqlite3_errmsg()]. The underlying xFileControl method might 7508** also return SQLITE_ERROR. There is no way to distinguish between 7509** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7510** xFileControl method. 7511** 7512** See also: [file control opcodes] 7513*/ 7514int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7515 7516/* 7517** CAPI3REF: Testing Interface 7518** 7519** ^The sqlite3_test_control() interface is used to read out internal 7520** state of SQLite and to inject faults into SQLite for testing 7521** purposes. ^The first parameter is an operation code that determines 7522** the number, meaning, and operation of all subsequent parameters. 7523** 7524** This interface is not for use by applications. It exists solely 7525** for verifying the correct operation of the SQLite library. Depending 7526** on how the SQLite library is compiled, this interface might not exist. 7527** 7528** The details of the operation codes, their meanings, the parameters 7529** they take, and what they do are all subject to change without notice. 7530** Unlike most of the SQLite API, this function is not guaranteed to 7531** operate consistently from one release to the next. 7532*/ 7533int sqlite3_test_control(int op, ...); 7534 7535/* 7536** CAPI3REF: Testing Interface Operation Codes 7537** 7538** These constants are the valid operation code parameters used 7539** as the first argument to [sqlite3_test_control()]. 7540** 7541** These parameters and their meanings are subject to change 7542** without notice. These values are for testing purposes only. 7543** Applications should not use any of these parameters or the 7544** [sqlite3_test_control()] interface. 7545*/ 7546#define SQLITE_TESTCTRL_FIRST 5 7547#define SQLITE_TESTCTRL_PRNG_SAVE 5 7548#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7549#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7550#define SQLITE_TESTCTRL_BITVEC_TEST 8 7551#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7552#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7553#define SQLITE_TESTCTRL_PENDING_BYTE 11 7554#define SQLITE_TESTCTRL_ASSERT 12 7555#define SQLITE_TESTCTRL_ALWAYS 13 7556#define SQLITE_TESTCTRL_RESERVE 14 7557#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7558#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7559#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7560#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7561#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7562#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7563#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7564#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7565#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7566#define SQLITE_TESTCTRL_BYTEORDER 22 7567#define SQLITE_TESTCTRL_ISINIT 23 7568#define SQLITE_TESTCTRL_SORTER_MMAP 24 7569#define SQLITE_TESTCTRL_IMPOSTER 25 7570#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7571#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7572#define SQLITE_TESTCTRL_PRNG_SEED 28 7573#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7574#define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7575 7576/* 7577** CAPI3REF: SQL Keyword Checking 7578** 7579** These routines provide access to the set of SQL language keywords 7580** recognized by SQLite. Applications can uses these routines to determine 7581** whether or not a specific identifier needs to be escaped (for example, 7582** by enclosing in double-quotes) so as not to confuse the parser. 7583** 7584** The sqlite3_keyword_count() interface returns the number of distinct 7585** keywords understood by SQLite. 7586** 7587** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7588** makes *Z point to that keyword expressed as UTF8 and writes the number 7589** of bytes in the keyword into *L. The string that *Z points to is not 7590** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7591** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7592** or L are NULL or invalid pointers then calls to 7593** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7594** 7595** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7596** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7597** if it is and zero if not. 7598** 7599** The parser used by SQLite is forgiving. It is often possible to use 7600** a keyword as an identifier as long as such use does not result in a 7601** parsing ambiguity. For example, the statement 7602** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7603** creates a new table named "BEGIN" with three columns named 7604** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7605** using keywords as identifiers. Common techniques used to avoid keyword 7606** name collisions include: 7607** <ul> 7608** <li> Put all identifier names inside double-quotes. This is the official 7609** SQL way to escape identifier names. 7610** <li> Put identifier names inside [...]. This is not standard SQL, 7611** but it is what SQL Server does and so lots of programmers use this 7612** technique. 7613** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7614** with "Z". 7615** <li> Include a digit somewhere in every identifier name. 7616** </ul> 7617** 7618** Note that the number of keywords understood by SQLite can depend on 7619** compile-time options. For example, "VACUUM" is not a keyword if 7620** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7621** new keywords may be added to future releases of SQLite. 7622*/ 7623int sqlite3_keyword_count(void); 7624int sqlite3_keyword_name(int,const char**,int*); 7625int sqlite3_keyword_check(const char*,int); 7626 7627/* 7628** CAPI3REF: Dynamic String Object 7629** KEYWORDS: {dynamic string} 7630** 7631** An instance of the sqlite3_str object contains a dynamically-sized 7632** string under construction. 7633** 7634** The lifecycle of an sqlite3_str object is as follows: 7635** <ol> 7636** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7637** <li> ^Text is appended to the sqlite3_str object using various 7638** methods, such as [sqlite3_str_appendf()]. 7639** <li> ^The sqlite3_str object is destroyed and the string it created 7640** is returned using the [sqlite3_str_finish()] interface. 7641** </ol> 7642*/ 7643typedef struct sqlite3_str sqlite3_str; 7644 7645/* 7646** CAPI3REF: Create A New Dynamic String Object 7647** CONSTRUCTOR: sqlite3_str 7648** 7649** ^The [sqlite3_str_new(D)] interface allocates and initializes 7650** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7651** [sqlite3_str_new()] must be freed by a subsequent call to 7652** [sqlite3_str_finish(X)]. 7653** 7654** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7655** valid [sqlite3_str] object, though in the event of an out-of-memory 7656** error the returned object might be a special singleton that will 7657** silently reject new text, always return SQLITE_NOMEM from 7658** [sqlite3_str_errcode()], always return 0 for 7659** [sqlite3_str_length()], and always return NULL from 7660** [sqlite3_str_finish(X)]. It is always safe to use the value 7661** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7662** to any of the other [sqlite3_str] methods. 7663** 7664** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7665** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7666** length of the string contained in the [sqlite3_str] object will be 7667** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7668** of [SQLITE_MAX_LENGTH]. 7669*/ 7670sqlite3_str *sqlite3_str_new(sqlite3*); 7671 7672/* 7673** CAPI3REF: Finalize A Dynamic String 7674** DESTRUCTOR: sqlite3_str 7675** 7676** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7677** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7678** that contains the constructed string. The calling application should 7679** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7680** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7681** errors were encountered during construction of the string. ^The 7682** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7683** string in [sqlite3_str] object X is zero bytes long. 7684*/ 7685char *sqlite3_str_finish(sqlite3_str*); 7686 7687/* 7688** CAPI3REF: Add Content To A Dynamic String 7689** METHOD: sqlite3_str 7690** 7691** These interfaces add content to an sqlite3_str object previously obtained 7692** from [sqlite3_str_new()]. 7693** 7694** ^The [sqlite3_str_appendf(X,F,...)] and 7695** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7696** functionality of SQLite to append formatted text onto the end of 7697** [sqlite3_str] object X. 7698** 7699** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7700** onto the end of the [sqlite3_str] object X. N must be non-negative. 7701** S must contain at least N non-zero bytes of content. To append a 7702** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7703** method instead. 7704** 7705** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7706** zero-terminated string S onto the end of [sqlite3_str] object X. 7707** 7708** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7709** single-byte character C onto the end of [sqlite3_str] object X. 7710** ^This method can be used, for example, to add whitespace indentation. 7711** 7712** ^The [sqlite3_str_reset(X)] method resets the string under construction 7713** inside [sqlite3_str] object X back to zero bytes in length. 7714** 7715** These methods do not return a result code. ^If an error occurs, that fact 7716** is recorded in the [sqlite3_str] object and can be recovered by a 7717** subsequent call to [sqlite3_str_errcode(X)]. 7718*/ 7719void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7720void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7721void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7722void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7723void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7724void sqlite3_str_reset(sqlite3_str*); 7725 7726/* 7727** CAPI3REF: Status Of A Dynamic String 7728** METHOD: sqlite3_str 7729** 7730** These interfaces return the current status of an [sqlite3_str] object. 7731** 7732** ^If any prior errors have occurred while constructing the dynamic string 7733** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7734** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7735** [SQLITE_NOMEM] following any out-of-memory error, or 7736** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7737** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7738** 7739** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7740** of the dynamic string under construction in [sqlite3_str] object X. 7741** ^The length returned by [sqlite3_str_length(X)] does not include the 7742** zero-termination byte. 7743** 7744** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7745** content of the dynamic string under construction in X. The value 7746** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7747** and might be freed or altered by any subsequent method on the same 7748** [sqlite3_str] object. Applications must not used the pointer returned 7749** [sqlite3_str_value(X)] after any subsequent method call on the same 7750** object. ^Applications may change the content of the string returned 7751** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7752** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7753** write any byte after any subsequent sqlite3_str method call. 7754*/ 7755int sqlite3_str_errcode(sqlite3_str*); 7756int sqlite3_str_length(sqlite3_str*); 7757char *sqlite3_str_value(sqlite3_str*); 7758 7759/* 7760** CAPI3REF: SQLite Runtime Status 7761** 7762** ^These interfaces are used to retrieve runtime status information 7763** about the performance of SQLite, and optionally to reset various 7764** highwater marks. ^The first argument is an integer code for 7765** the specific parameter to measure. ^(Recognized integer codes 7766** are of the form [status parameters | SQLITE_STATUS_...].)^ 7767** ^The current value of the parameter is returned into *pCurrent. 7768** ^The highest recorded value is returned in *pHighwater. ^If the 7769** resetFlag is true, then the highest record value is reset after 7770** *pHighwater is written. ^(Some parameters do not record the highest 7771** value. For those parameters 7772** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7773** ^(Other parameters record only the highwater mark and not the current 7774** value. For these latter parameters nothing is written into *pCurrent.)^ 7775** 7776** ^The sqlite3_status() and sqlite3_status64() routines return 7777** SQLITE_OK on success and a non-zero [error code] on failure. 7778** 7779** If either the current value or the highwater mark is too large to 7780** be represented by a 32-bit integer, then the values returned by 7781** sqlite3_status() are undefined. 