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#endif 193 194/* 195** CAPI3REF: Test To See If The Library Is Threadsafe 196** 197** ^The sqlite3_threadsafe() function returns zero if and only if 198** SQLite was compiled with mutexing code omitted due to the 199** [SQLITE_THREADSAFE] compile-time option being set to 0. 200** 201** SQLite can be compiled with or without mutexes. When 202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 203** are enabled and SQLite is threadsafe. When the 204** [SQLITE_THREADSAFE] macro is 0, 205** the mutexes are omitted. Without the mutexes, it is not safe 206** to use SQLite concurrently from more than one thread. 207** 208** Enabling mutexes incurs a measurable performance penalty. 209** So if speed is of utmost importance, it makes sense to disable 210** the mutexes. But for maximum safety, mutexes should be enabled. 211** ^The default behavior is for mutexes to be enabled. 212** 213** This interface can be used by an application to make sure that the 214** version of SQLite that it is linking against was compiled with 215** the desired setting of the [SQLITE_THREADSAFE] macro. 216** 217** This interface only reports on the compile-time mutex setting 218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 220** can be fully or partially disabled using a call to [sqlite3_config()] 221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 223** sqlite3_threadsafe() function shows only the compile-time setting of 224** thread safety, not any run-time changes to that setting made by 225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 226** is unchanged by calls to sqlite3_config().)^ 227** 228** See the [threading mode] documentation for additional information. 229*/ 230int sqlite3_threadsafe(void); 231 232/* 233** CAPI3REF: Database Connection Handle 234** KEYWORDS: {database connection} {database connections} 235** 236** Each open SQLite database is represented by a pointer to an instance of 237** the opaque structure named "sqlite3". It is useful to think of an sqlite3 238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 240** and [sqlite3_close_v2()] are its destructors. There are many other 241** interfaces (such as 242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 243** [sqlite3_busy_timeout()] to name but three) that are methods on an 244** sqlite3 object. 245*/ 246typedef struct sqlite3 sqlite3; 247 248/* 249** CAPI3REF: 64-Bit Integer Types 250** KEYWORDS: sqlite_int64 sqlite_uint64 251** 252** Because there is no cross-platform way to specify 64-bit integer types 253** SQLite includes typedefs for 64-bit signed and unsigned integers. 254** 255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 256** The sqlite_int64 and sqlite_uint64 types are supported for backwards 257** compatibility only. 258** 259** ^The sqlite3_int64 and sqlite_int64 types can store integer values 260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 261** sqlite3_uint64 and sqlite_uint64 types can store integer values 262** between 0 and +18446744073709551615 inclusive. 263*/ 264#ifdef SQLITE_INT64_TYPE 265 typedef SQLITE_INT64_TYPE sqlite_int64; 266# ifdef SQLITE_UINT64_TYPE 267 typedef SQLITE_UINT64_TYPE sqlite_uint64; 268# else 269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 270# endif 271#elif defined(_MSC_VER) || defined(__BORLANDC__) 272 typedef __int64 sqlite_int64; 273 typedef unsigned __int64 sqlite_uint64; 274#else 275 typedef long long int sqlite_int64; 276 typedef unsigned long long int sqlite_uint64; 277#endif 278typedef sqlite_int64 sqlite3_int64; 279typedef sqlite_uint64 sqlite3_uint64; 280 281/* 282** If compiling for a processor that lacks floating point support, 283** substitute integer for floating-point. 284*/ 285#ifdef SQLITE_OMIT_FLOATING_POINT 286# define double sqlite3_int64 287#endif 288 289/* 290** CAPI3REF: Closing A Database Connection 291** DESTRUCTOR: sqlite3 292** 293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 294** for the [sqlite3] object. 295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 296** the [sqlite3] object is successfully destroyed and all associated 297** resources are deallocated. 298** 299** ^If the database connection is associated with unfinalized prepared 300** statements or unfinished sqlite3_backup objects then sqlite3_close() 301** will leave the database connection open and return [SQLITE_BUSY]. 302** ^If sqlite3_close_v2() is called with unfinalized prepared statements 303** and/or unfinished sqlite3_backups, then the database connection becomes 304** an unusable "zombie" which will automatically be deallocated when the 305** last prepared statement is finalized or the last sqlite3_backup is 306** finished. The sqlite3_close_v2() interface is intended for use with 307** host languages that are garbage collected, and where the order in which 308** destructors are called is arbitrary. 309** 310** Applications should [sqlite3_finalize | finalize] all [prepared statements], 311** [sqlite3_blob_close | close] all [BLOB handles], and 312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 313** with the [sqlite3] object prior to attempting to close the object. ^If 314** sqlite3_close_v2() is called on a [database connection] that still has 315** outstanding [prepared statements], [BLOB handles], and/or 316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 317** of resources is deferred until all [prepared statements], [BLOB handles], 318** and [sqlite3_backup] objects are also destroyed. 319** 320** ^If an [sqlite3] object is destroyed while a transaction is open, 321** the transaction is automatically rolled back. 322** 323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 324** must be either a NULL 325** pointer or an [sqlite3] object pointer obtained 326** from [sqlite3_open()], [sqlite3_open16()], or 327** [sqlite3_open_v2()], and not previously closed. 328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 329** argument is a harmless no-op. 330*/ 331int sqlite3_close(sqlite3*); 332int sqlite3_close_v2(sqlite3*); 333 334/* 335** The type for a callback function. 336** This is legacy and deprecated. It is included for historical 337** compatibility and is not documented. 338*/ 339typedef int (*sqlite3_callback)(void*,int,char**, char**); 340 341/* 342** CAPI3REF: One-Step Query Execution Interface 343** METHOD: sqlite3 344** 345** The sqlite3_exec() interface is a convenience wrapper around 346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 347** that allows an application to run multiple statements of SQL 348** without having to use a lot of C code. 349** 350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 351** semicolon-separate SQL statements passed into its 2nd argument, 352** in the context of the [database connection] passed in as its 1st 353** argument. ^If the callback function of the 3rd argument to 354** sqlite3_exec() is not NULL, then it is invoked for each result row 355** coming out of the evaluated SQL statements. ^The 4th argument to 356** sqlite3_exec() is relayed through to the 1st argument of each 357** callback invocation. ^If the callback pointer to sqlite3_exec() 358** is NULL, then no callback is ever invoked and result rows are 359** ignored. 360** 361** ^If an error occurs while evaluating the SQL statements passed into 362** sqlite3_exec(), then execution of the current statement stops and 363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 364** is not NULL then any error message is written into memory obtained 365** from [sqlite3_malloc()] and passed back through the 5th parameter. 366** To avoid memory leaks, the application should invoke [sqlite3_free()] 367** on error message strings returned through the 5th parameter of 368** sqlite3_exec() after the error message string is no longer needed. 369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 371** NULL before returning. 372** 373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 374** routine returns SQLITE_ABORT without invoking the callback again and 375** without running any subsequent SQL statements. 376** 377** ^The 2nd argument to the sqlite3_exec() callback function is the 378** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 379** callback is an array of pointers to strings obtained as if from 380** [sqlite3_column_text()], one for each column. ^If an element of a 381** result row is NULL then the corresponding string pointer for the 382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 383** sqlite3_exec() callback is an array of pointers to strings where each 384** entry represents the name of corresponding result column as obtained 385** from [sqlite3_column_name()]. 386** 387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 388** to an empty string, or a pointer that contains only whitespace and/or 389** SQL comments, then no SQL statements are evaluated and the database 390** is not changed. 391** 392** Restrictions: 393** 394** <ul> 395** <li> The application must ensure that the 1st parameter to sqlite3_exec() 396** is a valid and open [database connection]. 397** <li> The application must not close the [database connection] specified by 398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 399** <li> The application must not modify the SQL statement text passed into 400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 401** </ul> 402*/ 403int sqlite3_exec( 404 sqlite3*, /* An open database */ 405 const char *sql, /* SQL to be evaluated */ 406 int (*callback)(void*,int,char**,char**), /* Callback function */ 407 void *, /* 1st argument to callback */ 408 char **errmsg /* Error msg written here */ 409); 410 411/* 412** CAPI3REF: Result Codes 413** KEYWORDS: {result code definitions} 414** 415** Many SQLite functions return an integer result code from the set shown 416** here in order to indicate success or failure. 417** 418** New error codes may be added in future versions of SQLite. 419** 420** See also: [extended result code definitions] 421*/ 422#define SQLITE_OK 0 /* Successful result */ 423/* beginning-of-error-codes */ 424#define SQLITE_ERROR 1 /* Generic error */ 425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 426#define SQLITE_PERM 3 /* Access permission denied */ 427#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 428#define SQLITE_BUSY 5 /* The database file is locked */ 429#define SQLITE_LOCKED 6 /* A table in the database is locked */ 430#define SQLITE_NOMEM 7 /* A malloc() failed */ 431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 436#define SQLITE_FULL 13 /* Insertion failed because database is full */ 437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 439#define SQLITE_EMPTY 16 /* Internal use only */ 440#define SQLITE_SCHEMA 17 /* The database schema changed */ 441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 443#define SQLITE_MISMATCH 20 /* Data type mismatch */ 444#define SQLITE_MISUSE 21 /* Library used incorrectly */ 445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 446#define SQLITE_AUTH 23 /* Authorization denied */ 447#define SQLITE_FORMAT 24 /* Not used */ 448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 449#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 454/* end-of-error-codes */ 455 456/* 457** CAPI3REF: Extended Result Codes 458** KEYWORDS: {extended result code definitions} 459** 460** In its default configuration, SQLite API routines return one of 30 integer 461** [result codes]. However, experience has shown that many of 462** these result codes are too coarse-grained. They do not provide as 463** much information about problems as programmers might like. In an effort to 464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 465** and later) include 466** support for additional result codes that provide more detailed information 467** about errors. These [extended result codes] are enabled or disabled 468** on a per database connection basis using the 469** [sqlite3_extended_result_codes()] API. Or, the extended code for 470** the most recent error can be obtained using 471** [sqlite3_extended_errcode()]. 472*/ 473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 475#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 476#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 477#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 478#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 479#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 480#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 481#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 482#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 483#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 484#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 485#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 486#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 487#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 488#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 489#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 490#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 491#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 492#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 493#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 494#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 495#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 496#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 497#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 498#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 499#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 500#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 501#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 502#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 503#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 504#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 505#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 506#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 507#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 508#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 509#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 510#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 511#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 512#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 513#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 514#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 515#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 516#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 517#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 518#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 519#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 520#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 521#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 522#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 523#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 524#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 525#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 526#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 527#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 528#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 529#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 530#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 531#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 532#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 533#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 534#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 535#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 536#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 537#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 538#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 539#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 540 541/* 542** CAPI3REF: Flags For File Open Operations 543** 544** These bit values are intended for use in the 545** 3rd parameter to the [sqlite3_open_v2()] interface and 546** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 547*/ 548#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 550#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 551#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 552#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 553#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 554#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 557#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 558#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 559#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 560#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 561#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 562#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 563#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 564#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 565#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 566#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 567#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 568 569/* Reserved: 0x00F00000 */ 570 571/* 572** CAPI3REF: Device Characteristics 573** 574** The xDeviceCharacteristics method of the [sqlite3_io_methods] 575** object returns an integer which is a vector of these 576** bit values expressing I/O characteristics of the mass storage 577** device that holds the file that the [sqlite3_io_methods] 578** refers to. 579** 580** The SQLITE_IOCAP_ATOMIC property means that all writes of 581** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 582** mean that writes of blocks that are nnn bytes in size and 583** are aligned to an address which is an integer multiple of 584** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 585** that when data is appended to a file, the data is appended 586** first then the size of the file is extended, never the other 587** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 588** information is written to disk in the same order as calls 589** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 590** after reboot following a crash or power loss, the only bytes in a 591** file that were written at the application level might have changed 592** and that adjacent bytes, even bytes within the same sector are 593** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 594** flag indicates that a file cannot be deleted when open. The 595** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 596** read-only media and cannot be changed even by processes with 597** elevated privileges. 598** 599** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 600** filesystem supports doing multiple write operations atomically when those 601** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 602** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 603*/ 604#define SQLITE_IOCAP_ATOMIC 0x00000001 605#define SQLITE_IOCAP_ATOMIC512 0x00000002 606#define SQLITE_IOCAP_ATOMIC1K 0x00000004 607#define SQLITE_IOCAP_ATOMIC2K 0x00000008 608#define SQLITE_IOCAP_ATOMIC4K 0x00000010 609#define SQLITE_IOCAP_ATOMIC8K 0x00000020 610#define SQLITE_IOCAP_ATOMIC16K 0x00000040 611#define SQLITE_IOCAP_ATOMIC32K 0x00000080 612#define SQLITE_IOCAP_ATOMIC64K 0x00000100 613#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 614#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 615#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 616#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 617#define SQLITE_IOCAP_IMMUTABLE 0x00002000 618#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 619 620/* 621** CAPI3REF: File Locking Levels 622** 623** SQLite uses one of these integer values as the second 624** argument to calls it makes to the xLock() and xUnlock() methods 625** of an [sqlite3_io_methods] object. 626*/ 627#define SQLITE_LOCK_NONE 0 628#define SQLITE_LOCK_SHARED 1 629#define SQLITE_LOCK_RESERVED 2 630#define SQLITE_LOCK_PENDING 3 631#define SQLITE_LOCK_EXCLUSIVE 4 632 633/* 634** CAPI3REF: Synchronization Type Flags 635** 636** When SQLite invokes the xSync() method of an 637** [sqlite3_io_methods] object it uses a combination of 638** these integer values as the second argument. 639** 640** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 641** sync operation only needs to flush data to mass storage. Inode 642** information need not be flushed. If the lower four bits of the flag 643** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 644** If the lower four bits equal SQLITE_SYNC_FULL, that means 645** to use Mac OS X style fullsync instead of fsync(). 646** 647** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 648** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 649** settings. The [synchronous pragma] determines when calls to the 650** xSync VFS method occur and applies uniformly across all platforms. 651** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 652** energetic or rigorous or forceful the sync operations are and 653** only make a difference on Mac OSX for the default SQLite code. 654** (Third-party VFS implementations might also make the distinction 655** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 656** operating systems natively supported by SQLite, only Mac OSX 657** cares about the difference.) 658*/ 659#define SQLITE_SYNC_NORMAL 0x00002 660#define SQLITE_SYNC_FULL 0x00003 661#define SQLITE_SYNC_DATAONLY 0x00010 662 663/* 664** CAPI3REF: OS Interface Open File Handle 665** 666** An [sqlite3_file] object represents an open file in the 667** [sqlite3_vfs | OS interface layer]. Individual OS interface 668** implementations will 669** want to subclass this object by appending additional fields 670** for their own use. The pMethods entry is a pointer to an 671** [sqlite3_io_methods] object that defines methods for performing 672** I/O operations on the open file. 673*/ 674typedef struct sqlite3_file sqlite3_file; 675struct sqlite3_file { 676 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 677}; 678 679/* 680** CAPI3REF: OS Interface File Virtual Methods Object 681** 682** Every file opened by the [sqlite3_vfs.xOpen] method populates an 683** [sqlite3_file] object (or, more commonly, a subclass of the 684** [sqlite3_file] object) with a pointer to an instance of this object. 685** This object defines the methods used to perform various operations 686** against the open file represented by the [sqlite3_file] object. 687** 688** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 689** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 690** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 691** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 692** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 693** to NULL. 694** 695** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 696** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 697** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 698** flag may be ORed in to indicate that only the data of the file 699** and not its inode needs to be synced. 700** 701** The integer values to xLock() and xUnlock() are one of 702** <ul> 703** <li> [SQLITE_LOCK_NONE], 704** <li> [SQLITE_LOCK_SHARED], 705** <li> [SQLITE_LOCK_RESERVED], 706** <li> [SQLITE_LOCK_PENDING], or 707** <li> [SQLITE_LOCK_EXCLUSIVE]. 708** </ul> 709** xLock() increases the lock. xUnlock() decreases the lock. 710** The xCheckReservedLock() method checks whether any database connection, 711** either in this process or in some other process, is holding a RESERVED, 712** PENDING, or EXCLUSIVE lock on the file. It returns true 713** if such a lock exists and false otherwise. 714** 715** The xFileControl() method is a generic interface that allows custom 716** VFS implementations to directly control an open file using the 717** [sqlite3_file_control()] interface. The second "op" argument is an 718** integer opcode. The third argument is a generic pointer intended to 719** point to a structure that may contain arguments or space in which to 720** write return values. Potential uses for xFileControl() might be 721** functions to enable blocking locks with timeouts, to change the 722** locking strategy (for example to use dot-file locks), to inquire 723** about the status of a lock, or to break stale locks. The SQLite 724** core reserves all opcodes less than 100 for its own use. 725** A [file control opcodes | list of opcodes] less than 100 is available. 726** Applications that define a custom xFileControl method should use opcodes 727** greater than 100 to avoid conflicts. VFS implementations should 728** return [SQLITE_NOTFOUND] for file control opcodes that they do not 729** recognize. 730** 731** The xSectorSize() method returns the sector size of the 732** device that underlies the file. The sector size is the 733** minimum write that can be performed without disturbing 734** other bytes in the file. The xDeviceCharacteristics() 735** method returns a bit vector describing behaviors of the 736** underlying device: 737** 738** <ul> 739** <li> [SQLITE_IOCAP_ATOMIC] 740** <li> [SQLITE_IOCAP_ATOMIC512] 741** <li> [SQLITE_IOCAP_ATOMIC1K] 742** <li> [SQLITE_IOCAP_ATOMIC2K] 743** <li> [SQLITE_IOCAP_ATOMIC4K] 744** <li> [SQLITE_IOCAP_ATOMIC8K] 745** <li> [SQLITE_IOCAP_ATOMIC16K] 746** <li> [SQLITE_IOCAP_ATOMIC32K] 747** <li> [SQLITE_IOCAP_ATOMIC64K] 748** <li> [SQLITE_IOCAP_SAFE_APPEND] 749** <li> [SQLITE_IOCAP_SEQUENTIAL] 750** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 751** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 752** <li> [SQLITE_IOCAP_IMMUTABLE] 753** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 754** </ul> 755** 756** The SQLITE_IOCAP_ATOMIC property means that all writes of 757** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 758** mean that writes of blocks that are nnn bytes in size and 759** are aligned to an address which is an integer multiple of 760** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 761** that when data is appended to a file, the data is appended 762** first then the size of the file is extended, never the other 763** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 764** information is written to disk in the same order as calls 765** to xWrite(). 766** 767** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 768** in the unread portions of the buffer with zeros. A VFS that 769** fails to zero-fill short reads might seem to work. However, 770** failure to zero-fill short reads will eventually lead to 771** database corruption. 772*/ 773typedef struct sqlite3_io_methods sqlite3_io_methods; 774struct sqlite3_io_methods { 775 int iVersion; 776 int (*xClose)(sqlite3_file*); 777 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 778 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 779 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 780 int (*xSync)(sqlite3_file*, int flags); 781 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 782 int (*xLock)(sqlite3_file*, int); 783 int (*xUnlock)(sqlite3_file*, int); 784 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 785 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 786 int (*xSectorSize)(sqlite3_file*); 787 int (*xDeviceCharacteristics)(sqlite3_file*); 788 /* Methods above are valid for version 1 */ 789 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 790 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 791 void (*xShmBarrier)(sqlite3_file*); 792 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 793 /* Methods above are valid for version 2 */ 794 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 795 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 796 /* Methods above are valid for version 3 */ 797 /* Additional methods may be added in future releases */ 798}; 799 800/* 801** CAPI3REF: Standard File Control Opcodes 802** KEYWORDS: {file control opcodes} {file control opcode} 803** 804** These integer constants are opcodes for the xFileControl method 805** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 806** interface. 807** 808** <ul> 809** <li>[[SQLITE_FCNTL_LOCKSTATE]] 810** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 811** opcode causes the xFileControl method to write the current state of 812** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 813** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 814** into an integer that the pArg argument points to. This capability 815** is used during testing and is only available when the SQLITE_TEST 816** compile-time option is used. 817** 818** <li>[[SQLITE_FCNTL_SIZE_HINT]] 819** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 820** layer a hint of how large the database file will grow to be during the 821** current transaction. This hint is not guaranteed to be accurate but it 822** is often close. The underlying VFS might choose to preallocate database 823** file space based on this hint in order to help writes to the database 824** file run faster. 825** 826** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 827** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 828** extends and truncates the database file in chunks of a size specified 829** by the user. The fourth argument to [sqlite3_file_control()] should 830** point to an integer (type int) containing the new chunk-size to use 831** for the nominated database. Allocating database file space in large 832** chunks (say 1MB at a time), may reduce file-system fragmentation and 833** improve performance on some systems. 834** 835** <li>[[SQLITE_FCNTL_FILE_POINTER]] 836** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 837** to the [sqlite3_file] object associated with a particular database 838** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 839** 840** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 841** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 842** to the [sqlite3_file] object associated with the journal file (either 843** the [rollback journal] or the [write-ahead log]) for a particular database 844** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 845** 846** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 847** No longer in use. 848** 849** <li>[[SQLITE_FCNTL_SYNC]] 850** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 851** sent to the VFS immediately before the xSync method is invoked on a 852** database file descriptor. Or, if the xSync method is not invoked 853** because the user has configured SQLite with 854** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 855** of the xSync method. In most cases, the pointer argument passed with 856** this file-control is NULL. However, if the database file is being synced 857** as part of a multi-database commit, the argument points to a nul-terminated 858** string containing the transactions master-journal file name. VFSes that 859** do not need this signal should silently ignore this opcode. Applications 860** should not call [sqlite3_file_control()] with this opcode as doing so may 861** disrupt the operation of the specialized VFSes that do require it. 862** 863** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 864** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 865** and sent to the VFS after a transaction has been committed immediately 866** but before the database is unlocked. VFSes that do not need this signal 867** should silently ignore this opcode. Applications should not call 868** [sqlite3_file_control()] with this opcode as doing so may disrupt the 869** operation of the specialized VFSes that do require it. 870** 871** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 872** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 873** retry counts and intervals for certain disk I/O operations for the 874** windows [VFS] in order to provide robustness in the presence of 875** anti-virus programs. By default, the windows VFS will retry file read, 876** file write, and file delete operations up to 10 times, with a delay 877** of 25 milliseconds before the first retry and with the delay increasing 878** by an additional 25 milliseconds with each subsequent retry. This 879** opcode allows these two values (10 retries and 25 milliseconds of delay) 880** to be adjusted. The values are changed for all database connections 881** within the same process. The argument is a pointer to an array of two 882** integers where the first integer is the new retry count and the second 883** integer is the delay. If either integer is negative, then the setting 884** is not changed but instead the prior value of that setting is written 885** into the array entry, allowing the current retry settings to be 886** interrogated. The zDbName parameter is ignored. 887** 888** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 889** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 890** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 891** write ahead log ([WAL file]) and shared memory 892** files used for transaction control 893** are automatically deleted when the latest connection to the database 894** closes. Setting persistent WAL mode causes those files to persist after 895** close. Persisting the files is useful when other processes that do not 896** have write permission on the directory containing the database file want 897** to read the database file, as the WAL and shared memory files must exist 898** in order for the database to be readable. The fourth parameter to 899** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 900** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 901** WAL mode. If the integer is -1, then it is overwritten with the current 902** WAL persistence setting. 903** 904** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 905** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 906** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 907** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 908** xDeviceCharacteristics methods. The fourth parameter to 909** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 910** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 911** mode. If the integer is -1, then it is overwritten with the current 912** zero-damage mode setting. 913** 914** <li>[[SQLITE_FCNTL_OVERWRITE]] 915** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 916** a write transaction to indicate that, unless it is rolled back for some 917** reason, the entire database file will be overwritten by the current 918** transaction. This is used by VACUUM operations. 919** 920** <li>[[SQLITE_FCNTL_VFSNAME]] 921** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 922** all [VFSes] in the VFS stack. The names are of all VFS shims and the 923** final bottom-level VFS are written into memory obtained from 924** [sqlite3_malloc()] and the result is stored in the char* variable 925** that the fourth parameter of [sqlite3_file_control()] points to. 926** The caller is responsible for freeing the memory when done. As with 927** all file-control actions, there is no guarantee that this will actually 928** do anything. Callers should initialize the char* variable to a NULL 929** pointer in case this file-control is not implemented. This file-control 930** is intended for diagnostic use only. 931** 932** <li>[[SQLITE_FCNTL_VFS_POINTER]] 933** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 934** [VFSes] currently in use. ^(The argument X in 935** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 936** of type "[sqlite3_vfs] **". This opcodes will set *X 937** to a pointer to the top-level VFS.)^ 938** ^When there are multiple VFS shims in the stack, this opcode finds the 939** upper-most shim only. 940** 941** <li>[[SQLITE_FCNTL_PRAGMA]] 942** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 943** file control is sent to the open [sqlite3_file] object corresponding 944** to the database file to which the pragma statement refers. ^The argument 945** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 946** pointers to strings (char**) in which the second element of the array 947** is the name of the pragma and the third element is the argument to the 948** pragma or NULL if the pragma has no argument. ^The handler for an 949** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 950** of the char** argument point to a string obtained from [sqlite3_mprintf()] 951** or the equivalent and that string will become the result of the pragma or 952** the error message if the pragma fails. ^If the 953** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 954** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 955** file control returns [SQLITE_OK], then the parser assumes that the 956** VFS has handled the PRAGMA itself and the parser generates a no-op 957** prepared statement if result string is NULL, or that returns a copy 958** of the result string if the string is non-NULL. 959** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 960** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 961** that the VFS encountered an error while handling the [PRAGMA] and the 962** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 963** file control occurs at the beginning of pragma statement analysis and so 964** it is able to override built-in [PRAGMA] statements. 965** 966** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 967** ^The [SQLITE_FCNTL_BUSYHANDLER] 968** file-control may be invoked by SQLite on the database file handle 969** shortly after it is opened in order to provide a custom VFS with access 970** to the connections busy-handler callback. The argument is of type (void **) 971** - an array of two (void *) values. The first (void *) actually points 972** to a function of type (int (*)(void *)). In order to invoke the connections 973** busy-handler, this function should be invoked with the second (void *) in 974** the array as the only argument. If it returns non-zero, then the operation 975** should be retried. If it returns zero, the custom VFS should abandon the 976** current operation. 977** 978** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 979** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 980** to have SQLite generate a 981** temporary filename using the same algorithm that is followed to generate 982** temporary filenames for TEMP tables and other internal uses. The 983** argument should be a char** which will be filled with the filename 984** written into memory obtained from [sqlite3_malloc()]. The caller should 985** invoke [sqlite3_free()] on the result to avoid a memory leak. 986** 987** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 988** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 989** maximum number of bytes that will be used for memory-mapped I/O. 990** The argument is a pointer to a value of type sqlite3_int64 that 991** is an advisory maximum number of bytes in the file to memory map. The 992** pointer is overwritten with the old value. The limit is not changed if 993** the value originally pointed to is negative, and so the current limit 994** can be queried by passing in a pointer to a negative number. This 995** file-control is used internally to implement [PRAGMA mmap_size]. 996** 997** <li>[[SQLITE_FCNTL_TRACE]] 998** The [SQLITE_FCNTL_TRACE] file control provides advisory information 999** to the VFS about what the higher layers of the SQLite stack are doing. 1000** This file control is used by some VFS activity tracing [shims]. 1001** The argument is a zero-terminated string. Higher layers in the 1002** SQLite stack may generate instances of this file control if 1003** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1004** 1005** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1006** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1007** pointer to an integer and it writes a boolean into that integer depending 1008** on whether or not the file has been renamed, moved, or deleted since it 1009** was first opened. 1010** 1011** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1012** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1013** underlying native file handle associated with a file handle. This file 1014** control interprets its argument as a pointer to a native file handle and 1015** writes the resulting value there. 1016** 1017** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1018** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1019** opcode causes the xFileControl method to swap the file handle with the one 1020** pointed to by the pArg argument. This capability is used during testing 1021** and only needs to be supported when SQLITE_TEST is defined. 1022** 1023** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1024** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1025** be advantageous to block on the next WAL lock if the lock is not immediately 1026** available. The WAL subsystem issues this signal during rare 1027** circumstances in order to fix a problem with priority inversion. 1028** Applications should <em>not</em> use this file-control. 1029** 1030** <li>[[SQLITE_FCNTL_ZIPVFS]] 1031** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1032** VFS should return SQLITE_NOTFOUND for this opcode. 1033** 1034** <li>[[SQLITE_FCNTL_RBU]] 1035** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1036** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1037** this opcode. 1038** 1039** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1040** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1041** the file descriptor is placed in "batch write mode", which 1042** means all subsequent write operations will be deferred and done 1043** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1044** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1045** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1046** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1047** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1048** no VFS interface calls on the same [sqlite3_file] file descriptor 1049** except for calls to the xWrite method and the xFileControl method 1050** with [SQLITE_FCNTL_SIZE_HINT]. 1051** 1052** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1053** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1054** operations since the previous successful call to 1055** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1056** This file control returns [SQLITE_OK] if and only if the writes were 1057** all performed successfully and have been committed to persistent storage. 1058** ^Regardless of whether or not it is successful, this file control takes 1059** the file descriptor out of batch write mode so that all subsequent 1060** write operations are independent. 1061** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1062** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1063** 1064** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1065** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1066** operations since the previous successful call to 1067** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1068** ^This file control takes the file descriptor out of batch write mode 1069** so that all subsequent write operations are independent. 1070** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1071** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1072** 1073** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1074** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1075** a file lock using the xLock or xShmLock methods of the VFS to wait 1076** for up to M milliseconds before failing, where M is the single 1077** unsigned integer parameter. 1078** 1079** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1080** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1081** a database file. The argument is a pointer to a 32-bit unsigned integer. 1082** The "data version" for the pager is written into the pointer. The 1083** "data version" changes whenever any change occurs to the corresponding 1084** database file, either through SQL statements on the same database 1085** connection, or through transactions committed by separate database 1086** connections possibly in other processes. The [sqlite3_total_changes()] 1087** interface can be used to find if any database on the connection has changed, 1088** but that interface response to changes on TEMP as well as MAIN and does 1089** not provide a mechanism to detect changes to MAIN only. Also, the 1090** [sqlite3_total_changes()] interface response to internal changes only and 1091** omits changes made by other database connections. The 1092** [PRAGMA data_version] command provide a mechanism to detect changes to 1093** a single attached database that occur due to other database connections, 1094** but omits changes implemented by the database connection for which it is 1095** called. This file control is the only mechanism to detect changes that 1096** happen either internally or externally on a single database. 1097** </ul> 1098*/ 1099#define SQLITE_FCNTL_LOCKSTATE 1 1100#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1101#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1102#define SQLITE_FCNTL_LAST_ERRNO 4 1103#define SQLITE_FCNTL_SIZE_HINT 5 1104#define SQLITE_FCNTL_CHUNK_SIZE 6 1105#define SQLITE_FCNTL_FILE_POINTER 7 1106#define SQLITE_FCNTL_SYNC_OMITTED 8 1107#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1108#define SQLITE_FCNTL_PERSIST_WAL 10 1109#define SQLITE_FCNTL_OVERWRITE 11 1110#define SQLITE_FCNTL_VFSNAME 12 1111#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1112#define SQLITE_FCNTL_PRAGMA 14 1113#define SQLITE_FCNTL_BUSYHANDLER 15 1114#define SQLITE_FCNTL_TEMPFILENAME 16 1115#define SQLITE_FCNTL_MMAP_SIZE 18 1116#define SQLITE_FCNTL_TRACE 19 1117#define SQLITE_FCNTL_HAS_MOVED 20 1118#define SQLITE_FCNTL_SYNC 21 1119#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1120#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1121#define SQLITE_FCNTL_WAL_BLOCK 24 1122#define SQLITE_FCNTL_ZIPVFS 25 1123#define SQLITE_FCNTL_RBU 26 1124#define SQLITE_FCNTL_VFS_POINTER 27 1125#define SQLITE_FCNTL_JOURNAL_POINTER 28 1126#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1127#define SQLITE_FCNTL_PDB 30 1128#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1129#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1130#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1131#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1132#define SQLITE_FCNTL_DATA_VERSION 35 1133 1134/* deprecated names */ 1135#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1136#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1137#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1138 1139 1140/* 1141** CAPI3REF: Mutex Handle 1142** 1143** The mutex module within SQLite defines [sqlite3_mutex] to be an 1144** abstract type for a mutex object. The SQLite core never looks 1145** at the internal representation of an [sqlite3_mutex]. It only 1146** deals with pointers to the [sqlite3_mutex] object. 1147** 1148** Mutexes are created using [sqlite3_mutex_alloc()]. 1149*/ 1150typedef struct sqlite3_mutex sqlite3_mutex; 1151 1152/* 1153** CAPI3REF: Loadable Extension Thunk 1154** 1155** A pointer to the opaque sqlite3_api_routines structure is passed as 1156** the third parameter to entry points of [loadable extensions]. This 1157** structure must be typedefed in order to work around compiler warnings 1158** on some platforms. 1159*/ 1160typedef struct sqlite3_api_routines sqlite3_api_routines; 1161 1162/* 1163** CAPI3REF: OS Interface Object 1164** 1165** An instance of the sqlite3_vfs object defines the interface between 1166** the SQLite core and the underlying operating system. The "vfs" 1167** in the name of the object stands for "virtual file system". See 1168** the [VFS | VFS documentation] for further information. 1169** 1170** The VFS interface is sometimes extended by adding new methods onto 1171** the end. Each time such an extension occurs, the iVersion field 1172** is incremented. The iVersion value started out as 1 in 1173** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1174** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1175** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1176** may be appended to the sqlite3_vfs object and the iVersion value 1177** may increase again in future versions of SQLite. 1178** Note that the structure 1179** of the sqlite3_vfs object changes in the transition from 1180** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1181** and yet the iVersion field was not modified. 1182** 1183** The szOsFile field is the size of the subclassed [sqlite3_file] 1184** structure used by this VFS. mxPathname is the maximum length of 1185** a pathname in this VFS. 1186** 1187** Registered sqlite3_vfs objects are kept on a linked list formed by 1188** the pNext pointer. The [sqlite3_vfs_register()] 1189** and [sqlite3_vfs_unregister()] interfaces manage this list 1190** in a thread-safe way. The [sqlite3_vfs_find()] interface 1191** searches the list. Neither the application code nor the VFS 1192** implementation should use the pNext pointer. 1193** 1194** The pNext field is the only field in the sqlite3_vfs 1195** structure that SQLite will ever modify. SQLite will only access 1196** or modify this field while holding a particular static mutex. 1197** The application should never modify anything within the sqlite3_vfs 1198** object once the object has been registered. 1199** 1200** The zName field holds the name of the VFS module. The name must 1201** be unique across all VFS modules. 1202** 1203** [[sqlite3_vfs.xOpen]] 1204** ^SQLite guarantees that the zFilename parameter to xOpen 1205** is either a NULL pointer or string obtained 1206** from xFullPathname() with an optional suffix added. 1207** ^If a suffix is added to the zFilename parameter, it will 1208** consist of a single "-" character followed by no more than 1209** 11 alphanumeric and/or "-" characters. 1210** ^SQLite further guarantees that 1211** the string will be valid and unchanged until xClose() is 1212** called. Because of the previous sentence, 1213** the [sqlite3_file] can safely store a pointer to the 1214** filename if it needs to remember the filename for some reason. 1215** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1216** must invent its own temporary name for the file. ^Whenever the 1217** xFilename parameter is NULL it will also be the case that the 1218** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1219** 1220** The flags argument to xOpen() includes all bits set in 1221** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1222** or [sqlite3_open16()] is used, then flags includes at least 1223** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1224** If xOpen() opens a file read-only then it sets *pOutFlags to 1225** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1226** 1227** ^(SQLite will also add one of the following flags to the xOpen() 1228** call, depending on the object being opened: 1229** 1230** <ul> 1231** <li> [SQLITE_OPEN_MAIN_DB] 1232** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1233** <li> [SQLITE_OPEN_TEMP_DB] 1234** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1235** <li> [SQLITE_OPEN_TRANSIENT_DB] 1236** <li> [SQLITE_OPEN_SUBJOURNAL] 1237** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1238** <li> [SQLITE_OPEN_WAL] 1239** </ul>)^ 1240** 1241** The file I/O implementation can use the object type flags to 1242** change the way it deals with files. For example, an application 1243** that does not care about crash recovery or rollback might make 1244** the open of a journal file a no-op. Writes to this journal would 1245** also be no-ops, and any attempt to read the journal would return 1246** SQLITE_IOERR. Or the implementation might recognize that a database 1247** file will be doing page-aligned sector reads and writes in a random 1248** order and set up its I/O subsystem accordingly. 1249** 1250** SQLite might also add one of the following flags to the xOpen method: 1251** 1252** <ul> 1253** <li> [SQLITE_OPEN_DELETEONCLOSE] 1254** <li> [SQLITE_OPEN_EXCLUSIVE] 1255** </ul> 1256** 1257** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1258** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1259** will be set for TEMP databases and their journals, transient 1260** databases, and subjournals. 1261** 1262** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1263** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1264** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1265** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1266** SQLITE_OPEN_CREATE, is used to indicate that file should always 1267** be created, and that it is an error if it already exists. 1268** It is <i>not</i> used to indicate the file should be opened 1269** for exclusive access. 1270** 1271** ^At least szOsFile bytes of memory are allocated by SQLite 1272** to hold the [sqlite3_file] structure passed as the third 1273** argument to xOpen. The xOpen method does not have to 1274** allocate the structure; it should just fill it in. Note that 1275** the xOpen method must set the sqlite3_file.pMethods to either 1276** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1277** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1278** element will be valid after xOpen returns regardless of the success 1279** or failure of the xOpen call. 1280** 1281** [[sqlite3_vfs.xAccess]] 1282** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1283** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1284** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1285** to test whether a file is at least readable. The file can be a 1286** directory. 1287** 1288** ^SQLite will always allocate at least mxPathname+1 bytes for the 1289** output buffer xFullPathname. The exact size of the output buffer 1290** is also passed as a parameter to both methods. If the output buffer 1291** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1292** handled as a fatal error by SQLite, vfs implementations should endeavor 1293** to prevent this by setting mxPathname to a sufficiently large value. 1294** 1295** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1296** interfaces are not strictly a part of the filesystem, but they are 1297** included in the VFS structure for completeness. 1298** The xRandomness() function attempts to return nBytes bytes 1299** of good-quality randomness into zOut. The return value is 1300** the actual number of bytes of randomness obtained. 1301** The xSleep() method causes the calling thread to sleep for at 1302** least the number of microseconds given. ^The xCurrentTime() 1303** method returns a Julian Day Number for the current date and time as 1304** a floating point value. 1305** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1306** Day Number multiplied by 86400000 (the number of milliseconds in 1307** a 24-hour day). 1308** ^SQLite will use the xCurrentTimeInt64() method to get the current 1309** date and time if that method is available (if iVersion is 2 or 1310** greater and the function pointer is not NULL) and will fall back 1311** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1312** 1313** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1314** are not used by the SQLite core. These optional interfaces are provided 1315** by some VFSes to facilitate testing of the VFS code. By overriding 1316** system calls with functions under its control, a test program can 1317** simulate faults and error conditions that would otherwise be difficult 1318** or impossible to induce. The set of system calls that can be overridden 1319** varies from one VFS to another, and from one version of the same VFS to the 1320** next. Applications that use these interfaces must be prepared for any 1321** or all of these interfaces to be NULL or for their behavior to change 1322** from one release to the next. Applications must not attempt to access 1323** any of these methods if the iVersion of the VFS is less than 3. 1324*/ 1325typedef struct sqlite3_vfs sqlite3_vfs; 1326typedef void (*sqlite3_syscall_ptr)(void); 1327struct sqlite3_vfs { 1328 int iVersion; /* Structure version number (currently 3) */ 1329 int szOsFile; /* Size of subclassed sqlite3_file */ 1330 int mxPathname; /* Maximum file pathname length */ 1331 sqlite3_vfs *pNext; /* Next registered VFS */ 1332 const char *zName; /* Name of this virtual file system */ 1333 void *pAppData; /* Pointer to application-specific data */ 1334 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1335 int flags, int *pOutFlags); 1336 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1337 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1338 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1339 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1340 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1341 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1342 void (*xDlClose)(sqlite3_vfs*, void*); 1343 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1344 int (*xSleep)(sqlite3_vfs*, int microseconds); 1345 int (*xCurrentTime)(sqlite3_vfs*, double*); 1346 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1347 /* 1348 ** The methods above are in version 1 of the sqlite_vfs object 1349 ** definition. Those that follow are added in version 2 or later 1350 */ 1351 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1352 /* 1353 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1354 ** Those below are for version 3 and greater. 1355 */ 1356 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1357 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1358 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1359 /* 1360 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1361 ** New fields may be appended in future versions. The iVersion 1362 ** value will increment whenever this happens. 1363 */ 1364}; 1365 1366/* 1367** CAPI3REF: Flags for the xAccess VFS method 1368** 1369** These integer constants can be used as the third parameter to 1370** the xAccess method of an [sqlite3_vfs] object. They determine 1371** what kind of permissions the xAccess method is looking for. 1372** With SQLITE_ACCESS_EXISTS, the xAccess method 1373** simply checks whether the file exists. 1374** With SQLITE_ACCESS_READWRITE, the xAccess method 1375** checks whether the named directory is both readable and writable 1376** (in other words, if files can be added, removed, and renamed within 1377** the directory). 1378** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1379** [temp_store_directory pragma], though this could change in a future 1380** release of SQLite. 1381** With SQLITE_ACCESS_READ, the xAccess method 1382** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1383** currently unused, though it might be used in a future release of 1384** SQLite. 1385*/ 1386#define SQLITE_ACCESS_EXISTS 0 1387#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1388#define SQLITE_ACCESS_READ 2 /* Unused */ 1389 1390/* 1391** CAPI3REF: Flags for the xShmLock VFS method 1392** 1393** These integer constants define the various locking operations 1394** allowed by the xShmLock method of [sqlite3_io_methods]. The 1395** following are the only legal combinations of flags to the 1396** xShmLock method: 1397** 1398** <ul> 1399** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1400** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1401** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1402** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1403** </ul> 1404** 1405** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1406** was given on the corresponding lock. 1407** 1408** The xShmLock method can transition between unlocked and SHARED or 1409** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1410** and EXCLUSIVE. 1411*/ 1412#define SQLITE_SHM_UNLOCK 1 1413#define SQLITE_SHM_LOCK 2 1414#define SQLITE_SHM_SHARED 4 1415#define SQLITE_SHM_EXCLUSIVE 8 1416 1417/* 1418** CAPI3REF: Maximum xShmLock index 1419** 1420** The xShmLock method on [sqlite3_io_methods] may use values 1421** between 0 and this upper bound as its "offset" argument. 1422** The SQLite core will never attempt to acquire or release a 1423** lock outside of this range 1424*/ 1425#define SQLITE_SHM_NLOCK 8 1426 1427 1428/* 1429** CAPI3REF: Initialize The SQLite Library 1430** 1431** ^The sqlite3_initialize() routine initializes the 1432** SQLite library. ^The sqlite3_shutdown() routine 1433** deallocates any resources that were allocated by sqlite3_initialize(). 1434** These routines are designed to aid in process initialization and 1435** shutdown on embedded systems. Workstation applications using 1436** SQLite normally do not need to invoke either of these routines. 1437** 1438** A call to sqlite3_initialize() is an "effective" call if it is 1439** the first time sqlite3_initialize() is invoked during the lifetime of 1440** the process, or if it is the first time sqlite3_initialize() is invoked 1441** following a call to sqlite3_shutdown(). ^(Only an effective call 1442** of sqlite3_initialize() does any initialization. All other calls 1443** are harmless no-ops.)^ 1444** 1445** A call to sqlite3_shutdown() is an "effective" call if it is the first 1446** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1447** an effective call to sqlite3_shutdown() does any deinitialization. 1448** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1449** 1450** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1451** is not. The sqlite3_shutdown() interface must only be called from a 1452** single thread. All open [database connections] must be closed and all 1453** other SQLite resources must be deallocated prior to invoking 1454** sqlite3_shutdown(). 1455** 1456** Among other things, ^sqlite3_initialize() will invoke 1457** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1458** will invoke sqlite3_os_end(). 1459** 1460** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1461** ^If for some reason, sqlite3_initialize() is unable to initialize 1462** the library (perhaps it is unable to allocate a needed resource such 1463** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1464** 1465** ^The sqlite3_initialize() routine is called internally by many other 1466** SQLite interfaces so that an application usually does not need to 1467** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1468** calls sqlite3_initialize() so the SQLite library will be automatically 1469** initialized when [sqlite3_open()] is called if it has not be initialized 1470** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1471** compile-time option, then the automatic calls to sqlite3_initialize() 1472** are omitted and the application must call sqlite3_initialize() directly 1473** prior to using any other SQLite interface. For maximum portability, 1474** it is recommended that applications always invoke sqlite3_initialize() 1475** directly prior to using any other SQLite interface. Future releases 1476** of SQLite may require this. In other words, the behavior exhibited 1477** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1478** default behavior in some future release of SQLite. 1479** 1480** The sqlite3_os_init() routine does operating-system specific 1481** initialization of the SQLite library. The sqlite3_os_end() 1482** routine undoes the effect of sqlite3_os_init(). Typical tasks 1483** performed by these routines include allocation or deallocation 1484** of static resources, initialization of global variables, 1485** setting up a default [sqlite3_vfs] module, or setting up 1486** a default configuration using [sqlite3_config()]. 1487** 1488** The application should never invoke either sqlite3_os_init() 1489** or sqlite3_os_end() directly. The application should only invoke 1490** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1491** interface is called automatically by sqlite3_initialize() and 1492** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1493** implementations for sqlite3_os_init() and sqlite3_os_end() 1494** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1495** When [custom builds | built for other platforms] 1496** (using the [SQLITE_OS_OTHER=1] compile-time 1497** option) the application must supply a suitable implementation for 1498** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1499** implementation of sqlite3_os_init() or sqlite3_os_end() 1500** must return [SQLITE_OK] on success and some other [error code] upon 1501** failure. 1502*/ 1503int sqlite3_initialize(void); 1504int sqlite3_shutdown(void); 1505int sqlite3_os_init(void); 1506int sqlite3_os_end(void); 1507 1508/* 1509** CAPI3REF: Configuring The SQLite Library 1510** 1511** The sqlite3_config() interface is used to make global configuration 1512** changes to SQLite in order to tune SQLite to the specific needs of 1513** the application. The default configuration is recommended for most 1514** applications and so this routine is usually not necessary. It is 1515** provided to support rare applications with unusual needs. 1516** 1517** <b>The sqlite3_config() interface is not threadsafe. The application 1518** must ensure that no other SQLite interfaces are invoked by other 1519** threads while sqlite3_config() is running.</b> 1520** 1521** The sqlite3_config() interface 1522** may only be invoked prior to library initialization using 1523** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1524** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1525** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1526** Note, however, that ^sqlite3_config() can be called as part of the 1527** implementation of an application-defined [sqlite3_os_init()]. 1528** 1529** The first argument to sqlite3_config() is an integer 1530** [configuration option] that determines 1531** what property of SQLite is to be configured. Subsequent arguments 1532** vary depending on the [configuration option] 1533** in the first argument. 1534** 1535** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1536** ^If the option is unknown or SQLite is unable to set the option 1537** then this routine returns a non-zero [error code]. 1538*/ 1539int sqlite3_config(int, ...); 1540 1541/* 1542** CAPI3REF: Configure database connections 1543** METHOD: sqlite3 1544** 1545** The sqlite3_db_config() interface is used to make configuration 1546** changes to a [database connection]. The interface is similar to 1547** [sqlite3_config()] except that the changes apply to a single 1548** [database connection] (specified in the first argument). 1549** 1550** The second argument to sqlite3_db_config(D,V,...) is the 1551** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1552** that indicates what aspect of the [database connection] is being configured. 1553** Subsequent arguments vary depending on the configuration verb. 1554** 1555** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1556** the call is considered successful. 1557*/ 1558int sqlite3_db_config(sqlite3*, int op, ...); 1559 1560/* 1561** CAPI3REF: Memory Allocation Routines 1562** 1563** An instance of this object defines the interface between SQLite 1564** and low-level memory allocation routines. 1565** 1566** This object is used in only one place in the SQLite interface. 1567** A pointer to an instance of this object is the argument to 1568** [sqlite3_config()] when the configuration option is 1569** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1570** By creating an instance of this object 1571** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1572** during configuration, an application can specify an alternative 1573** memory allocation subsystem for SQLite to use for all of its 1574** dynamic memory needs. 1575** 1576** Note that SQLite comes with several [built-in memory allocators] 1577** that are perfectly adequate for the overwhelming majority of applications 1578** and that this object is only useful to a tiny minority of applications 1579** with specialized memory allocation requirements. This object is 1580** also used during testing of SQLite in order to specify an alternative 1581** memory allocator that simulates memory out-of-memory conditions in 1582** order to verify that SQLite recovers gracefully from such 1583** conditions. 1584** 1585** The xMalloc, xRealloc, and xFree methods must work like the 1586** malloc(), realloc() and free() functions from the standard C library. 1587** ^SQLite guarantees that the second argument to 1588** xRealloc is always a value returned by a prior call to xRoundup. 1589** 1590** xSize should return the allocated size of a memory allocation 1591** previously obtained from xMalloc or xRealloc. The allocated size 1592** is always at least as big as the requested size but may be larger. 1593** 1594** The xRoundup method returns what would be the allocated size of 1595** a memory allocation given a particular requested size. Most memory 1596** allocators round up memory allocations at least to the next multiple 1597** of 8. Some allocators round up to a larger multiple or to a power of 2. 1598** Every memory allocation request coming in through [sqlite3_malloc()] 1599** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1600** that causes the corresponding memory allocation to fail. 1601** 1602** The xInit method initializes the memory allocator. For example, 1603** it might allocate any require mutexes or initialize internal data 1604** structures. The xShutdown method is invoked (indirectly) by 1605** [sqlite3_shutdown()] and should deallocate any resources acquired 1606** by xInit. The pAppData pointer is used as the only parameter to 1607** xInit and xShutdown. 1608** 1609** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1610** the xInit method, so the xInit method need not be threadsafe. The 1611** xShutdown method is only called from [sqlite3_shutdown()] so it does 1612** not need to be threadsafe either. For all other methods, SQLite 1613** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1614** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1615** it is by default) and so the methods are automatically serialized. 1616** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1617** methods must be threadsafe or else make their own arrangements for 1618** serialization. 1619** 1620** SQLite will never invoke xInit() more than once without an intervening 1621** call to xShutdown(). 1622*/ 1623typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1624struct sqlite3_mem_methods { 1625 void *(*xMalloc)(int); /* Memory allocation function */ 1626 void (*xFree)(void*); /* Free a prior allocation */ 1627 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1628 int (*xSize)(void*); /* Return the size of an allocation */ 1629 int (*xRoundup)(int); /* Round up request size to allocation size */ 1630 int (*xInit)(void*); /* Initialize the memory allocator */ 1631 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1632 void *pAppData; /* Argument to xInit() and xShutdown() */ 1633}; 1634 1635/* 1636** CAPI3REF: Configuration Options 1637** KEYWORDS: {configuration option} 1638** 1639** These constants are the available integer configuration options that 1640** can be passed as the first argument to the [sqlite3_config()] interface. 1641** 1642** New configuration options may be added in future releases of SQLite. 1643** Existing configuration options might be discontinued. Applications 1644** should check the return code from [sqlite3_config()] to make sure that 1645** the call worked. The [sqlite3_config()] interface will return a 1646** non-zero [error code] if a discontinued or unsupported configuration option 1647** is invoked. 1648** 1649** <dl> 1650** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1651** <dd>There are no arguments to this option. ^This option sets the 1652** [threading mode] to Single-thread. In other words, it disables 1653** all mutexing and puts SQLite into a mode where it can only be used 1654** by a single thread. ^If SQLite is compiled with 1655** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1656** it is not possible to change the [threading mode] from its default 1657** value of Single-thread and so [sqlite3_config()] will return 1658** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1659** configuration option.</dd> 1660** 1661** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1662** <dd>There are no arguments to this option. ^This option sets the 1663** [threading mode] to Multi-thread. In other words, it disables 1664** mutexing on [database connection] and [prepared statement] objects. 1665** The application is responsible for serializing access to 1666** [database connections] and [prepared statements]. But other mutexes 1667** are enabled so that SQLite will be safe to use in a multi-threaded 1668** environment as long as no two threads attempt to use the same 1669** [database connection] at the same time. ^If SQLite is compiled with 1670** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1671** it is not possible to set the Multi-thread [threading mode] and 1672** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1673** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1674** 1675** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1676** <dd>There are no arguments to this option. ^This option sets the 1677** [threading mode] to Serialized. In other words, this option enables 1678** all mutexes including the recursive 1679** mutexes on [database connection] and [prepared statement] objects. 1680** In this mode (which is the default when SQLite is compiled with 1681** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1682** to [database connections] and [prepared statements] so that the 1683** application is free to use the same [database connection] or the 1684** same [prepared statement] in different threads at the same time. 1685** ^If SQLite is compiled with 1686** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1687** it is not possible to set the Serialized [threading mode] and 1688** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1689** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1690** 1691** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1692** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1693** a pointer to an instance of the [sqlite3_mem_methods] structure. 1694** The argument specifies 1695** alternative low-level memory allocation routines to be used in place of 1696** the memory allocation routines built into SQLite.)^ ^SQLite makes 1697** its own private copy of the content of the [sqlite3_mem_methods] structure 1698** before the [sqlite3_config()] call returns.</dd> 1699** 1700** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1701** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1702** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1703** The [sqlite3_mem_methods] 1704** structure is filled with the currently defined memory allocation routines.)^ 1705** This option can be used to overload the default memory allocation 1706** routines with a wrapper that simulations memory allocation failure or 1707** tracks memory usage, for example. </dd> 1708** 1709** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1710** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1711** type int, interpreted as a boolean, which if true provides a hint to 1712** SQLite that it should avoid large memory allocations if possible. 1713** SQLite will run faster if it is free to make large memory allocations, 1714** but some application might prefer to run slower in exchange for 1715** guarantees about memory fragmentation that are possible if large 1716** allocations are avoided. This hint is normally off. 1717** </dd> 1718** 1719** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1720** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1721** interpreted as a boolean, which enables or disables the collection of 1722** memory allocation statistics. ^(When memory allocation statistics are 1723** disabled, the following SQLite interfaces become non-operational: 1724** <ul> 1725** <li> [sqlite3_memory_used()] 1726** <li> [sqlite3_memory_highwater()] 1727** <li> [sqlite3_soft_heap_limit64()] 1728** <li> [sqlite3_status64()] 1729** </ul>)^ 1730** ^Memory allocation statistics are enabled by default unless SQLite is 1731** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1732** allocation statistics are disabled by default. 1733** </dd> 1734** 1735** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1736** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1737** </dd> 1738** 1739** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1740** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1741** that SQLite can use for the database page cache with the default page 1742** cache implementation. 1743** This configuration option is a no-op if an application-define page 1744** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1745** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1746** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1747** and the number of cache lines (N). 1748** The sz argument should be the size of the largest database page 1749** (a power of two between 512 and 65536) plus some extra bytes for each 1750** page header. ^The number of extra bytes needed by the page header 1751** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1752** ^It is harmless, apart from the wasted memory, 1753** for the sz parameter to be larger than necessary. The pMem 1754** argument must be either a NULL pointer or a pointer to an 8-byte 1755** aligned block of memory of at least sz*N bytes, otherwise 1756** subsequent behavior is undefined. 1757** ^When pMem is not NULL, SQLite will strive to use the memory provided 1758** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1759** a page cache line is larger than sz bytes or if all of the pMem buffer 1760** is exhausted. 1761** ^If pMem is NULL and N is non-zero, then each database connection 1762** does an initial bulk allocation for page cache memory 1763** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1764** of -1024*N bytes if N is negative, . ^If additional 1765** page cache memory is needed beyond what is provided by the initial 1766** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1767** additional cache line. </dd> 1768** 1769** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1770** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1771** that SQLite will use for all of its dynamic memory allocation needs 1772** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1773** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1774** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1775** [SQLITE_ERROR] if invoked otherwise. 1776** ^There are three arguments to SQLITE_CONFIG_HEAP: 1777** An 8-byte aligned pointer to the memory, 1778** the number of bytes in the memory buffer, and the minimum allocation size. 1779** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1780** to using its default memory allocator (the system malloc() implementation), 1781** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1782** memory pointer is not NULL then the alternative memory 1783** allocator is engaged to handle all of SQLites memory allocation needs. 1784** The first pointer (the memory pointer) must be aligned to an 8-byte 1785** boundary or subsequent behavior of SQLite will be undefined. 1786** The minimum allocation size is capped at 2**12. Reasonable values 1787** for the minimum allocation size are 2**5 through 2**8.</dd> 1788** 1789** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1790** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1791** pointer to an instance of the [sqlite3_mutex_methods] structure. 1792** The argument specifies alternative low-level mutex routines to be used 1793** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1794** the content of the [sqlite3_mutex_methods] structure before the call to 1795** [sqlite3_config()] returns. ^If SQLite is compiled with 1796** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1797** the entire mutexing subsystem is omitted from the build and hence calls to 1798** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1799** return [SQLITE_ERROR].</dd> 1800** 1801** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1802** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1803** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1804** [sqlite3_mutex_methods] 1805** structure is filled with the currently defined mutex routines.)^ 1806** This option can be used to overload the default mutex allocation 1807** routines with a wrapper used to track mutex usage for performance 1808** profiling or testing, for example. ^If SQLite is compiled with 1809** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1810** the entire mutexing subsystem is omitted from the build and hence calls to 1811** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1812** return [SQLITE_ERROR].</dd> 1813** 1814** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1815** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1816** the default size of lookaside memory on each [database connection]. 1817** The first argument is the 1818** size of each lookaside buffer slot and the second is the number of 1819** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1820** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1821** option to [sqlite3_db_config()] can be used to change the lookaside 1822** configuration on individual connections.)^ </dd> 1823** 1824** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1825** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1826** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1827** the interface to a custom page cache implementation.)^ 1828** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1829** 1830** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1831** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1832** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1833** the current page cache implementation into that object.)^ </dd> 1834** 1835** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1836** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1837** global [error log]. 1838** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1839** function with a call signature of void(*)(void*,int,const char*), 1840** and a pointer to void. ^If the function pointer is not NULL, it is 1841** invoked by [sqlite3_log()] to process each logging event. ^If the 1842** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1843** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1844** passed through as the first parameter to the application-defined logger 1845** function whenever that function is invoked. ^The second parameter to 1846** the logger function is a copy of the first parameter to the corresponding 1847** [sqlite3_log()] call and is intended to be a [result code] or an 1848** [extended result code]. ^The third parameter passed to the logger is 1849** log message after formatting via [sqlite3_snprintf()]. 1850** The SQLite logging interface is not reentrant; the logger function 1851** supplied by the application must not invoke any SQLite interface. 1852** In a multi-threaded application, the application-defined logger 1853** function must be threadsafe. </dd> 1854** 1855** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1856** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1857** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1858** then URI handling is globally disabled.)^ ^If URI handling is globally 1859** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1860** [sqlite3_open16()] or 1861** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1862** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1863** connection is opened. ^If it is globally disabled, filenames are 1864** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1865** database connection is opened. ^(By default, URI handling is globally 1866** disabled. The default value may be changed by compiling with the 1867** [SQLITE_USE_URI] symbol defined.)^ 1868** 1869** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1870** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1871** argument which is interpreted as a boolean in order to enable or disable 1872** the use of covering indices for full table scans in the query optimizer. 1873** ^The default setting is determined 1874** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1875** if that compile-time option is omitted. 1876** The ability to disable the use of covering indices for full table scans 1877** is because some incorrectly coded legacy applications might malfunction 1878** when the optimization is enabled. Providing the ability to 1879** disable the optimization allows the older, buggy application code to work 1880** without change even with newer versions of SQLite. 1881** 1882** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1883** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1884** <dd> These options are obsolete and should not be used by new code. 1885** They are retained for backwards compatibility but are now no-ops. 1886** </dd> 1887** 1888** [[SQLITE_CONFIG_SQLLOG]] 1889** <dt>SQLITE_CONFIG_SQLLOG 1890** <dd>This option is only available if sqlite is compiled with the 1891** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1892** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1893** The second should be of type (void*). The callback is invoked by the library 1894** in three separate circumstances, identified by the value passed as the 1895** fourth parameter. If the fourth parameter is 0, then the database connection 1896** passed as the second argument has just been opened. The third argument 1897** points to a buffer containing the name of the main database file. If the 1898** fourth parameter is 1, then the SQL statement that the third parameter 1899** points to has just been executed. Or, if the fourth parameter is 2, then 1900** the connection being passed as the second parameter is being closed. The 1901** third parameter is passed NULL In this case. An example of using this 1902** configuration option can be seen in the "test_sqllog.c" source file in 1903** the canonical SQLite source tree.</dd> 1904** 1905** [[SQLITE_CONFIG_MMAP_SIZE]] 1906** <dt>SQLITE_CONFIG_MMAP_SIZE 1907** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1908** that are the default mmap size limit (the default setting for 1909** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1910** ^The default setting can be overridden by each database connection using 1911** either the [PRAGMA mmap_size] command, or by using the 1912** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1913** will be silently truncated if necessary so that it does not exceed the 1914** compile-time maximum mmap size set by the 1915** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1916** ^If either argument to this option is negative, then that argument is 1917** changed to its compile-time default. 1918** 1919** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1920** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1921** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1922** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1923** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1924** that specifies the maximum size of the created heap. 1925** 1926** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1927** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1928** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1929** is a pointer to an integer and writes into that integer the number of extra 1930** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1931** The amount of extra space required can change depending on the compiler, 1932** target platform, and SQLite version. 1933** 1934** [[SQLITE_CONFIG_PMASZ]] 1935** <dt>SQLITE_CONFIG_PMASZ 1936** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1937** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1938** sorter to that integer. The default minimum PMA Size is set by the 1939** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1940** to help with sort operations when multithreaded sorting 1941** is enabled (using the [PRAGMA threads] command) and the amount of content 1942** to be sorted exceeds the page size times the minimum of the 1943** [PRAGMA cache_size] setting and this value. 1944** 1945** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1946** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1947** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1948** becomes the [statement journal] spill-to-disk threshold. 1949** [Statement journals] are held in memory until their size (in bytes) 1950** exceeds this threshold, at which point they are written to disk. 1951** Or if the threshold is -1, statement journals are always held 1952** exclusively in memory. 1953** Since many statement journals never become large, setting the spill 1954** threshold to a value such as 64KiB can greatly reduce the amount of 1955** I/O required to support statement rollback. 