7782** 7783** See also: [sqlite3_db_status()] 7784*/ 7785int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7786int sqlite3_status64( 7787 int op, 7788 sqlite3_int64 *pCurrent, 7789 sqlite3_int64 *pHighwater, 7790 int resetFlag 7791); 7792 7793 7794/* 7795** CAPI3REF: Status Parameters 7796** KEYWORDS: {status parameters} 7797** 7798** These integer constants designate various run-time status parameters 7799** that can be returned by [sqlite3_status()]. 7800** 7801** <dl> 7802** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7803** <dd>This parameter is the current amount of memory checked out 7804** using [sqlite3_malloc()], either directly or indirectly. The 7805** figure includes calls made to [sqlite3_malloc()] by the application 7806** and internal memory usage by the SQLite library. Auxiliary page-cache 7807** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7808** this parameter. The amount returned is the sum of the allocation 7809** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7810** 7811** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7812** <dd>This parameter records the largest memory allocation request 7813** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7814** internal equivalents). Only the value returned in the 7815** *pHighwater parameter to [sqlite3_status()] is of interest. 7816** The value written into the *pCurrent parameter is undefined.</dd>)^ 7817** 7818** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7819** <dd>This parameter records the number of separate memory allocations 7820** currently checked out.</dd>)^ 7821** 7822** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7823** <dd>This parameter returns the number of pages used out of the 7824** [pagecache memory allocator] that was configured using 7825** [SQLITE_CONFIG_PAGECACHE]. The 7826** value returned is in pages, not in bytes.</dd>)^ 7827** 7828** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7829** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7830** <dd>This parameter returns the number of bytes of page cache 7831** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7832** buffer and where forced to overflow to [sqlite3_malloc()]. The 7833** returned value includes allocations that overflowed because they 7834** where too large (they were larger than the "sz" parameter to 7835** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7836** no space was left in the page cache.</dd>)^ 7837** 7838** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7839** <dd>This parameter records the largest memory allocation request 7840** handed to the [pagecache memory allocator]. Only the value returned in the 7841** *pHighwater parameter to [sqlite3_status()] is of interest. 7842** The value written into the *pCurrent parameter is undefined.</dd>)^ 7843** 7844** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7845** <dd>No longer used.</dd> 7846** 7847** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7848** <dd>No longer used.</dd> 7849** 7850** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7851** <dd>No longer used.</dd> 7852** 7853** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7854** <dd>The *pHighwater parameter records the deepest parser stack. 7855** The *pCurrent value is undefined. The *pHighwater value is only 7856** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7857** </dl> 7858** 7859** New status parameters may be added from time to time. 7860*/ 7861#define SQLITE_STATUS_MEMORY_USED 0 7862#define SQLITE_STATUS_PAGECACHE_USED 1 7863#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7864#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7865#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7866#define SQLITE_STATUS_MALLOC_SIZE 5 7867#define SQLITE_STATUS_PARSER_STACK 6 7868#define SQLITE_STATUS_PAGECACHE_SIZE 7 7869#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7870#define SQLITE_STATUS_MALLOC_COUNT 9 7871 7872/* 7873** CAPI3REF: Database Connection Status 7874** METHOD: sqlite3 7875** 7876** ^This interface is used to retrieve runtime status information 7877** about a single [database connection]. ^The first argument is the 7878** database connection object to be interrogated. ^The second argument 7879** is an integer constant, taken from the set of 7880** [SQLITE_DBSTATUS options], that 7881** determines the parameter to interrogate. The set of 7882** [SQLITE_DBSTATUS options] is likely 7883** to grow in future releases of SQLite. 7884** 7885** ^The current value of the requested parameter is written into *pCur 7886** and the highest instantaneous value is written into *pHiwtr. ^If 7887** the resetFlg is true, then the highest instantaneous value is 7888** reset back down to the current value. 7889** 7890** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7891** non-zero [error code] on failure. 7892** 7893** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7894*/ 7895int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7896 7897/* 7898** CAPI3REF: Status Parameters for database connections 7899** KEYWORDS: {SQLITE_DBSTATUS options} 7900** 7901** These constants are the available integer "verbs" that can be passed as 7902** the second argument to the [sqlite3_db_status()] interface. 7903** 7904** New verbs may be added in future releases of SQLite. Existing verbs 7905** might be discontinued. Applications should check the return code from 7906** [sqlite3_db_status()] to make sure that the call worked. 7907** The [sqlite3_db_status()] interface will return a non-zero error code 7908** if a discontinued or unsupported verb is invoked. 7909** 7910** <dl> 7911** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7912** <dd>This parameter returns the number of lookaside memory slots currently 7913** checked out.</dd>)^ 7914** 7915** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7916** <dd>This parameter returns the number of malloc attempts that were 7917** satisfied using lookaside memory. Only the high-water value is meaningful; 7918** the current value is always zero.)^ 7919** 7920** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7921** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7922** <dd>This parameter returns the number malloc attempts that might have 7923** been satisfied using lookaside memory but failed due to the amount of 7924** memory requested being larger than the lookaside slot size. 7925** Only the high-water value is meaningful; 7926** the current value is always zero.)^ 7927** 7928** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7929** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7930** <dd>This parameter returns the number malloc attempts that might have 7931** been satisfied using lookaside memory but failed due to all lookaside 7932** memory already being in use. 7933** Only the high-water value is meaningful; 7934** the current value is always zero.)^ 7935** 7936** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7937** <dd>This parameter returns the approximate number of bytes of heap 7938** memory used by all pager caches associated with the database connection.)^ 7939** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7940** 7941** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7942** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7943** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7944** pager cache is shared between two or more connections the bytes of heap 7945** memory used by that pager cache is divided evenly between the attached 7946** connections.)^ In other words, if none of the pager caches associated 7947** with the database connection are shared, this request returns the same 7948** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7949** shared, the value returned by this call will be smaller than that returned 7950** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7951** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7952** 7953** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7954** <dd>This parameter returns the approximate number of bytes of heap 7955** memory used to store the schema for all databases associated 7956** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7957** ^The full amount of memory used by the schemas is reported, even if the 7958** schema memory is shared with other database connections due to 7959** [shared cache mode] being enabled. 7960** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7961** 7962** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7963** <dd>This parameter returns the approximate number of bytes of heap 7964** and lookaside memory used by all prepared statements associated with 7965** the database connection.)^ 7966** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7967** </dd> 7968** 7969** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7970** <dd>This parameter returns the number of pager cache hits that have 7971** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7972** is always 0. 7973** </dd> 7974** 7975** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7976** <dd>This parameter returns the number of pager cache misses that have 7977** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7978** is always 0. 7979** </dd> 7980** 7981** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7982** <dd>This parameter returns the number of dirty cache entries that have 7983** been written to disk. Specifically, the number of pages written to the 7984** wal file in wal mode databases, or the number of pages written to the 7985** database file in rollback mode databases. Any pages written as part of 7986** transaction rollback or database recovery operations are not included. 7987** If an IO or other error occurs while writing a page to disk, the effect 7988** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7989** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7990** </dd> 7991** 7992** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7993** <dd>This parameter returns the number of dirty cache entries that have 7994** been written to disk in the middle of a transaction due to the page 7995** cache overflowing. Transactions are more efficient if they are written 7996** to disk all at once. When pages spill mid-transaction, that introduces 7997** additional overhead. This parameter can be used help identify 7998** inefficiencies that can be resolved by increasing the cache size. 7999** </dd> 8000** 8001** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 8002** <dd>This parameter returns zero for the current value if and only if 8003** all foreign key constraints (deferred or immediate) have been 8004** resolved.)^ ^The highwater mark is always 0. 8005** </dd> 8006** </dl> 8007*/ 8008#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 8009#define SQLITE_DBSTATUS_CACHE_USED 1 8010#define SQLITE_DBSTATUS_SCHEMA_USED 2 8011#define SQLITE_DBSTATUS_STMT_USED 3 8012#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 8013#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 8014#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 8015#define SQLITE_DBSTATUS_CACHE_HIT 7 8016#define SQLITE_DBSTATUS_CACHE_MISS 8 8017#define SQLITE_DBSTATUS_CACHE_WRITE 9 8018#define SQLITE_DBSTATUS_DEFERRED_FKS 10 8019#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 8020#define SQLITE_DBSTATUS_CACHE_SPILL 12 8021#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 8022 8023 8024/* 8025** CAPI3REF: Prepared Statement Status 8026** METHOD: sqlite3_stmt 8027** 8028** ^(Each prepared statement maintains various 8029** [SQLITE_STMTSTATUS counters] that measure the number 8030** of times it has performed specific operations.)^ These counters can 8031** be used to monitor the performance characteristics of the prepared 8032** statements. For example, if the number of table steps greatly exceeds 8033** the number of table searches or result rows, that would tend to indicate 8034** that the prepared statement is using a full table scan rather than 8035** an index. 8036** 8037** ^(This interface is used to retrieve and reset counter values from 8038** a [prepared statement]. The first argument is the prepared statement 8039** object to be interrogated. The second argument 8040** is an integer code for a specific [SQLITE_STMTSTATUS counter] 8041** to be interrogated.)^ 8042** ^The current value of the requested counter is returned. 8043** ^If the resetFlg is true, then the counter is reset to zero after this 8044** interface call returns. 8045** 8046** See also: [sqlite3_status()] and [sqlite3_db_status()]. 8047*/ 8048int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 8049 8050/* 8051** CAPI3REF: Status Parameters for prepared statements 8052** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 8053** 8054** These preprocessor macros define integer codes that name counter 8055** values associated with the [sqlite3_stmt_status()] interface. 8056** The meanings of the various counters are as follows: 8057** 8058** <dl> 8059** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 8060** <dd>^This is the number of times that SQLite has stepped forward in 8061** a table as part of a full table scan. Large numbers for this counter 8062** may indicate opportunities for performance improvement through 8063** careful use of indices.