1956** The default value for this setting is controlled by the 1957** [SQLITE_STMTJRNL_SPILL] compile-time option. 1958** 1959** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1960** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1961** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1962** of type (int) - the new value of the sorter-reference size threshold. 1963** Usually, when SQLite uses an external sort to order records according 1964** to an ORDER BY clause, all fields required by the caller are present in the 1965** sorted records. However, if SQLite determines based on the declared type 1966** of a table column that its values are likely to be very large - larger 1967** than the configured sorter-reference size threshold - then a reference 1968** is stored in each sorted record and the required column values loaded 1969** from the database as records are returned in sorted order. The default 1970** value for this option is to never use this optimization. Specifying a 1971** negative value for this option restores the default behaviour. 1972** This option is only available if SQLite is compiled with the 1973** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1974** </dl> 1975*/ 1976#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1977#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1978#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1979#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1980#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1981#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 1982#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1983#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1984#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1985#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1986#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1987/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1988#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1989#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1990#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1991#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1992#define SQLITE_CONFIG_URI 17 /* int */ 1993#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1994#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1995#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1996#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1997#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1998#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1999#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2000#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2001#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2002#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2003#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2004 2005/* 2006** CAPI3REF: Database Connection Configuration Options 2007** 2008** These constants are the available integer configuration options that 2009** can be passed as the second argument to the [sqlite3_db_config()] interface. 2010** 2011** New configuration options may be added in future releases of SQLite. 2012** Existing configuration options might be discontinued. Applications 2013** should check the return code from [sqlite3_db_config()] to make sure that 2014** the call worked. ^The [sqlite3_db_config()] interface will return a 2015** non-zero [error code] if a discontinued or unsupported configuration option 2016** is invoked. 2017** 2018** <dl> 2019** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2020** <dd> ^This option takes three additional arguments that determine the 2021** [lookaside memory allocator] configuration for the [database connection]. 2022** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2023** pointer to a memory buffer to use for lookaside memory. 2024** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2025** may be NULL in which case SQLite will allocate the 2026** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2027** size of each lookaside buffer slot. ^The third argument is the number of 2028** slots. The size of the buffer in the first argument must be greater than 2029** or equal to the product of the second and third arguments. The buffer 2030** must be aligned to an 8-byte boundary. ^If the second argument to 2031** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2032** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2033** configuration for a database connection can only be changed when that 2034** connection is not currently using lookaside memory, or in other words 2035** when the "current value" returned by 2036** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2037** Any attempt to change the lookaside memory configuration when lookaside 2038** memory is in use leaves the configuration unchanged and returns 2039** [SQLITE_BUSY].)^</dd> 2040** 2041** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2042** <dd> ^This option is used to enable or disable the enforcement of 2043** [foreign key constraints]. There should be two additional arguments. 2044** The first argument is an integer which is 0 to disable FK enforcement, 2045** positive to enable FK enforcement or negative to leave FK enforcement 2046** unchanged. The second parameter is a pointer to an integer into which 2047** is written 0 or 1 to indicate whether FK enforcement is off or on 2048** following this call. The second parameter may be a NULL pointer, in 2049** which case the FK enforcement setting is not reported back. </dd> 2050** 2051** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2052** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2053** There should be two additional arguments. 2054** The first argument is an integer which is 0 to disable triggers, 2055** positive to enable triggers or negative to leave the setting unchanged. 2056** The second parameter is a pointer to an integer into which 2057** is written 0 or 1 to indicate whether triggers are disabled or enabled 2058** following this call. The second parameter may be a NULL pointer, in 2059** which case the trigger setting is not reported back. </dd> 2060** 2061** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2062** <dd> ^This option is used to enable or disable the two-argument 2063** version of the [fts3_tokenizer()] function which is part of the 2064** [FTS3] full-text search engine extension. 2065** There should be two additional arguments. 2066** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2067** positive to enable fts3_tokenizer() or negative to leave the setting 2068** unchanged. 2069** The second parameter is a pointer to an integer into which 2070** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2071** following this call. The second parameter may be a NULL pointer, in 2072** which case the new setting is not reported back. </dd> 2073** 2074** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2075** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2076** interface independently of the [load_extension()] SQL function. 2077** The [sqlite3_enable_load_extension()] API enables or disables both the 2078** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2079** There should be two additional arguments. 2080** When the first argument to this interface is 1, then only the C-API is 2081** enabled and the SQL function remains disabled. If the first argument to 2082** this interface is 0, then both the C-API and the SQL function are disabled. 2083** If the first argument is -1, then no changes are made to state of either the 2084** C-API or the SQL function. 2085** The second parameter is a pointer to an integer into which 2086** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2087** is disabled or enabled following this call. The second parameter may 2088** be a NULL pointer, in which case the new setting is not reported back. 2089** </dd> 2090** 2091** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2092** <dd> ^This option is used to change the name of the "main" database 2093** schema. ^The sole argument is a pointer to a constant UTF8 string 2094** which will become the new schema name in place of "main". ^SQLite 2095** does not make a copy of the new main schema name string, so the application 2096** must ensure that the argument passed into this DBCONFIG option is unchanged 2097** until after the database connection closes. 2098** </dd> 2099** 2100** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2101** <dd> Usually, when a database in wal mode is closed or detached from a 2102** database handle, SQLite checks if this will mean that there are now no 2103** connections at all to the database. If so, it performs a checkpoint 2104** operation before closing the connection. This option may be used to 2105** override this behaviour. The first parameter passed to this operation 2106** is an integer - positive to disable checkpoints-on-close, or zero (the 2107** default) to enable them, and negative to leave the setting unchanged. 2108** The second parameter is a pointer to an integer 2109** into which is written 0 or 1 to indicate whether checkpoints-on-close 2110** have been disabled - 0 if they are not disabled, 1 if they are. 2111** </dd> 2112** 2113** <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2114** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2115** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2116** a single SQL query statement will always use the same algorithm regardless 2117** of values of [bound parameters].)^ The QPSG disables some query optimizations 2118** that look at the values of bound parameters, which can make some queries 2119** slower. But the QPSG has the advantage of more predictable behavior. With 2120** the QPSG active, SQLite will always use the same query plan in the field as 2121** was used during testing in the lab. 2122** The first argument to this setting is an integer which is 0 to disable 2123** the QPSG, positive to enable QPSG, or negative to leave the setting 2124** unchanged. The second parameter is a pointer to an integer into which 2125** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2126** following this call. 2127** </dd> 2128** 2129** <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2130** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2131** include output for any operations performed by trigger programs. This 2132** option is used to set or clear (the default) a flag that governs this 2133** behavior. The first parameter passed to this operation is an integer - 2134** positive to enable output for trigger programs, or zero to disable it, 2135** or negative to leave the setting unchanged. 2136** The second parameter is a pointer to an integer into which is written 2137** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2138** it is not disabled, 1 if it is. 2139** </dd> 2140** 2141** <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2142** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2143** [VACUUM] in order to reset a database back to an empty database 2144** with no schema and no content. The following process works even for 2145** a badly corrupted database file: 2146** <ol> 2147** <li> If the database connection is newly opened, make sure it has read the 2148** database schema by preparing then discarding some query against the 2149** database, or calling sqlite3_table_column_metadata(), ignoring any 2150** errors. This step is only necessary if the application desires to keep 2151** the database in WAL mode after the reset if it was in WAL mode before 2152** the reset. 2153** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2154** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2155** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2156** </ol> 2157** Because resetting a database is destructive and irreversible, the 2158** process requires the use of this obscure API and multiple steps to help 2159** ensure that it does not happen by accident. 2160** </dd> 2161** </dl> 2162*/ 2163#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2164#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2165#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2166#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2167#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2168#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2169#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2170#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2171#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2172#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2173#define SQLITE_DBCONFIG_MAX 1009 /* Largest DBCONFIG */ 2174 2175/* 2176** CAPI3REF: Enable Or Disable Extended Result Codes 2177** METHOD: sqlite3 2178** 2179** ^The sqlite3_extended_result_codes() routine enables or disables the 2180** [extended result codes] feature of SQLite. ^The extended result 2181** codes are disabled by default for historical compatibility. 2182*/ 2183int sqlite3_extended_result_codes(sqlite3*, int onoff); 2184 2185/* 2186** CAPI3REF: Last Insert Rowid 2187** METHOD: sqlite3 2188** 2189** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2190** has a unique 64-bit signed 2191** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2192** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2193** names are not also used by explicitly declared columns. ^If 2194** the table has a column of type [INTEGER PRIMARY KEY] then that column 2195** is another alias for the rowid. 2196** 2197** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2198** the most recent successful [INSERT] into a rowid table or [virtual table] 2199** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2200** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2201** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2202** zero. 2203** 2204** As well as being set automatically as rows are inserted into database 2205** tables, the value returned by this function may be set explicitly by 2206** [sqlite3_set_last_insert_rowid()] 2207** 2208** Some virtual table implementations may INSERT rows into rowid tables as 2209** part of committing a transaction (e.g. to flush data accumulated in memory 2210** to disk). In this case subsequent calls to this function return the rowid 2211** associated with these internal INSERT operations, which leads to 2212** unintuitive results. Virtual table implementations that do write to rowid 2213** tables in this way can avoid this problem by restoring the original 2214** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2215** control to the user. 2216** 2217** ^(If an [INSERT] occurs within a trigger then this routine will 2218** return the [rowid] of the inserted row as long as the trigger is 2219** running. Once the trigger program ends, the value returned 2220** by this routine reverts to what it was before the trigger was fired.)^ 2221** 2222** ^An [INSERT] that fails due to a constraint violation is not a 2223** successful [INSERT] and does not change the value returned by this 2224** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2225** and INSERT OR ABORT make no changes to the return value of this 2226** routine when their insertion fails. ^(When INSERT OR REPLACE 2227** encounters a constraint violation, it does not fail. The 2228** INSERT continues to completion after deleting rows that caused 2229** the constraint problem so INSERT OR REPLACE will always change 2230** the return value of this interface.)^ 2231** 2232** ^For the purposes of this routine, an [INSERT] is considered to 2233** be successful even if it is subsequently rolled back. 2234** 2235** This function is accessible to SQL statements via the 2236** [last_insert_rowid() SQL function]. 2237** 2238** If a separate thread performs a new [INSERT] on the same 2239** database connection while the [sqlite3_last_insert_rowid()] 2240** function is running and thus changes the last insert [rowid], 2241** then the value returned by [sqlite3_last_insert_rowid()] is 2242** unpredictable and might not equal either the old or the new 2243** last insert [rowid]. 2244*/ 2245sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2246 2247/* 2248** CAPI3REF: Set the Last Insert Rowid value. 2249** METHOD: sqlite3 2250** 2251** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2252** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2253** without inserting a row into the database. 2254*/ 2255void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2256 2257/* 2258** CAPI3REF: Count The Number Of Rows Modified 2259** METHOD: sqlite3 2260** 2261** ^This function returns the number of rows modified, inserted or 2262** deleted by the most recently completed INSERT, UPDATE or DELETE 2263** statement on the database connection specified by the only parameter. 2264** ^Executing any other type of SQL statement does not modify the value 2265** returned by this function. 2266** 2267** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2268** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2269** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2270** 2271** Changes to a view that are intercepted by 2272** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2273** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2274** DELETE statement run on a view is always zero. Only changes made to real 2275** tables are counted. 2276** 2277** Things are more complicated if the sqlite3_changes() function is 2278** executed while a trigger program is running. This may happen if the 2279** program uses the [changes() SQL function], or if some other callback 2280** function invokes sqlite3_changes() directly. Essentially: 2281** 2282** <ul> 2283** <li> ^(Before entering a trigger program the value returned by 2284** sqlite3_changes() function is saved. After the trigger program 2285** has finished, the original value is restored.)^ 2286** 2287** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2288** statement sets the value returned by sqlite3_changes() 2289** upon completion as normal. Of course, this value will not include 2290** any changes performed by sub-triggers, as the sqlite3_changes() 2291** value will be saved and restored after each sub-trigger has run.)^ 2292** </ul> 2293** 2294** ^This means that if the changes() SQL function (or similar) is used 2295** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2296** returns the value as set when the calling statement began executing. 2297** ^If it is used by the second or subsequent such statement within a trigger 2298** program, the value returned reflects the number of rows modified by the 2299** previous INSERT, UPDATE or DELETE statement within the same trigger. 2300** 2301** If a separate thread makes changes on the same database connection 2302** while [sqlite3_changes()] is running then the value returned 2303** is unpredictable and not meaningful. 2304** 2305** See also: 2306** <ul> 2307** <li> the [sqlite3_total_changes()] interface 2308** <li> the [count_changes pragma] 2309** <li> the [changes() SQL function] 2310** <li> the [data_version pragma] 2311** </ul> 2312*/ 2313int sqlite3_changes(sqlite3*); 2314 2315/* 2316** CAPI3REF: Total Number Of Rows Modified 2317** METHOD: sqlite3 2318** 2319** ^This function returns the total number of rows inserted, modified or 2320** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2321** since the database connection was opened, including those executed as 2322** part of trigger programs. ^Executing any other type of SQL statement 2323** does not affect the value returned by sqlite3_total_changes(). 2324** 2325** ^Changes made as part of [foreign key actions] are included in the 2326** count, but those made as part of REPLACE constraint resolution are 2327** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2328** are not counted. 2329** 2330** This the [sqlite3_total_changes(D)] interface only reports the number 2331** of rows that changed due to SQL statement run against database 2332** connection D. Any changes by other database connections are ignored. 2333** To detect changes against a database file from other database 2334** connections use the [PRAGMA data_version] command or the 2335** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2336** 2337** If a separate thread makes changes on the same database connection 2338** while [sqlite3_total_changes()] is running then the value 2339** returned is unpredictable and not meaningful. 2340** 2341** See also: 2342** <ul> 2343** <li> the [sqlite3_changes()] interface 2344** <li> the [count_changes pragma] 2345** <li> the [changes() SQL function] 2346** <li> the [data_version pragma] 2347** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2348** </ul> 2349*/ 2350int sqlite3_total_changes(sqlite3*); 2351 2352/* 2353** CAPI3REF: Interrupt A Long-Running Query 2354** METHOD: sqlite3 2355** 2356** ^This function causes any pending database operation to abort and 2357** return at its earliest opportunity. This routine is typically 2358** called in response to a user action such as pressing "Cancel" 2359** or Ctrl-C where the user wants a long query operation to halt 2360** immediately. 2361** 2362** ^It is safe to call this routine from a thread different from the 2363** thread that is currently running the database operation. But it 2364** is not safe to call this routine with a [database connection] that 2365** is closed or might close before sqlite3_interrupt() returns. 2366** 2367** ^If an SQL operation is very nearly finished at the time when 2368** sqlite3_interrupt() is called, then it might not have an opportunity 2369** to be interrupted and might continue to completion. 2370** 2371** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2372** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2373** that is inside an explicit transaction, then the entire transaction 2374** will be rolled back automatically. 2375** 2376** ^The sqlite3_interrupt(D) call is in effect until all currently running 2377** SQL statements on [database connection] D complete. ^Any new SQL statements 2378** that are started after the sqlite3_interrupt() call and before the 2379** running statements reaches zero are interrupted as if they had been 2380** running prior to the sqlite3_interrupt() call. ^New SQL statements 2381** that are started after the running statement count reaches zero are 2382** not effected by the sqlite3_interrupt(). 2383** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2384** SQL statements is a no-op and has no effect on SQL statements 2385** that are started after the sqlite3_interrupt() call returns. 2386*/ 2387void sqlite3_interrupt(sqlite3*); 2388 2389/* 2390** CAPI3REF: Determine If An SQL Statement Is Complete 2391** 2392** These routines are useful during command-line input to determine if the 2393** currently entered text seems to form a complete SQL statement or 2394** if additional input is needed before sending the text into 2395** SQLite for parsing. ^These routines return 1 if the input string 2396** appears to be a complete SQL statement. ^A statement is judged to be 2397** complete if it ends with a semicolon token and is not a prefix of a 2398** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2399** string literals or quoted identifier names or comments are not 2400** independent tokens (they are part of the token in which they are 2401** embedded) and thus do not count as a statement terminator. ^Whitespace 2402** and comments that follow the final semicolon are ignored. 2403** 2404** ^These routines return 0 if the statement is incomplete. ^If a 2405** memory allocation fails, then SQLITE_NOMEM is returned. 2406** 2407** ^These routines do not parse the SQL statements thus 2408** will not detect syntactically incorrect SQL. 2409** 2410** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2411** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2412** automatically by sqlite3_complete16(). If that initialization fails, 2413** then the return value from sqlite3_complete16() will be non-zero 2414** regardless of whether or not the input SQL is complete.)^ 2415** 2416** The input to [sqlite3_complete()] must be a zero-terminated 2417** UTF-8 string. 2418** 2419** The input to [sqlite3_complete16()] must be a zero-terminated 2420** UTF-16 string in native byte order. 2421*/ 2422int sqlite3_complete(const char *sql); 2423int sqlite3_complete16(const void *sql); 2424 2425/* 2426** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2427** KEYWORDS: {busy-handler callback} {busy handler} 2428** METHOD: sqlite3 2429** 2430** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2431** that might be invoked with argument P whenever 2432** an attempt is made to access a database table associated with 2433** [database connection] D when another thread 2434** or process has the table locked. 2435** The sqlite3_busy_handler() interface is used to implement 2436** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2437** 2438** ^If the busy callback is NULL, then [SQLITE_BUSY] 2439** is returned immediately upon encountering the lock. ^If the busy callback 2440** is not NULL, then the callback might be invoked with two arguments. 2441** 2442** ^The first argument to the busy handler is a copy of the void* pointer which 2443** is the third argument to sqlite3_busy_handler(). ^The second argument to 2444** the busy handler callback is the number of times that the busy handler has 2445** been invoked previously for the same locking event. ^If the 2446** busy callback returns 0, then no additional attempts are made to 2447** access the database and [SQLITE_BUSY] is returned 2448** to the application. 2449** ^If the callback returns non-zero, then another attempt 2450** is made to access the database and the cycle repeats. 2451** 2452** The presence of a busy handler does not guarantee that it will be invoked 2453** when there is lock contention. ^If SQLite determines that invoking the busy 2454** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2455** to the application instead of invoking the 2456** busy handler. 2457** Consider a scenario where one process is holding a read lock that 2458** it is trying to promote to a reserved lock and 2459** a second process is holding a reserved lock that it is trying 2460** to promote to an exclusive lock. The first process cannot proceed 2461** because it is blocked by the second and the second process cannot 2462** proceed because it is blocked by the first. If both processes 2463** invoke the busy handlers, neither will make any progress. Therefore, 2464** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2465** will induce the first process to release its read lock and allow 2466** the second process to proceed. 2467** 2468** ^The default busy callback is NULL. 2469** 2470** ^(There can only be a single busy handler defined for each 2471** [database connection]. Setting a new busy handler clears any 2472** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2473** or evaluating [PRAGMA busy_timeout=N] will change the 2474** busy handler and thus clear any previously set busy handler. 2475** 2476** The busy callback should not take any actions which modify the 2477** database connection that invoked the busy handler. In other words, 2478** the busy handler is not reentrant. Any such actions 2479** result in undefined behavior. 2480** 2481** A busy handler must not close the database connection 2482** or [prepared statement] that invoked the busy handler. 2483*/ 2484int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2485 2486/* 2487** CAPI3REF: Set A Busy Timeout 2488** METHOD: sqlite3 2489** 2490** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2491** for a specified amount of time when a table is locked. ^The handler 2492** will sleep multiple times until at least "ms" milliseconds of sleeping 2493** have accumulated. ^After at least "ms" milliseconds of sleeping, 2494** the handler returns 0 which causes [sqlite3_step()] to return 2495** [SQLITE_BUSY]. 2496** 2497** ^Calling this routine with an argument less than or equal to zero 2498** turns off all busy handlers. 2499** 2500** ^(There can only be a single busy handler for a particular 2501** [database connection] at any given moment. If another busy handler 2502** was defined (using [sqlite3_busy_handler()]) prior to calling 2503** this routine, that other busy handler is cleared.)^ 2504** 2505** See also: [PRAGMA busy_timeout] 2506*/ 2507int sqlite3_busy_timeout(sqlite3*, int ms); 2508 2509/* 2510** CAPI3REF: Convenience Routines For Running Queries 2511** METHOD: sqlite3 2512** 2513** This is a legacy interface that is preserved for backwards compatibility. 2514** Use of this interface is not recommended. 2515** 2516** Definition: A <b>result table</b> is memory data structure created by the 2517** [sqlite3_get_table()] interface. A result table records the 2518** complete query results from one or more queries. 2519** 2520** The table conceptually has a number of rows and columns. But 2521** these numbers are not part of the result table itself. These 2522** numbers are obtained separately. Let N be the number of rows 2523** and M be the number of columns. 2524** 2525** A result table is an array of pointers to zero-terminated UTF-8 strings. 2526** There are (N+1)*M elements in the array. The first M pointers point 2527** to zero-terminated strings that contain the names of the columns. 2528** The remaining entries all point to query results. NULL values result 2529** in NULL pointers. All other values are in their UTF-8 zero-terminated 2530** string representation as returned by [sqlite3_column_text()]. 2531** 2532** A result table might consist of one or more memory allocations. 2533** It is not safe to pass a result table directly to [sqlite3_free()]. 2534** A result table should be deallocated using [sqlite3_free_table()]. 2535** 2536** ^(As an example of the result table format, suppose a query result 2537** is as follows: 2538** 2539** <blockquote><pre> 2540** Name | Age 2541** ----------------------- 2542** Alice | 43 2543** Bob | 28 2544** Cindy | 21 2545** </pre></blockquote> 2546** 2547** There are two column (M==2) and three rows (N==3). Thus the 2548** result table has 8 entries. Suppose the result table is stored 2549** in an array names azResult. Then azResult holds this content: 2550** 2551** <blockquote><pre> 2552** azResult[0] = "Name"; 2553** azResult[1] = "Age"; 2554** azResult[2] = "Alice"; 2555** azResult[3] = "43"; 2556** azResult[4] = "Bob"; 2557** azResult[5] = "28"; 2558** azResult[6] = "Cindy"; 2559** azResult[7] = "21"; 2560** </pre></blockquote>)^ 2561** 2562** ^The sqlite3_get_table() function evaluates one or more 2563** semicolon-separated SQL statements in the zero-terminated UTF-8 2564** string of its 2nd parameter and returns a result table to the 2565** pointer given in its 3rd parameter. 2566** 2567** After the application has finished with the result from sqlite3_get_table(), 2568** it must pass the result table pointer to sqlite3_free_table() in order to 2569** release the memory that was malloced. Because of the way the 2570** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2571** function must not try to call [sqlite3_free()] directly. Only 2572** [sqlite3_free_table()] is able to release the memory properly and safely. 2573** 2574** The sqlite3_get_table() interface is implemented as a wrapper around 2575** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2576** to any internal data structures of SQLite. It uses only the public 2577** interface defined here. As a consequence, errors that occur in the 2578** wrapper layer outside of the internal [sqlite3_exec()] call are not 2579** reflected in subsequent calls to [sqlite3_errcode()] or 2580** [sqlite3_errmsg()]. 2581*/ 2582int sqlite3_get_table( 2583 sqlite3 *db, /* An open database */ 2584 const char *zSql, /* SQL to be evaluated */ 2585 char ***pazResult, /* Results of the query */ 2586 int *pnRow, /* Number of result rows written here */ 2587 int *pnColumn, /* Number of result columns written here */ 2588 char **pzErrmsg /* Error msg written here */ 2589); 2590void sqlite3_free_table(char **result); 2591 2592/* 2593** CAPI3REF: Formatted String Printing Functions 2594** 2595** These routines are work-alikes of the "printf()" family of functions 2596** from the standard C library. 2597** These routines understand most of the common formatting options from 2598** the standard library printf() 2599** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2600** See the [built-in printf()] documentation for details. 2601** 2602** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2603** results into memory obtained from [sqlite3_malloc64()]. 2604** The strings returned by these two routines should be 2605** released by [sqlite3_free()]. ^Both routines return a 2606** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2607** memory to hold the resulting string. 2608** 2609** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2610** the standard C library. The result is written into the 2611** buffer supplied as the second parameter whose size is given by 2612** the first parameter. Note that the order of the 2613** first two parameters is reversed from snprintf().)^ This is an 2614** historical accident that cannot be fixed without breaking 2615** backwards compatibility. ^(Note also that sqlite3_snprintf() 2616** returns a pointer to its buffer instead of the number of 2617** characters actually written into the buffer.)^ We admit that 2618** the number of characters written would be a more useful return 2619** value but we cannot change the implementation of sqlite3_snprintf() 2620** now without breaking compatibility. 2621** 2622** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2623** guarantees that the buffer is always zero-terminated. ^The first 2624** parameter "n" is the total size of the buffer, including space for 2625** the zero terminator. So the longest string that can be completely 2626** written will be n-1 characters. 2627** 2628** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2629** 2630** See also: [built-in printf()], [printf() SQL function] 2631*/ 2632char *sqlite3_mprintf(const char*,...); 2633char *sqlite3_vmprintf(const char*, va_list); 2634char *sqlite3_snprintf(int,char*,const char*, ...); 2635char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2636 2637/* 2638** CAPI3REF: Memory Allocation Subsystem 2639** 2640** The SQLite core uses these three routines for all of its own 2641** internal memory allocation needs. "Core" in the previous sentence 2642** does not include operating-system specific VFS implementation. The 2643** Windows VFS uses native malloc() and free() for some operations. 2644** 2645** ^The sqlite3_malloc() routine returns a pointer to a block 2646** of memory at least N bytes in length, where N is the parameter. 2647** ^If sqlite3_malloc() is unable to obtain sufficient free 2648** memory, it returns a NULL pointer. ^If the parameter N to 2649** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2650** a NULL pointer. 2651** 2652** ^The sqlite3_malloc64(N) routine works just like 2653** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2654** of a signed 32-bit integer. 2655** 2656** ^Calling sqlite3_free() with a pointer previously returned 2657** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2658** that it might be reused. ^The sqlite3_free() routine is 2659** a no-op if is called with a NULL pointer. Passing a NULL pointer 2660** to sqlite3_free() is harmless. After being freed, memory 2661** should neither be read nor written. Even reading previously freed 2662** memory might result in a segmentation fault or other severe error. 2663** Memory corruption, a segmentation fault, or other severe error 2664** might result if sqlite3_free() is called with a non-NULL pointer that 2665** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2666** 2667** ^The sqlite3_realloc(X,N) interface attempts to resize a 2668** prior memory allocation X to be at least N bytes. 2669** ^If the X parameter to sqlite3_realloc(X,N) 2670** is a NULL pointer then its behavior is identical to calling 2671** sqlite3_malloc(N). 2672** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2673** negative then the behavior is exactly the same as calling 2674** sqlite3_free(X). 2675** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2676** of at least N bytes in size or NULL if insufficient memory is available. 2677** ^If M is the size of the prior allocation, then min(N,M) bytes 2678** of the prior allocation are copied into the beginning of buffer returned 2679** by sqlite3_realloc(X,N) and the prior allocation is freed. 2680** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2681** prior allocation is not freed. 2682** 2683** ^The sqlite3_realloc64(X,N) interfaces works the same as 2684** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2685** of a 32-bit signed integer. 2686** 2687** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2688** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2689** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2690** ^The value returned by sqlite3_msize(X) might be larger than the number 2691** of bytes requested when X was allocated. ^If X is a NULL pointer then 2692** sqlite3_msize(X) returns zero. If X points to something that is not 2693** the beginning of memory allocation, or if it points to a formerly 2694** valid memory allocation that has now been freed, then the behavior 2695** of sqlite3_msize(X) is undefined and possibly harmful. 2696** 2697** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2698** sqlite3_malloc64(), and sqlite3_realloc64() 2699** is always aligned to at least an 8 byte boundary, or to a 2700** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2701** option is used. 2702** 2703** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2704** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2705** implementation of these routines to be omitted. That capability 2706** is no longer provided. Only built-in memory allocators can be used. 2707** 2708** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2709** the system malloc() and free() directly when converting 2710** filenames between the UTF-8 encoding used by SQLite 2711** and whatever filename encoding is used by the particular Windows 2712** installation. Memory allocation errors were detected, but 2713** they were reported back as [SQLITE_CANTOPEN] or 2714** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2715** 2716** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2717** must be either NULL or else pointers obtained from a prior 2718** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2719** not yet been released. 2720** 2721** The application must not read or write any part of 2722** a block of memory after it has been released using 2723** [sqlite3_free()] or [sqlite3_realloc()]. 2724*/ 2725void *sqlite3_malloc(int); 2726void *sqlite3_malloc64(sqlite3_uint64); 2727void *sqlite3_realloc(void*, int); 2728void *sqlite3_realloc64(void*, sqlite3_uint64); 2729void sqlite3_free(void*); 2730sqlite3_uint64 sqlite3_msize(void*); 2731 2732/* 2733** CAPI3REF: Memory Allocator Statistics 2734** 2735** SQLite provides these two interfaces for reporting on the status 2736** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2737** routines, which form the built-in memory allocation subsystem. 2738** 2739** ^The [sqlite3_memory_used()] routine returns the number of bytes 2740** of memory currently outstanding (malloced but not freed). 2741** ^The [sqlite3_memory_highwater()] routine returns the maximum 2742** value of [sqlite3_memory_used()] since the high-water mark 2743** was last reset. ^The values returned by [sqlite3_memory_used()] and 2744** [sqlite3_memory_highwater()] include any overhead 2745** added by SQLite in its implementation of [sqlite3_malloc()], 2746** but not overhead added by the any underlying system library 2747** routines that [sqlite3_malloc()] may call. 2748** 2749** ^The memory high-water mark is reset to the current value of 2750** [sqlite3_memory_used()] if and only if the parameter to 2751** [sqlite3_memory_highwater()] is true. ^The value returned 2752** by [sqlite3_memory_highwater(1)] is the high-water mark 2753** prior to the reset. 2754*/ 2755sqlite3_int64 sqlite3_memory_used(void); 2756sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2757 2758/* 2759** CAPI3REF: Pseudo-Random Number Generator 2760** 2761** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2762** select random [ROWID | ROWIDs] when inserting new records into a table that 2763** already uses the largest possible [ROWID]. The PRNG is also used for 2764** the build-in random() and randomblob() SQL functions. This interface allows 2765** applications to access the same PRNG for other purposes. 2766** 2767** ^A call to this routine stores N bytes of randomness into buffer P. 2768** ^The P parameter can be a NULL pointer. 2769** 2770** ^If this routine has not been previously called or if the previous 2771** call had N less than one or a NULL pointer for P, then the PRNG is 2772** seeded using randomness obtained from the xRandomness method of 2773** the default [sqlite3_vfs] object. 2774** ^If the previous call to this routine had an N of 1 or more and a 2775** non-NULL P then the pseudo-randomness is generated 2776** internally and without recourse to the [sqlite3_vfs] xRandomness 2777** method. 2778*/ 2779void sqlite3_randomness(int N, void *P); 2780 2781/* 2782** CAPI3REF: Compile-Time Authorization Callbacks 2783** METHOD: sqlite3 2784** KEYWORDS: {authorizer callback} 2785** 2786** ^This routine registers an authorizer callback with a particular 2787** [database connection], supplied in the first argument. 2788** ^The authorizer callback is invoked as SQL statements are being compiled 2789** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2790** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2791** and [sqlite3_prepare16_v3()]. ^At various 2792** points during the compilation process, as logic is being created 2793** to perform various actions, the authorizer callback is invoked to 2794** see if those actions are allowed. ^The authorizer callback should 2795** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2796** specific action but allow the SQL statement to continue to be 2797** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2798** rejected with an error. ^If the authorizer callback returns 2799** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2800** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2801** the authorizer will fail with an error message. 2802** 2803** When the callback returns [SQLITE_OK], that means the operation 2804** requested is ok. ^When the callback returns [SQLITE_DENY], the 2805** [sqlite3_prepare_v2()] or equivalent call that triggered the 2806** authorizer will fail with an error message explaining that 2807** access is denied. 2808** 2809** ^The first parameter to the authorizer callback is a copy of the third 2810** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2811** to the callback is an integer [SQLITE_COPY | action code] that specifies 2812** the particular action to be authorized. ^The third through sixth parameters 2813** to the callback are either NULL pointers or zero-terminated strings 2814** that contain additional details about the action to be authorized. 2815** Applications must always be prepared to encounter a NULL pointer in any 2816** of the third through the sixth parameters of the authorization callback. 2817** 2818** ^If the action code is [SQLITE_READ] 2819** and the callback returns [SQLITE_IGNORE] then the 2820** [prepared statement] statement is constructed to substitute 2821** a NULL value in place of the table column that would have 2822** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2823** return can be used to deny an untrusted user access to individual 2824** columns of a table. 2825** ^When a table is referenced by a [SELECT] but no column values are 2826** extracted from that table (for example in a query like 2827** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2828** is invoked once for that table with a column name that is an empty string. 2829** ^If the action code is [SQLITE_DELETE] and the callback returns 2830** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2831** [truncate optimization] is disabled and all rows are deleted individually. 