</dd> 8064** 8065** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 8066** <dd>^This is the number of sort operations that have occurred. 8067** A non-zero value in this counter may indicate an opportunity to 8068** improvement performance through careful use of indices.</dd> 8069** 8070** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 8071** <dd>^This is the number of rows inserted into transient indices that 8072** were created automatically in order to help joins run faster. 8073** A non-zero value in this counter may indicate an opportunity to 8074** improvement performance by adding permanent indices that do not 8075** need to be reinitialized each time the statement is run.</dd> 8076** 8077** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 8078** <dd>^This is the number of virtual machine operations executed 8079** by the prepared statement if that number is less than or equal 8080** to 2147483647. The number of virtual machine operations can be 8081** used as a proxy for the total work done by the prepared statement. 8082** If the number of virtual machine operations exceeds 2147483647 8083** then the value returned by this statement status code is undefined. 8084** 8085** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 8086** <dd>^This is the number of times that the prepare statement has been 8087** automatically regenerated due to schema changes or changes to 8088** [bound parameters] that might affect the query plan. 8089** 8090** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 8091** <dd>^This is the number of times that the prepared statement has 8092** been run. A single "run" for the purposes of this counter is one 8093** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 8094** The counter is incremented on the first [sqlite3_step()] call of each 8095** cycle. 8096** 8097** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 8098** <dd>^This is the approximate number of bytes of heap memory 8099** used to store the prepared statement. ^This value is not actually 8100** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 8101** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 8102** </dd> 8103** </dl> 8104*/ 8105#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 8106#define SQLITE_STMTSTATUS_SORT 2 8107#define SQLITE_STMTSTATUS_AUTOINDEX 3 8108#define SQLITE_STMTSTATUS_VM_STEP 4 8109#define SQLITE_STMTSTATUS_REPREPARE 5 8110#define SQLITE_STMTSTATUS_RUN 6 8111#define SQLITE_STMTSTATUS_MEMUSED 99 8112 8113/* 8114** CAPI3REF: Custom Page Cache Object 8115** 8116** The sqlite3_pcache type is opaque. It is implemented by 8117** the pluggable module. The SQLite core has no knowledge of 8118** its size or internal structure and never deals with the 8119** sqlite3_pcache object except by holding and passing pointers 8120** to the object. 8121** 8122** See [sqlite3_pcache_methods2] for additional information. 8123*/ 8124typedef struct sqlite3_pcache sqlite3_pcache; 8125 8126/* 8127** CAPI3REF: Custom Page Cache Object 8128** 8129** The sqlite3_pcache_page object represents a single page in the 8130** page cache. The page cache will allocate instances of this 8131** object. Various methods of the page cache use pointers to instances 8132** of this object as parameters or as their return value. 8133** 8134** See [sqlite3_pcache_methods2] for additional information. 8135*/ 8136typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8137struct sqlite3_pcache_page { 8138 void *pBuf; /* The content of the page */ 8139 void *pExtra; /* Extra information associated with the page */ 8140}; 8141 8142/* 8143** CAPI3REF: Application Defined Page Cache. 8144** KEYWORDS: {page cache} 8145** 8146** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8147** register an alternative page cache implementation by passing in an 8148** instance of the sqlite3_pcache_methods2 structure.)^ 8149** In many applications, most of the heap memory allocated by 8150** SQLite is used for the page cache. 8151** By implementing a 8152** custom page cache using this API, an application can better control 8153** the amount of memory consumed by SQLite, the way in which 8154** that memory is allocated and released, and the policies used to 8155** determine exactly which parts of a database file are cached and for 8156** how long. 8157** 8158** The alternative page cache mechanism is an 8159** extreme measure that is only needed by the most demanding applications. 8160** The built-in page cache is recommended for most uses. 8161** 8162** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8163** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8164** the application may discard the parameter after the call to 8165** [sqlite3_config()] returns.)^ 8166** 8167** [[the xInit() page cache method]] 8168** ^(The xInit() method is called once for each effective 8169** call to [sqlite3_initialize()])^ 8170** (usually only once during the lifetime of the process). ^(The xInit() 8171** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8172** The intent of the xInit() method is to set up global data structures 8173** required by the custom page cache implementation. 8174** ^(If the xInit() method is NULL, then the 8175** built-in default page cache is used instead of the application defined 8176** page cache.)^ 8177** 8178** [[the xShutdown() page cache method]] 8179** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8180** It can be used to clean up 8181** any outstanding resources before process shutdown, if required. 8182** ^The xShutdown() method may be NULL. 8183** 8184** ^SQLite automatically serializes calls to the xInit method, 8185** so the xInit method need not be threadsafe. ^The 8186** xShutdown method is only called from [sqlite3_shutdown()] so it does 8187** not need to be threadsafe either. All other methods must be threadsafe 8188** in multithreaded applications. 8189** 8190** ^SQLite will never invoke xInit() more than once without an intervening 8191** call to xShutdown(). 8192** 8193** [[the xCreate() page cache methods]] 8194** ^SQLite invokes the xCreate() method to construct a new cache instance. 8195** SQLite will typically create one cache instance for each open database file, 8196** though this is not guaranteed. ^The 8197** first parameter, szPage, is the size in bytes of the pages that must 8198** be allocated by the cache. ^szPage will always a power of two. ^The 8199** second parameter szExtra is a number of bytes of extra storage 8200** associated with each page cache entry. ^The szExtra parameter will 8201** a number less than 250. SQLite will use the 8202** extra szExtra bytes on each page to store metadata about the underlying 8203** database page on disk. The value passed into szExtra depends 8204** on the SQLite version, the target platform, and how SQLite was compiled. 8205** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8206** created will be used to cache database pages of a file stored on disk, or 8207** false if it is used for an in-memory database. The cache implementation 8208** does not have to do anything special based with the value of bPurgeable; 8209** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8210** never invoke xUnpin() except to deliberately delete a page. 8211** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8212** false will always have the "discard" flag set to true. 8213** ^Hence, a cache created with bPurgeable false will 8214** never contain any unpinned pages. 8215** 8216** [[the xCachesize() page cache method]] 8217** ^(The xCachesize() method may be called at any time by SQLite to set the 8218** suggested maximum cache-size (number of pages stored by) the cache 8219** instance passed as the first argument. This is the value configured using 8220** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8221** parameter, the implementation is not required to do anything with this 8222** value; it is advisory only. 8223** 8224** [[the xPagecount() page cache methods]] 8225** The xPagecount() method must return the number of pages currently 8226** stored in the cache, both pinned and unpinned. 8227** 8228** [[the xFetch() page cache methods]] 8229** The xFetch() method locates a page in the cache and returns a pointer to 8230** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8231** The pBuf element of the returned sqlite3_pcache_page object will be a 8232** pointer to a buffer of szPage bytes used to store the content of a 8233** single database page. The pExtra element of sqlite3_pcache_page will be 8234** a pointer to the szExtra bytes of extra storage that SQLite has requested 8235** for each entry in the page cache. 8236** 8237** The page to be fetched is determined by the key. ^The minimum key value 8238** is 1. After it has been retrieved using xFetch, the page is considered 8239** to be "pinned". 8240** 8241** If the requested page is already in the page cache, then the page cache 8242** implementation must return a pointer to the page buffer with its content 8243** intact. If the requested page is not already in the cache, then the 8244** cache implementation should use the value of the createFlag 8245** parameter to help it determined what action to take: 8246** 8247** <table border=1 width=85% align=center> 8248** <tr><th> createFlag <th> Behavior when page is not already in cache 8249** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8250** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8251** Otherwise return NULL. 8252** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8253** NULL if allocating a new page is effectively impossible. 8254** </table> 8255** 8256** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8257** will only use a createFlag of 2 after a prior call with a createFlag of 1 8258** failed.)^ In between the xFetch() calls, SQLite may 8259** attempt to unpin one or more cache pages by spilling the content of 8260** pinned pages to disk and synching the operating system disk cache. 8261** 8262** [[the xUnpin() page cache method]] 8263** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8264** as its second argument. If the third parameter, discard, is non-zero, 8265** then the page must be evicted from the cache. 8266** ^If the discard parameter is 8267** zero, then the page may be discarded or retained at the discretion of 8268** page cache implementation. ^The page cache implementation 8269** may choose to evict unpinned pages at any time. 8270** 8271** The cache must not perform any reference counting. A single 8272** call to xUnpin() unpins the page regardless of the number of prior calls 8273** to xFetch(). 8274** 8275** [[the xRekey() page cache methods]] 8276** The xRekey() method is used to change the key value associated with the 8277** page passed as the second argument. If the cache 8278** previously contains an entry associated with newKey, it must be 8279** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8280** to be pinned. 8281** 8282** When SQLite calls the xTruncate() method, the cache must discard all 8283** existing cache entries with page numbers (keys) greater than or equal 8284** to the value of the iLimit parameter passed to xTruncate(). If any 8285** of these pages are pinned, they are implicitly unpinned, meaning that 8286** they can be safely discarded. 8287** 8288** [[the xDestroy() page cache method]] 8289** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8290** All resources associated with the specified cache should be freed. ^After 8291** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8292** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8293** functions. 8294** 8295** [[the xShrink() page cache method]] 8296** ^SQLite invokes the xShrink() method when it wants the page cache to 8297** free up as much of heap memory as possible. The page cache implementation 8298** is not obligated to free any memory, but well-behaved implementations should 8299** do their best. 8300*/ 8301typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8302struct sqlite3_pcache_methods2 { 8303 int iVersion; 8304 void *pArg; 8305 int (*xInit)(void*); 8306 void (*xShutdown)(void*); 8307 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8308 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8309 int (*xPagecount)(sqlite3_pcache*); 8310 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8311 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8312 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8313 unsigned oldKey, unsigned newKey); 8314 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8315 void (*xDestroy)(sqlite3_pcache*); 8316 void (*xShrink)(sqlite3_pcache*); 8317}; 8318 8319/* 8320** This is the obsolete pcache_methods object that has now been replaced 8321** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8322** retained in the header file for backwards compatibility only. 8323*/ 8324typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8325struct sqlite3_pcache_methods { 8326 void *pArg; 8327 int (*xInit)(void*); 8328 void (*xShutdown)(void*); 8329 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8330 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8331 int (*xPagecount)(sqlite3_pcache*); 8332 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8333 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8334 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8335 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8336 void (*xDestroy)(sqlite3_pcache*); 8337}; 8338 8339 8340/* 8341** CAPI3REF: Online Backup Object 8342** 8343** The sqlite3_backup object records state information about an ongoing 8344** online backup operation. ^The sqlite3_backup object is created by 8345** a call to [sqlite3_backup_init()] and is destroyed by a call to 8346** [sqlite3_backup_finish()]. 8347** 8348** See Also: [Using the SQLite Online Backup API] 8349*/ 8350typedef struct sqlite3_backup sqlite3_backup; 8351 8352/* 8353** CAPI3REF: Online Backup API. 8354** 8355** The backup API copies the content of one database into another. 8356** It is useful either for creating backups of databases or 8357** for copying in-memory databases to or from persistent files. 8358** 8359** See Also: [Using the SQLite Online Backup API] 8360** 8361** ^SQLite holds a write transaction open on the destination database file 8362** for the duration of the backup operation. 8363** ^The source database is read-locked only while it is being read; 8364** it is not locked continuously for the entire backup operation. 8365** ^Thus, the backup may be performed on a live source database without 8366** preventing other database connections from 8367** reading or writing to the source database while the backup is underway. 8368** 8369** ^(To perform a backup operation: 8370** <ol> 8371** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8372** backup, 8373** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8374** the data between the two databases, and finally 8375** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8376** associated with the backup operation. 8377** </ol>)^ 8378** There should be exactly one call to sqlite3_backup_finish() for each 8379** successful call to sqlite3_backup_init(). 8380** 8381** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8382** 8383** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8384** [database connection] associated with the destination database 8385** and the database name, respectively. 8386** ^The database name is "main" for the main database, "temp" for the 8387** temporary database, or the name specified after the AS keyword in 8388** an [ATTACH] statement for an attached database. 8389** ^The S and M arguments passed to 8390** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8391** and database name of the source database, respectively. 8392** ^The source and destination [database connections] (parameters S and D) 8393** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8394** an error. 8395** 8396** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8397** there is already a read or read-write transaction open on the 8398** destination database. 8399** 8400** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8401** returned and an error code and error message are stored in the 8402** destination [database connection] D. 8403** ^The error code and message for the failed call to sqlite3_backup_init() 8404** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8405** [sqlite3_errmsg16()] functions. 8406** ^A successful call to sqlite3_backup_init() returns a pointer to an 8407** [sqlite3_backup] object. 8408** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8409** sqlite3_backup_finish() functions to perform the specified backup 8410** operation. 8411** 8412** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8413** 8414** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8415** the source and destination databases specified by [sqlite3_backup] object B. 8416** ^If N is negative, all remaining source pages are copied. 8417** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8418** are still more pages to be copied, then the function returns [SQLITE_OK]. 8419** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8420** from source to destination, then it returns [SQLITE_DONE]. 8421** ^If an error occurs while running sqlite3_backup_step(B,N), 8422** then an [error code] is returned. ^As well as [SQLITE_OK] and 8423** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8424** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8425** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8426** 8427** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8428** <ol> 8429** <li> the destination database was opened read-only, or 8430** <li> the destination database is using write-ahead-log journaling 8431** and the destination and source page sizes differ, or 8432** <li> the destination database is an in-memory database and the 8433** destination and source page sizes differ. 8434** </ol>)^ 8435** 8436** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8437** the [sqlite3_busy_handler | busy-handler function] 8438** is invoked (if one is specified). ^If the 8439** busy-handler returns non-zero before the lock is available, then 8440** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8441** sqlite3_backup_step() can be retried later. ^If the source 8442** [database connection] 8443** is being used to write to the source database when sqlite3_backup_step() 8444** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8445** case the call to sqlite3_backup_step() can be retried later on. ^(If 8446** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8447** [SQLITE_READONLY] is returned, then 8448** there is no point in retrying the call to sqlite3_backup_step(). These 8449** errors are considered fatal.)^ The application must accept 8450** that the backup operation has failed and pass the backup operation handle 8451** to the sqlite3_backup_finish() to release associated resources. 8452** 8453** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8454** on the destination file. ^The exclusive lock is not released until either 8455** sqlite3_backup_finish() is called or the backup operation is complete 8456** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8457** sqlite3_backup_step() obtains a [shared lock] on the source database that 8458** lasts for the duration of the sqlite3_backup_step() call. 8459** ^Because the source database is not locked between calls to 8460** sqlite3_backup_step(), the source database may be modified mid-way 8461** through the backup process. ^If the source database is modified by an 8462** external process or via a database connection other than the one being 8463** used by the backup operation, then the backup will be automatically 8464** restarted by the next call to sqlite3_backup_step(). ^If the source 8465** database is modified by the using the same database connection as is used 8466** by the backup operation, then the backup database is automatically 8467** updated at the same time. 8468** 8469** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8470** 8471** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8472** application wishes to abandon the backup operation, the application 8473** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8474** ^The sqlite3_backup_finish() interfaces releases all 8475** resources associated with the [sqlite3_backup] object. 8476** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8477** active write-transaction on the destination database is rolled back. 8478** The [sqlite3_backup] object is invalid 8479** and may not be used following a call to sqlite3_backup_finish(). 8480** 8481** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8482** sqlite3_backup_step() errors occurred, regardless or whether or not 8483** sqlite3_backup_step() completed. 8484** ^If an out-of-memory condition or IO error occurred during any prior 8485** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8486** sqlite3_backup_finish() returns the corresponding [error code]. 8487** 8488** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8489** is not a permanent error and does not affect the return value of 8490** sqlite3_backup_finish(). 8491** 8492** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8493** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8494** 8495** ^The sqlite3_backup_remaining() routine returns the number of pages still 8496** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8497** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8498** in the source database at the conclusion of the most recent 8499** sqlite3_backup_step(). 8500** ^(The values returned by these functions are only updated by 8501** sqlite3_backup_step(). If the source database is modified in a way that 8502** changes the size of the source database or the number of pages remaining, 8503** those changes are not reflected in the output of sqlite3_backup_pagecount() 8504** and sqlite3_backup_remaining() until after the next 8505** sqlite3_backup_step().)^ 8506** 8507** <b>Concurrent Usage of Database Handles</b> 8508** 8509** ^The source [database connection] may be used by the application for other 8510** purposes while a backup operation is underway or being initialized. 8511** ^If SQLite is compiled and configured to support threadsafe database 8512** connections, then the source database connection may be used concurrently 8513** from within other threads. 8514** 8515** However, the application must guarantee that the destination 8516** [database connection] is not passed to any other API (by any thread) after 8517** sqlite3_backup_init() is called and before the corresponding call to 8518** sqlite3_backup_finish(). SQLite does not currently check to see 8519** if the application incorrectly accesses the destination [database connection] 8520** and so no error code is reported, but the operations may malfunction 8521** nevertheless. Use of the destination database connection while a 8522** backup is in progress might also also cause a mutex deadlock. 8523** 8524** If running in [shared cache mode], the application must 8525** guarantee that the shared cache used by the destination database 8526** is not accessed while the backup is running. In practice this means 8527** that the application must guarantee that the disk file being 8528** backed up to is not accessed by any connection within the process, 8529** not just the specific connection that was passed to sqlite3_backup_init(). 8530** 8531** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8532** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8533** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8534** APIs are not strictly speaking threadsafe. If they are invoked at the 8535** same time as another thread is invoking sqlite3_backup_step() it is 8536** possible that they return invalid values. 8537*/ 8538sqlite3_backup *sqlite3_backup_init( 8539 sqlite3 *pDest, /* Destination database handle */ 8540 const char *zDestName, /* Destination database name */ 8541 sqlite3 *pSource, /* Source database handle */ 8542 const char *zSourceName /* Source database name */ 8543); 8544int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8545int sqlite3_backup_finish(sqlite3_backup *p); 8546int sqlite3_backup_remaining(sqlite3_backup *p); 8547int sqlite3_backup_pagecount(sqlite3_backup *p); 8548 8549/* 8550** CAPI3REF: Unlock Notification 8551** METHOD: sqlite3 8552** 8553** ^When running in shared-cache mode, a database operation may fail with 8554** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8555** individual tables within the shared-cache cannot be obtained. See 8556** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8557** ^This API may be used to register a callback that SQLite will invoke 8558** when the connection currently holding the required lock relinquishes it. 8559** ^This API is only available if the library was compiled with the 8560** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8561** 8562** See Also: [Using the SQLite Unlock Notification Feature]. 8563** 8564** ^Shared-cache locks are released when a database connection concludes 8565** its current transaction, either by committing it or rolling it back. 8566** 8567** ^When a connection (known as the blocked connection) fails to obtain a 8568** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8569** identity of the database connection (the blocking connection) that 8570** has locked the required resource is stored internally. ^After an 8571** application receives an SQLITE_LOCKED error, it may call the 8572** sqlite3_unlock_notify() method with the blocked connection handle as 8573** the first argument to register for a callback that will be invoked 8574** when the blocking connections current transaction is concluded. ^The 8575** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8576** call that concludes the blocking connection's transaction. 