2832** 2833** An authorizer is used when [sqlite3_prepare | preparing] 2834** SQL statements from an untrusted source, to ensure that the SQL statements 2835** do not try to access data they are not allowed to see, or that they do not 2836** try to execute malicious statements that damage the database. For 2837** example, an application may allow a user to enter arbitrary 2838** SQL queries for evaluation by a database. But the application does 2839** not want the user to be able to make arbitrary changes to the 2840** database. An authorizer could then be put in place while the 2841** user-entered SQL is being [sqlite3_prepare | prepared] that 2842** disallows everything except [SELECT] statements. 2843** 2844** Applications that need to process SQL from untrusted sources 2845** might also consider lowering resource limits using [sqlite3_limit()] 2846** and limiting database size using the [max_page_count] [PRAGMA] 2847** in addition to using an authorizer. 2848** 2849** ^(Only a single authorizer can be in place on a database connection 2850** at a time. Each call to sqlite3_set_authorizer overrides the 2851** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2852** The authorizer is disabled by default. 2853** 2854** The authorizer callback must not do anything that will modify 2855** the database connection that invoked the authorizer callback. 2856** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2857** database connections for the meaning of "modify" in this paragraph. 2858** 2859** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2860** statement might be re-prepared during [sqlite3_step()] due to a 2861** schema change. Hence, the application should ensure that the 2862** correct authorizer callback remains in place during the [sqlite3_step()]. 2863** 2864** ^Note that the authorizer callback is invoked only during 2865** [sqlite3_prepare()] or its variants. Authorization is not 2866** performed during statement evaluation in [sqlite3_step()], unless 2867** as stated in the previous paragraph, sqlite3_step() invokes 2868** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2869*/ 2870int sqlite3_set_authorizer( 2871 sqlite3*, 2872 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2873 void *pUserData 2874); 2875 2876/* 2877** CAPI3REF: Authorizer Return Codes 2878** 2879** The [sqlite3_set_authorizer | authorizer callback function] must 2880** return either [SQLITE_OK] or one of these two constants in order 2881** to signal SQLite whether or not the action is permitted. See the 2882** [sqlite3_set_authorizer | authorizer documentation] for additional 2883** information. 2884** 2885** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2886** returned from the [sqlite3_vtab_on_conflict()] interface. 2887*/ 2888#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2889#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2890 2891/* 2892** CAPI3REF: Authorizer Action Codes 2893** 2894** The [sqlite3_set_authorizer()] interface registers a callback function 2895** that is invoked to authorize certain SQL statement actions. The 2896** second parameter to the callback is an integer code that specifies 2897** what action is being authorized. These are the integer action codes that 2898** the authorizer callback may be passed. 2899** 2900** These action code values signify what kind of operation is to be 2901** authorized. The 3rd and 4th parameters to the authorization 2902** callback function will be parameters or NULL depending on which of these 2903** codes is used as the second parameter. ^(The 5th parameter to the 2904** authorizer callback is the name of the database ("main", "temp", 2905** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2906** is the name of the inner-most trigger or view that is responsible for 2907** the access attempt or NULL if this access attempt is directly from 2908** top-level SQL code. 2909*/ 2910/******************************************* 3rd ************ 4th ***********/ 2911#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2912#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2913#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2914#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2915#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2916#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2917#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2918#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2919#define SQLITE_DELETE 9 /* Table Name NULL */ 2920#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2921#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2922#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2923#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2924#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2925#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2926#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2927#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2928#define SQLITE_INSERT 18 /* Table Name NULL */ 2929#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2930#define SQLITE_READ 20 /* Table Name Column Name */ 2931#define SQLITE_SELECT 21 /* NULL NULL */ 2932#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2933#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2934#define SQLITE_ATTACH 24 /* Filename NULL */ 2935#define SQLITE_DETACH 25 /* Database Name NULL */ 2936#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2937#define SQLITE_REINDEX 27 /* Index Name NULL */ 2938#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2939#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2940#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2941#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2942#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2943#define SQLITE_COPY 0 /* No longer used */ 2944#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2945 2946/* 2947** CAPI3REF: Tracing And Profiling Functions 2948** METHOD: sqlite3 2949** 2950** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2951** instead of the routines described here. 2952** 2953** These routines register callback functions that can be used for 2954** tracing and profiling the execution of SQL statements. 2955** 2956** ^The callback function registered by sqlite3_trace() is invoked at 2957** various times when an SQL statement is being run by [sqlite3_step()]. 2958** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2959** SQL statement text as the statement first begins executing. 2960** ^(Additional sqlite3_trace() callbacks might occur 2961** as each triggered subprogram is entered. The callbacks for triggers 2962** contain a UTF-8 SQL comment that identifies the trigger.)^ 2963** 2964** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2965** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2966** 2967** ^The callback function registered by sqlite3_profile() is invoked 2968** as each SQL statement finishes. ^The profile callback contains 2969** the original statement text and an estimate of wall-clock time 2970** of how long that statement took to run. ^The profile callback 2971** time is in units of nanoseconds, however the current implementation 2972** is only capable of millisecond resolution so the six least significant 2973** digits in the time are meaningless. Future versions of SQLite 2974** might provide greater resolution on the profiler callback. The 2975** sqlite3_profile() function is considered experimental and is 2976** subject to change in future versions of SQLite. 2977*/ 2978SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2979 void(*xTrace)(void*,const char*), void*); 2980SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2981 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2982 2983/* 2984** CAPI3REF: SQL Trace Event Codes 2985** KEYWORDS: SQLITE_TRACE 2986** 2987** These constants identify classes of events that can be monitored 2988** using the [sqlite3_trace_v2()] tracing logic. The M argument 2989** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 2990** the following constants. ^The first argument to the trace callback 2991** is one of the following constants. 2992** 2993** New tracing constants may be added in future releases. 2994** 2995** ^A trace callback has four arguments: xCallback(T,C,P,X). 2996** ^The T argument is one of the integer type codes above. 2997** ^The C argument is a copy of the context pointer passed in as the 2998** fourth argument to [sqlite3_trace_v2()]. 2999** The P and X arguments are pointers whose meanings depend on T. 3000** 3001** <dl> 3002** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3003** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3004** first begins running and possibly at other times during the 3005** execution of the prepared statement, such as at the start of each 3006** trigger subprogram. ^The P argument is a pointer to the 3007** [prepared statement]. ^The X argument is a pointer to a string which 3008** is the unexpanded SQL text of the prepared statement or an SQL comment 3009** that indicates the invocation of a trigger. ^The callback can compute 3010** the same text that would have been returned by the legacy [sqlite3_trace()] 3011** interface by using the X argument when X begins with "--" and invoking 3012** [sqlite3_expanded_sql(P)] otherwise. 3013** 3014** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3015** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3016** information as is provided by the [sqlite3_profile()] callback. 3017** ^The P argument is a pointer to the [prepared statement] and the 3018** X argument points to a 64-bit integer which is the estimated of 3019** the number of nanosecond that the prepared statement took to run. 3020** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3021** 3022** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3023** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3024** statement generates a single row of result. 3025** ^The P argument is a pointer to the [prepared statement] and the 3026** X argument is unused. 3027** 3028** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3029** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3030** connection closes. 3031** ^The P argument is a pointer to the [database connection] object 3032** and the X argument is unused. 3033** </dl> 3034*/ 3035#define SQLITE_TRACE_STMT 0x01 3036#define SQLITE_TRACE_PROFILE 0x02 3037#define SQLITE_TRACE_ROW 0x04 3038#define SQLITE_TRACE_CLOSE 0x08 3039 3040/* 3041** CAPI3REF: SQL Trace Hook 3042** METHOD: sqlite3 3043** 3044** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3045** function X against [database connection] D, using property mask M 3046** and context pointer P. ^If the X callback is 3047** NULL or if the M mask is zero, then tracing is disabled. The 3048** M argument should be the bitwise OR-ed combination of 3049** zero or more [SQLITE_TRACE] constants. 3050** 3051** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3052** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3053** 3054** ^The X callback is invoked whenever any of the events identified by 3055** mask M occur. ^The integer return value from the callback is currently 3056** ignored, though this may change in future releases. Callback 3057** implementations should return zero to ensure future compatibility. 3058** 3059** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3060** ^The T argument is one of the [SQLITE_TRACE] 3061** constants to indicate why the callback was invoked. 3062** ^The C argument is a copy of the context pointer. 3063** The P and X arguments are pointers whose meanings depend on T. 3064** 3065** The sqlite3_trace_v2() interface is intended to replace the legacy 3066** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3067** are deprecated. 3068*/ 3069int sqlite3_trace_v2( 3070 sqlite3*, 3071 unsigned uMask, 3072 int(*xCallback)(unsigned,void*,void*,void*), 3073 void *pCtx 3074); 3075 3076/* 3077** CAPI3REF: Query Progress Callbacks 3078** METHOD: sqlite3 3079** 3080** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3081** function X to be invoked periodically during long running calls to 3082** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3083** database connection D. An example use for this 3084** interface is to keep a GUI updated during a large query. 3085** 3086** ^The parameter P is passed through as the only parameter to the 3087** callback function X. ^The parameter N is the approximate number of 3088** [virtual machine instructions] that are evaluated between successive 3089** invocations of the callback X. ^If N is less than one then the progress 3090** handler is disabled. 3091** 3092** ^Only a single progress handler may be defined at one time per 3093** [database connection]; setting a new progress handler cancels the 3094** old one. ^Setting parameter X to NULL disables the progress handler. 3095** ^The progress handler is also disabled by setting N to a value less 3096** than 1. 3097** 3098** ^If the progress callback returns non-zero, the operation is 3099** interrupted. This feature can be used to implement a 3100** "Cancel" button on a GUI progress dialog box. 3101** 3102** The progress handler callback must not do anything that will modify 3103** the database connection that invoked the progress handler. 3104** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3105** database connections for the meaning of "modify" in this paragraph. 3106** 3107*/ 3108void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3109 3110/* 3111** CAPI3REF: Opening A New Database Connection 3112** CONSTRUCTOR: sqlite3 3113** 3114** ^These routines open an SQLite database file as specified by the 3115** filename argument. ^The filename argument is interpreted as UTF-8 for 3116** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3117** order for sqlite3_open16(). ^(A [database connection] handle is usually 3118** returned in *ppDb, even if an error occurs. The only exception is that 3119** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3120** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3121** object.)^ ^(If the database is opened (and/or created) successfully, then 3122** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3123** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3124** an English language description of the error following a failure of any 3125** of the sqlite3_open() routines. 3126** 3127** ^The default encoding will be UTF-8 for databases created using 3128** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3129** created using sqlite3_open16() will be UTF-16 in the native byte order. 3130** 3131** Whether or not an error occurs when it is opened, resources 3132** associated with the [database connection] handle should be released by 3133** passing it to [sqlite3_close()] when it is no longer required. 3134** 3135** The sqlite3_open_v2() interface works like sqlite3_open() 3136** except that it accepts two additional parameters for additional control 3137** over the new database connection. ^(The flags parameter to 3138** sqlite3_open_v2() can take one of 3139** the following three values, optionally combined with the 3140** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3141** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3142** 3143** <dl> 3144** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3145** <dd>The database is opened in read-only mode. If the database does not 3146** already exist, an error is returned.</dd>)^ 3147** 3148** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3149** <dd>The database is opened for reading and writing if possible, or reading 3150** only if the file is write protected by the operating system. In either 3151** case the database must already exist, otherwise an error is returned.</dd>)^ 3152** 3153** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3154** <dd>The database is opened for reading and writing, and is created if 3155** it does not already exist. This is the behavior that is always used for 3156** sqlite3_open() and sqlite3_open16().</dd>)^ 3157** </dl> 3158** 3159** If the 3rd parameter to sqlite3_open_v2() is not one of the 3160** combinations shown above optionally combined with other 3161** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3162** then the behavior is undefined. 3163** 3164** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3165** opens in the multi-thread [threading mode] as long as the single-thread 3166** mode has not been set at compile-time or start-time. ^If the 3167** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3168** in the serialized [threading mode] unless single-thread was 3169** previously selected at compile-time or start-time. 3170** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3171** eligible to use [shared cache mode], regardless of whether or not shared 3172** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3173** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3174** participate in [shared cache mode] even if it is enabled. 3175** 3176** ^The fourth parameter to sqlite3_open_v2() is the name of the 3177** [sqlite3_vfs] object that defines the operating system interface that 3178** the new database connection should use. ^If the fourth parameter is 3179** a NULL pointer then the default [sqlite3_vfs] object is used. 3180** 3181** ^If the filename is ":memory:", then a private, temporary in-memory database 3182** is created for the connection. ^This in-memory database will vanish when 3183** the database connection is closed. Future versions of SQLite might 3184** make use of additional special filenames that begin with the ":" character. 3185** It is recommended that when a database filename actually does begin with 3186** a ":" character you should prefix the filename with a pathname such as 3187** "./" to avoid ambiguity. 3188** 3189** ^If the filename is an empty string, then a private, temporary 3190** on-disk database will be created. ^This private database will be 3191** automatically deleted as soon as the database connection is closed. 3192** 3193** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3194** 3195** ^If [URI filename] interpretation is enabled, and the filename argument 3196** begins with "file:", then the filename is interpreted as a URI. ^URI 3197** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3198** set in the third argument to sqlite3_open_v2(), or if it has 3199** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3200** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3201** URI filename interpretation is turned off 3202** by default, but future releases of SQLite might enable URI filename 3203** interpretation by default. See "[URI filenames]" for additional 3204** information. 3205** 3206** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3207** authority, then it must be either an empty string or the string 3208** "localhost". ^If the authority is not an empty string or "localhost", an 3209** error is returned to the caller. ^The fragment component of a URI, if 3210** present, is ignored. 3211** 3212** ^SQLite uses the path component of the URI as the name of the disk file 3213** which contains the database. ^If the path begins with a '/' character, 3214** then it is interpreted as an absolute path. ^If the path does not begin 3215** with a '/' (meaning that the authority section is omitted from the URI) 3216** then the path is interpreted as a relative path. 3217** ^(On windows, the first component of an absolute path 3218** is a drive specification (e.g. "C:").)^ 3219** 3220** [[core URI query parameters]] 3221** The query component of a URI may contain parameters that are interpreted 3222** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3223** SQLite and its built-in [VFSes] interpret the 3224** following query parameters: 3225** 3226** <ul> 3227** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3228** a VFS object that provides the operating system interface that should 3229** be used to access the database file on disk. ^If this option is set to 3230** an empty string the default VFS object is used. ^Specifying an unknown 3231** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3232** present, then the VFS specified by the option takes precedence over 3233** the value passed as the fourth parameter to sqlite3_open_v2(). 3234** 3235** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3236** "rwc", or "memory". Attempting to set it to any other value is 3237** an error)^. 3238** ^If "ro" is specified, then the database is opened for read-only 3239** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3240** third argument to sqlite3_open_v2(). ^If the mode option is set to 3241** "rw", then the database is opened for read-write (but not create) 3242** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3243** been set. ^Value "rwc" is equivalent to setting both 3244** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3245** set to "memory" then a pure [in-memory database] that never reads 3246** or writes from disk is used. ^It is an error to specify a value for 3247** the mode parameter that is less restrictive than that specified by 3248** the flags passed in the third parameter to sqlite3_open_v2(). 3249** 3250** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3251** "private". ^Setting it to "shared" is equivalent to setting the 3252** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3253** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3254** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3255** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3256** a URI filename, its value overrides any behavior requested by setting 3257** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3258** 3259** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3260** [powersafe overwrite] property does or does not apply to the 3261** storage media on which the database file resides. 3262** 3263** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3264** which if set disables file locking in rollback journal modes. This 3265** is useful for accessing a database on a filesystem that does not 3266** support locking. Caution: Database corruption might result if two 3267** or more processes write to the same database and any one of those 3268** processes uses nolock=1. 3269** 3270** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3271** parameter that indicates that the database file is stored on 3272** read-only media. ^When immutable is set, SQLite assumes that the 3273** database file cannot be changed, even by a process with higher 3274** privilege, and so the database is opened read-only and all locking 3275** and change detection is disabled. Caution: Setting the immutable 3276** property on a database file that does in fact change can result 3277** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3278** See also: [SQLITE_IOCAP_IMMUTABLE]. 3279** 3280** </ul> 3281** 3282** ^Specifying an unknown parameter in the query component of a URI is not an 3283** error. Future versions of SQLite might understand additional query 3284** parameters. See "[query parameters with special meaning to SQLite]" for 3285** additional information. 3286** 3287** [[URI filename examples]] <h3>URI filename examples</h3> 3288** 3289** <table border="1" align=center cellpadding=5> 3290** <tr><th> URI filenames <th> Results 3291** <tr><td> file:data.db <td> 3292** Open the file "data.db" in the current directory. 3293** <tr><td> file:/home/fred/data.db<br> 3294** file:///home/fred/data.db <br> 3295** file://localhost/home/fred/data.db <br> <td> 3296** Open the database file "/home/fred/data.db". 3297** <tr><td> file://darkstar/home/fred/data.db <td> 3298** An error. "darkstar" is not a recognized authority. 3299** <tr><td style="white-space:nowrap"> 3300** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3301** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3302** C:. Note that the %20 escaping in this example is not strictly 3303** necessary - space characters can be used literally 3304** in URI filenames. 3305** <tr><td> file:data.db?mode=ro&cache=private <td> 3306** Open file "data.db" in the current directory for read-only access. 3307** Regardless of whether or not shared-cache mode is enabled by 3308** default, use a private cache. 3309** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3310** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3311** that uses dot-files in place of posix advisory locking. 3312** <tr><td> file:data.db?mode=readonly <td> 3313** An error. "readonly" is not a valid option for the "mode" parameter. 3314** </table> 3315** 3316** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3317** query components of a URI. A hexadecimal escape sequence consists of a 3318** percent sign - "%" - followed by exactly two hexadecimal digits 3319** specifying an octet value. ^Before the path or query components of a 3320** URI filename are interpreted, they are encoded using UTF-8 and all 3321** hexadecimal escape sequences replaced by a single byte containing the 3322** corresponding octet. If this process generates an invalid UTF-8 encoding, 3323** the results are undefined. 3324** 3325** <b>Note to Windows users:</b> The encoding used for the filename argument 3326** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3327** codepage is currently defined. Filenames containing international 3328** characters must be converted to UTF-8 prior to passing them into 3329** sqlite3_open() or sqlite3_open_v2(). 3330** 3331** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3332** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3333** features that require the use of temporary files may fail. 3334** 3335** See also: [sqlite3_temp_directory] 3336*/ 3337int sqlite3_open( 3338 const char *filename, /* Database filename (UTF-8) */ 3339 sqlite3 **ppDb /* OUT: SQLite db handle */ 3340); 3341int sqlite3_open16( 3342 const void *filename, /* Database filename (UTF-16) */ 3343 sqlite3 **ppDb /* OUT: SQLite db handle */ 3344); 3345int sqlite3_open_v2( 3346 const char *filename, /* Database filename (UTF-8) */ 3347 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3348 int flags, /* Flags */ 3349 const char *zVfs /* Name of VFS module to use */ 3350); 3351 3352/* 3353** CAPI3REF: Obtain Values For URI Parameters 3354** 3355** These are utility routines, useful to VFS implementations, that check 3356** to see if a database file was a URI that contained a specific query 3357** parameter, and if so obtains the value of that query parameter. 3358** 3359** If F is the database filename pointer passed into the xOpen() method of 3360** a VFS implementation when the flags parameter to xOpen() has one or 3361** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3362** P is the name of the query parameter, then 3363** sqlite3_uri_parameter(F,P) returns the value of the P 3364** parameter if it exists or a NULL pointer if P does not appear as a 3365** query parameter on F. If P is a query parameter of F 3366** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3367** a pointer to an empty string. 3368** 3369** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3370** parameter and returns true (1) or false (0) according to the value 3371** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3372** value of query parameter P is one of "yes", "true", or "on" in any 3373** case or if the value begins with a non-zero number. The 3374** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3375** query parameter P is one of "no", "false", or "off" in any case or 3376** if the value begins with a numeric zero. If P is not a query 3377** parameter on F or if the value of P is does not match any of the 3378** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3379** 3380** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3381** 64-bit signed integer and returns that integer, or D if P does not 3382** exist. If the value of P is something other than an integer, then 3383** zero is returned. 3384** 3385** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3386** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3387** is not a database file pathname pointer that SQLite passed into the xOpen 3388** VFS method, then the behavior of this routine is undefined and probably 3389** undesirable. 3390*/ 3391const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3392int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3393sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3394 3395 3396/* 3397** CAPI3REF: Error Codes And Messages 3398** METHOD: sqlite3 3399** 3400** ^If the most recent sqlite3_* API call associated with 3401** [database connection] D failed, then the sqlite3_errcode(D) interface 3402** returns the numeric [result code] or [extended result code] for that 3403** API call. 3404** ^The sqlite3_extended_errcode() 3405** interface is the same except that it always returns the 3406** [extended result code] even when extended result codes are 3407** disabled. 3408** 3409** The values returned by sqlite3_errcode() and/or 3410** sqlite3_extended_errcode() might change with each API call. 3411** Except, there are some interfaces that are guaranteed to never 3412** change the value of the error code. The error-code preserving 3413** interfaces are: 3414** 3415** <ul> 3416** <li> sqlite3_errcode() 3417** <li> sqlite3_extended_errcode() 3418** <li> sqlite3_errmsg() 3419** <li> sqlite3_errmsg16() 3420** </ul> 3421** 3422** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3423** text that describes the error, as either UTF-8 or UTF-16 respectively. 3424** ^(Memory to hold the error message string is managed internally. 3425** The application does not need to worry about freeing the result. 3426** However, the error string might be overwritten or deallocated by 3427** subsequent calls to other SQLite interface functions.)^ 3428** 3429** ^The sqlite3_errstr() interface returns the English-language text 3430** that describes the [result code], as UTF-8. 3431** ^(Memory to hold the error message string is managed internally 3432** and must not be freed by the application)^. 3433** 3434** When the serialized [threading mode] is in use, it might be the 3435** case that a second error occurs on a separate thread in between 3436** the time of the first error and the call to these interfaces. 3437** When that happens, the second error will be reported since these 3438** interfaces always report the most recent result. To avoid 3439** this, each thread can obtain exclusive use of the [database connection] D 3440** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3441** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3442** all calls to the interfaces listed here are completed. 3443** 3444** If an interface fails with SQLITE_MISUSE, that means the interface 3445** was invoked incorrectly by the application. In that case, the 3446** error code and message may or may not be set. 3447*/ 3448int sqlite3_errcode(sqlite3 *db); 3449int sqlite3_extended_errcode(sqlite3 *db); 3450const char *sqlite3_errmsg(sqlite3*); 3451const void *sqlite3_errmsg16(sqlite3*); 3452const char *sqlite3_errstr(int); 3453 3454/* 3455** CAPI3REF: Prepared Statement Object 3456** KEYWORDS: {prepared statement} {prepared statements} 3457** 3458** An instance of this object represents a single SQL statement that 3459** has been compiled into binary form and is ready to be evaluated. 3460** 3461** Think of each SQL statement as a separate computer program. The 3462** original SQL text is source code. A prepared statement object 3463** is the compiled object code. All SQL must be converted into a 3464** prepared statement before it can be run. 3465** 3466** The life-cycle of a prepared statement object usually goes like this: 3467** 3468** <ol> 3469** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3470** <li> Bind values to [parameters] using the sqlite3_bind_*() 3471** interfaces. 3472** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3473** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3474** to step 2. Do this zero or more times. 3475** <li> Destroy the object using [sqlite3_finalize()]. 3476** </ol> 3477*/ 3478typedef struct sqlite3_stmt sqlite3_stmt; 3479 3480/* 3481** CAPI3REF: Run-time Limits 3482** METHOD: sqlite3 3483** 3484** ^(This interface allows the size of various constructs to be limited 3485** on a connection by connection basis. The first parameter is the 3486** [database connection] whose limit is to be set or queried. The 3487** second parameter is one of the [limit categories] that define a 3488** class of constructs to be size limited. The third parameter is the 3489** new limit for that construct.)^ 3490** 3491** ^If the new limit is a negative number, the limit is unchanged. 3492** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3493** [limits | hard upper bound] 3494** set at compile-time by a C preprocessor macro called 3495** [limits | SQLITE_MAX_<i>NAME</i>]. 3496** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3497** ^Attempts to increase a limit above its hard upper bound are 3498** silently truncated to the hard upper bound. 3499** 3500** ^Regardless of whether or not the limit was changed, the 3501** [sqlite3_limit()] interface returns the prior value of the limit. 3502** ^Hence, to find the current value of a limit without changing it, 3503** simply invoke this interface with the third parameter set to -1. 3504** 3505** Run-time limits are intended for use in applications that manage 3506** both their own internal database and also databases that are controlled 3507** by untrusted external sources. An example application might be a 3508** web browser that has its own databases for storing history and 3509** separate databases controlled by JavaScript applications downloaded 3510** off the Internet. The internal databases can be given the 3511** large, default limits. Databases managed by external sources can 3512** be given much smaller limits designed to prevent a denial of service 3513** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3514** interface to further control untrusted SQL. The size of the database 3515** created by an untrusted script can be contained using the 3516** [max_page_count] [PRAGMA]. 3517** 3518** New run-time limit categories may be added in future releases. 3519*/ 3520int sqlite3_limit(sqlite3*, int id, int newVal); 3521 3522/* 3523** CAPI3REF: Run-Time Limit Categories 3524** KEYWORDS: {limit category} {*limit categories} 3525** 3526** These constants define various performance limits 3527** that can be lowered at run-time using [sqlite3_limit()]. 3528** The synopsis of the meanings of the various limits is shown below. 3529** Additional information is available at [limits | Limits in SQLite]. 3530** 3531** <dl> 3532** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3533** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3534** 3535** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3536** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3537** 3538** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3539** <dd>The maximum number of columns in a table definition or in the 3540** result set of a [SELECT] or the maximum number of columns in an index 3541** or in an ORDER BY or GROUP BY clause.</dd>)^ 3542** 3543** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3544** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3545** 3546** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3547** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3548** 3549** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3550** <dd>The maximum number of instructions in a virtual machine program 3551** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3552** the equivalent tries to allocate space for more than this many opcodes 3553** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3554** 3555** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3556** <dd>The maximum number of arguments on a function.</dd>)^ 3557** 3558** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3559** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3560** 3561** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3562** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3563** <dd>The maximum length of the pattern argument to the [LIKE] or 3564** [GLOB] operators.</dd>)^ 3565** 3566** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3567** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3568** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3569** 3570** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3571** <dd>The maximum depth of recursion for triggers.</dd>)^ 3572** 3573** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3574** <dd>The maximum number of auxiliary worker threads that a single 3575** [prepared statement] may start.</dd>)^ 3576** </dl> 3577*/ 3578#define SQLITE_LIMIT_LENGTH 0 3579#define SQLITE_LIMIT_SQL_LENGTH 1 3580#define SQLITE_LIMIT_COLUMN 2 3581#define SQLITE_LIMIT_EXPR_DEPTH 3 3582#define SQLITE_LIMIT_COMPOUND_SELECT 4 3583#define SQLITE_LIMIT_VDBE_OP 5 3584#define SQLITE_LIMIT_FUNCTION_ARG 6 3585#define SQLITE_LIMIT_ATTACHED 7 3586#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3587#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3588#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3589#define SQLITE_LIMIT_WORKER_THREADS 11 3590 3591/* 3592** CAPI3REF: Prepare Flags 3593** 3594** These constants define various flags that can be passed into 3595** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3596** [sqlite3_prepare16_v3()] interfaces. 3597** 3598** New flags may be added in future releases of SQLite. 3599** 3600** <dl> 3601** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3602** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3603** that the prepared statement will be retained for a long time and 3604** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3605** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3606** be used just once or at most a few times and then destroyed using 3607** [sqlite3_finalize()] relatively soon. The current implementation acts 3608** on this hint by avoiding the use of [lookaside memory] so as not to 3609** deplete the limited store of lookaside memory. Future versions of 3610** SQLite may act on this hint differently. 3611** </dl> 3612*/ 3613#define SQLITE_PREPARE_PERSISTENT 0x01 3614 3615/* 3616** CAPI3REF: Compiling An SQL Statement 3617** KEYWORDS: {SQL statement compiler} 3618** METHOD: sqlite3 3619** CONSTRUCTOR: sqlite3_stmt 3620** 3621** To execute an SQL statement, it must first be compiled into a byte-code 3622** program using one of these routines. Or, in other words, these routines 3623** are constructors for the [prepared statement] object. 3624** 3625** The preferred routine to use is [sqlite3_prepare_v2()]. The 3626** [sqlite3_prepare()] interface is legacy and should be avoided. 3627** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3628** for special purposes. 3629** 3630** The use of the UTF-8 interfaces is preferred, as SQLite currently 3631** does all parsing using UTF-8. The UTF-16 interfaces are provided 3632** as a convenience. The UTF-16 interfaces work by converting the 3633** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3634** 3635** The first argument, "db", is a [database connection] obtained from a 3636** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3637** [sqlite3_open16()]. The database connection must not have been closed. 3638** 3639** The second argument, "zSql", is the statement to be compiled, encoded 3640** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3641** and sqlite3_prepare_v3() 3642** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3643** and sqlite3_prepare16_v3() use UTF-16. 3644** 3645** ^If the nByte argument is negative, then zSql is read up to the 3646** first zero terminator. ^If nByte is positive, then it is the 3647** number of bytes read from zSql. ^If nByte is zero, then no prepared 3648** statement is generated. 3649** If the caller knows that the supplied string is nul-terminated, then 3650** there is a small performance advantage to passing an nByte parameter that 3651** is the number of bytes in the input string <i>including</i> 3652** the nul-terminator. 3653** 3654** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3655** past the end of the first SQL statement in zSql. These routines only 3656** compile the first statement in zSql, so *pzTail is left pointing to 3657** what remains uncompiled. 3658** 3659** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3660** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3661** to NULL. ^If the input text contains no SQL (if the input is an empty 3662** string or a comment) then *ppStmt is set to NULL. 3663** The calling procedure is responsible for deleting the compiled 3664** SQL statement using [sqlite3_finalize()] after it has finished with it. 3665** ppStmt may not be NULL. 3666** 3667** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3668** otherwise an [error code] is returned. 3669** 3670** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3671** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3672** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3673** are retained for backwards compatibility, but their use is discouraged. 3674** ^In the "vX" interfaces, the prepared statement 3675** that is returned (the [sqlite3_stmt] object) contains a copy of the 3676** original SQL text. This causes the [sqlite3_step()] interface to 3677** behave differently in three ways: 3678** 3679** <ol> 3680** <li> 3681** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3682** always used to do, [sqlite3_step()] will automatically recompile the SQL 3683** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3684** retries will occur before sqlite3_step() gives up and returns an error. 3685** </li> 3686** 3687** <li> 3688** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3689** [error codes] or [extended error codes]. ^The legacy behavior was that 3690** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3691** and the application would have to make a second call to [sqlite3_reset()] 3692** in order to find the underlying cause of the problem. With the "v2" prepare 3693** interfaces, the underlying reason for the error is returned immediately. 3694** </li> 3695** 3696** <li> 3697** ^If the specific value bound to [parameter | host parameter] in the 3698** WHERE clause might influence the choice of query plan for a statement, 3699** then the statement will be automatically recompiled, as if there had been 3700** a schema change, on the first [sqlite3_step()] call following any change 3701** to the [sqlite3_bind_text | bindings] of that [parameter]. 3702** ^The specific value of WHERE-clause [parameter] might influence the 3703** choice of query plan if the parameter is the left-hand side of a [LIKE] 3704** or [GLOB] operator or if the parameter is compared to an indexed column 3705** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3706** </li> 3707** </ol> 3708** 3709** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3710** the extra prepFlags parameter, which is a bit array consisting of zero or 3711** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3712** sqlite3_prepare_v2() interface works exactly the same as 3713** sqlite3_prepare_v3() with a zero prepFlags parameter. 3714*/ 3715int sqlite3_prepare( 3716 sqlite3 *db, /* Database handle */ 3717 const char *zSql, /* SQL statement, UTF-8 encoded */ 3718 int nByte, /* Maximum length of zSql in bytes. */ 3719 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3720 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3721); 3722int sqlite3_prepare_v2( 3723 sqlite3 *db, /* Database handle */ 3724 const char *zSql, /* SQL statement, UTF-8 encoded */ 3725 int nByte, /* Maximum length of zSql in bytes. */ 3726 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3727 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3728); 3729int sqlite3_prepare_v3( 3730 sqlite3 *db, /* Database handle */ 3731 const char *zSql, /* SQL statement, UTF-8 encoded */ 3732 int nByte, /* Maximum length of zSql in bytes. */ 3733 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3734 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3735 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3736); 3737int sqlite3_prepare16( 3738 sqlite3 *db, /* Database handle */ 3739 const void *zSql, /* SQL statement, UTF-16 encoded */ 3740 int nByte, /* Maximum length of zSql in bytes. */ 3741 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3742 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3743); 3744int sqlite3_prepare16_v2( 3745 sqlite3 *db, /* Database handle */ 3746 const void *zSql, /* SQL statement, UTF-16 encoded */ 3747 int nByte, /* Maximum length of zSql in bytes. */ 3748 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3749 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3750); 3751int sqlite3_prepare16_v3( 3752 sqlite3 *db, /* Database handle */ 3753 const void *zSql, /* SQL statement, UTF-16 encoded */ 3754 int nByte, /* Maximum length of zSql in bytes. */ 3755 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3756 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3757 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3758); 3759 3760/* 3761** CAPI3REF: Retrieving Statement SQL 3762** METHOD: sqlite3_stmt 3763** 3764** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3765** SQL text used to create [prepared statement] P if P was 3766** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3767** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3768** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3769** string containing the SQL text of prepared statement P with 3770** [bound parameters] expanded. 3771** 3772** ^(For example, if a prepared statement is created using the SQL 3773** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3774** and parameter :xyz is unbound, then sqlite3_sql() will return 3775** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3776** will return "SELECT 2345,NULL".)^ 3777** 3778** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3779** is available to hold the result, or if the result would exceed the 3780** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3781** 3782** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3783** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3784** option causes sqlite3_expanded_sql() to always return NULL. 3785** 3786** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3787** automatically freed when the prepared statement is finalized. 3788** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3789** is obtained from [sqlite3_malloc()] and must be free by the application 3790** by passing it to [sqlite3_free()]. 3791*/ 3792const char *sqlite3_sql(sqlite3_stmt *pStmt); 3793char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3794 3795/* 3796** CAPI3REF: Determine If An SQL Statement Writes The Database 3797** METHOD: sqlite3_stmt 3798** 3799** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3800** and only if the [prepared statement] X makes no direct changes to 3801** the content of the database file. 3802** 3803** Note that [application-defined SQL functions] or 3804** [virtual tables] might change the database indirectly as a side effect. 3805** ^(For example, if an application defines a function "eval()" that 3806** calls [sqlite3_exec()], then the following SQL statement would 3807** change the database file through side-effects: 3808** 3809** <blockquote><pre> 3810** SELECT eval('DELETE FROM t1') FROM t2; 3811** </pre></blockquote> 3812** 3813** But because the [SELECT] statement does not change the database file 3814** directly, sqlite3_stmt_readonly() would still return true.)^ 3815** 3816** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3817** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3818** since the statements themselves do not actually modify the database but 3819** rather they control the timing of when other statements modify the 3820** database. ^The [ATTACH] and [DETACH] statements also cause 3821** sqlite3_stmt_readonly() to return true since, while those statements 3822** change the configuration of a database connection, they do not make 3823** changes to the content of the database files on disk. 3824** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3825** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3826** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3827** sqlite3_stmt_readonly() returns false for those commands. 3828*/ 3829int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3830 3831/* 3832** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3833** METHOD: sqlite3_stmt 3834** 3835** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3836** [prepared statement] S has been stepped at least once using 3837** [sqlite3_step(S)] but has neither run to completion (returned 3838** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3839** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3840** interface returns false if S is a NULL pointer. If S is not a 3841** NULL pointer and is not a pointer to a valid [prepared statement] 3842** object, then the behavior is undefined and probably undesirable. 3843** 3844** This interface can be used in combination [sqlite3_next_stmt()] 3845** to locate all prepared statements associated with a database 3846** connection that are in need of being reset. This can be used, 3847** for example, in diagnostic routines to search for prepared 3848** statements that are holding a transaction open. 3849*/ 3850int sqlite3_stmt_busy(sqlite3_stmt*); 3851 3852/* 3853** CAPI3REF: Dynamically Typed Value Object 3854** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3855** 3856** SQLite uses the sqlite3_value object to represent all values 3857** that can be stored in a database table. SQLite uses dynamic typing 3858** for the values it stores. ^Values stored in sqlite3_value objects 3859** can be integers, floating point values, strings, BLOBs, or NULL. 3860** 3861** An sqlite3_value object may be either "protected" or "unprotected". 3862** Some interfaces require a protected sqlite3_value. Other interfaces 3863** will accept either a protected or an unprotected sqlite3_value. 3864** Every interface that accepts sqlite3_value arguments specifies 3865** whether or not it requires a protected sqlite3_value. The 3866** [sqlite3_value_dup()] interface can be used to construct a new 3867** protected sqlite3_value from an unprotected sqlite3_value. 3868** 3869** The terms "protected" and "unprotected" refer to whether or not 3870** a mutex is held. An internal mutex is held for a protected 3871** sqlite3_value object but no mutex is held for an unprotected 3872** sqlite3_value object. If SQLite is compiled to be single-threaded 3873** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3874** or if SQLite is run in one of reduced mutex modes 3875** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3876** then there is no distinction between protected and unprotected 3877** sqlite3_value objects and they can be used interchangeably. However, 3878** for maximum code portability it is recommended that applications 3879** still make the distinction between protected and unprotected 3880** sqlite3_value objects even when not strictly required. 3881** 3882** ^The sqlite3_value objects that are passed as parameters into the 3883** implementation of [application-defined SQL functions] are protected. 3884** ^The sqlite3_value object returned by 3885** [sqlite3_column_value()] is unprotected. 3886** Unprotected sqlite3_value objects may only be used as arguments 3887** to [sqlite3_result_value()], [sqlite3_bind_value()], and 3888** [sqlite3_value_dup()]. 3889** The [sqlite3_value_blob | sqlite3_value_type()] family of 3890** interfaces require protected sqlite3_value objects. 3891*/ 3892typedef struct sqlite3_value sqlite3_value; 3893 3894/* 3895** CAPI3REF: SQL Function Context Object 3896** 3897** The context in which an SQL function executes is stored in an 3898** sqlite3_context object. ^A pointer to an sqlite3_context object 3899** is always first parameter to [application-defined SQL functions]. 3900** The application-defined SQL function implementation will pass this 3901** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3902** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3903** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3904** and/or [sqlite3_set_auxdata()]. 3905*/ 3906typedef struct sqlite3_context sqlite3_context; 3907 3908/* 3909** CAPI3REF: Binding Values To Prepared Statements 3910** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3911** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3912** METHOD: sqlite3_stmt 3913** 3914** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3915** literals may be replaced by a [parameter] that matches one of following 3916** templates: 3917** 3918** <ul> 3919** <li> ? 3920** <li> ?NNN 3921** <li> :VVV 3922** <li> @VVV 3923** <li> $VVV 3924** </ul> 3925** 3926** In the templates above, NNN represents an integer literal, 3927** and VVV represents an alphanumeric identifier.)^ ^The values of these 3928** parameters (also called "host parameter names" or "SQL parameters") 3929** can be set using the sqlite3_bind_*() routines defined here. 3930** 3931** ^The first argument to the sqlite3_bind_*() routines is always 3932** a pointer to the [sqlite3_stmt] object returned from 3933** [sqlite3_prepare_v2()] or its variants. 3934** 3935** ^The second argument is the index of the SQL parameter to be set. 3936** ^The leftmost SQL parameter has an index of 1. ^When the same named 3937** SQL parameter is used more than once, second and subsequent 3938** occurrences have the same index as the first occurrence. 3939** ^The index for named parameters can be looked up using the 3940** [sqlite3_bind_parameter_index()] API if desired. ^The index 3941** for "?NNN" parameters is the value of NNN. 3942** ^The NNN value must be between 1 and the [sqlite3_limit()] 3943** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3944** 3945** ^The third argument is the value to bind to the parameter. 3946** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3947** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3948** is ignored and the end result is the same as sqlite3_bind_null(). 3949** 3950** ^(In those routines that have a fourth argument, its value is the 3951** number of bytes in the parameter. To be clear: the value is the 3952** number of <u>bytes</u> in the value, not the number of characters.)^ 3953** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3954** is negative, then the length of the string is 3955** the number of bytes up to the first zero terminator. 3956** If the fourth parameter to sqlite3_bind_blob() is negative, then 3957** the behavior is undefined. 3958** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3959** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3960** that parameter must be the byte offset 3961** where the NUL terminator would occur assuming the string were NUL 3962** terminated. If any NUL characters occur at byte offsets less than 3963** the value of the fourth parameter then the resulting string value will 3964** contain embedded NULs. The result of expressions involving strings 3965** with embedded NULs is undefined. 3966** 3967** ^The fifth argument to the BLOB and string binding interfaces 3968** is a destructor used to dispose of the BLOB or 3969** string after SQLite has finished with it. ^The destructor is called 3970** to dispose of the BLOB or string even if the call to bind API fails. 3971** ^If the fifth argument is 3972** the special value [SQLITE_STATIC], then SQLite assumes that the 3973** information is in static, unmanaged space and does not need to be freed. 3974** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3975** SQLite makes its own private copy of the data immediately, before 3976** the sqlite3_bind_*() routine returns. 3977** 3978** ^The sixth argument to sqlite3_bind_text64() must be one of 3979** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3980** to specify the encoding of the text in the third parameter. If 3981** the sixth argument to sqlite3_bind_text64() is not one of the 3982** allowed values shown above, or if the text encoding is different 3983** from the encoding specified by the sixth parameter, then the behavior 3984** is undefined. 3985** 3986** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3987** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3988** (just an integer to hold its size) while it is being processed. 3989** Zeroblobs are intended to serve as placeholders for BLOBs whose 3990** content is later written using 3991** [sqlite3_blob_open | incremental BLOB I/O] routines. 3992** ^A negative value for the zeroblob results in a zero-length BLOB. 3993** 3994** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 3995** [prepared statement] S to have an SQL value of NULL, but to also be 3996** associated with the pointer P of type T. ^D is either a NULL pointer or 3997** a pointer to a destructor function for P. ^SQLite will invoke the 3998** destructor D with a single argument of P when it is finished using 3999** P. The T parameter should be a static string, preferably a string 4000** literal. The sqlite3_bind_pointer() routine is part of the 4001** [pointer passing interface] added for SQLite 3.20.0. 4002** 4003** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4004** for the [prepared statement] or with a prepared statement for which 4005** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4006** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4007** routine is passed a [prepared statement] that has been finalized, the 4008** result is undefined and probably harmful. 4009** 4010** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4011** ^Unbound parameters are interpreted as NULL. 4012** 4013** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4014** [error code] if anything goes wrong. 4015** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4016** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4017** [SQLITE_MAX_LENGTH]. 4018** ^[SQLITE_RANGE] is returned if the parameter 4019** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4020** 4021** See also: [sqlite3_bind_parameter_count()], 4022** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4023*/ 4024int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4025int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4026 void(*)(void*)); 4027int sqlite3_bind_double(sqlite3_stmt*, int, double); 4028int sqlite3_bind_int(sqlite3_stmt*, int, int); 4029int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4030int sqlite3_bind_null(sqlite3_stmt*, int); 4031int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4032int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4033int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4034 void(*)(void*), unsigned char encoding); 4035int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4036int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4037int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4038int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4039 4040/* 4041** CAPI3REF: Number Of SQL Parameters 4042** METHOD: sqlite3_stmt 4043** 4044** ^This routine can be used to find the number of [SQL parameters] 4045** in a [prepared statement]. SQL parameters are tokens of the 4046** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4047** placeholders for values that are [sqlite3_bind_blob | bound] 4048** to the parameters at a later time. 4049** 4050** ^(This routine actually returns the index of the largest (rightmost) 4051** parameter. For all forms except ?NNN, this will correspond to the 4052** number of unique parameters. If parameters of the ?NNN form are used, 4053** there may be gaps in the list.)^ 4054** 4055** See also: [sqlite3_bind_blob|sqlite3_bind()], 4056** [sqlite3_bind_parameter_name()], and 4057** [sqlite3_bind_parameter_index()]. 4058*/ 4059int sqlite3_bind_parameter_count(sqlite3_stmt*); 4060 4061/* 4062** CAPI3REF: Name Of A Host Parameter 4063** METHOD: sqlite3_stmt 4064** 4065** ^The sqlite3_bind_parameter_name(P,N) interface returns 4066** the name of the N-th [SQL parameter] in the [prepared statement] P. 4067** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4068** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4069** respectively. 4070** In other words, the initial ":" or "$" or "@" or "?" 4071** is included as part of the name.)^ 4072** ^Parameters of the form "?" without a following integer have no name 4073** and are referred to as "nameless" or "anonymous parameters". 4074** 4075** ^The first host parameter has an index of 1, not 0. 4076** 4077** ^If the value N is out of range or if the N-th parameter is 4078** nameless, then NULL is returned. ^The returned string is 4079** always in UTF-8 encoding even if the named parameter was 4080** originally specified as UTF-16 in [sqlite3_prepare16()], 4081** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4082** 4083** See also: [sqlite3_bind_blob|sqlite3_bind()], 4084** [sqlite3_bind_parameter_count()], and 4085** [sqlite3_bind_parameter_index()]. 4086*/ 4087const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4088 4089/* 4090** CAPI3REF: Index Of A Parameter With A Given Name 4091** METHOD: sqlite3_stmt 4092** 4093** ^Return the index of an SQL parameter given its name. ^The 4094** index value returned is suitable for use as the second 4095** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4096** is returned if no matching parameter is found. ^The parameter 4097** name must be given in UTF-8 even if the original statement 4098** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4099** [sqlite3_prepare16_v3()]. 4100** 4101** See also: [sqlite3_bind_blob|sqlite3_bind()], 4102** [sqlite3_bind_parameter_count()], and 4103** [sqlite3_bind_parameter_name()]. 4104*/ 4105int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4106 4107/* 4108** CAPI3REF: Reset All Bindings On A Prepared Statement 4109** METHOD: sqlite3_stmt 4110** 4111** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4112** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4113** ^Use this routine to reset all host parameters to NULL. 4114*/ 4115int sqlite3_clear_bindings(sqlite3_stmt*); 4116 4117/* 4118** CAPI3REF: Number Of Columns In A Result Set 4119** METHOD: sqlite3_stmt 4120** 4121** ^Return the number of columns in the result set returned by the 4122** [prepared statement]. ^If this routine returns 0, that means the 4123** [prepared statement] returns no data (for example an [UPDATE]). 4124** ^However, just because this routine returns a positive number does not 4125** mean that one or more rows of data will be returned. ^A SELECT statement 4126** will always have a positive sqlite3_column_count() but depending on the 4127** WHERE clause constraints and the table content, it might return no rows. 4128** 4129** See also: [sqlite3_data_count()] 4130*/ 4131int sqlite3_column_count(sqlite3_stmt *pStmt); 4132 4133/* 4134** CAPI3REF: Column Names In A Result Set 4135** METHOD: sqlite3_stmt 4136** 4137** ^These routines return the name assigned to a particular column 4138** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4139** interface returns a pointer to a zero-terminated UTF-8 string 4140** and sqlite3_column_name16() returns a pointer to a zero-terminated 4141** UTF-16 string. ^The first parameter is the [prepared statement] 4142** that implements the [SELECT] statement. ^The second parameter is the 4143** column number. ^The leftmost column is number 0. 4144** 4145** ^The returned string pointer is valid until either the [prepared statement] 4146** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4147** reprepared by the first call to [sqlite3_step()] for a particular run 4148** or until the next call to 4149** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4150** 4151** ^If sqlite3_malloc() fails during the processing of either routine 4152** (for example during a conversion from UTF-8 to UTF-16) then a 4153** NULL pointer is returned. 4154** 4155** ^The name of a result column is the value of the "AS" clause for 4156** that column, if there is an AS clause. If there is no AS clause 4157** then the name of the column is unspecified and may change from 4158** one release of SQLite to the next. 4159*/ 4160const char *sqlite3_column_name(sqlite3_stmt*, int N); 4161const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4162 4163/* 4164** CAPI3REF: Source Of Data In A Query Result 4165** METHOD: sqlite3_stmt 4166** 4167** ^These routines provide a means to determine the database, table, and 4168** table column that is the origin of a particular result column in 4169** [SELECT] statement. 4170** ^The name of the database or table or column can be returned as 4171** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4172** the database name, the _table_ routines return the table name, and 4173** the origin_ routines return the column name. 4174** ^The returned string is valid until the [prepared statement] is destroyed 4175** using [sqlite3_finalize()] or until the statement is automatically 4176** reprepared by the first call to [sqlite3_step()] for a particular run 4177** or until the same information is requested 4178** again in a different encoding. 4179** 4180** ^The names returned are the original un-aliased names of the 4181** database, table, and column. 4182** 4183** ^The first argument to these interfaces is a [prepared statement]. 4184** ^These functions return information about the Nth result column returned by 4185** the statement, where N is the second function argument. 4186** ^The left-most column is column 0 for these routines. 4187** 4188** ^If the Nth column returned by the statement is an expression or 4189** subquery and is not a column value, then all of these functions return 4190** NULL. ^These routine might also return NULL if a memory allocation error 4191** occurs. ^Otherwise, they return the name of the attached database, table, 4192** or column that query result column was extracted from. 4193** 4194** ^As with all other SQLite APIs, those whose names end with "16" return 4195** UTF-16 encoded strings and the other functions return UTF-8. 4196** 4197** ^These APIs are only available if the library was compiled with the 4198** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4199** 4200** If two or more threads call one or more of these routines against the same 4201** prepared statement and column at the same time then the results are 4202** undefined. 4203** 4204** If two or more threads call one or more 4205** [sqlite3_column_database_name | column metadata interfaces] 4206** for the same [prepared statement] and result column 4207** at the same time then the results are undefined. 4208*/ 4209const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4210const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4211const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4212const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4213const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4214const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4215 4216/* 4217** CAPI3REF: Declared Datatype Of A Query Result 4218** METHOD: sqlite3_stmt 4219** 4220** ^(The first parameter is a [prepared statement]. 4221** If this statement is a [SELECT] statement and the Nth column of the 4222** returned result set of that [SELECT] is a table column (not an 4223** expression or subquery) then the declared type of the table 4224** column is returned.)^ ^If the Nth column of the result set is an 4225** expression or subquery, then a NULL pointer is returned. 4226** ^The returned string is always UTF-8 encoded. 4227** 4228** ^(For example, given the database schema: 4229** 4230** CREATE TABLE t1(c1 VARIANT); 4231** 4232** and the following statement to be compiled: 4233** 4234** SELECT c1 + 1, c1 FROM t1; 4235** 4236** this routine would return the string "VARIANT" for the second result 4237** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4238** 4239** ^SQLite uses dynamic run-time typing. ^So just because a column 4240** is declared to contain a particular type does not mean that the 4241** data stored in that column is of the declared type. SQLite is 4242** strongly typed, but the typing is dynamic not static. ^Type 4243** is associated with individual values, not with the containers 4244** used to hold those values. 4245*/ 4246const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4247const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4248 4249/* 4250** CAPI3REF: Evaluate An SQL Statement 4251** METHOD: sqlite3_stmt 4252** 4253** After a [prepared statement] has been prepared using any of 4254** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4255** or [sqlite3_prepare16_v3()] or one of the legacy 4256** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4257** must be called one or more times to evaluate the statement. 4258** 4259** The details of the behavior of the sqlite3_step() interface depend 4260** on whether the statement was prepared using the newer "vX" interfaces 4261** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4262** [sqlite3_prepare16_v2()] or the older legacy 4263** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4264** new "vX" interface is recommended for new applications but the legacy 4265** interface will continue to be supported. 4266** 4267** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4268** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4269** ^With the "v2" interface, any of the other [result codes] or 4270** [extended result codes] might be returned as well. 4271** 4272** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4273** database locks it needs to do its job. ^If the statement is a [COMMIT] 4274** or occurs outside of an explicit transaction, then you can retry the 4275** statement. If the statement is not a [COMMIT] and occurs within an 4276** explicit transaction then you should rollback the transaction before 4277** continuing. 4278** 4279** ^[SQLITE_DONE] means that the statement has finished executing 4280** successfully. sqlite3_step() should not be called again on this virtual 4281** machine without first calling [sqlite3_reset()] to reset the virtual 4282** machine back to its initial state. 4283** 4284** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4285** is returned each time a new row of data is ready for processing by the 4286** caller. The values may be accessed using the [column access functions]. 4287** sqlite3_step() is called again to retrieve the next row of data. 4288** 4289** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4290** violation) has occurred. sqlite3_step() should not be called again on 4291** the VM. More information may be found by calling [sqlite3_errmsg()]. 4292** ^With the legacy interface, a more specific error code (for example, 4293** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4294** can be obtained by calling [sqlite3_reset()] on the 4295** [prepared statement]. ^In the "v2" interface, 4296** the more specific error code is returned directly by sqlite3_step(). 4297** 4298** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4299** Perhaps it was called on a [prepared statement] that has 4300** already been [sqlite3_finalize | finalized] or on one that had 4301** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4302** be the case that the same database connection is being used by two or 4303** more threads at the same moment in time. 4304** 4305** For all versions of SQLite up to and including 3.6.23.1, a call to 4306** [sqlite3_reset()] was required after sqlite3_step() returned anything 4307** other than [SQLITE_ROW] before any subsequent invocation of 4308** sqlite3_step(). Failure to reset the prepared statement using 4309** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4310** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4311** sqlite3_step() began 4312** calling [sqlite3_reset()] automatically in this circumstance rather 4313** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4314** break because any application that ever receives an SQLITE_MISUSE error 4315** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4316** can be used to restore the legacy behavior. 4317** 4318** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4319** API always returns a generic error code, [SQLITE_ERROR], following any 4320** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4321** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4322** specific [error codes] that better describes the error. 4323** We admit that this is a goofy design. The problem has been fixed 4324** with the "v2" interface. If you prepare all of your SQL statements 4325** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4326** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4327** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4328** then the more specific [error codes] are returned directly 4329** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4330*/ 4331int sqlite3_step(sqlite3_stmt*); 4332 4333/* 4334** CAPI3REF: Number of columns in a result set 4335** METHOD: sqlite3_stmt 4336** 4337** ^The sqlite3_data_count(P) interface returns the number of columns in the 4338** current row of the result set of [prepared statement] P. 4339** ^If prepared statement P does not have results ready to return 4340** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4341** interfaces) then sqlite3_data_count(P) returns 0. 4342** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4343** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4344** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4345** will return non-zero if previous call to [sqlite3_step](P) returned 4346** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4347** where it always returns zero since each step of that multi-step 4348** pragma returns 0 columns of data. 4349** 4350** See also: [sqlite3_column_count()] 4351*/ 4352int sqlite3_data_count(sqlite3_stmt *pStmt); 4353 4354/* 4355** CAPI3REF: Fundamental Datatypes 4356** KEYWORDS: SQLITE_TEXT 4357** 4358** ^(Every value in SQLite has one of five fundamental datatypes: 4359** 4360** <ul> 4361** <li> 64-bit signed integer 4362** <li> 64-bit IEEE floating point number 4363** <li> string 4364** <li> BLOB 4365** <li> NULL 4366** </ul>)^ 4367** 4368** These constants are codes for each of those types. 4369** 4370** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4371** for a completely different meaning. Software that links against both 4372** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4373** SQLITE_TEXT. 4374*/ 4375#define SQLITE_INTEGER 1 4376#define SQLITE_FLOAT 2 4377#define SQLITE_BLOB 4 4378#define SQLITE_NULL 5 4379#ifdef SQLITE_TEXT 4380# undef SQLITE_TEXT 4381#else 4382# define SQLITE_TEXT 3 4383#endif 4384#define SQLITE3_TEXT 3 4385 4386/* 4387** CAPI3REF: Result Values From A Query 4388** KEYWORDS: {column access functions} 4389** METHOD: sqlite3_stmt 4390** 4391** <b>Summary:</b> 4392** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4393** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4394** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4395** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4396** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4397** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4398** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4399** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4400** [sqlite3_value|unprotected sqlite3_value] object. 4401** <tr><td> <td> <td> 4402** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4403** or a UTF-8 TEXT result in bytes 4404** <tr><td><b>sqlite3_column_bytes16 </b> 4405** <td>→ <td>Size of UTF-16 4406** TEXT in bytes 4407** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4408** datatype of the result 4409** </table></blockquote> 4410** 4411** <b>Details:</b> 4412** 4413** ^These routines return information about a single column of the current 4414** result row of a query. ^In every case the first argument is a pointer 4415** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4416** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4417** and the second argument is the index of the column for which information 4418** should be returned. ^The leftmost column of the result set has the index 0. 4419** ^The number of columns in the result can be determined using 4420** [sqlite3_column_count()]. 4421** 4422** If the SQL statement does not currently point to a valid row, or if the 4423** column index is out of range, the result is undefined. 4424** These routines may only be called when the most recent call to 4425** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4426** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4427** If any of these routines are called after [sqlite3_reset()] or 4428** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4429** something other than [SQLITE_ROW], the results are undefined. 4430** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4431** are called from a different thread while any of these routines 4432** are pending, then the results are undefined. 4433** 4434** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4435** each return the value of a result column in a specific data format. If 4436** the result column is not initially in the requested format (for example, 4437** if the query returns an integer but the sqlite3_column_text() interface 4438** is used to extract the value) then an automatic type conversion is performed. 4439** 4440** ^The sqlite3_column_type() routine returns the 4441** [SQLITE_INTEGER | datatype code] for the initial data type 4442** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4443** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4444** The return value of sqlite3_column_type() can be used to decide which 4445** of the first six interface should be used to extract the column value. 4446** The value returned by sqlite3_column_type() is only meaningful if no 4447** automatic type conversions have occurred for the value in question. 4448** After a type conversion, the result of calling sqlite3_column_type() 4449** is undefined, though harmless. Future 4450** versions of SQLite may change the behavior of sqlite3_column_type() 4451** following a type conversion. 4452** 4453** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4454** or sqlite3_column_bytes16() interfaces can be used to determine the size 4455** of that BLOB or string. 4456** 4457** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4458** routine returns the number of bytes in that BLOB or string. 4459** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4460** the string to UTF-8 and then returns the number of bytes. 4461** ^If the result is a numeric value then sqlite3_column_bytes() uses 4462** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4463** the number of bytes in that string. 4464** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4465** 4466** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4467** routine returns the number of bytes in that BLOB or string. 4468** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4469** the string to UTF-16 and then returns the number of bytes. 4470** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4471** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4472** the number of bytes in that string. 4473** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4474** 4475** ^The values returned by [sqlite3_column_bytes()] and 4476** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4477** of the string. ^For clarity: the values returned by 4478** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4479** bytes in the string, not the number of characters. 4480** 4481** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4482** even empty strings, are always zero-terminated. ^The return 4483** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4484** 4485** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4486** [unprotected sqlite3_value] object. In a multithreaded environment, 4487** an unprotected sqlite3_value object may only be used safely with 4488** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4489** If the [unprotected sqlite3_value] object returned by 4490** [sqlite3_column_value()] is used in any other way, including calls 4491** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4492** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4493** Hence, the sqlite3_column_value() interface 4494** is normally only useful within the implementation of 4495** [application-defined SQL functions] or [virtual tables], not within 4496** top-level application code. 4497** 4498** The these routines may attempt to convert the datatype of the result. 4499** ^For example, if the internal representation is FLOAT and a text result 4500** is requested, [sqlite3_snprintf()] is used internally to perform the 4501** conversion automatically. ^(The following table details the conversions 4502** that are applied: 4503** 4504** <blockquote> 4505** <table border="1"> 4506** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4507** 4508** <tr><td> NULL <td> INTEGER <td> Result is 0 4509** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4510** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4511** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4512** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4513** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4514** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4515** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4516** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4517** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4518** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4519** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4520** <tr><td> TEXT <td> BLOB <td> No change 4521** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4522** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4523** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4524** </table> 4525** </blockquote>)^ 4526** 4527** Note that when type conversions occur, pointers returned by prior 4528** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4529** sqlite3_column_text16() may be invalidated. 4530** Type conversions and pointer invalidations might occur 4531** in the following cases: 4532** 4533** <ul> 4534** <li> The initial content is a BLOB and sqlite3_column_text() or 4535** sqlite3_column_text16() is called. A zero-terminator might 4536** need to be added to the string.</li> 4537** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4538** sqlite3_column_text16() is called. The content must be converted 4539** to UTF-16.</li> 4540** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4541** sqlite3_column_text() is called. The content must be converted 4542** to UTF-8.</li> 4543** </ul> 4544** 4545** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4546** not invalidate a prior pointer, though of course the content of the buffer 4547** that the prior pointer references will have been modified. Other kinds 4548** of conversion are done in place when it is possible, but sometimes they 4549** are not possible and in those cases prior pointers are invalidated. 4550** 4551** The safest policy is to invoke these routines 4552** in one of the following ways: 4553** 4554** <ul> 4555** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4556** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4557** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4558** </ul> 4559** 4560** In other words, you should call sqlite3_column_text(), 4561** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4562** into the desired format, then invoke sqlite3_column_bytes() or 4563** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4564** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4565** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4566** with calls to sqlite3_column_bytes(). 4567** 4568** ^The pointers returned are valid until a type conversion occurs as 4569** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4570** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4571** and BLOBs is freed automatically. Do not pass the pointers returned 4572** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4573** [sqlite3_free()]. 4574** 4575** As long as the input parameters are correct, these routines will only 4576** fail if an out-of-memory error occurs during a format conversion. 4577** Only the following subset of interfaces are subject to out-of-memory 4578** errors: 4579** 4580** <ul> 4581** <li> sqlite3_column_blob() 4582** <li> sqlite3_column_text() 4583** <li> sqlite3_column_text16() 4584** <li> sqlite3_column_bytes() 4585** <li> sqlite3_column_bytes16() 4586** </ul> 4587** 4588** If an out-of-memory error occurs, then the return value from these 4589** routines is the same as if the column had contained an SQL NULL value. 4590** Valid SQL NULL returns can be distinguished from out-of-memory errors 4591** by invoking the [sqlite3_errcode()] immediately after the suspect 4592** return value is obtained and before any 4593** other SQLite interface is called on the same [database connection]. 4594*/ 4595const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4596double sqlite3_column_double(sqlite3_stmt*, int iCol); 4597int sqlite3_column_int(sqlite3_stmt*, int iCol); 4598sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4599const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4600const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4601sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4602int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4603int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4604int sqlite3_column_type(sqlite3_stmt*, int iCol); 4605 4606/* 4607** CAPI3REF: Destroy A Prepared Statement Object 4608** DESTRUCTOR: sqlite3_stmt 4609** 4610** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4611** ^If the most recent evaluation of the statement encountered no errors 4612** or if the statement is never been evaluated, then sqlite3_finalize() returns 4613** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4614** sqlite3_finalize(S) returns the appropriate [error code] or 4615** [extended error code]. 4616** 4617** ^The sqlite3_finalize(S) routine can be called at any point during 4618** the life cycle of [prepared statement] S: 4619** before statement S is ever evaluated, after 4620** one or more calls to [sqlite3_reset()], or after any call 4621** to [sqlite3_step()] regardless of whether or not the statement has 4622** completed execution. 4623** 4624** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4625** 4626** The application must finalize every [prepared statement] in order to avoid 4627** resource leaks. It is a grievous error for the application to try to use 4628** a prepared statement after it has been finalized. Any use of a prepared 4629** statement after it has been finalized can result in undefined and 4630** undesirable behavior such as segfaults and heap corruption. 4631*/ 4632int sqlite3_finalize(sqlite3_stmt *pStmt); 4633 4634/* 4635** CAPI3REF: Reset A Prepared Statement Object 4636** METHOD: sqlite3_stmt 4637** 4638** The sqlite3_reset() function is called to reset a [prepared statement] 4639** object back to its initial state, ready to be re-executed. 4640** ^Any SQL statement variables that had values bound to them using 4641** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4642** Use [sqlite3_clear_bindings()] to reset the bindings. 4643** 4644** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4645** back to the beginning of its program. 4646** 4647** ^If the most recent call to [sqlite3_step(S)] for the 4648** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4649** or if [sqlite3_step(S)] has never before been called on S, 4650** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4651** 4652** ^If the most recent call to [sqlite3_step(S)] for the 4653** [prepared statement] S indicated an error, then 4654** [sqlite3_reset(S)] returns an appropriate [error code]. 