8577** 8578** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8579** there is a chance that the blocking connection will have already 8580** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8581** If this happens, then the specified callback is invoked immediately, 8582** from within the call to sqlite3_unlock_notify().)^ 8583** 8584** ^If the blocked connection is attempting to obtain a write-lock on a 8585** shared-cache table, and more than one other connection currently holds 8586** a read-lock on the same table, then SQLite arbitrarily selects one of 8587** the other connections to use as the blocking connection. 8588** 8589** ^(There may be at most one unlock-notify callback registered by a 8590** blocked connection. If sqlite3_unlock_notify() is called when the 8591** blocked connection already has a registered unlock-notify callback, 8592** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8593** called with a NULL pointer as its second argument, then any existing 8594** unlock-notify callback is canceled. ^The blocked connections 8595** unlock-notify callback may also be canceled by closing the blocked 8596** connection using [sqlite3_close()]. 8597** 8598** The unlock-notify callback is not reentrant. If an application invokes 8599** any sqlite3_xxx API functions from within an unlock-notify callback, a 8600** crash or deadlock may be the result. 8601** 8602** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8603** returns SQLITE_OK. 8604** 8605** <b>Callback Invocation Details</b> 8606** 8607** When an unlock-notify callback is registered, the application provides a 8608** single void* pointer that is passed to the callback when it is invoked. 8609** However, the signature of the callback function allows SQLite to pass 8610** it an array of void* context pointers. The first argument passed to 8611** an unlock-notify callback is a pointer to an array of void* pointers, 8612** and the second is the number of entries in the array. 8613** 8614** When a blocking connection's transaction is concluded, there may be 8615** more than one blocked connection that has registered for an unlock-notify 8616** callback. ^If two or more such blocked connections have specified the 8617** same callback function, then instead of invoking the callback function 8618** multiple times, it is invoked once with the set of void* context pointers 8619** specified by the blocked connections bundled together into an array. 8620** This gives the application an opportunity to prioritize any actions 8621** related to the set of unblocked database connections. 8622** 8623** <b>Deadlock Detection</b> 8624** 8625** Assuming that after registering for an unlock-notify callback a 8626** database waits for the callback to be issued before taking any further 8627** action (a reasonable assumption), then using this API may cause the 8628** application to deadlock. For example, if connection X is waiting for 8629** connection Y's transaction to be concluded, and similarly connection 8630** Y is waiting on connection X's transaction, then neither connection 8631** will proceed and the system may remain deadlocked indefinitely. 8632** 8633** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8634** detection. ^If a given call to sqlite3_unlock_notify() would put the 8635** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8636** unlock-notify callback is registered. The system is said to be in 8637** a deadlocked state if connection A has registered for an unlock-notify 8638** callback on the conclusion of connection B's transaction, and connection 8639** B has itself registered for an unlock-notify callback when connection 8640** A's transaction is concluded. ^Indirect deadlock is also detected, so 8641** the system is also considered to be deadlocked if connection B has 8642** registered for an unlock-notify callback on the conclusion of connection 8643** C's transaction, where connection C is waiting on connection A. ^Any 8644** number of levels of indirection are allowed. 8645** 8646** <b>The "DROP TABLE" Exception</b> 8647** 8648** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8649** always appropriate to call sqlite3_unlock_notify(). There is however, 8650** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8651** SQLite checks if there are any currently executing SELECT statements 8652** that belong to the same connection. If there are, SQLITE_LOCKED is 8653** returned. In this case there is no "blocking connection", so invoking 8654** sqlite3_unlock_notify() results in the unlock-notify callback being 8655** invoked immediately. If the application then re-attempts the "DROP TABLE" 8656** or "DROP INDEX" query, an infinite loop might be the result. 8657** 8658** One way around this problem is to check the extended error code returned 8659** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8660** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8661** the special "DROP TABLE/INDEX" case, the extended error code is just 8662** SQLITE_LOCKED.)^ 8663*/ 8664int sqlite3_unlock_notify( 8665 sqlite3 *pBlocked, /* Waiting connection */ 8666 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8667 void *pNotifyArg /* Argument to pass to xNotify */ 8668); 8669 8670 8671/* 8672** CAPI3REF: String Comparison 8673** 8674** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8675** and extensions to compare the contents of two buffers containing UTF-8 8676** strings in a case-independent fashion, using the same definition of "case 8677** independence" that SQLite uses internally when comparing identifiers. 8678*/ 8679int sqlite3_stricmp(const char *, const char *); 8680int sqlite3_strnicmp(const char *, const char *, int); 8681 8682/* 8683** CAPI3REF: String Globbing 8684* 8685** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8686** string X matches the [GLOB] pattern P. 8687** ^The definition of [GLOB] pattern matching used in 8688** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8689** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8690** is case sensitive. 8691** 8692** Note that this routine returns zero on a match and non-zero if the strings 8693** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8694** 8695** See also: [sqlite3_strlike()]. 8696*/ 8697int sqlite3_strglob(const char *zGlob, const char *zStr); 8698 8699/* 8700** CAPI3REF: String LIKE Matching 8701* 8702** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8703** string X matches the [LIKE] pattern P with escape character E. 8704** ^The definition of [LIKE] pattern matching used in 8705** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8706** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8707** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8708** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8709** insensitive - equivalent upper and lower case ASCII characters match 8710** one another. 8711** 8712** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8713** only ASCII characters are case folded. 8714** 8715** Note that this routine returns zero on a match and non-zero if the strings 8716** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8717** 8718** See also: [sqlite3_strglob()]. 8719*/ 8720int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8721 8722/* 8723** CAPI3REF: Error Logging Interface 8724** 8725** ^The [sqlite3_log()] interface writes a message into the [error log] 8726** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8727** ^If logging is enabled, the zFormat string and subsequent arguments are 8728** used with [sqlite3_snprintf()] to generate the final output string. 8729** 8730** The sqlite3_log() interface is intended for use by extensions such as 8731** virtual tables, collating functions, and SQL functions. While there is 8732** nothing to prevent an application from calling sqlite3_log(), doing so 8733** is considered bad form. 8734** 8735** The zFormat string must not be NULL. 8736** 8737** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8738** will not use dynamically allocated memory. The log message is stored in 8739** a fixed-length buffer on the stack. If the log message is longer than 8740** a few hundred characters, it will be truncated to the length of the 8741** buffer. 8742*/ 8743void sqlite3_log(int iErrCode, const char *zFormat, ...); 8744 8745/* 8746** CAPI3REF: Write-Ahead Log Commit Hook 8747** METHOD: sqlite3 8748** 8749** ^The [sqlite3_wal_hook()] function is used to register a callback that 8750** is invoked each time data is committed to a database in wal mode. 8751** 8752** ^(The callback is invoked by SQLite after the commit has taken place and 8753** the associated write-lock on the database released)^, so the implementation 8754** may read, write or [checkpoint] the database as required. 8755** 8756** ^The first parameter passed to the callback function when it is invoked 8757** is a copy of the third parameter passed to sqlite3_wal_hook() when 8758** registering the callback. ^The second is a copy of the database handle. 8759** ^The third parameter is the name of the database that was written to - 8760** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8761** is the number of pages currently in the write-ahead log file, 8762** including those that were just committed. 8763** 8764** The callback function should normally return [SQLITE_OK]. ^If an error 8765** code is returned, that error will propagate back up through the 8766** SQLite code base to cause the statement that provoked the callback 8767** to report an error, though the commit will have still occurred. If the 8768** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8769** that does not correspond to any valid SQLite error code, the results 8770** are undefined. 8771** 8772** A single database handle may have at most a single write-ahead log callback 8773** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8774** previously registered write-ahead log callback. ^Note that the 8775** [sqlite3_wal_autocheckpoint()] interface and the 8776** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8777** overwrite any prior [sqlite3_wal_hook()] settings. 8778*/ 8779void *sqlite3_wal_hook( 8780 sqlite3*, 8781 int(*)(void *,sqlite3*,const char*,int), 8782 void* 8783); 8784 8785/* 8786** CAPI3REF: Configure an auto-checkpoint 8787** METHOD: sqlite3 8788** 8789** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8790** [sqlite3_wal_hook()] that causes any database on [database connection] D 8791** to automatically [checkpoint] 8792** after committing a transaction if there are N or 8793** more frames in the [write-ahead log] file. ^Passing zero or 8794** a negative value as the nFrame parameter disables automatic 8795** checkpoints entirely. 8796** 8797** ^The callback registered by this function replaces any existing callback 8798** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8799** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8800** configured by this function. 8801** 8802** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8803** from SQL. 8804** 8805** ^Checkpoints initiated by this mechanism are 8806** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8807** 8808** ^Every new [database connection] defaults to having the auto-checkpoint 8809** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8810** pages. The use of this interface 8811** is only necessary if the default setting is found to be suboptimal 8812** for a particular application. 8813*/ 8814int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8815 8816/* 8817** CAPI3REF: Checkpoint a database 8818** METHOD: sqlite3 8819** 8820** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8821** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8822** 8823** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8824** [write-ahead log] for database X on [database connection] D to be 8825** transferred into the database file and for the write-ahead log to 8826** be reset. See the [checkpointing] documentation for addition 8827** information. 8828** 8829** This interface used to be the only way to cause a checkpoint to 8830** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8831** interface was added. This interface is retained for backwards 8832** compatibility and as a convenience for applications that need to manually 8833** start a callback but which do not need the full power (and corresponding 8834** complication) of [sqlite3_wal_checkpoint_v2()]. 8835*/ 8836int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8837 8838/* 8839** CAPI3REF: Checkpoint a database 8840** METHOD: sqlite3 8841** 8842** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8843** operation on database X of [database connection] D in mode M. Status 8844** information is written back into integers pointed to by L and C.)