4655** 4656** ^The [sqlite3_reset(S)] interface does not change the values 4657** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4658*/ 4659int sqlite3_reset(sqlite3_stmt *pStmt); 4660 4661/* 4662** CAPI3REF: Create Or Redefine SQL Functions 4663** KEYWORDS: {function creation routines} 4664** KEYWORDS: {application-defined SQL function} 4665** KEYWORDS: {application-defined SQL functions} 4666** METHOD: sqlite3 4667** 4668** ^These functions (collectively known as "function creation routines") 4669** are used to add SQL functions or aggregates or to redefine the behavior 4670** of existing SQL functions or aggregates. The only differences between 4671** the three "sqlite3_create_function*" routines are the text encoding 4672** expected for the second parameter (the name of the function being 4673** created) and the presence or absence of a destructor callback for 4674** the application data pointer. Function sqlite3_create_window_function() 4675** is similar, but allows the user to supply the extra callback functions 4676** needed by [aggregate window functions]. 4677** 4678** ^The first parameter is the [database connection] to which the SQL 4679** function is to be added. ^If an application uses more than one database 4680** connection then application-defined SQL functions must be added 4681** to each database connection separately. 4682** 4683** ^The second parameter is the name of the SQL function to be created or 4684** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4685** representation, exclusive of the zero-terminator. ^Note that the name 4686** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4687** ^Any attempt to create a function with a longer name 4688** will result in [SQLITE_MISUSE] being returned. 4689** 4690** ^The third parameter (nArg) 4691** is the number of arguments that the SQL function or 4692** aggregate takes. ^If this parameter is -1, then the SQL function or 4693** aggregate may take any number of arguments between 0 and the limit 4694** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4695** parameter is less than -1 or greater than 127 then the behavior is 4696** undefined. 4697** 4698** ^The fourth parameter, eTextRep, specifies what 4699** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4700** its parameters. The application should set this parameter to 4701** [SQLITE_UTF16LE] if the function implementation invokes 4702** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4703** implementation invokes [sqlite3_value_text16be()] on an input, or 4704** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4705** otherwise. ^The same SQL function may be registered multiple times using 4706** different preferred text encodings, with different implementations for 4707** each encoding. 4708** ^When multiple implementations of the same function are available, SQLite 4709** will pick the one that involves the least amount of data conversion. 4710** 4711** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4712** to signal that the function will always return the same result given 4713** the same inputs within a single SQL statement. Most SQL functions are 4714** deterministic. The built-in [random()] SQL function is an example of a 4715** function that is not deterministic. The SQLite query planner is able to 4716** perform additional optimizations on deterministic functions, so use 4717** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4718** 4719** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4720** function can gain access to this pointer using [sqlite3_user_data()].)^ 4721** 4722** ^The sixth, seventh and eighth parameters passed to the three 4723** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4724** pointers to C-language functions that implement the SQL function or 4725** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4726** callback only; NULL pointers must be passed as the xStep and xFinal 4727** parameters. ^An aggregate SQL function requires an implementation of xStep 4728** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4729** SQL function or aggregate, pass NULL pointers for all three function 4730** callbacks. 4731** 4732** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4733** and xInverse) passed to sqlite3_create_window_function are pointers to 4734** C-lanugage callbacks that implement the new function. xStep and xFinal 4735** must both be non-NULL. xValue and xInverse may either both be NULL, in 4736** which case a regular aggregate function is created, or must both be 4737** non-NULL, in which case the new function may be used as either an aggregate 4738** or aggregate window function. More details regarding the implementation 4739** of aggregate window functions are 4740** [user-defined window functions|available here]. 4741** 4742** ^(If the final parameter to sqlite3_create_function_v2() or 4743** sqlite3_create_window_function() is not NULL, then it is destructor for 4744** the application data pointer. The destructor is invoked when the function 4745** is deleted, either by being overloaded or when the database connection 4746** closes.)^ ^The destructor is also invoked if the call to 4747** sqlite3_create_function_v2() fails. ^When the destructor callback is 4748** invoked, it is passed a single argument which is a copy of the application 4749** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4750** 4751** ^It is permitted to register multiple implementations of the same 4752** functions with the same name but with either differing numbers of 4753** arguments or differing preferred text encodings. ^SQLite will use 4754** the implementation that most closely matches the way in which the 4755** SQL function is used. ^A function implementation with a non-negative 4756** nArg parameter is a better match than a function implementation with 4757** a negative nArg. ^A function where the preferred text encoding 4758** matches the database encoding is a better 4759** match than a function where the encoding is different. 4760** ^A function where the encoding difference is between UTF16le and UTF16be 4761** is a closer match than a function where the encoding difference is 4762** between UTF8 and UTF16. 4763** 4764** ^Built-in functions may be overloaded by new application-defined functions. 4765** 4766** ^An application-defined function is permitted to call other 4767** SQLite interfaces. However, such calls must not 4768** close the database connection nor finalize or reset the prepared 4769** statement in which the function is running. 4770*/ 4771int sqlite3_create_function( 4772 sqlite3 *db, 4773 const char *zFunctionName, 4774 int nArg, 4775 int eTextRep, 4776 void *pApp, 4777 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4778 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4779 void (*xFinal)(sqlite3_context*) 4780); 4781int sqlite3_create_function16( 4782 sqlite3 *db, 4783 const void *zFunctionName, 4784 int nArg, 4785 int eTextRep, 4786 void *pApp, 4787 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4788 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4789 void (*xFinal)(sqlite3_context*) 4790); 4791int sqlite3_create_function_v2( 4792 sqlite3 *db, 4793 const char *zFunctionName, 4794 int nArg, 4795 int eTextRep, 4796 void *pApp, 4797 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4798 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4799 void (*xFinal)(sqlite3_context*), 4800 void(*xDestroy)(void*) 4801); 4802int sqlite3_create_window_function( 4803 sqlite3 *db, 4804 const char *zFunctionName, 4805 int nArg, 4806 int eTextRep, 4807 void *pApp, 4808 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4809 void (*xFinal)(sqlite3_context*), 4810 void (*xValue)(sqlite3_context*), 4811 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4812 void(*xDestroy)(void*) 4813); 4814 4815/* 4816** CAPI3REF: Text Encodings 4817** 4818** These constant define integer codes that represent the various 4819** text encodings supported by SQLite. 4820*/ 4821#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4822#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4823#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4824#define SQLITE_UTF16 4 /* Use native byte order */ 4825#define SQLITE_ANY 5 /* Deprecated */ 4826#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4827 4828/* 4829** CAPI3REF: Function Flags 4830** 4831** These constants may be ORed together with the 4832** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4833** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4834** [sqlite3_create_function_v2()]. 4835*/ 4836#define SQLITE_DETERMINISTIC 0x800 4837 4838/* 4839** CAPI3REF: Deprecated Functions 4840** DEPRECATED 4841** 4842** These functions are [deprecated]. In order to maintain 4843** backwards compatibility with older code, these functions continue 4844** to be supported. However, new applications should avoid 4845** the use of these functions. To encourage programmers to avoid 4846** these functions, we will not explain what they do. 4847*/ 4848#ifndef SQLITE_OMIT_DEPRECATED 4849SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4850SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4851SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4852SQLITE_DEPRECATED int sqlite3_global_recover(void); 4853SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4854SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4855 void*,sqlite3_int64); 4856#endif 4857 4858/* 4859** CAPI3REF: Obtaining SQL Values 4860** METHOD: sqlite3_value 4861** 4862** <b>Summary:</b> 4863** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4864** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 4865** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 4866** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 4867** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 4868** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 4869** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 4870** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 4871** the native byteorder 4872** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 4873** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 4874** <tr><td> <td> <td> 4875** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 4876** or a UTF-8 TEXT in bytes 4877** <tr><td><b>sqlite3_value_bytes16 </b> 4878** <td>→ <td>Size of UTF-16 4879** TEXT in bytes 4880** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 4881** datatype of the value 4882** <tr><td><b>sqlite3_value_numeric_type </b> 4883** <td>→ <td>Best numeric datatype of the value 4884** <tr><td><b>sqlite3_value_nochange </b> 4885** <td>→ <td>True if the column is unchanged in an UPDATE 4886** against a virtual table. 4887** </table></blockquote> 4888** 4889** <b>Details:</b> 4890** 4891** These routines extract type, size, and content information from 4892** [protected sqlite3_value] objects. Protected sqlite3_value objects 4893** are used to pass parameter information into implementation of 4894** [application-defined SQL functions] and [virtual tables]. 4895** 4896** These routines work only with [protected sqlite3_value] objects. 4897** Any attempt to use these routines on an [unprotected sqlite3_value] 4898** is not threadsafe. 4899** 4900** ^These routines work just like the corresponding [column access functions] 4901** except that these routines take a single [protected sqlite3_value] object 4902** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4903** 4904** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4905** in the native byte-order of the host machine. ^The 4906** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4907** extract UTF-16 strings as big-endian and little-endian respectively. 4908** 4909** ^If [sqlite3_value] object V was initialized 4910** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 4911** and if X and Y are strings that compare equal according to strcmp(X,Y), 4912** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 4913** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 4914** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 4915** 4916** ^(The sqlite3_value_type(V) interface returns the 4917** [SQLITE_INTEGER | datatype code] for the initial datatype of the 4918** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 4919** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 4920** Other interfaces might change the datatype for an sqlite3_value object. 4921** For example, if the datatype is initially SQLITE_INTEGER and 4922** sqlite3_value_text(V) is called to extract a text value for that 4923** integer, then subsequent calls to sqlite3_value_type(V) might return 4924** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 4925** occurs is undefined and may change from one release of SQLite to the next. 4926** 4927** ^(The sqlite3_value_numeric_type() interface attempts to apply 4928** numeric affinity to the value. This means that an attempt is 4929** made to convert the value to an integer or floating point. If 4930** such a conversion is possible without loss of information (in other 4931** words, if the value is a string that looks like a number) 4932** then the conversion is performed. Otherwise no conversion occurs. 4933** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4934** 4935** ^Within the [xUpdate] method of a [virtual table], the 4936** sqlite3_value_nochange(X) interface returns true if and only if 4937** the column corresponding to X is unchanged by the UPDATE operation 4938** that the xUpdate method call was invoked to implement and if 4939** and the prior [xColumn] method call that was invoked to extracted 4940** the value for that column returned without setting a result (probably 4941** because it queried [sqlite3_vtab_nochange()] and found that the column 4942** was unchanging). ^Within an [xUpdate] method, any value for which 4943** sqlite3_value_nochange(X) is true will in all other respects appear 4944** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 4945** than within an [xUpdate] method call for an UPDATE statement, then 4946** the return value is arbitrary and meaningless. 4947** 4948** Please pay particular attention to the fact that the pointer returned 4949** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4950** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4951** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4952** or [sqlite3_value_text16()]. 4953** 4954** These routines must be called from the same thread as 4955** the SQL function that supplied the [sqlite3_value*] parameters. 4956** 4957** As long as the input parameter is correct, these routines can only 4958** fail if an out-of-memory error occurs during a format conversion. 4959** Only the following subset of interfaces are subject to out-of-memory 4960** errors: 4961** 4962** <ul> 4963** <li> sqlite3_value_blob() 4964** <li> sqlite3_value_text() 4965** <li> sqlite3_value_text16() 4966** <li> sqlite3_value_text16le() 4967** <li> sqlite3_value_text16be() 4968** <li> sqlite3_value_bytes() 4969** <li> sqlite3_value_bytes16() 4970** </ul> 4971** 4972** If an out-of-memory error occurs, then the return value from these 4973** routines is the same as if the column had contained an SQL NULL value. 4974** Valid SQL NULL returns can be distinguished from out-of-memory errors 4975** by invoking the [sqlite3_errcode()] immediately after the suspect 4976** return value is obtained and before any 4977** other SQLite interface is called on the same [database connection]. 4978*/ 4979const void *sqlite3_value_blob(sqlite3_value*); 4980double sqlite3_value_double(sqlite3_value*); 4981int sqlite3_value_int(sqlite3_value*); 4982sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4983void *sqlite3_value_pointer(sqlite3_value*, const char*); 4984const unsigned char *sqlite3_value_text(sqlite3_value*); 4985const void *sqlite3_value_text16(sqlite3_value*); 4986const void *sqlite3_value_text16le(sqlite3_value*); 4987const void *sqlite3_value_text16be(sqlite3_value*); 4988int sqlite3_value_bytes(sqlite3_value*); 4989int sqlite3_value_bytes16(sqlite3_value*); 4990int sqlite3_value_type(sqlite3_value*); 4991int sqlite3_value_numeric_type(sqlite3_value*); 4992int sqlite3_value_nochange(sqlite3_value*); 4993 4994/* 4995** CAPI3REF: Finding The Subtype Of SQL Values 4996** METHOD: sqlite3_value 4997** 4998** The sqlite3_value_subtype(V) function returns the subtype for 4999** an [application-defined SQL function] argument V. The subtype 5000** information can be used to pass a limited amount of context from 5001** one SQL function to another. Use the [sqlite3_result_subtype()] 5002** routine to set the subtype for the return value of an SQL function. 5003*/ 5004unsigned int sqlite3_value_subtype(sqlite3_value*); 5005 5006/* 5007** CAPI3REF: Copy And Free SQL Values 5008** METHOD: sqlite3_value 5009** 5010** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5011** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5012** is a [protected sqlite3_value] object even if the input is not. 5013** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5014** memory allocation fails. 5015** 5016** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5017** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5018** then sqlite3_value_free(V) is a harmless no-op. 5019*/ 5020sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5021void sqlite3_value_free(sqlite3_value*); 5022 5023/* 5024** CAPI3REF: Obtain Aggregate Function Context 5025** METHOD: sqlite3_context 5026** 5027** Implementations of aggregate SQL functions use this 5028** routine to allocate memory for storing their state. 5029** 5030** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5031** for a particular aggregate function, SQLite 5032** allocates N of memory, zeroes out that memory, and returns a pointer 5033** to the new memory. ^On second and subsequent calls to 5034** sqlite3_aggregate_context() for the same aggregate function instance, 5035** the same buffer is returned. Sqlite3_aggregate_context() is normally 5036** called once for each invocation of the xStep callback and then one 5037** last time when the xFinal callback is invoked. ^(When no rows match 5038** an aggregate query, the xStep() callback of the aggregate function 5039** implementation is never called and xFinal() is called exactly once. 5040** In those cases, sqlite3_aggregate_context() might be called for the 5041** first time from within xFinal().)^ 5042** 5043** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5044** when first called if N is less than or equal to zero or if a memory 5045** allocate error occurs. 5046** 5047** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5048** determined by the N parameter on first successful call. Changing the 5049** value of N in subsequent call to sqlite3_aggregate_context() within 5050** the same aggregate function instance will not resize the memory 5051** allocation.)^ Within the xFinal callback, it is customary to set 5052** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5053** pointless memory allocations occur. 5054** 5055** ^SQLite automatically frees the memory allocated by 5056** sqlite3_aggregate_context() when the aggregate query concludes. 5057** 5058** The first parameter must be a copy of the 5059** [sqlite3_context | SQL function context] that is the first parameter 5060** to the xStep or xFinal callback routine that implements the aggregate 5061** function. 5062** 5063** This routine must be called from the same thread in which 5064** the aggregate SQL function is running. 5065*/ 5066void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5067 5068/* 5069** CAPI3REF: User Data For Functions 5070** METHOD: sqlite3_context 5071** 5072** ^The sqlite3_user_data() interface returns a copy of 5073** the pointer that was the pUserData parameter (the 5th parameter) 5074** of the [sqlite3_create_function()] 5075** and [sqlite3_create_function16()] routines that originally 5076** registered the application defined function. 5077** 5078** This routine must be called from the same thread in which 5079** the application-defined function is running. 5080*/ 5081void *sqlite3_user_data(sqlite3_context*); 5082 5083/* 5084** CAPI3REF: Database Connection For Functions 5085** METHOD: sqlite3_context 5086** 5087** ^The sqlite3_context_db_handle() interface returns a copy of 5088** the pointer to the [database connection] (the 1st parameter) 5089** of the [sqlite3_create_function()] 5090** and [sqlite3_create_function16()] routines that originally 5091** registered the application defined function. 5092*/ 5093sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5094 5095/* 5096** CAPI3REF: Function Auxiliary Data 5097** METHOD: sqlite3_context 5098** 5099** These functions may be used by (non-aggregate) SQL functions to 5100** associate metadata with argument values. If the same value is passed to 5101** multiple invocations of the same SQL function during query execution, under 5102** some circumstances the associated metadata may be preserved. An example 5103** of where this might be useful is in a regular-expression matching 5104** function. The compiled version of the regular expression can be stored as 5105** metadata associated with the pattern string. 5106** Then as long as the pattern string remains the same, 5107** the compiled regular expression can be reused on multiple 5108** invocations of the same function. 5109** 5110** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5111** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5112** value to the application-defined function. ^N is zero for the left-most 5113** function argument. ^If there is no metadata 5114** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5115** returns a NULL pointer. 5116** 5117** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5118** argument of the application-defined function. ^Subsequent 5119** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5120** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5121** NULL if the metadata has been discarded. 5122** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5123** SQLite will invoke the destructor function X with parameter P exactly 5124** once, when the metadata is discarded. 5125** SQLite is free to discard the metadata at any time, including: <ul> 5126** <li> ^(when the corresponding function parameter changes)^, or 5127** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5128** SQL statement)^, or 5129** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5130** parameter)^, or 5131** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5132** allocation error occurs.)^ </ul> 5133** 5134** Note the last bullet in particular. The destructor X in 5135** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5136** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5137** should be called near the end of the function implementation and the 5138** function implementation should not make any use of P after 5139** sqlite3_set_auxdata() has been called. 5140** 5141** ^(In practice, metadata is preserved between function calls for 5142** function parameters that are compile-time constants, including literal 5143** values and [parameters] and expressions composed from the same.)^ 5144** 5145** The value of the N parameter to these interfaces should be non-negative. 5146** Future enhancements may make use of negative N values to define new 5147** kinds of function caching behavior. 5148** 5149** These routines must be called from the same thread in which 5150** the SQL function is running. 5151*/ 5152void *sqlite3_get_auxdata(sqlite3_context*, int N); 5153void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5154 5155 5156/* 5157** CAPI3REF: Constants Defining Special Destructor Behavior 5158** 5159** These are special values for the destructor that is passed in as the 5160** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5161** argument is SQLITE_STATIC, it means that the content pointer is constant 5162** and will never change. It does not need to be destroyed. ^The 5163** SQLITE_TRANSIENT value means that the content will likely change in 5164** the near future and that SQLite should make its own private copy of 5165** the content before returning. 5166** 5167** The typedef is necessary to work around problems in certain 5168** C++ compilers. 5169*/ 5170typedef void (*sqlite3_destructor_type)(void*); 5171#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5172#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5173 5174/* 5175** CAPI3REF: Setting The Result Of An SQL Function 5176** METHOD: sqlite3_context 5177** 5178** These routines are used by the xFunc or xFinal callbacks that 5179** implement SQL functions and aggregates. See 5180** [sqlite3_create_function()] and [sqlite3_create_function16()] 5181** for additional information. 5182** 5183** These functions work very much like the [parameter binding] family of 5184** functions used to bind values to host parameters in prepared statements. 5185** Refer to the [SQL parameter] documentation for additional information. 5186** 5187** ^The sqlite3_result_blob() interface sets the result from 5188** an application-defined function to be the BLOB whose content is pointed 5189** to by the second parameter and which is N bytes long where N is the 5190** third parameter. 5191** 5192** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5193** interfaces set the result of the application-defined function to be 5194** a BLOB containing all zero bytes and N bytes in size. 5195** 5196** ^The sqlite3_result_double() interface sets the result from 5197** an application-defined function to be a floating point value specified 5198** by its 2nd argument. 5199** 5200** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5201** cause the implemented SQL function to throw an exception. 5202** ^SQLite uses the string pointed to by the 5203** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5204** as the text of an error message. ^SQLite interprets the error 5205** message string from sqlite3_result_error() as UTF-8. ^SQLite 5206** interprets the string from sqlite3_result_error16() as UTF-16 in native 5207** byte order. ^If the third parameter to sqlite3_result_error() 5208** or sqlite3_result_error16() is negative then SQLite takes as the error 5209** message all text up through the first zero character. 5210** ^If the third parameter to sqlite3_result_error() or 5211** sqlite3_result_error16() is non-negative then SQLite takes that many 5212** bytes (not characters) from the 2nd parameter as the error message. 5213** ^The sqlite3_result_error() and sqlite3_result_error16() 5214** routines make a private copy of the error message text before 5215** they return. Hence, the calling function can deallocate or 5216** modify the text after they return without harm. 5217** ^The sqlite3_result_error_code() function changes the error code 5218** returned by SQLite as a result of an error in a function. ^By default, 5219** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5220** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5221** 5222** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5223** error indicating that a string or BLOB is too long to represent. 5224** 5225** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5226** error indicating that a memory allocation failed. 5227** 5228** ^The sqlite3_result_int() interface sets the return value 5229** of the application-defined function to be the 32-bit signed integer 5230** value given in the 2nd argument. 5231** ^The sqlite3_result_int64() interface sets the return value 5232** of the application-defined function to be the 64-bit signed integer 5233** value given in the 2nd argument. 5234** 5235** ^The sqlite3_result_null() interface sets the return value 5236** of the application-defined function to be NULL. 5237** 5238** ^The sqlite3_result_text(), sqlite3_result_text16(), 5239** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5240** set the return value of the application-defined function to be 5241** a text string which is represented as UTF-8, UTF-16 native byte order, 5242** UTF-16 little endian, or UTF-16 big endian, respectively. 5243** ^The sqlite3_result_text64() interface sets the return value of an 5244** application-defined function to be a text string in an encoding 5245** specified by the fifth (and last) parameter, which must be one 5246** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5247** ^SQLite takes the text result from the application from 5248** the 2nd parameter of the sqlite3_result_text* interfaces. 5249** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5250** is negative, then SQLite takes result text from the 2nd parameter 5251** through the first zero character. 5252** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5253** is non-negative, then as many bytes (not characters) of the text 5254** pointed to by the 2nd parameter are taken as the application-defined 5255** function result. If the 3rd parameter is non-negative, then it 5256** must be the byte offset into the string where the NUL terminator would 5257** appear if the string where NUL terminated. If any NUL characters occur 5258** in the string at a byte offset that is less than the value of the 3rd 5259** parameter, then the resulting string will contain embedded NULs and the 5260** result of expressions operating on strings with embedded NULs is undefined. 5261** ^If the 4th parameter to the sqlite3_result_text* interfaces 5262** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5263** function as the destructor on the text or BLOB result when it has 5264** finished using that result. 5265** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5266** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5267** assumes that the text or BLOB result is in constant space and does not 5268** copy the content of the parameter nor call a destructor on the content 5269** when it has finished using that result. 5270** ^If the 4th parameter to the sqlite3_result_text* interfaces 5271** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5272** then SQLite makes a copy of the result into space obtained 5273** from [sqlite3_malloc()] before it returns. 5274** 5275** ^The sqlite3_result_value() interface sets the result of 5276** the application-defined function to be a copy of the 5277** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5278** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5279** so that the [sqlite3_value] specified in the parameter may change or 5280** be deallocated after sqlite3_result_value() returns without harm. 5281** ^A [protected sqlite3_value] object may always be used where an 5282** [unprotected sqlite3_value] object is required, so either 5283** kind of [sqlite3_value] object can be used with this interface. 5284** 5285** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5286** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5287** also associates the host-language pointer P or type T with that 5288** NULL value such that the pointer can be retrieved within an 5289** [application-defined SQL function] using [sqlite3_value_pointer()]. 5290** ^If the D parameter is not NULL, then it is a pointer to a destructor 5291** for the P parameter. ^SQLite invokes D with P as its only argument 5292** when SQLite is finished with P. The T parameter should be a static 5293** string and preferably a string literal. The sqlite3_result_pointer() 5294** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5295** 5296** If these routines are called from within the different thread 5297** than the one containing the application-defined function that received 5298** the [sqlite3_context] pointer, the results are undefined. 5299*/ 5300void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5301void sqlite3_result_blob64(sqlite3_context*,const void*, 5302 sqlite3_uint64,void(*)(void*)); 5303void sqlite3_result_double(sqlite3_context*, double); 5304void sqlite3_result_error(sqlite3_context*, const char*, int); 5305void sqlite3_result_error16(sqlite3_context*, const void*, int); 5306void sqlite3_result_error_toobig(sqlite3_context*); 5307void sqlite3_result_error_nomem(sqlite3_context*); 5308void sqlite3_result_error_code(sqlite3_context*, int); 5309void sqlite3_result_int(sqlite3_context*, int); 5310void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5311void sqlite3_result_null(sqlite3_context*); 5312void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5313void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5314 void(*)(void*), unsigned char encoding); 5315void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5316void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5317void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5318void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5319void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5320void sqlite3_result_zeroblob(sqlite3_context*, int n); 5321int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5322 5323 5324/* 5325** CAPI3REF: Setting The Subtype Of An SQL Function 5326** METHOD: sqlite3_context 5327** 5328** The sqlite3_result_subtype(C,T) function causes the subtype of 5329** the result from the [application-defined SQL function] with 5330** [sqlite3_context] C to be the value T. Only the lower 8 bits 5331** of the subtype T are preserved in current versions of SQLite; 5332** higher order bits are discarded. 5333** The number of subtype bytes preserved by SQLite might increase 5334** in future releases of SQLite. 5335*/ 5336void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5337 5338/* 5339** CAPI3REF: Define New Collating Sequences 5340** METHOD: sqlite3 5341** 5342** ^These functions add, remove, or modify a [collation] associated 5343** with the [database connection] specified as the first argument. 5344** 5345** ^The name of the collation is a UTF-8 string 5346** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5347** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5348** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5349** considered to be the same name. 5350** 5351** ^(The third argument (eTextRep) must be one of the constants: 5352** <ul> 5353** <li> [SQLITE_UTF8], 5354** <li> [SQLITE_UTF16LE], 5355** <li> [SQLITE_UTF16BE], 5356** <li> [SQLITE_UTF16], or 5357** <li> [SQLITE_UTF16_ALIGNED]. 5358** </ul>)^ 5359** ^The eTextRep argument determines the encoding of strings passed 5360** to the collating function callback, xCallback. 5361** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5362** force strings to be UTF16 with native byte order. 5363** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5364** on an even byte address. 5365** 5366** ^The fourth argument, pArg, is an application data pointer that is passed 5367** through as the first argument to the collating function callback. 5368** 5369** ^The fifth argument, xCallback, is a pointer to the collating function. 5370** ^Multiple collating functions can be registered using the same name but 5371** with different eTextRep parameters and SQLite will use whichever 5372** function requires the least amount of data transformation. 5373** ^If the xCallback argument is NULL then the collating function is 5374** deleted. ^When all collating functions having the same name are deleted, 5375** that collation is no longer usable. 5376** 5377** ^The collating function callback is invoked with a copy of the pArg 5378** application data pointer and with two strings in the encoding specified 5379** by the eTextRep argument. The collating function must return an 5380** integer that is negative, zero, or positive 5381** if the first string is less than, equal to, or greater than the second, 5382** respectively. A collating function must always return the same answer 5383** given the same inputs. If two or more collating functions are registered 5384** to the same collation name (using different eTextRep values) then all 5385** must give an equivalent answer when invoked with equivalent strings. 5386** The collating function must obey the following properties for all 5387** strings A, B, and C: 5388** 5389** <ol> 5390** <li> If A==B then B==A. 5391** <li> If A==B and B==C then A==C. 5392** <li> If A<B THEN B>A. 5393** <li> If A<B and B<C then A<C. 5394** </ol> 5395** 5396** If a collating function fails any of the above constraints and that 5397** collating function is registered and used, then the behavior of SQLite 5398** is undefined. 5399** 5400** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5401** with the addition that the xDestroy callback is invoked on pArg when 5402** the collating function is deleted. 5403** ^Collating functions are deleted when they are overridden by later 5404** calls to the collation creation functions or when the 5405** [database connection] is closed using [sqlite3_close()]. 5406** 5407** ^The xDestroy callback is <u>not</u> called if the 5408** sqlite3_create_collation_v2() function fails. Applications that invoke 5409** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5410** check the return code and dispose of the application data pointer 5411** themselves rather than expecting SQLite to deal with it for them. 5412** This is different from every other SQLite interface. The inconsistency 5413** is unfortunate but cannot be changed without breaking backwards 5414** compatibility. 5415** 5416** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5417*/ 5418int sqlite3_create_collation( 5419 sqlite3*, 5420 const char *zName, 5421 int eTextRep, 5422 void *pArg, 5423 int(*xCompare)(void*,int,const void*,int,const void*) 5424); 5425int sqlite3_create_collation_v2( 5426 sqlite3*, 5427 const char *zName, 5428 int eTextRep, 5429 void *pArg, 5430 int(*xCompare)(void*,int,const void*,int,const void*), 5431 void(*xDestroy)(void*) 5432); 5433int sqlite3_create_collation16( 5434 sqlite3*, 5435 const void *zName, 5436 int eTextRep, 5437 void *pArg, 5438 int(*xCompare)(void*,int,const void*,int,const void*) 5439); 5440 5441/* 5442** CAPI3REF: Collation Needed Callbacks 5443** METHOD: sqlite3 5444** 5445** ^To avoid having to register all collation sequences before a database 5446** can be used, a single callback function may be registered with the 5447** [database connection] to be invoked whenever an undefined collation 5448** sequence is required. 5449** 5450** ^If the function is registered using the sqlite3_collation_needed() API, 5451** then it is passed the names of undefined collation sequences as strings 5452** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5453** the names are passed as UTF-16 in machine native byte order. 5454** ^A call to either function replaces the existing collation-needed callback. 5455** 5456** ^(When the callback is invoked, the first argument passed is a copy 5457** of the second argument to sqlite3_collation_needed() or 5458** sqlite3_collation_needed16(). The second argument is the database 5459** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5460** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5461** sequence function required. The fourth parameter is the name of the 5462** required collation sequence.)^ 5463** 5464** The callback function should register the desired collation using 5465** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5466** [sqlite3_create_collation_v2()]. 5467*/ 5468int sqlite3_collation_needed( 5469 sqlite3*, 5470 void*, 5471 void(*)(void*,sqlite3*,int eTextRep,const char*) 5472); 5473int sqlite3_collation_needed16( 5474 sqlite3*, 5475 void*, 5476 void(*)(void*,sqlite3*,int eTextRep,const void*) 5477); 5478 5479#ifdef SQLITE_HAS_CODEC 5480/* 5481** Specify the key for an encrypted database. This routine should be 5482** called right after sqlite3_open(). 5483** 5484** The code to implement this API is not available in the public release 5485** of SQLite. 5486*/ 5487int sqlite3_key( 5488 sqlite3 *db, /* Database to be rekeyed */ 5489 const void *pKey, int nKey /* The key */ 5490); 5491int sqlite3_key_v2( 5492 sqlite3 *db, /* Database to be rekeyed */ 5493 const char *zDbName, /* Name of the database */ 5494 const void *pKey, int nKey /* The key */ 5495); 5496 5497/* 5498** Change the key on an open database. If the current database is not 5499** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5500** database is decrypted. 5501** 5502** The code to implement this API is not available in the public release 5503** of SQLite. 5504*/ 5505int sqlite3_rekey( 5506 sqlite3 *db, /* Database to be rekeyed */ 5507 const void *pKey, int nKey /* The new key */ 5508); 5509int sqlite3_rekey_v2( 5510 sqlite3 *db, /* Database to be rekeyed */ 5511 const char *zDbName, /* Name of the database */ 5512 const void *pKey, int nKey /* The new key */ 5513); 5514 5515/* 5516** Specify the activation key for a SEE database. Unless 5517** activated, none of the SEE routines will work. 5518*/ 5519void sqlite3_activate_see( 5520 const char *zPassPhrase /* Activation phrase */ 5521); 5522#endif 5523 5524#ifdef SQLITE_ENABLE_CEROD 5525/* 5526** Specify the activation key for a CEROD database. Unless 5527** activated, none of the CEROD routines will work. 5528*/ 5529void sqlite3_activate_cerod( 5530 const char *zPassPhrase /* Activation phrase */ 5531); 5532#endif 5533 5534/* 5535** CAPI3REF: Suspend Execution For A Short Time 5536** 5537** The sqlite3_sleep() function causes the current thread to suspend execution 5538** for at least a number of milliseconds specified in its parameter. 5539** 5540** If the operating system does not support sleep requests with 5541** millisecond time resolution, then the time will be rounded up to 5542** the nearest second. The number of milliseconds of sleep actually 5543** requested from the operating system is returned. 5544** 5545** ^SQLite implements this interface by calling the xSleep() 5546** method of the default [sqlite3_vfs] object. If the xSleep() method 5547** of the default VFS is not implemented correctly, or not implemented at 5548** all, then the behavior of sqlite3_sleep() may deviate from the description 5549** in the previous paragraphs. 5550*/ 5551int sqlite3_sleep(int); 5552 5553/* 5554** CAPI3REF: Name Of The Folder Holding Temporary Files 5555** 5556** ^(If this global variable is made to point to a string which is 5557** the name of a folder (a.k.a. directory), then all temporary files 5558** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5559** will be placed in that directory.)^ ^If this variable 5560** is a NULL pointer, then SQLite performs a search for an appropriate 5561** temporary file directory. 5562** 5563** Applications are strongly discouraged from using this global variable. 5564** It is required to set a temporary folder on Windows Runtime (WinRT). 5565** But for all other platforms, it is highly recommended that applications 5566** neither read nor write this variable. This global variable is a relic 5567** that exists for backwards compatibility of legacy applications and should 5568** be avoided in new projects. 5569** 5570** It is not safe to read or modify this variable in more than one 5571** thread at a time. It is not safe to read or modify this variable 5572** if a [database connection] is being used at the same time in a separate 5573** thread. 5574** It is intended that this variable be set once 5575** as part of process initialization and before any SQLite interface 5576** routines have been called and that this variable remain unchanged 5577** thereafter. 5578** 5579** ^The [temp_store_directory pragma] may modify this variable and cause 5580** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5581** the [temp_store_directory pragma] always assumes that any string 5582** that this variable points to is held in memory obtained from 5583** [sqlite3_malloc] and the pragma may attempt to free that memory 5584** using [sqlite3_free]. 5585** Hence, if this variable is modified directly, either it should be 5586** made NULL or made to point to memory obtained from [sqlite3_malloc] 5587** or else the use of the [temp_store_directory pragma] should be avoided. 5588** Except when requested by the [temp_store_directory pragma], SQLite 5589** does not free the memory that sqlite3_temp_directory points to. If 5590** the application wants that memory to be freed, it must do 5591** so itself, taking care to only do so after all [database connection] 5592** objects have been destroyed. 5593** 5594** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5595** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5596** features that require the use of temporary files may fail. Here is an 5597** example of how to do this using C++ with the Windows Runtime: 5598** 5599** <blockquote><pre> 5600** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5601** TemporaryFolder->Path->Data(); 5602** char zPathBuf[MAX_PATH + 1]; 5603** memset(zPathBuf, 0, sizeof(zPathBuf)); 5604** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5605** NULL, NULL); 5606** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5607** </pre></blockquote> 5608*/ 5609SQLITE_EXTERN char *sqlite3_temp_directory; 5610 5611/* 5612** CAPI3REF: Name Of The Folder Holding Database Files 5613** 5614** ^(If this global variable is made to point to a string which is 5615** the name of a folder (a.k.a. directory), then all database files 5616** specified with a relative pathname and created or accessed by 5617** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5618** to be relative to that directory.)^ ^If this variable is a NULL 5619** pointer, then SQLite assumes that all database files specified 5620** with a relative pathname are relative to the current directory 5621** for the process. Only the windows VFS makes use of this global 5622** variable; it is ignored by the unix VFS. 5623** 5624** Changing the value of this variable while a database connection is 5625** open can result in a corrupt database. 5626** 5627** It is not safe to read or modify this variable in more than one 5628** thread at a time. It is not safe to read or modify this variable 5629** if a [database connection] is being used at the same time in a separate 5630** thread. 5631** It is intended that this variable be set once 5632** as part of process initialization and before any SQLite interface 5633** routines have been called and that this variable remain unchanged 5634** thereafter. 5635** 5636** ^The [data_store_directory pragma] may modify this variable and cause 5637** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5638** the [data_store_directory pragma] always assumes that any string 5639** that this variable points to is held in memory obtained from 5640** [sqlite3_malloc] and the pragma may attempt to free that memory 5641** using [sqlite3_free]. 5642** Hence, if this variable is modified directly, either it should be 5643** made NULL or made to point to memory obtained from [sqlite3_malloc] 5644** or else the use of the [data_store_directory pragma] should be avoided. 5645*/ 5646SQLITE_EXTERN char *sqlite3_data_directory; 5647 5648/* 5649** CAPI3REF: Win32 Specific Interface 5650** 5651** These interfaces are available only on Windows. The 5652** [sqlite3_win32_set_directory] interface is used to set the value associated 5653** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5654** zValue, depending on the value of the type parameter. The zValue parameter 5655** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5656** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5657** prior to being used. The [sqlite3_win32_set_directory] interface returns 5658** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5659** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5660** [sqlite3_data_directory] variable is intended to act as a replacement for 5661** the current directory on the sub-platforms of Win32 where that concept is 5662** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5663** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5664** sqlite3_win32_set_directory interface except the string parameter must be 5665** UTF-8 or UTF-16, respectively. 5666*/ 5667int sqlite3_win32_set_directory( 5668 unsigned long type, /* Identifier for directory being set or reset */ 5669 void *zValue /* New value for directory being set or reset */ 5670); 5671int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5672int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5673 5674/* 5675** CAPI3REF: Win32 Directory Types 5676** 5677** These macros are only available on Windows. They define the allowed values 5678** for the type argument to the [sqlite3_win32_set_directory] interface. 5679*/ 5680#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5681#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5682 5683/* 5684** CAPI3REF: Test For Auto-Commit Mode 5685** KEYWORDS: {autocommit mode} 5686** METHOD: sqlite3 5687** 5688** ^The sqlite3_get_autocommit() interface returns non-zero or 5689** zero if the given database connection is or is not in autocommit mode, 5690** respectively. ^Autocommit mode is on by default. 5691** ^Autocommit mode is disabled by a [BEGIN] statement. 5692** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5693** 5694** If certain kinds of errors occur on a statement within a multi-statement 5695** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5696** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5697** transaction might be rolled back automatically. The only way to 5698** find out whether SQLite automatically rolled back the transaction after 5699** an error is to use this function. 5700** 5701** If another thread changes the autocommit status of the database 5702** connection while this routine is running, then the return value 5703** is undefined. 5704*/ 5705int sqlite3_get_autocommit(sqlite3*); 5706 5707/* 5708** CAPI3REF: Find The Database Handle Of A Prepared Statement 5709** METHOD: sqlite3_stmt 5710** 5711** ^The sqlite3_db_handle interface returns the [database connection] handle 5712** to which a [prepared statement] belongs. ^The [database connection] 5713** returned by sqlite3_db_handle is the same [database connection] 5714** that was the first argument 5715** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5716** create the statement in the first place. 5717*/ 5718sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5719 5720/* 5721** CAPI3REF: Return The Filename For A Database Connection 5722** METHOD: sqlite3 5723** 5724** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5725** associated with database N of connection D. ^The main database file 5726** has the name "main". If there is no attached database N on the database 5727** connection D, or if database N is a temporary or in-memory database, then 5728** a NULL pointer is returned. 5729** 5730** ^The filename returned by this function is the output of the 5731** xFullPathname method of the [VFS]. ^In other words, the filename 5732** will be an absolute pathname, even if the filename used 5733** to open the database originally was a URI or relative pathname. 5734*/ 5735const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5736 5737/* 5738** CAPI3REF: Determine if a database is read-only 5739** METHOD: sqlite3 5740** 5741** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5742** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5743** the name of a database on connection D. 5744*/ 5745int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5746 5747/* 5748** CAPI3REF: Find the next prepared statement 5749** METHOD: sqlite3 5750** 5751** ^This interface returns a pointer to the next [prepared statement] after 5752** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5753** then this interface returns a pointer to the first prepared statement 5754** associated with the database connection pDb. ^If no prepared statement 5755** satisfies the conditions of this routine, it returns NULL. 5756** 5757** The [database connection] pointer D in a call to 5758** [sqlite3_next_stmt(D,S)] must refer to an open database 5759** connection and in particular must not be a NULL pointer. 5760*/ 5761sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5762 5763/* 5764** CAPI3REF: Commit And Rollback Notification Callbacks 5765** METHOD: sqlite3 5766** 5767** ^The sqlite3_commit_hook() interface registers a callback 5768** function to be invoked whenever a transaction is [COMMIT | committed]. 5769** ^Any callback set by a previous call to sqlite3_commit_hook() 5770** for the same database connection is overridden. 5771** ^The sqlite3_rollback_hook() interface registers a callback 5772** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5773** ^Any callback set by a previous call to sqlite3_rollback_hook() 5774** for the same database connection is overridden. 5775** ^The pArg argument is passed through to the callback. 5776** ^If the callback on a commit hook function returns non-zero, 5777** then the commit is converted into a rollback. 5778** 5779** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5780** return the P argument from the previous call of the same function 5781** on the same [database connection] D, or NULL for 5782** the first call for each function on D. 5783** 5784** The commit and rollback hook callbacks are not reentrant. 5785** The callback implementation must not do anything that will modify 5786** the database connection that invoked the callback. Any actions 5787** to modify the database connection must be deferred until after the 5788** completion of the [sqlite3_step()] call that triggered the commit 5789** or rollback hook in the first place. 5790** Note that running any other SQL statements, including SELECT statements, 5791** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5792** the database connections for the meaning of "modify" in this paragraph. 5793** 5794** ^Registering a NULL function disables the callback. 5795** 5796** ^When the commit hook callback routine returns zero, the [COMMIT] 5797** operation is allowed to continue normally. ^If the commit hook 5798** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5799** ^The rollback hook is invoked on a rollback that results from a commit 5800** hook returning non-zero, just as it would be with any other rollback. 5801** 5802** ^For the purposes of this API, a transaction is said to have been 5803** rolled back if an explicit "ROLLBACK" statement is executed, or 5804** an error or constraint causes an implicit rollback to occur. 5805** ^The rollback callback is not invoked if a transaction is 5806** automatically rolled back because the database connection is closed. 5807** 5808** See also the [sqlite3_update_hook()] interface. 5809*/ 5810void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5811void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5812 5813/* 5814** CAPI3REF: Data Change Notification Callbacks 5815** METHOD: sqlite3 5816** 5817** ^The sqlite3_update_hook() interface registers a callback function 5818** with the [database connection] identified by the first argument 5819** to be invoked whenever a row is updated, inserted or deleted in 5820** a [rowid table]. 5821** ^Any callback set by a previous call to this function 5822** for the same database connection is overridden. 5823** 5824** ^The second argument is a pointer to the function to invoke when a 5825** row is updated, inserted or deleted in a rowid table. 5826** ^The first argument to the callback is a copy of the third argument 5827** to sqlite3_update_hook(). 5828** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5829** or [SQLITE_UPDATE], depending on the operation that caused the callback 5830** to be invoked. 5831** ^The third and fourth arguments to the callback contain pointers to the 5832** database and table name containing the affected row. 5833** ^The final callback parameter is the [rowid] of the row. 5834** ^In the case of an update, this is the [rowid] after the update takes place. 5835** 5836** ^(The update hook is not invoked when internal system tables are 5837** modified (i.e. sqlite_master and sqlite_sequence).)^ 5838** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5839** 5840** ^In the current implementation, the update hook 5841** is not invoked when conflicting rows are deleted because of an 5842** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5843** invoked when rows are deleted using the [truncate optimization]. 5844** The exceptions defined in this paragraph might change in a future 5845** release of SQLite. 5846** 5847** The update hook implementation must not do anything that will modify 5848** the database connection that invoked the update hook. Any actions 5849** to modify the database connection must be deferred until after the 5850** completion of the [sqlite3_step()] call that triggered the update hook. 5851** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5852** database connections for the meaning of "modify" in this paragraph. 5853** 5854** ^The sqlite3_update_hook(D,C,P) function 5855** returns the P argument from the previous call 5856** on the same [database connection] D, or NULL for 5857** the first call on D. 5858** 5859** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5860** and [sqlite3_preupdate_hook()] interfaces. 5861*/ 5862void *sqlite3_update_hook( 5863 sqlite3*, 5864 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5865 void* 5866); 5867 5868/* 5869** CAPI3REF: Enable Or Disable Shared Pager Cache 5870** 5871** ^(This routine enables or disables the sharing of the database cache 5872** and schema data structures between [database connection | connections] 5873** to the same database. Sharing is enabled if the argument is true 5874** and disabled if the argument is false.)^ 5875** 5876** ^Cache sharing is enabled and disabled for an entire process. 5877** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5878** In prior versions of SQLite, 5879** sharing was enabled or disabled for each thread separately. 5880** 5881** ^(The cache sharing mode set by this interface effects all subsequent 5882** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5883** Existing database connections continue use the sharing mode 5884** that was in effect at the time they were opened.)^ 5885** 5886** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5887** successfully. An [error code] is returned otherwise.)^ 5888** 5889** ^Shared cache is disabled by default. But this might change in 5890** future releases of SQLite. Applications that care about shared 5891** cache setting should set it explicitly. 5892** 5893** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5894** and will always return SQLITE_MISUSE. On those systems, 5895** shared cache mode should be enabled per-database connection via 5896** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5897** 5898** This interface is threadsafe on processors where writing a 5899** 32-bit integer is atomic. 5900** 5901** See Also: [SQLite Shared-Cache Mode] 5902*/ 5903int sqlite3_enable_shared_cache(int); 5904 5905/* 5906** CAPI3REF: Attempt To Free Heap Memory 5907** 5908** ^The sqlite3_release_memory() interface attempts to free N bytes 5909** of heap memory by deallocating non-essential memory allocations 5910** held by the database library. Memory used to cache database 5911** pages to improve performance is an example of non-essential memory. 5912** ^sqlite3_release_memory() returns the number of bytes actually freed, 5913** which might be more or less than the amount requested. 5914** ^The sqlite3_release_memory() routine is a no-op returning zero 5915** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5916** 5917** See also: [sqlite3_db_release_memory()] 5918*/ 5919int sqlite3_release_memory(int); 5920 5921/* 5922** CAPI3REF: Free Memory Used By A Database Connection 5923** METHOD: sqlite3 5924** 5925** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5926** memory as possible from database connection D. Unlike the 5927** [sqlite3_release_memory()] interface, this interface is in effect even 5928** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5929** omitted. 5930** 5931** See also: [sqlite3_release_memory()] 5932*/ 5933int sqlite3_db_release_memory(sqlite3*); 5934 5935/* 5936** CAPI3REF: Impose A Limit On Heap Size 5937** 5938** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5939** soft limit on the amount of heap memory that may be allocated by SQLite. 5940** ^SQLite strives to keep heap memory utilization below the soft heap 5941** limit by reducing the number of pages held in the page cache 5942** as heap memory usages approaches the limit. 5943** ^The soft heap limit is "soft" because even though SQLite strives to stay 5944** below the limit, it will exceed the limit rather than generate 5945** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5946** is advisory only. 5947** 5948** ^The return value from sqlite3_soft_heap_limit64() is the size of 5949** the soft heap limit prior to the call, or negative in the case of an 5950** error. ^If the argument N is negative 5951** then no change is made to the soft heap limit. Hence, the current 5952** size of the soft heap limit can be determined by invoking 5953** sqlite3_soft_heap_limit64() with a negative argument. 5954** 5955** ^If the argument N is zero then the soft heap limit is disabled. 5956** 5957** ^(The soft heap limit is not enforced in the current implementation 5958** if one or more of following conditions are true: 5959** 5960** <ul> 5961** <li> The soft heap limit is set to zero. 5962** <li> Memory accounting is disabled using a combination of the 5963** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5964** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5965** <li> An alternative page cache implementation is specified using 5966** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5967** <li> The page cache allocates from its own memory pool supplied 5968** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5969** from the heap. 5970** </ul>)^ 5971** 5972** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5973** the soft heap limit is enforced 5974** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5975** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5976** the soft heap limit is enforced on every memory allocation. Without 5977** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5978** when memory is allocated by the page cache. Testing suggests that because 5979** the page cache is the predominate memory user in SQLite, most 5980** applications will achieve adequate soft heap limit enforcement without 5981** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5982** 5983** The circumstances under which SQLite will enforce the soft heap limit may 5984** changes in future releases of SQLite. 5985*/ 5986sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5987 5988/* 5989** CAPI3REF: Deprecated Soft Heap Limit Interface 5990** DEPRECATED 5991** 5992** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5993** interface. This routine is provided for historical compatibility 5994** only. All new applications should use the 5995** [sqlite3_soft_heap_limit64()] interface rather than this one. 5996*/ 5997SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5998 5999 6000/* 6001** CAPI3REF: Extract Metadata About A Column Of A Table 6002** METHOD: sqlite3 6003** 6004** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6005** information about column C of table T in database D 6006** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6007** interface returns SQLITE_OK and fills in the non-NULL pointers in 6008** the final five arguments with appropriate values if the specified 6009** column exists. ^The sqlite3_table_column_metadata() interface returns 6010** SQLITE_ERROR and if the specified column does not exist. 6011** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6012** NULL pointer, then this routine simply checks for the existence of the 6013** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6014** does not. If the table name parameter T in a call to 6015** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6016** undefined behavior. 6017** 6018** ^The column is identified by the second, third and fourth parameters to 6019** this function. ^(The second parameter is either the name of the database 6020** (i.e. "main", "temp", or an attached database) containing the specified 6021** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6022** for the table using the same algorithm used by the database engine to 6023** resolve unqualified table references. 6024** 6025** ^The third and fourth parameters to this function are the table and column 6026** name of the desired column, respectively. 6027** 6028** ^Metadata is returned by writing to the memory locations passed as the 5th 6029** and subsequent parameters to this function. ^Any of these arguments may be 6030** NULL, in which case the corresponding element of metadata is omitted. 6031** 6032** ^(<blockquote> 6033** <table border="1"> 6034** <tr><th> Parameter <th> Output<br>Type <th> Description 6035** 6036** <tr><td> 5th <td> const char* <td> Data type 6037** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6038** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6039** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6040** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6041** </table> 6042** </blockquote>)^ 6043** 6044** ^The memory pointed to by the character pointers returned for the 6045** declaration type and collation sequence is valid until the next 6046** call to any SQLite API function. 6047** 6048** ^If the specified table is actually a view, an [error code] is returned. 6049** 6050** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6051** is not a [WITHOUT ROWID] table and an 6052** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6053** parameters are set for the explicitly declared column. ^(If there is no 6054** [INTEGER PRIMARY KEY] column, then the outputs 6055** for the [rowid] are set as follows: 6056** 6057** <pre> 6058** data type: "INTEGER" 6059** collation sequence: "BINARY" 6060** not null: 0 6061** primary key: 1 6062** auto increment: 0 6063** </pre>)^ 6064** 6065** ^This function causes all database schemas to be read from disk and 6066** parsed, if that has not already been done, and returns an error if 6067** any errors are encountered while loading the schema. 6068*/ 6069int sqlite3_table_column_metadata( 6070 sqlite3 *db, /* Connection handle */ 6071 const char *zDbName, /* Database name or NULL */ 6072 const char *zTableName, /* Table name */ 6073 const char *zColumnName, /* Column name */ 6074 char const **pzDataType, /* OUTPUT: Declared data type */ 6075 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6076 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6077 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6078 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6079); 6080 6081/* 6082** CAPI3REF: Load An Extension 6083** METHOD: sqlite3 6084** 6085** ^This interface loads an SQLite extension library from the named file. 6086** 6087** ^The sqlite3_load_extension() interface attempts to load an 6088** [SQLite extension] library contained in the file zFile. If 6089** the file cannot be loaded directly, attempts are made to load 6090** with various operating-system specific extensions added. 6091** So for example, if "samplelib" cannot be loaded, then names like 6092** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6093** be tried also. 6094** 6095** ^The entry point is zProc. 6096** ^(zProc may be 0, in which case SQLite will try to come up with an 6097** entry point name on its own. It first tries "sqlite3_extension_init". 6098** If that does not work, it constructs a name "sqlite3_X_init" where the 6099** X is consists of the lower-case equivalent of all ASCII alphabetic 6100** characters in the filename from the last "/" to the first following 6101** "." and omitting any initial "lib".)^ 6102** ^The sqlite3_load_extension() interface returns 6103** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6104** ^If an error occurs and pzErrMsg is not 0, then the 6105** [sqlite3_load_extension()] interface shall attempt to 6106** fill *pzErrMsg with error message text stored in memory 6107** obtained from [sqlite3_malloc()]. The calling function 6108** should free this memory by calling [sqlite3_free()]. 6109** 6110** ^Extension loading must be enabled using 6111** [sqlite3_enable_load_extension()] or 6112** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6113** prior to calling this API, 6114** otherwise an error will be returned. 6115** 6116** <b>Security warning:</b> It is recommended that the 6117** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6118** interface. The use of the [sqlite3_enable_load_extension()] interface 6119** should be avoided. This will keep the SQL function [load_extension()] 6120** disabled and prevent SQL injections from giving attackers 6121** access to extension loading capabilities. 6122** 6123** See also the [load_extension() SQL function]. 6124*/ 6125int sqlite3_load_extension( 6126 sqlite3 *db, /* Load the extension into this database connection */ 6127 const char *zFile, /* Name of the shared library containing extension */ 6128 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6129 char **pzErrMsg /* Put error message here if not 0 */ 6130); 6131 6132/* 6133** CAPI3REF: Enable Or Disable Extension Loading 6134** METHOD: sqlite3 6135** 6136** ^So as not to open security holes in older applications that are 6137** unprepared to deal with [extension loading], and as a means of disabling 6138** [extension loading] while evaluating user-entered SQL, the following API 6139** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6140** 6141** ^Extension loading is off by default. 6142** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6143** to turn extension loading on and call it with onoff==0 to turn 6144** it back off again. 6145** 6146** ^This interface enables or disables both the C-API 6147** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6148** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6149** to enable or disable only the C-API.)^ 6150** 6151** <b>Security warning:</b> It is recommended that extension loading 6152** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6153** rather than this interface, so the [load_extension()] SQL function 6154** remains disabled. This will prevent SQL injections from giving attackers 6155** access to extension loading capabilities. 6156*/ 6157int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6158 6159/* 6160** CAPI3REF: Automatically Load Statically Linked Extensions 6161** 6162** ^This interface causes the xEntryPoint() function to be invoked for 6163** each new [database connection] that is created. The idea here is that 6164** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6165** that is to be automatically loaded into all new database connections. 6166** 6167** ^(Even though the function prototype shows that xEntryPoint() takes 6168** no arguments and returns void, SQLite invokes xEntryPoint() with three 6169** arguments and expects an integer result as if the signature of the 6170** entry point where as follows: 6171** 6172** <blockquote><pre> 6173** int xEntryPoint( 6174** sqlite3 *db, 6175** const char **pzErrMsg, 6176** const struct sqlite3_api_routines *pThunk 6177** ); 6178** </pre></blockquote>)^ 6179** 6180** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6181** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6182** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6183** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6184** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6185** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6186** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6187** 6188** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6189** on the list of automatic extensions is a harmless no-op. ^No entry point 6190** will be called more than once for each database connection that is opened. 6191** 6192** See also: [sqlite3_reset_auto_extension()] 6193** and [sqlite3_cancel_auto_extension()] 6194*/ 6195int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6196 6197/* 6198** CAPI3REF: Cancel Automatic Extension Loading 6199** 6200** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6201** initialization routine X that was registered using a prior call to 6202** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6203** routine returns 1 if initialization routine X was successfully 6204** unregistered and it returns 0 if X was not on the list of initialization 6205** routines. 6206*/ 6207int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6208 6209/* 6210** CAPI3REF: Reset Automatic Extension Loading 6211** 6212** ^This interface disables all automatic extensions previously 6213** registered using [sqlite3_auto_extension()]. 6214*/ 6215void sqlite3_reset_auto_extension(void); 6216 6217/* 6218** The interface to the virtual-table mechanism is currently considered 6219** to be experimental. The interface might change in incompatible ways. 6220** If this is a problem for you, do not use the interface at this time. 6221** 6222** When the virtual-table mechanism stabilizes, we will declare the 6223** interface fixed, support it indefinitely, and remove this comment. 6224*/ 6225 6226/* 6227** Structures used by the virtual table interface 6228*/ 6229typedef struct sqlite3_vtab sqlite3_vtab; 6230typedef struct sqlite3_index_info sqlite3_index_info; 6231typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6232typedef struct sqlite3_module sqlite3_module; 6233 6234/* 6235** CAPI3REF: Virtual Table Object 6236** KEYWORDS: sqlite3_module {virtual table module} 6237** 6238** This structure, sometimes called a "virtual table module", 6239** defines the implementation of a [virtual tables]. 6240** This structure consists mostly of methods for the module. 6241** 6242** ^A virtual table module is created by filling in a persistent 6243** instance of this structure and passing a pointer to that instance 6244** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6245** ^The registration remains valid until it is replaced by a different 6246** module or until the [database connection] closes. The content 6247** of this structure must not change while it is registered with 6248** any database connection. 6249*/ 6250struct sqlite3_module { 6251 int iVersion; 6252 int (*xCreate)(sqlite3*, void *pAux, 6253 int argc, const char *const*argv, 6254 sqlite3_vtab **ppVTab, char**); 6255 int (*xConnect)(sqlite3*, void *pAux, 6256 int argc, const char *const*argv, 6257 sqlite3_vtab **ppVTab, char**); 6258 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6259 int (*xDisconnect)(sqlite3_vtab *pVTab); 6260 int (*xDestroy)(sqlite3_vtab *pVTab); 6261 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6262 int (*xClose)(sqlite3_vtab_cursor*); 6263 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6264 int argc, sqlite3_value **argv); 6265 int (*xNext)(sqlite3_vtab_cursor*); 6266 int (*xEof)(sqlite3_vtab_cursor*); 6267 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6268 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6269 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6270 int (*xBegin)(sqlite3_vtab *pVTab); 6271 int (*xSync)(sqlite3_vtab *pVTab); 6272 int (*xCommit)(sqlite3_vtab *pVTab); 6273 int (*xRollback)(sqlite3_vtab *pVTab); 6274 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6275 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6276 void **ppArg); 6277 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6278 /* The methods above are in version 1 of the sqlite_module object. Those 6279 ** below are for version 2 and greater. */ 6280 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6281 int (*xRelease)(sqlite3_vtab *pVTab, int); 6282 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6283}; 6284 6285/* 6286** CAPI3REF: Virtual Table Indexing Information 6287** KEYWORDS: sqlite3_index_info 6288** 6289** The sqlite3_index_info structure and its substructures is used as part 6290** of the [virtual table] interface to 6291** pass information into and receive the reply from the [xBestIndex] 6292** method of a [virtual table module]. The fields under **Inputs** are the 6293** inputs to xBestIndex and are read-only. xBestIndex inserts its 6294** results into the **Outputs** fields. 6295** 6296** ^(The aConstraint[] array records WHERE clause constraints of the form: 6297** 6298** <blockquote>column OP expr</blockquote> 6299** 6300** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6301** stored in aConstraint[].op using one of the 6302** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6303** ^(The index of the column is stored in 6304** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6305** expr on the right-hand side can be evaluated (and thus the constraint 6306** is usable) and false if it cannot.)^ 6307** 6308** ^The optimizer automatically inverts terms of the form "expr OP column" 6309** and makes other simplifications to the WHERE clause in an attempt to 6310** get as many WHERE clause terms into the form shown above as possible. 6311** ^The aConstraint[] array only reports WHERE clause terms that are 6312** relevant to the particular virtual table being queried. 6313** 6314** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6315** ^Each term of aOrderBy records a column of the ORDER BY clause. 6316** 6317** The colUsed field indicates which columns of the virtual table may be 6318** required by the current scan. Virtual table columns are numbered from 6319** zero in the order in which they appear within the CREATE TABLE statement 6320** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6321** the corresponding bit is set within the colUsed mask if the column may be 6322** required by SQLite. If the table has at least 64 columns and any column 6323** to the right of the first 63 is required, then bit 63 of colUsed is also 6324** set. In other words, column iCol may be required if the expression 6325** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6326** non-zero. 6327** 6328** The [xBestIndex] method must fill aConstraintUsage[] with information 6329** about what parameters to pass to xFilter. ^If argvIndex>0 then 6330** the right-hand side of the corresponding aConstraint[] is evaluated 6331** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6332** is true, then the constraint is assumed to be fully handled by the 6333** virtual table and is not checked again by SQLite.)^ 6334** 6335** ^The idxNum and idxPtr values are recorded and passed into the 6336** [xFilter] method. 6337** ^[sqlite3_free()] is used to free idxPtr if and only if 6338** needToFreeIdxPtr is true. 6339** 6340** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6341** the correct order to satisfy the ORDER BY clause so that no separate 6342** sorting step is required. 6343** 6344** ^The estimatedCost value is an estimate of the cost of a particular 6345** strategy. A cost of N indicates that the cost of the strategy is similar 6346** to a linear scan of an SQLite table with N rows. A cost of log(N) 6347** indicates that the expense of the operation is similar to that of a 6348** binary search on a unique indexed field of an SQLite table with N rows. 6349** 6350** ^The estimatedRows value is an estimate of the number of rows that 6351** will be returned by the strategy. 6352** 6353** The xBestIndex method may optionally populate the idxFlags field with a 6354** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6355** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6356** assumes that the strategy may visit at most one row. 6357** 6358** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6359** SQLite also assumes that if a call to the xUpdate() method is made as 6360** part of the same statement to delete or update a virtual table row and the 6361** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6362** any database changes. In other words, if the xUpdate() returns 6363** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6364** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6365** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6366** the xUpdate method are automatically rolled back by SQLite. 6367** 6368** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6369** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6370** If a virtual table extension is 6371** used with an SQLite version earlier than 3.8.2, the results of attempting 6372** to read or write the estimatedRows field are undefined (but are likely 6373** to included crashing the application). The estimatedRows field should 6374** therefore only be used if [sqlite3_libversion_number()] returns a 6375** value greater than or equal to 3008002. Similarly, the idxFlags field 6376** was added for [version 3.9.0] ([dateof:3.9.0]). 6377** It may therefore only be used if 6378** sqlite3_libversion_number() returns a value greater than or equal to 6379** 3009000. 6380*/ 6381struct sqlite3_index_info { 6382 /* Inputs */ 6383 int nConstraint; /* Number of entries in aConstraint */ 6384 struct sqlite3_index_constraint { 6385 int iColumn; /* Column constrained. -1 for ROWID */ 6386 unsigned char op; /* Constraint operator */ 6387 unsigned char usable; /* True if this constraint is usable */ 6388 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6389 } *aConstraint; /* Table of WHERE clause constraints */ 6390 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6391 struct sqlite3_index_orderby { 6392 int iColumn; /* Column number */ 6393 unsigned char desc; /* True for DESC. False for ASC. */ 6394 } *aOrderBy; /* The ORDER BY clause */ 6395 /* Outputs */ 6396 struct sqlite3_index_constraint_usage { 6397 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6398 unsigned char omit; /* Do not code a test for this constraint */ 6399 } *aConstraintUsage; 6400 int idxNum; /* Number used to identify the index */ 6401 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6402 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6403 int orderByConsumed; /* True if output is already ordered */ 6404 double estimatedCost; /* Estimated cost of using this index */ 6405 /* Fields below are only available in SQLite 3.8.2 and later */ 6406 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6407 /* Fields below are only available in SQLite 3.9.0 and later */ 6408 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6409 /* Fields below are only available in SQLite 3.10.0 and later */ 6410 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6411}; 6412 6413/* 6414** CAPI3REF: Virtual Table Scan Flags 6415** 6416** Virtual table implementations are allowed to set the 6417** [sqlite3_index_info].idxFlags field to some combination of 6418** these bits. 6419*/ 6420#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6421 6422/* 6423** CAPI3REF: Virtual Table Constraint Operator Codes 6424** 6425** These macros defined the allowed values for the 6426** [sqlite3_index_info].aConstraint[].op field. Each value represents 6427** an operator that is part of a constraint term in the wHERE clause of 6428** a query that uses a [virtual table]. 6429*/ 6430#define SQLITE_INDEX_CONSTRAINT_EQ 2 6431#define SQLITE_INDEX_CONSTRAINT_GT 4 6432#define SQLITE_INDEX_CONSTRAINT_LE 8 6433#define SQLITE_INDEX_CONSTRAINT_LT 16 6434#define SQLITE_INDEX_CONSTRAINT_GE 32 6435#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6436#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6437#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6438#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6439#define SQLITE_INDEX_CONSTRAINT_NE 68 6440#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6441#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6442#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6443#define SQLITE_INDEX_CONSTRAINT_IS 72 6444#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6445 6446/* 6447** CAPI3REF: Register A Virtual Table Implementation 6448** METHOD: sqlite3 6449** 6450** ^These routines are used to register a new [virtual table module] name. 6451** ^Module names must be registered before 6452** creating a new [virtual table] using the module and before using a 6453** preexisting [virtual table] for the module. 6454** 6455** ^The module name is registered on the [database connection] specified 6456** by the first parameter. ^The name of the module is given by the 6457** second parameter. ^The third parameter is a pointer to 6458** the implementation of the [virtual table module]. ^The fourth 6459** parameter is an arbitrary client data pointer that is passed through 6460** into the [xCreate] and [xConnect] methods of the virtual table module 6461** when a new virtual table is be being created or reinitialized. 6462** 6463** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6464** is a pointer to a destructor for the pClientData. ^SQLite will 6465** invoke the destructor function (if it is not NULL) when SQLite 6466** no longer needs the pClientData pointer. ^The destructor will also 6467** be invoked if the call to sqlite3_create_module_v2() fails. 6468** ^The sqlite3_create_module() 6469** interface is equivalent to sqlite3_create_module_v2() with a NULL 6470** destructor. 6471*/ 6472int sqlite3_create_module( 6473 sqlite3 *db, /* SQLite connection to register module with */ 6474 const char *zName, /* Name of the module */ 6475 const sqlite3_module *p, /* Methods for the module */ 6476 void *pClientData /* Client data for xCreate/xConnect */ 6477); 6478int sqlite3_create_module_v2( 6479 sqlite3 *db, /* SQLite connection to register module with */ 6480 const char *zName, /* Name of the module */ 6481 const sqlite3_module *p, /* Methods for the module */ 6482 void *pClientData, /* Client data for xCreate/xConnect */ 6483 void(*xDestroy)(void*) /* Module destructor function */ 6484); 6485 6486/* 6487** CAPI3REF: Virtual Table Instance Object 6488** KEYWORDS: sqlite3_vtab 6489** 6490** Every [virtual table module] implementation uses a subclass 6491** of this object to describe a particular instance 6492** of the [virtual table]. Each subclass will 6493** be tailored to the specific needs of the module implementation. 6494** The purpose of this superclass is to define certain fields that are 6495** common to all module implementations. 6496** 6497** ^Virtual tables methods can set an error message by assigning a 6498** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6499** take care that any prior string is freed by a call to [sqlite3_free()] 6500** prior to assigning a new string to zErrMsg. ^After the error message 6501** is delivered up to the client application, the string will be automatically 6502** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6503*/ 6504struct sqlite3_vtab { 6505 const sqlite3_module *pModule; /* The module for this virtual table */ 6506 int nRef; /* Number of open cursors */ 6507 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6508 /* Virtual table implementations will typically add additional fields */ 6509}; 6510 6511/* 6512** CAPI3REF: Virtual Table Cursor Object 6513** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6514** 6515** Every [virtual table module] implementation uses a subclass of the 6516** following structure to describe cursors that point into the 6517** [virtual table] and are used 6518** to loop through the virtual table. Cursors are created using the 6519** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6520** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6521** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6522** of the module. Each module implementation will define 6523** the content of a cursor structure to suit its own needs. 6524** 6525** This superclass exists in order to define fields of the cursor that 6526** are common to all implementations. 6527*/ 6528struct sqlite3_vtab_cursor { 6529 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6530 /* Virtual table implementations will typically add additional fields */ 6531}; 6532 6533/* 6534** CAPI3REF: Declare The Schema Of A Virtual Table 6535** 6536** ^The [xCreate] and [xConnect] methods of a 6537** [virtual table module] call this interface 6538** to declare the format (the names and datatypes of the columns) of 6539** the virtual tables they implement. 6540*/ 6541int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6542 6543/* 6544** CAPI3REF: Overload A Function For A Virtual Table 6545** METHOD: sqlite3 6546** 6547** ^(Virtual tables can provide alternative implementations of functions 6548** using the [xFindFunction] method of the [virtual table module]. 6549** But global versions of those functions 6550** must exist in order to be overloaded.)^ 6551** 6552** ^(This API makes sure a global version of a function with a particular 6553** name and number of parameters exists. If no such function exists 6554** before this API is called, a new function is created.)^ ^The implementation 6555** of the new function always causes an exception to be thrown. So 6556** the new function is not good for anything by itself. Its only 6557** purpose is to be a placeholder function that can be overloaded 6558** by a [virtual table]. 