^ 8845** ^(The M parameter must be a valid [checkpoint mode]:)^ 8846** 8847** <dl> 8848** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8849** ^Checkpoint as many frames as possible without waiting for any database 8850** readers or writers to finish, then sync the database file if all frames 8851** in the log were checkpointed. ^The [busy-handler callback] 8852** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8853** ^On the other hand, passive mode might leave the checkpoint unfinished 8854** if there are concurrent readers or writers. 8855** 8856** <dt>SQLITE_CHECKPOINT_FULL<dd> 8857** ^This mode blocks (it invokes the 8858** [sqlite3_busy_handler|busy-handler callback]) until there is no 8859** database writer and all readers are reading from the most recent database 8860** snapshot. ^It then checkpoints all frames in the log file and syncs the 8861** database file. ^This mode blocks new database writers while it is pending, 8862** but new database readers are allowed to continue unimpeded. 8863** 8864** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8865** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8866** that after checkpointing the log file it blocks (calls the 8867** [busy-handler callback]) 8868** until all readers are reading from the database file only. ^This ensures 8869** that the next writer will restart the log file from the beginning. 8870** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8871** database writer attempts while it is pending, but does not impede readers. 8872** 8873** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8874** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8875** addition that it also truncates the log file to zero bytes just prior 8876** to a successful return. 8877** </dl> 8878** 8879** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8880** the log file or to -1 if the checkpoint could not run because 8881** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8882** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8883** log file (including any that were already checkpointed before the function 8884** was called) or to -1 if the checkpoint could not run due to an error or 8885** because the database is not in WAL mode. ^Note that upon successful 8886** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8887** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8888** 8889** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8890** any other process is running a checkpoint operation at the same time, the 8891** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8892** busy-handler configured, it will not be invoked in this case. 8893** 8894** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8895** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8896** obtained immediately, and a busy-handler is configured, it is invoked and 8897** the writer lock retried until either the busy-handler returns 0 or the lock 8898** is successfully obtained. ^The busy-handler is also invoked while waiting for 8899** database readers as described above. ^If the busy-handler returns 0 before 8900** the writer lock is obtained or while waiting for database readers, the 8901** checkpoint operation proceeds from that point in the same way as 8902** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8903** without blocking any further. ^SQLITE_BUSY is returned in this case. 8904** 8905** ^If parameter zDb is NULL or points to a zero length string, then the 8906** specified operation is attempted on all WAL databases [attached] to 8907** [database connection] db. In this case the 8908** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8909** an SQLITE_BUSY error is encountered when processing one or more of the 8910** attached WAL databases, the operation is still attempted on any remaining 8911** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8912** error occurs while processing an attached database, processing is abandoned 8913** and the error code is returned to the caller immediately. ^If no error 8914** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8915** databases, SQLITE_OK is returned. 8916** 8917** ^If database zDb is the name of an attached database that is not in WAL 8918** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8919** zDb is not NULL (or a zero length string) and is not the name of any 8920** attached database, SQLITE_ERROR is returned to the caller. 8921** 8922** ^Unless it returns SQLITE_MISUSE, 8923** the sqlite3_wal_checkpoint_v2() interface 8924** sets the error information that is queried by 8925** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8926** 8927** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8928** from SQL. 8929*/ 8930int sqlite3_wal_checkpoint_v2( 8931 sqlite3 *db, /* Database handle */ 8932 const char *zDb, /* Name of attached database (or NULL) */ 8933 int eMode, /* SQLITE_CHECKPOINT_* value */ 8934 int *pnLog, /* OUT: Size of WAL log in frames */ 8935 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8936); 8937 8938/* 8939** CAPI3REF: Checkpoint Mode Values 8940** KEYWORDS: {checkpoint mode} 8941** 8942** These constants define all valid values for the "checkpoint mode" passed 8943** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8944** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8945** meaning of each of these checkpoint modes. 8946*/ 8947#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8948#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8949#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8950#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8951 8952/* 8953** CAPI3REF: Virtual Table Interface Configuration 8954** 8955** This function may be called by either the [xConnect] or [xCreate] method 8956** of a [virtual table] implementation to configure 8957** various facets of the virtual table interface. 8958** 8959** If this interface is invoked outside the context of an xConnect or 8960** xCreate virtual table method then the behavior is undefined. 8961** 8962** At present, there is only one option that may be configured using 8963** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8964** may be added in the future. 8965*/ 8966int sqlite3_vtab_config(sqlite3*, int op, ...); 8967 8968/* 8969** CAPI3REF: Virtual Table Configuration Options 8970** 8971** These macros define the various options to the 8972** [sqlite3_vtab_config()] interface that [virtual table] implementations 8973** can use to customize and optimize their behavior. 8974** 8975** <dl> 8976** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8977** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt> 8978** <dd>Calls of the form 8979** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8980** where X is an integer. If X is zero, then the [virtual table] whose 8981** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8982** support constraints. In this configuration (which is the default) if 8983** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8984** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8985** specified as part of the users SQL statement, regardless of the actual 8986** ON CONFLICT mode specified. 8987** 8988** If X is non-zero, then the virtual table implementation guarantees 8989** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8990** any modifications to internal or persistent data structures have been made. 8991** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8992** is able to roll back a statement or database transaction, and abandon 8993** or continue processing the current SQL statement as appropriate. 8994** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8995** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8996** had been ABORT. 8997** 8998** Virtual table implementations that are required to handle OR REPLACE 8999** must do so within the [xUpdate] method. If a call to the 9000** [sqlite3_vtab_on_conflict()] function indicates that the current ON 9001** CONFLICT policy is REPLACE, the virtual table implementation should 9002** silently replace the appropriate rows within the xUpdate callback and 9003** return SQLITE_OK. Or, if this is not possible, it may return 9004** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 9005** constraint handling. 9006** </dd> 9007** 9008** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt> 9009** <dd>Calls of the form 9010** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the 9011** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9012** identify that virtual table as being safe to use from within triggers 9013** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the 9014** virtual table can do no serious harm even if it is controlled by a 9015** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS 9016** flag unless absolutely necessary. 9017** </dd> 9018** 9019** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt> 9020** <dd>Calls of the form 9021** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the 9022** the [xConnect] or [xCreate] methods of a [virtual table] implmentation 9023** prohibits that virtual table from being used from within triggers and 9024** views. 9025** </dd> 9026** </dl> 9027*/ 9028#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 9029#define SQLITE_VTAB_INNOCUOUS 2 9030#define SQLITE_VTAB_DIRECTONLY 3 9031 9032/* 9033** CAPI3REF: Determine The Virtual Table Conflict Policy 9034** 9035** This function may only be called from within a call to the [xUpdate] method 9036** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 9037** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 9038** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 9039** of the SQL statement that triggered the call to the [xUpdate] method of the 9040** [virtual table]. 9041*/ 9042int sqlite3_vtab_on_conflict(sqlite3 *); 9043 9044/* 9045** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 9046** 9047** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 9048** method of a [virtual table], then it returns true if and only if the 9049** column is being fetched as part of an UPDATE operation during which the 9050** column value will not change. Applications might use this to substitute 9051** a return value that is less expensive to compute and that the corresponding 9052** [xUpdate] method understands as a "no-change" value. 9053** 9054** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 9055** the column is not changed by the UPDATE statement, then the xColumn 9056** method can optionally return without setting a result, without calling 9057** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 9058** In that case, [sqlite3_value_nochange(X)] will return true for the 9059** same column in the [xUpdate] method. 9060*/ 9061int sqlite3_vtab_nochange(sqlite3_context*); 9062 9063/* 9064** CAPI3REF: Determine The Collation For a Virtual Table Constraint 9065** 9066** This function may only be called from within a call to the [xBestIndex] 9067** method of a [virtual table]. 9068** 9069** The first argument must be the sqlite3_index_info object that is the 9070** first parameter to the xBestIndex() method. The second argument must be 9071** an index into the aConstraint[] array belonging to the sqlite3_index_info 9072** structure passed to xBestIndex. This function returns a pointer to a buffer 9073** containing the name of the collation sequence for the corresponding 9074** constraint. 9075*/ 9076SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 9077 9078/* 9079** CAPI3REF: Conflict resolution modes 9080** KEYWORDS: {conflict resolution mode} 9081** 9082** These constants are returned by [sqlite3_vtab_on_conflict()] to 9083** inform a [virtual table] implementation what the [ON CONFLICT] mode 9084** is for the SQL statement being evaluated. 9085** 9086** Note that the [SQLITE_IGNORE] constant is also used as a potential 9087** return value from the [sqlite3_set_authorizer()] callback and that 9088** [SQLITE_ABORT] is also a [result code]. 9089*/ 9090#define SQLITE_ROLLBACK 1 9091/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 9092#define SQLITE_FAIL 3 9093/* #define SQLITE_ABORT 4 // Also an error code */ 9094#define SQLITE_REPLACE 5 9095 9096/* 9097** CAPI3REF: Prepared Statement Scan Status Opcodes 9098** KEYWORDS: {scanstatus options} 9099** 9100** The following constants can be used for the T parameter to the 9101** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 9102** different metric for sqlite3_stmt_scanstatus() to return. 9103** 9104** When the value returned to V is a string, space to hold that string is 9105** managed by the prepared statement S and will be automatically freed when 9106** S is finalized. 9107** 9108** <dl> 9109** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 9110** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 9111** set to the total number of times that the X-th loop has run.</dd> 9112** 9113** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 9114** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 9115** to the total number of rows examined by all iterations of the X-th loop.</dd> 9116** 9117** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 9118** <dd>^The "double" variable pointed to by the V parameter will be set to the 9119** query planner's estimate for the average number of rows output from each 9120** iteration of the X-th loop. If the query planner's estimates was accurate, 9121** then this value will approximate the quotient NVISIT/NLOOP and the 9122** product of this value for all prior loops with the same SELECTID will 9123** be the NLOOP value for the current loop. 9124** 9125** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 9126** <dd>^The "const char *" variable pointed to by the V parameter will be set 9127** to a zero-terminated UTF-8 string containing the name of the index or table 9128** used for the X-th loop. 9129** 9130** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9131** <dd>^The "const char *" variable pointed to by the V parameter will be set 9132** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9133** description for the X-th loop. 9134** 9135** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9136** <dd>^The "int" variable pointed to by the V parameter will be set to the 9137** "select-id" for the X-th loop. The select-id identifies which query or 9138** subquery the loop is part of. The main query has a select-id of zero. 9139** The select-id is the same value as is output in the first column 9140** of an [EXPLAIN QUERY PLAN] query. 9141** </dl> 9142*/ 9143#define SQLITE_SCANSTAT_NLOOP 0 9144#define SQLITE_SCANSTAT_NVISIT 1 9145#define SQLITE_SCANSTAT_EST 2 9146#define SQLITE_SCANSTAT_NAME 3 9147#define SQLITE_SCANSTAT_EXPLAIN 4 9148#define SQLITE_SCANSTAT_SELECTID 5 9149 9150/* 9151** CAPI3REF: Prepared Statement Scan Status 9152** METHOD: sqlite3_stmt 9153** 9154** This interface returns information about the predicted and measured 9155** performance for pStmt. Advanced applications can use this 9156** interface to compare the predicted and the measured performance and 9157** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9158** 9159** Since this interface is expected to be rarely used, it is only 9160** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9161** compile-time option. 9162** 9163** The "iScanStatusOp" parameter determines which status information to return. 9164** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9165** of this interface is undefined. 9166** ^The requested measurement is written into a variable pointed to by 9167** the "pOut" parameter. 9168** Parameter "idx" identifies the specific loop to retrieve statistics for. 9169** Loops are numbered starting from zero. ^If idx is out of range - less than 9170** zero or greater than or equal to the total number of loops used to implement 9171** the statement - a non-zero value is returned and the variable that pOut 9172** points to is unchanged. 9173** 9174** ^Statistics might not be available for all loops in all statements. ^In cases 9175** where there exist loops with no available statistics, this function behaves 9176** as if the loop did not exist - it returns non-zero and leave the variable 9177** that pOut points to unchanged. 9178** 9179** See also: [sqlite3_stmt_scanstatus_reset()] 9180*/ 9181int sqlite3_stmt_scanstatus( 9182 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9183 int idx, /* Index of loop to report on */ 9184 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9185 void *pOut /* Result written here */ 9186); 9187 9188/* 9189** CAPI3REF: Zero Scan-Status Counters 9190** METHOD: sqlite3_stmt 9191** 9192** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9193** 9194** This API is only available if the library is built with pre-processor 9195** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9196*/ 9197void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9198 9199/* 9200** CAPI3REF: Flush caches to disk mid-transaction 9201** 9202** ^If a write-transaction is open on [database connection] D when the 9203** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9204** pages in the pager-cache that are not currently in use are written out 9205** to disk. A dirty page may be in use if a database cursor created by an 9206** active SQL statement is reading from it, or if it is page 1 of a database 9207** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9208** interface flushes caches for all schemas - "main", "temp", and 9209** any [attached] databases. 9210** 9211** ^If this function needs to obtain extra database locks before dirty pages 9212** can be flushed to disk, it does so. ^If those locks cannot be obtained 9213** immediately and there is a busy-handler callback configured, it is invoked 9214** in the usual manner. ^If the required lock still cannot be obtained, then 9215** the database is skipped and an attempt made to flush any dirty pages 9216** belonging to the next (if any) database. ^If any databases are skipped 9217** because locks cannot be obtained, but no other error occurs, this 9218** function returns SQLITE_BUSY. 9219** 9220** ^If any other error occurs while flushing dirty pages to disk (for 9221** example an IO error or out-of-memory condition), then processing is 9222** abandoned and an SQLite [error code] is returned to the caller immediately. 9223** 9224** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9225** 9226** ^This function does not set the database handle error code or message 9227** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9228*/ 9229int sqlite3_db_cacheflush(sqlite3*); 9230 9231/* 9232** CAPI3REF: The pre-update hook. 9233** 9234** ^These interfaces are only available if SQLite is compiled using the 9235** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9236** 9237** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9238** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9239** on a database table. 9240** ^At most one preupdate hook may be registered at a time on a single 9241** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9242** the previous setting. 9243** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9244** with a NULL pointer as the second parameter. 9245** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9246** the first parameter to callbacks. 9247** 9248** ^The preupdate hook only fires for changes to real database tables; the 9249** preupdate hook is not invoked for changes to [virtual tables] or to 9250** system tables like sqlite_master or sqlite_stat1. 9251** 9252** ^The second parameter to the preupdate callback is a pointer to 9253** the [database connection] that registered the preupdate hook. 9254** ^The third parameter to the preupdate callback is one of the constants 9255** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9256** kind of update operation that is about to occur. 9257** ^(The fourth parameter to the preupdate callback is the name of the 9258** database within the database connection that is being modified. This 9259** will be "main" for the main database or "temp" for TEMP tables or 9260** the name given after the AS keyword in the [ATTACH] statement for attached 9261** databases.)^ 9262** ^The fifth parameter to the preupdate callback is the name of the 9263** table that is being modified. 9264** 9265** For an UPDATE or DELETE operation on a [rowid table], the sixth 9266** parameter passed to the preupdate callback is the initial [rowid] of the 9267** row being modified or deleted. For an INSERT operation on a rowid table, 9268** or any operation on a WITHOUT ROWID table, the value of the sixth 9269** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9270** seventh parameter is the final rowid value of the row being inserted 9271** or updated. The value of the seventh parameter passed to the callback 9272** function is not defined for operations on WITHOUT ROWID tables, or for 9273** INSERT operations on rowid tables. 9274** 9275** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9276** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9277** provide additional information about a preupdate event. These routines 9278** may only be called from within a preupdate callback. Invoking any of 9279** these routines from outside of a preupdate callback or with a 9280** [database connection] pointer that is different from the one supplied 9281** to the preupdate callback results in undefined and probably undesirable 9282** behavior. 9283** 9284** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9285** in the row that is being inserted, updated, or deleted. 9286** 9287** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9288** a [protected sqlite3_value] that contains the value of the Nth column of 9289** the table row before it is updated. The N parameter must be between 0 9290** and one less than the number of columns or the behavior will be 9291** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9292** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9293** behavior is undefined. The [sqlite3_value] that P points to 9294** will be destroyed when the preupdate callback returns. 9295** 9296** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9297** a [protected sqlite3_value] that contains the value of the Nth column of 9298** the table row after it is updated. The N parameter must be between 0 9299** and one less than the number of columns or the behavior will be 9300** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9301** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9302** behavior is undefined. The [sqlite3_value] that P points to 9303** will be destroyed when the preupdate callback returns. 9304** 9305** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9306** callback was invoked as a result of a direct insert, update, or delete 9307** operation; or 1 for inserts, updates, or deletes invoked by top-level 9308** triggers; or 2 for changes resulting from triggers called by top-level 9309** triggers; and so forth. 9310** 9311** See also: [sqlite3_update_hook()] 9312*/ 9313#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9314void *sqlite3_preupdate_hook( 9315 sqlite3 *db, 9316 void(*xPreUpdate)( 9317 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9318 sqlite3 *db, /* Database handle */ 9319 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9320 char const *zDb, /* Database name */ 9321 char const *zName, /* Table name */ 9322 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9323 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9324 ), 9325 void* 9326); 9327int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9328int sqlite3_preupdate_count(sqlite3 *); 9329int sqlite3_preupdate_depth(sqlite3 *); 9330int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9331#endif 9332 9333/* 9334** CAPI3REF: Low-level system error code 9335** 9336** ^Attempt to return the underlying operating system error code or error 9337** number that caused the most recent I/O error or failure to open a file. 9338** The return value is OS-dependent. For example, on unix systems, after 9339** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9340** called to get back the underlying "errno" that caused the problem, such 9341** as ENOSPC, EAUTH, EISDIR, and so forth. 9342*/ 9343int sqlite3_system_errno(sqlite3*); 9344 9345/* 9346** CAPI3REF: Database Snapshot 9347** KEYWORDS: {snapshot} {sqlite3_snapshot} 9348** 9349** An instance of the snapshot object records the state of a [WAL mode] 9350** database for some specific point in history. 9351** 9352** In [WAL mode], multiple [database connections] that are open on the 9353** same database file can each be reading a different historical version 9354** of the database file. When a [database connection] begins a read 9355** transaction, that connection sees an unchanging copy of the database 9356** as it existed for the point in time when the transaction first started. 9357** Subsequent changes to the database from other connections are not seen 9358** by the reader until a new read transaction is started. 9359** 9360** The sqlite3_snapshot object records state information about an historical 9361** version of the database file so that it is possible to later open a new read 9362** transaction that sees that historical version of the database rather than 9363** the most recent version. 9364*/ 9365typedef struct sqlite3_snapshot { 9366 unsigned char hidden[48]; 9367} sqlite3_snapshot; 9368 9369/* 9370** CAPI3REF: Record A Database Snapshot 9371** CONSTRUCTOR: sqlite3_snapshot 9372** 9373** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9374** new [sqlite3_snapshot] object that records the current state of 9375** schema S in database connection D. ^On success, the 9376** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9377** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9378** If there is not already a read-transaction open on schema S when 9379** this function is called, one is opened automatically. 9380** 9381** The following must be true for this function to succeed. If any of 9382** the following statements are false when sqlite3_snapshot_get() is 9383** called, SQLITE_ERROR is returned. The final value of *P is undefined 9384** in this case. 9385** 9386** <ul> 9387** <li> The database handle must not be in [autocommit mode]. 9388** 9389** <li> Schema S of [database connection] D must be a [WAL mode] database. 9390** 9391** <li> There must not be a write transaction open on schema S of database 9392** connection D. 9393** 9394** <li> One or more transactions must have been written to the current wal 9395** file since it was created on disk (by any connection). This means 9396** that a snapshot cannot be taken on a wal mode database with no wal 9397** file immediately after it is first opened. At least one transaction 9398** must be written to it first. 9399** </ul> 9400** 9401** This function may also return SQLITE_NOMEM. If it is called with the 9402** database handle in autocommit mode but fails for some other reason, 9403** whether or not a read transaction is opened on schema S is undefined. 9404** 9405** The [sqlite3_snapshot] object returned from a successful call to 9406** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9407** to avoid a memory leak. 9408** 9409** The [sqlite3_snapshot_get()] interface is only available when the 9410** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9411*/ 9412SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9413 sqlite3 *db, 9414 const char *zSchema, 9415 sqlite3_snapshot **ppSnapshot 9416); 9417 9418/* 9419** CAPI3REF: Start a read transaction on an historical snapshot 9420** METHOD: sqlite3_snapshot 9421** 9422** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9423** transaction or upgrades an existing one for schema S of 9424** [database connection] D such that the read transaction refers to 9425** historical [snapshot] P, rather than the most recent change to the 9426** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9427** on success or an appropriate [error code] if it fails. 9428** 9429** ^In order to succeed, the database connection must not be in 9430** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9431** is already a read transaction open on schema S, then the database handle 9432** must have no active statements (SELECT statements that have been passed 9433** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9434** SQLITE_ERROR is returned if either of these conditions is violated, or 9435** if schema S does not exist, or if the snapshot object is invalid. 9436** 9437** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9438** snapshot has been overwritten by a [checkpoint]. In this case 9439** SQLITE_ERROR_SNAPSHOT is returned. 9440** 9441** If there is already a read transaction open when this function is 9442** invoked, then the same read transaction remains open (on the same 9443** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9444** is returned. If another error code - for example SQLITE_PROTOCOL or an 9445** SQLITE_IOERR error code - is returned, then the final state of the 9446** read transaction is undefined. If SQLITE_OK is returned, then the 9447** read transaction is now open on database snapshot P. 9448** 9449** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9450** database connection D does not know that the database file for 9451** schema S is in [WAL mode]. A database connection might not know 9452** that the database file is in [WAL mode] if there has been no prior 9453** I/O on that database connection, or if the database entered [WAL mode] 9454** after the most recent I/O on the database connection.)^ 9455** (Hint: Run "[PRAGMA application_id]" against a newly opened 9456** database connection in order to make it ready to use snapshots.) 9457** 9458** The [sqlite3_snapshot_open()] interface is only available when the 9459** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9460*/ 9461SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9462 sqlite3 *db, 9463 const char *zSchema, 9464 sqlite3_snapshot *pSnapshot 9465); 9466 9467/* 9468** CAPI3REF: Destroy a snapshot 9469** DESTRUCTOR: sqlite3_snapshot 9470** 9471** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9472** The application must eventually free every [sqlite3_snapshot] object 9473** using this routine to avoid a memory leak. 9474** 9475** The [sqlite3_snapshot_free()] interface is only available when the 9476** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9477*/ 9478SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9479 9480/* 9481** CAPI3REF: Compare the ages of two snapshot handles. 9482** METHOD: sqlite3_snapshot 9483** 9484** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9485** of two valid snapshot handles. 9486** 9487** If the two snapshot handles are not associated with the same database 9488** file, the result of the comparison is undefined. 9489** 9490** Additionally, the result of the comparison is only valid if both of the 9491** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9492** last time the wal file was deleted. The wal file is deleted when the 9493** database is changed back to rollback mode or when the number of database 9494** clients drops to zero. If either snapshot handle was obtained before the 9495** wal file was last deleted, the value returned by this function 9496** is undefined. 9497** 9498** Otherwise, this API returns a negative value if P1 refers to an older 9499** snapshot than P2, zero if the two handles refer to the same database 9500** snapshot, and a positive value if P1 is a newer snapshot than P2. 9501** 9502** This interface is only available if SQLite is compiled with the 9503** [SQLITE_ENABLE_SNAPSHOT] option. 9504*/ 9505SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9506 sqlite3_snapshot *p1, 9507 sqlite3_snapshot *p2 9508); 9509 9510/* 9511** CAPI3REF: Recover snapshots from a wal file 9512** METHOD: sqlite3_snapshot 9513** 9514** If a [WAL file] remains on disk after all database connections close 9515** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9516** or because the last process to have the database opened exited without 9517** calling [sqlite3_close()]) and a new connection is subsequently opened 9518** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9519** will only be able to open the last transaction added to the WAL file 9520** even though the WAL file contains other valid transactions. 9521** 9522** This function attempts to scan the WAL file associated with database zDb 9523** of database handle db and make all valid snapshots available to 9524** sqlite3_snapshot_open(). It is an error if there is already a read 9525** transaction open on the database, or if the database is not a WAL mode 9526** database. 9527** 9528** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9529** 9530** This interface is only available if SQLite is compiled with the 9531** [SQLITE_ENABLE_SNAPSHOT] option. 9532*/ 9533SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9534 9535/* 9536** CAPI3REF: Serialize a database 9537** 9538** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9539** that is a serialization of the S database on [database connection] D. 9540** If P is not a NULL pointer, then the size of the database in bytes 9541** is written into *P. 9542** 9543** For an ordinary on-disk database file, the serialization is just a 9544** copy of the disk file. For an in-memory database or a "TEMP" database, 9545** the serialization is the same sequence of bytes which would be written 9546** to disk if that database where backed up to disk. 9547** 9548** The usual case is that sqlite3_serialize() copies the serialization of 9549** the database into memory obtained from [sqlite3_malloc64()] and returns 9550** a pointer to that memory. The caller is responsible for freeing the 9551** returned value to avoid a memory leak. However, if the F argument 9552** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9553** are made, and the sqlite3_serialize() function will return a pointer 9554** to the contiguous memory representation of the database that SQLite 9555** is currently using for that database, or NULL if the no such contiguous 9556** memory representation of the database exists. A contiguous memory 9557** representation of the database will usually only exist if there has 9558** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9559** values of D and S. 9560** The size of the database is written into *P even if the 9561** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9562** of the database exists. 9563** 9564** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9565** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9566** allocation error occurs. 9567** 9568** This interface is only available if SQLite is compiled with the 9569** [SQLITE_ENABLE_DESERIALIZE] option. 9570*/ 9571unsigned char *sqlite3_serialize( 9572 sqlite3 *db, /* The database connection */ 9573 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9574 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9575 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9576); 9577 9578/* 9579** CAPI3REF: Flags for sqlite3_serialize 9580** 9581** Zero or more of the following constants can be OR-ed together for 9582** the F argument to [sqlite3_serialize(D,S,P,F)]. 9583** 9584** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9585** a pointer to contiguous in-memory database that it is currently using, 9586** without making a copy of the database. If SQLite is not currently using 9587** a contiguous in-memory database, then this option causes 9588** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9589** using a contiguous in-memory database if it has been initialized by a 9590** prior call to [sqlite3_deserialize()]. 9591*/ 9592#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9593 9594/* 9595** CAPI3REF: Deserialize a database 9596** 9597** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9598** [database connection] D to disconnect from database S and then 9599** reopen S as an in-memory database based on the serialization contained 9600** in P. The serialized database P is N bytes in size. M is the size of 9601** the buffer P, which might be larger than N. If M is larger than N, and 9602** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9603** permitted to add content to the in-memory database as long as the total 9604** size does not exceed M bytes. 9605** 9606** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9607** invoke sqlite3_free() on the serialization buffer when the database 9608** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9609** SQLite will try to increase the buffer size using sqlite3_realloc64() 9610** if writes on the database cause it to grow larger than M bytes. 9611** 9612** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9613** database is currently in a read transaction or is involved in a backup 9614** operation. 9615** 9616** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9617** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9618** [sqlite3_free()] is invoked on argument P prior to returning. 9619** 9620** This interface is only available if SQLite is compiled with the 9621** [SQLITE_ENABLE_DESERIALIZE] option. 9622*/ 9623int sqlite3_deserialize( 9624 sqlite3 *db, /* The database connection */ 9625 const char *zSchema, /* Which DB to reopen with the deserialization */ 9626 unsigned char *pData, /* The serialized database content */ 9627 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9628 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9629 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9630); 9631 9632/* 9633** CAPI3REF: Flags for sqlite3_deserialize() 9634** 9635** The following are allowed values for 6th argument (the F argument) to 9636** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9637** 9638** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9639** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9640** and that SQLite should take ownership of this memory and automatically 9641** free it when it has finished using it. Without this flag, the caller 9642** is responsible for freeing any dynamically allocated memory. 9643** 9644** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9645** grow the size of the database using calls to [sqlite3_realloc64()]. This 9646** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9647** Without this flag, the deserialized database cannot increase in size beyond 9648** the number of bytes specified by the M parameter. 9649** 9650** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9651** should be treated as read-only. 9652*/ 9653#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9654#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9655#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9656 9657/* 9658** Undo the hack that converts floating point types to integer for 9659** builds on processors without floating point support. 9660*/ 9661#ifdef SQLITE_OMIT_FLOATING_POINT 9662# undef double 9663#endif 9664 9665#ifdef __cplusplus 9666} /* End of the 'extern "C"' block */ 9667#endif 9668#endif /* SQLITE3_H */ 9669