6559*/ 6560int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6561 6562/* 6563** The interface to the virtual-table mechanism defined above (back up 6564** to a comment remarkably similar to this one) is currently considered 6565** to be experimental. The interface might change in incompatible ways. 6566** If this is a problem for you, do not use the interface at this time. 6567** 6568** When the virtual-table mechanism stabilizes, we will declare the 6569** interface fixed, support it indefinitely, and remove this comment. 6570*/ 6571 6572/* 6573** CAPI3REF: A Handle To An Open BLOB 6574** KEYWORDS: {BLOB handle} {BLOB handles} 6575** 6576** An instance of this object represents an open BLOB on which 6577** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6578** ^Objects of this type are created by [sqlite3_blob_open()] 6579** and destroyed by [sqlite3_blob_close()]. 6580** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6581** can be used to read or write small subsections of the BLOB. 6582** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6583*/ 6584typedef struct sqlite3_blob sqlite3_blob; 6585 6586/* 6587** CAPI3REF: Open A BLOB For Incremental I/O 6588** METHOD: sqlite3 6589** CONSTRUCTOR: sqlite3_blob 6590** 6591** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6592** in row iRow, column zColumn, table zTable in database zDb; 6593** in other words, the same BLOB that would be selected by: 6594** 6595** <pre> 6596** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6597** </pre>)^ 6598** 6599** ^(Parameter zDb is not the filename that contains the database, but 6600** rather the symbolic name of the database. For attached databases, this is 6601** the name that appears after the AS keyword in the [ATTACH] statement. 6602** For the main database file, the database name is "main". For TEMP 6603** tables, the database name is "temp".)^ 6604** 6605** ^If the flags parameter is non-zero, then the BLOB is opened for read 6606** and write access. ^If the flags parameter is zero, the BLOB is opened for 6607** read-only access. 6608** 6609** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6610** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6611** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6612** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6613** on *ppBlob after this function it returns. 6614** 6615** This function fails with SQLITE_ERROR if any of the following are true: 6616** <ul> 6617** <li> ^(Database zDb does not exist)^, 6618** <li> ^(Table zTable does not exist within database zDb)^, 6619** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6620** <li> ^(Column zColumn does not exist)^, 6621** <li> ^(Row iRow is not present in the table)^, 6622** <li> ^(The specified column of row iRow contains a value that is not 6623** a TEXT or BLOB value)^, 6624** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6625** constraint and the blob is being opened for read/write access)^, 6626** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6627** column zColumn is part of a [child key] definition and the blob is 6628** being opened for read/write access)^. 6629** </ul> 6630** 6631** ^Unless it returns SQLITE_MISUSE, this function sets the 6632** [database connection] error code and message accessible via 6633** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6634** 6635** A BLOB referenced by sqlite3_blob_open() may be read using the 6636** [sqlite3_blob_read()] interface and modified by using 6637** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6638** different row of the same table using the [sqlite3_blob_reopen()] 6639** interface. However, the column, table, or database of a [BLOB handle] 6640** cannot be changed after the [BLOB handle] is opened. 6641** 6642** ^(If the row that a BLOB handle points to is modified by an 6643** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6644** then the BLOB handle is marked as "expired". 6645** This is true if any column of the row is changed, even a column 6646** other than the one the BLOB handle is open on.)^ 6647** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6648** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6649** ^(Changes written into a BLOB prior to the BLOB expiring are not 6650** rolled back by the expiration of the BLOB. Such changes will eventually 6651** commit if the transaction continues to completion.)^ 6652** 6653** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6654** the opened blob. ^The size of a blob may not be changed by this 6655** interface. Use the [UPDATE] SQL command to change the size of a 6656** blob. 6657** 6658** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6659** and the built-in [zeroblob] SQL function may be used to create a 6660** zero-filled blob to read or write using the incremental-blob interface. 6661** 6662** To avoid a resource leak, every open [BLOB handle] should eventually 6663** be released by a call to [sqlite3_blob_close()]. 6664** 6665** See also: [sqlite3_blob_close()], 6666** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6667** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6668*/ 6669int sqlite3_blob_open( 6670 sqlite3*, 6671 const char *zDb, 6672 const char *zTable, 6673 const char *zColumn, 6674 sqlite3_int64 iRow, 6675 int flags, 6676 sqlite3_blob **ppBlob 6677); 6678 6679/* 6680** CAPI3REF: Move a BLOB Handle to a New Row 6681** METHOD: sqlite3_blob 6682** 6683** ^This function is used to move an existing [BLOB handle] so that it points 6684** to a different row of the same database table. ^The new row is identified 6685** by the rowid value passed as the second argument. Only the row can be 6686** changed. ^The database, table and column on which the blob handle is open 6687** remain the same. Moving an existing [BLOB handle] to a new row is 6688** faster than closing the existing handle and opening a new one. 6689** 6690** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6691** it must exist and there must be either a blob or text value stored in 6692** the nominated column.)^ ^If the new row is not present in the table, or if 6693** it does not contain a blob or text value, or if another error occurs, an 6694** SQLite error code is returned and the blob handle is considered aborted. 6695** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6696** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6697** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6698** always returns zero. 6699** 6700** ^This function sets the database handle error code and message. 6701*/ 6702int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6703 6704/* 6705** CAPI3REF: Close A BLOB Handle 6706** DESTRUCTOR: sqlite3_blob 6707** 6708** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6709** unconditionally. Even if this routine returns an error code, the 6710** handle is still closed.)^ 6711** 6712** ^If the blob handle being closed was opened for read-write access, and if 6713** the database is in auto-commit mode and there are no other open read-write 6714** blob handles or active write statements, the current transaction is 6715** committed. ^If an error occurs while committing the transaction, an error 6716** code is returned and the transaction rolled back. 6717** 6718** Calling this function with an argument that is not a NULL pointer or an 6719** open blob handle results in undefined behaviour. ^Calling this routine 6720** with a null pointer (such as would be returned by a failed call to 6721** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6722** is passed a valid open blob handle, the values returned by the 6723** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6724*/ 6725int sqlite3_blob_close(sqlite3_blob *); 6726 6727/* 6728** CAPI3REF: Return The Size Of An Open BLOB 6729** METHOD: sqlite3_blob 6730** 6731** ^Returns the size in bytes of the BLOB accessible via the 6732** successfully opened [BLOB handle] in its only argument. ^The 6733** incremental blob I/O routines can only read or overwriting existing 6734** blob content; they cannot change the size of a blob. 6735** 6736** This routine only works on a [BLOB handle] which has been created 6737** by a prior successful call to [sqlite3_blob_open()] and which has not 6738** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6739** to this routine results in undefined and probably undesirable behavior. 6740*/ 6741int sqlite3_blob_bytes(sqlite3_blob *); 6742 6743/* 6744** CAPI3REF: Read Data From A BLOB Incrementally 6745** METHOD: sqlite3_blob 6746** 6747** ^(This function is used to read data from an open [BLOB handle] into a 6748** caller-supplied buffer. N bytes of data are copied into buffer Z 6749** from the open BLOB, starting at offset iOffset.)^ 6750** 6751** ^If offset iOffset is less than N bytes from the end of the BLOB, 6752** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6753** less than zero, [SQLITE_ERROR] is returned and no data is read. 6754** ^The size of the blob (and hence the maximum value of N+iOffset) 6755** can be determined using the [sqlite3_blob_bytes()] interface. 6756** 6757** ^An attempt to read from an expired [BLOB handle] fails with an 6758** error code of [SQLITE_ABORT]. 6759** 6760** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6761** Otherwise, an [error code] or an [extended error code] is returned.)^ 6762** 6763** This routine only works on a [BLOB handle] which has been created 6764** by a prior successful call to [sqlite3_blob_open()] and which has not 6765** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6766** to this routine results in undefined and probably undesirable behavior. 6767** 6768** See also: [sqlite3_blob_write()]. 6769*/ 6770int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6771 6772/* 6773** CAPI3REF: Write Data Into A BLOB Incrementally 6774** METHOD: sqlite3_blob 6775** 6776** ^(This function is used to write data into an open [BLOB handle] from a 6777** caller-supplied buffer. N bytes of data are copied from the buffer Z 6778** into the open BLOB, starting at offset iOffset.)^ 6779** 6780** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6781** Otherwise, an [error code] or an [extended error code] is returned.)^ 6782** ^Unless SQLITE_MISUSE is returned, this function sets the 6783** [database connection] error code and message accessible via 6784** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6785** 6786** ^If the [BLOB handle] passed as the first argument was not opened for 6787** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6788** this function returns [SQLITE_READONLY]. 6789** 6790** This function may only modify the contents of the BLOB; it is 6791** not possible to increase the size of a BLOB using this API. 6792** ^If offset iOffset is less than N bytes from the end of the BLOB, 6793** [SQLITE_ERROR] is returned and no data is written. The size of the 6794** BLOB (and hence the maximum value of N+iOffset) can be determined 6795** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6796** than zero [SQLITE_ERROR] is returned and no data is written. 6797** 6798** ^An attempt to write to an expired [BLOB handle] fails with an 6799** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6800** before the [BLOB handle] expired are not rolled back by the 6801** expiration of the handle, though of course those changes might 6802** have been overwritten by the statement that expired the BLOB handle 6803** or by other independent statements. 6804** 6805** This routine only works on a [BLOB handle] which has been created 6806** by a prior successful call to [sqlite3_blob_open()] and which has not 6807** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6808** to this routine results in undefined and probably undesirable behavior. 6809** 6810** See also: [sqlite3_blob_read()]. 6811*/ 6812int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6813 6814/* 6815** CAPI3REF: Virtual File System Objects 6816** 6817** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6818** that SQLite uses to interact 6819** with the underlying operating system. Most SQLite builds come with a 6820** single default VFS that is appropriate for the host computer. 6821** New VFSes can be registered and existing VFSes can be unregistered. 6822** The following interfaces are provided. 6823** 6824** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6825** ^Names are case sensitive. 6826** ^Names are zero-terminated UTF-8 strings. 6827** ^If there is no match, a NULL pointer is returned. 6828** ^If zVfsName is NULL then the default VFS is returned. 6829** 6830** ^New VFSes are registered with sqlite3_vfs_register(). 6831** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6832** ^The same VFS can be registered multiple times without injury. 6833** ^To make an existing VFS into the default VFS, register it again 6834** with the makeDflt flag set. If two different VFSes with the 6835** same name are registered, the behavior is undefined. If a 6836** VFS is registered with a name that is NULL or an empty string, 6837** then the behavior is undefined. 6838** 6839** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6840** ^(If the default VFS is unregistered, another VFS is chosen as 6841** the default. The choice for the new VFS is arbitrary.)^ 6842*/ 6843sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6844int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6845int sqlite3_vfs_unregister(sqlite3_vfs*); 6846 6847/* 6848** CAPI3REF: Mutexes 6849** 6850** The SQLite core uses these routines for thread 6851** synchronization. Though they are intended for internal 6852** use by SQLite, code that links against SQLite is 6853** permitted to use any of these routines. 6854** 6855** The SQLite source code contains multiple implementations 6856** of these mutex routines. An appropriate implementation 6857** is selected automatically at compile-time. The following 6858** implementations are available in the SQLite core: 6859** 6860** <ul> 6861** <li> SQLITE_MUTEX_PTHREADS 6862** <li> SQLITE_MUTEX_W32 6863** <li> SQLITE_MUTEX_NOOP 6864** </ul> 6865** 6866** The SQLITE_MUTEX_NOOP implementation is a set of routines 6867** that does no real locking and is appropriate for use in 6868** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6869** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6870** and Windows. 6871** 6872** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6873** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6874** implementation is included with the library. In this case the 6875** application must supply a custom mutex implementation using the 6876** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6877** before calling sqlite3_initialize() or any other public sqlite3_ 6878** function that calls sqlite3_initialize(). 6879** 6880** ^The sqlite3_mutex_alloc() routine allocates a new 6881** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6882** routine returns NULL if it is unable to allocate the requested 6883** mutex. The argument to sqlite3_mutex_alloc() must one of these 6884** integer constants: 6885** 6886** <ul> 6887** <li> SQLITE_MUTEX_FAST 6888** <li> SQLITE_MUTEX_RECURSIVE 6889** <li> SQLITE_MUTEX_STATIC_MASTER 6890** <li> SQLITE_MUTEX_STATIC_MEM 6891** <li> SQLITE_MUTEX_STATIC_OPEN 6892** <li> SQLITE_MUTEX_STATIC_PRNG 6893** <li> SQLITE_MUTEX_STATIC_LRU 6894** <li> SQLITE_MUTEX_STATIC_PMEM 6895** <li> SQLITE_MUTEX_STATIC_APP1 6896** <li> SQLITE_MUTEX_STATIC_APP2 6897** <li> SQLITE_MUTEX_STATIC_APP3 6898** <li> SQLITE_MUTEX_STATIC_VFS1 6899** <li> SQLITE_MUTEX_STATIC_VFS2 6900** <li> SQLITE_MUTEX_STATIC_VFS3 6901** </ul> 6902** 6903** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6904** cause sqlite3_mutex_alloc() to create 6905** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6906** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6907** The mutex implementation does not need to make a distinction 6908** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6909** not want to. SQLite will only request a recursive mutex in 6910** cases where it really needs one. If a faster non-recursive mutex 6911** implementation is available on the host platform, the mutex subsystem 6912** might return such a mutex in response to SQLITE_MUTEX_FAST. 6913** 6914** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6915** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6916** a pointer to a static preexisting mutex. ^Nine static mutexes are 6917** used by the current version of SQLite. Future versions of SQLite 6918** may add additional static mutexes. Static mutexes are for internal 6919** use by SQLite only. Applications that use SQLite mutexes should 6920** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6921** SQLITE_MUTEX_RECURSIVE. 6922** 6923** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6924** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6925** returns a different mutex on every call. ^For the static 6926** mutex types, the same mutex is returned on every call that has 6927** the same type number. 6928** 6929** ^The sqlite3_mutex_free() routine deallocates a previously 6930** allocated dynamic mutex. Attempting to deallocate a static 6931** mutex results in undefined behavior. 6932** 6933** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6934** to enter a mutex. ^If another thread is already within the mutex, 6935** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6936** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6937** upon successful entry. ^(Mutexes created using 6938** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6939** In such cases, the 6940** mutex must be exited an equal number of times before another thread 6941** can enter.)^ If the same thread tries to enter any mutex other 6942** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6943** 6944** ^(Some systems (for example, Windows 95) do not support the operation 6945** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6946** will always return SQLITE_BUSY. The SQLite core only ever uses 6947** sqlite3_mutex_try() as an optimization so this is acceptable 6948** behavior.)^ 6949** 6950** ^The sqlite3_mutex_leave() routine exits a mutex that was 6951** previously entered by the same thread. The behavior 6952** is undefined if the mutex is not currently entered by the 6953** calling thread or is not currently allocated. 6954** 6955** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6956** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6957** behave as no-ops. 6958** 6959** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6960*/ 6961sqlite3_mutex *sqlite3_mutex_alloc(int); 6962void sqlite3_mutex_free(sqlite3_mutex*); 6963void sqlite3_mutex_enter(sqlite3_mutex*); 6964int sqlite3_mutex_try(sqlite3_mutex*); 6965void sqlite3_mutex_leave(sqlite3_mutex*); 6966 6967/* 6968** CAPI3REF: Mutex Methods Object 6969** 6970** An instance of this structure defines the low-level routines 6971** used to allocate and use mutexes. 6972** 6973** Usually, the default mutex implementations provided by SQLite are 6974** sufficient, however the application has the option of substituting a custom 6975** implementation for specialized deployments or systems for which SQLite 6976** does not provide a suitable implementation. In this case, the application 6977** creates and populates an instance of this structure to pass 6978** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6979** Additionally, an instance of this structure can be used as an 6980** output variable when querying the system for the current mutex 6981** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6982** 6983** ^The xMutexInit method defined by this structure is invoked as 6984** part of system initialization by the sqlite3_initialize() function. 6985** ^The xMutexInit routine is called by SQLite exactly once for each 6986** effective call to [sqlite3_initialize()]. 6987** 6988** ^The xMutexEnd method defined by this structure is invoked as 6989** part of system shutdown by the sqlite3_shutdown() function. The 6990** implementation of this method is expected to release all outstanding 6991** resources obtained by the mutex methods implementation, especially 6992** those obtained by the xMutexInit method. ^The xMutexEnd() 6993** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6994** 6995** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6996** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6997** xMutexNotheld) implement the following interfaces (respectively): 6998** 6999** <ul> 7000** <li> [sqlite3_mutex_alloc()] </li> 7001** <li> [sqlite3_mutex_free()] </li> 7002** <li> [sqlite3_mutex_enter()] </li> 7003** <li> [sqlite3_mutex_try()] </li> 7004** <li> [sqlite3_mutex_leave()] </li> 7005** <li> [sqlite3_mutex_held()] </li> 7006** <li> [sqlite3_mutex_notheld()] </li> 7007** </ul>)^ 7008** 7009** The only difference is that the public sqlite3_XXX functions enumerated 7010** above silently ignore any invocations that pass a NULL pointer instead 7011** of a valid mutex handle. The implementations of the methods defined 7012** by this structure are not required to handle this case, the results 7013** of passing a NULL pointer instead of a valid mutex handle are undefined 7014** (i.e. it is acceptable to provide an implementation that segfaults if 7015** it is passed a NULL pointer). 7016** 7017** The xMutexInit() method must be threadsafe. It must be harmless to 7018** invoke xMutexInit() multiple times within the same process and without 7019** intervening calls to xMutexEnd(). Second and subsequent calls to 7020** xMutexInit() must be no-ops. 7021** 7022** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7023** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7024** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7025** memory allocation for a fast or recursive mutex. 7026** 7027** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7028** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7029** If xMutexInit fails in any way, it is expected to clean up after itself 7030** prior to returning. 7031*/ 7032typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7033struct sqlite3_mutex_methods { 7034 int (*xMutexInit)(void); 7035 int (*xMutexEnd)(void); 7036 sqlite3_mutex *(*xMutexAlloc)(int); 7037 void (*xMutexFree)(sqlite3_mutex *); 7038 void (*xMutexEnter)(sqlite3_mutex *); 7039 int (*xMutexTry)(sqlite3_mutex *); 7040 void (*xMutexLeave)(sqlite3_mutex *); 7041 int (*xMutexHeld)(sqlite3_mutex *); 7042 int (*xMutexNotheld)(sqlite3_mutex *); 7043}; 7044 7045/* 7046** CAPI3REF: Mutex Verification Routines 7047** 7048** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7049** are intended for use inside assert() statements. The SQLite core 7050** never uses these routines except inside an assert() and applications 7051** are advised to follow the lead of the core. The SQLite core only 7052** provides implementations for these routines when it is compiled 7053** with the SQLITE_DEBUG flag. External mutex implementations 7054** are only required to provide these routines if SQLITE_DEBUG is 7055** defined and if NDEBUG is not defined. 7056** 7057** These routines should return true if the mutex in their argument 7058** is held or not held, respectively, by the calling thread. 7059** 7060** The implementation is not required to provide versions of these 7061** routines that actually work. If the implementation does not provide working 7062** versions of these routines, it should at least provide stubs that always 7063** return true so that one does not get spurious assertion failures. 7064** 7065** If the argument to sqlite3_mutex_held() is a NULL pointer then 7066** the routine should return 1. This seems counter-intuitive since 7067** clearly the mutex cannot be held if it does not exist. But 7068** the reason the mutex does not exist is because the build is not 7069** using mutexes. And we do not want the assert() containing the 7070** call to sqlite3_mutex_held() to fail, so a non-zero return is 7071** the appropriate thing to do. The sqlite3_mutex_notheld() 7072** interface should also return 1 when given a NULL pointer. 7073*/ 7074#ifndef NDEBUG 7075int sqlite3_mutex_held(sqlite3_mutex*); 7076int sqlite3_mutex_notheld(sqlite3_mutex*); 7077#endif 7078 7079/* 7080** CAPI3REF: Mutex Types 7081** 7082** The [sqlite3_mutex_alloc()] interface takes a single argument 7083** which is one of these integer constants. 7084** 7085** The set of static mutexes may change from one SQLite release to the 7086** next. Applications that override the built-in mutex logic must be 7087** prepared to accommodate additional static mutexes. 7088*/ 7089#define SQLITE_MUTEX_FAST 0 7090#define SQLITE_MUTEX_RECURSIVE 1 7091#define SQLITE_MUTEX_STATIC_MASTER 2 7092#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7093#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7094#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7095#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7096#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7097#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7098#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7099#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7100#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7101#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7102#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7103#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7104#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7105 7106/* 7107** CAPI3REF: Retrieve the mutex for a database connection 7108** METHOD: sqlite3 7109** 7110** ^This interface returns a pointer the [sqlite3_mutex] object that 7111** serializes access to the [database connection] given in the argument 7112** when the [threading mode] is Serialized. 7113** ^If the [threading mode] is Single-thread or Multi-thread then this 7114** routine returns a NULL pointer. 7115*/ 7116sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7117 7118/* 7119** CAPI3REF: Low-Level Control Of Database Files 7120** METHOD: sqlite3 7121** KEYWORDS: {file control} 7122** 7123** ^The [sqlite3_file_control()] interface makes a direct call to the 7124** xFileControl method for the [sqlite3_io_methods] object associated 7125** with a particular database identified by the second argument. ^The 7126** name of the database is "main" for the main database or "temp" for the 7127** TEMP database, or the name that appears after the AS keyword for 7128** databases that are added using the [ATTACH] SQL command. 7129** ^A NULL pointer can be used in place of "main" to refer to the 7130** main database file. 7131** ^The third and fourth parameters to this routine 7132** are passed directly through to the second and third parameters of 7133** the xFileControl method. ^The return value of the xFileControl 7134** method becomes the return value of this routine. 7135** 7136** A few opcodes for [sqlite3_file_control()] are handled directly 7137** by the SQLite core and never invoke the 7138** sqlite3_io_methods.xFileControl method. 7139** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7140** a pointer to the underlying [sqlite3_file] object to be written into 7141** the space pointed to by the 4th parameter. The 7142** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7143** the [sqlite3_file] object associated with the journal file instead of 7144** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7145** a pointer to the underlying [sqlite3_vfs] object for the file. 7146** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7147** from the pager. 7148** 7149** ^If the second parameter (zDbName) does not match the name of any 7150** open database file, then SQLITE_ERROR is returned. ^This error 7151** code is not remembered and will not be recalled by [sqlite3_errcode()] 7152** or [sqlite3_errmsg()]. The underlying xFileControl method might 7153** also return SQLITE_ERROR. There is no way to distinguish between 7154** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7155** xFileControl method. 7156** 7157** See also: [file control opcodes] 7158*/ 7159int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7160 7161/* 7162** CAPI3REF: Testing Interface 7163** 7164** ^The sqlite3_test_control() interface is used to read out internal 7165** state of SQLite and to inject faults into SQLite for testing 7166** purposes. ^The first parameter is an operation code that determines 7167** the number, meaning, and operation of all subsequent parameters. 7168** 7169** This interface is not for use by applications. It exists solely 7170** for verifying the correct operation of the SQLite library. Depending 7171** on how the SQLite library is compiled, this interface might not exist. 7172** 7173** The details of the operation codes, their meanings, the parameters 7174** they take, and what they do are all subject to change without notice. 7175** Unlike most of the SQLite API, this function is not guaranteed to 7176** operate consistently from one release to the next. 7177*/ 7178int sqlite3_test_control(int op, ...); 7179 7180/* 7181** CAPI3REF: Testing Interface Operation Codes 7182** 7183** These constants are the valid operation code parameters used 7184** as the first argument to [sqlite3_test_control()]. 7185** 7186** These parameters and their meanings are subject to change 7187** without notice. These values are for testing purposes only. 7188** Applications should not use any of these parameters or the 7189** [sqlite3_test_control()] interface. 7190*/ 7191#define SQLITE_TESTCTRL_FIRST 5 7192#define SQLITE_TESTCTRL_PRNG_SAVE 5 7193#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7194#define SQLITE_TESTCTRL_PRNG_RESET 7 7195#define SQLITE_TESTCTRL_BITVEC_TEST 8 7196#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7197#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7198#define SQLITE_TESTCTRL_PENDING_BYTE 11 7199#define SQLITE_TESTCTRL_ASSERT 12 7200#define SQLITE_TESTCTRL_ALWAYS 13 7201#define SQLITE_TESTCTRL_RESERVE 14 7202#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7203#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7204#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7205#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7206#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7207#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7208#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7209#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7210#define SQLITE_TESTCTRL_BYTEORDER 22 7211#define SQLITE_TESTCTRL_ISINIT 23 7212#define SQLITE_TESTCTRL_SORTER_MMAP 24 7213#define SQLITE_TESTCTRL_IMPOSTER 25 7214#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7215#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */ 7216 7217/* 7218** CAPI3REF: SQL Keyword Checking 7219** 7220** These routines provide access to the set of SQL language keywords 7221** recognized by SQLite. Applications can uses these routines to determine 7222** whether or not a specific identifier needs to be escaped (for example, 7223** by enclosing in double-quotes) so as not to confuse the parser. 7224** 7225** The sqlite3_keyword_count() interface returns the number of distinct 7226** keywords understood by SQLite. 7227** 7228** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7229** makes *Z point to that keyword expressed as UTF8 and writes the number 7230** of bytes in the keyword into *L. The string that *Z points to is not 7231** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7232** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7233** or L are NULL or invalid pointers then calls to 7234** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7235** 7236** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7237** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7238** if it is and zero if not. 7239** 7240** The parser used by SQLite is forgiving. It is often possible to use 7241** a keyword as an identifier as long as such use does not result in a 7242** parsing ambiguity. For example, the statement 7243** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7244** creates a new table named "BEGIN" with three columns named 7245** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7246** using keywords as identifiers. Common techniques used to avoid keyword 7247** name collisions include: 7248** <ul> 7249** <li> Put all identifier names inside double-quotes. This is the official 7250** SQL way to escape identifier names. 7251** <li> Put identifier names inside [...]. This is not standard SQL, 7252** but it is what SQL Server does and so lots of programmers use this 7253** technique. 7254** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7255** with "Z". 7256** <li> Include a digit somewhere in every identifier name. 7257** </ul> 7258** 7259** Note that the number of keywords understood by SQLite can depend on 7260** compile-time options. For example, "VACUUM" is not a keyword if 7261** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7262** new keywords may be added to future releases of SQLite. 7263*/ 7264int sqlite3_keyword_count(void); 7265int sqlite3_keyword_name(int,const char**,int*); 7266int sqlite3_keyword_check(const char*,int); 7267 7268/* 7269** CAPI3REF: Dynamic String Object 7270** KEYWORDS: {dynamic string} 7271** 7272** An instance of the sqlite3_str object contains a dynamically-sized 7273** string under construction. 7274** 7275** The lifecycle of an sqlite3_str object is as follows: 7276** <ol> 7277** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7278** <li> ^Text is appended to the sqlite3_str object using various 7279** methods, such as [sqlite3_str_appendf()]. 7280** <li> ^The sqlite3_str object is destroyed and the string it created 7281** is returned using the [sqlite3_str_finish()] interface. 7282** </ol> 7283*/ 7284typedef struct sqlite3_str sqlite3_str; 7285 7286/* 7287** CAPI3REF: Create A New Dynamic String Object 7288** CONSTRUCTOR: sqlite3_str 7289** 7290** ^The [sqlite3_str_new(D)] interface allocates and initializes 7291** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7292** [sqlite3_str_new()] must be freed by a subsequent call to 7293** [sqlite3_str_finish(X)]. 7294** 7295** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7296** valid [sqlite3_str] object, though in the event of an out-of-memory 7297** error the returned object might be a special singleton that will 7298** silently reject new text, always return SQLITE_NOMEM from 7299** [sqlite3_str_errcode()], always return 0 for 7300** [sqlite3_str_length()], and always return NULL from 7301** [sqlite3_str_finish(X)]. It is always safe to use the value 7302** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7303** to any of the other [sqlite3_str] methods. 7304** 7305** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7306** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7307** length of the string contained in the [sqlite3_str] object will be 7308** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7309** of [SQLITE_MAX_LENGTH]. 7310*/ 7311sqlite3_str *sqlite3_str_new(sqlite3*); 7312 7313/* 7314** CAPI3REF: Finalize A Dynamic String 7315** DESTRUCTOR: sqlite3_str 7316** 7317** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7318** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7319** that contains the constructed string. The calling application should 7320** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7321** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7322** errors were encountered during construction of the string. ^The 7323** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7324** string in [sqlite3_str] object X is zero bytes long. 7325*/ 7326char *sqlite3_str_finish(sqlite3_str*); 7327 7328/* 7329** CAPI3REF: Add Content To A Dynamic String 7330** METHOD: sqlite3_str 7331** 7332** These interfaces add content to an sqlite3_str object previously obtained 7333** from [sqlite3_str_new()]. 7334** 7335** ^The [sqlite3_str_appendf(X,F,...)] and 7336** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7337** functionality of SQLite to append formatted text onto the end of 7338** [sqlite3_str] object X. 7339** 7340** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7341** onto the end of the [sqlite3_str] object X. N must be non-negative. 7342** S must contain at least N non-zero bytes of content. To append a 7343** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7344** method instead. 7345** 7346** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7347** zero-terminated string S onto the end of [sqlite3_str] object X. 7348** 7349** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7350** single-byte character C onto the end of [sqlite3_str] object X. 7351** ^This method can be used, for example, to add whitespace indentation. 7352** 7353** ^The [sqlite3_str_reset(X)] method resets the string under construction 7354** inside [sqlite3_str] object X back to zero bytes in length. 7355** 7356** These methods do not return a result code. ^If an error occurs, that fact 7357** is recorded in the [sqlite3_str] object and can be recovered by a 7358** subsequent call to [sqlite3_str_errcode(X)]. 7359*/ 7360void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7361void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7362void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7363void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7364void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7365void sqlite3_str_reset(sqlite3_str*); 7366 7367/* 7368** CAPI3REF: Status Of A Dynamic String 7369** METHOD: sqlite3_str 7370** 7371** These interfaces return the current status of an [sqlite3_str] object. 7372** 7373** ^If any prior errors have occurred while constructing the dynamic string 7374** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7375** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7376** [SQLITE_NOMEM] following any out-of-memory error, or 7377** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7378** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7379** 7380** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7381** of the dynamic string under construction in [sqlite3_str] object X. 7382** ^The length returned by [sqlite3_str_length(X)] does not include the 7383** zero-termination byte. 7384** 7385** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7386** content of the dynamic string under construction in X. The value 7387** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7388** and might be freed or altered by any subsequent method on the same 7389** [sqlite3_str] object. Applications must not used the pointer returned 7390** [sqlite3_str_value(X)] after any subsequent method call on the same 7391** object. ^Applications may change the content of the string returned 7392** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7393** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7394** write any byte after any subsequent sqlite3_str method call. 7395*/ 7396int sqlite3_str_errcode(sqlite3_str*); 7397int sqlite3_str_length(sqlite3_str*); 7398char *sqlite3_str_value(sqlite3_str*); 7399 7400/* 7401** CAPI3REF: SQLite Runtime Status 7402** 7403** ^These interfaces are used to retrieve runtime status information 7404** about the performance of SQLite, and optionally to reset various 7405** highwater marks. ^The first argument is an integer code for 7406** the specific parameter to measure. ^(Recognized integer codes 7407** are of the form [status parameters | SQLITE_STATUS_...].)^ 7408** ^The current value of the parameter is returned into *pCurrent. 7409** ^The highest recorded value is returned in *pHighwater. ^If the 7410** resetFlag is true, then the highest record value is reset after 7411** *pHighwater is written. ^(Some parameters do not record the highest 7412** value. For those parameters 7413** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7414** ^(Other parameters record only the highwater mark and not the current 7415** value. For these latter parameters nothing is written into *pCurrent.)^ 7416** 7417** ^The sqlite3_status() and sqlite3_status64() routines return 7418** SQLITE_OK on success and a non-zero [error code] on failure. 7419** 7420** If either the current value or the highwater mark is too large to 7421** be represented by a 32-bit integer, then the values returned by 7422** sqlite3_status() are undefined. 7423** 7424** See also: [sqlite3_db_status()] 7425*/ 7426int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7427int sqlite3_status64( 7428 int op, 7429 sqlite3_int64 *pCurrent, 7430 sqlite3_int64 *pHighwater, 7431 int resetFlag 7432); 7433 7434 7435/* 7436** CAPI3REF: Status Parameters 7437** KEYWORDS: {status parameters} 7438** 7439** These integer constants designate various run-time status parameters 7440** that can be returned by [sqlite3_status()]. 7441** 7442** <dl> 7443** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7444** <dd>This parameter is the current amount of memory checked out 7445** using [sqlite3_malloc()], either directly or indirectly. The 7446** figure includes calls made to [sqlite3_malloc()] by the application 7447** and internal memory usage by the SQLite library. Auxiliary page-cache 7448** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7449** this parameter. The amount returned is the sum of the allocation 7450** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7451** 7452** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7453** <dd>This parameter records the largest memory allocation request 7454** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7455** internal equivalents). Only the value returned in the 7456** *pHighwater parameter to [sqlite3_status()] is of interest. 7457** The value written into the *pCurrent parameter is undefined.</dd>)^ 7458** 7459** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7460** <dd>This parameter records the number of separate memory allocations 7461** currently checked out.</dd>)^ 7462** 7463** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7464** <dd>This parameter returns the number of pages used out of the 7465** [pagecache memory allocator] that was configured using 7466** [SQLITE_CONFIG_PAGECACHE]. The 7467** value returned is in pages, not in bytes.</dd>)^ 7468** 7469** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7470** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7471** <dd>This parameter returns the number of bytes of page cache 7472** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7473** buffer and where forced to overflow to [sqlite3_malloc()]. The 7474** returned value includes allocations that overflowed because they 7475** where too large (they were larger than the "sz" parameter to 7476** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7477** no space was left in the page cache.</dd>)^ 7478** 7479** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7480** <dd>This parameter records the largest memory allocation request 7481** handed to [pagecache memory allocator]. Only the value returned in the 7482** *pHighwater parameter to [sqlite3_status()] is of interest. 7483** The value written into the *pCurrent parameter is undefined.</dd>)^ 7484** 7485** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7486** <dd>No longer used.</dd> 7487** 7488** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7489** <dd>No longer used.</dd> 7490** 7491** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7492** <dd>No longer used.</dd> 7493** 7494** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7495** <dd>The *pHighwater parameter records the deepest parser stack. 7496** The *pCurrent value is undefined. The *pHighwater value is only 7497** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7498** </dl> 7499** 7500** New status parameters may be added from time to time. 7501*/ 7502#define SQLITE_STATUS_MEMORY_USED 0 7503#define SQLITE_STATUS_PAGECACHE_USED 1 7504#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7505#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7506#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7507#define SQLITE_STATUS_MALLOC_SIZE 5 7508#define SQLITE_STATUS_PARSER_STACK 6 7509#define SQLITE_STATUS_PAGECACHE_SIZE 7 7510#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7511#define SQLITE_STATUS_MALLOC_COUNT 9 7512 7513/* 7514** CAPI3REF: Database Connection Status 7515** METHOD: sqlite3 7516** 7517** ^This interface is used to retrieve runtime status information 7518** about a single [database connection]. ^The first argument is the 7519** database connection object to be interrogated. ^The second argument 7520** is an integer constant, taken from the set of 7521** [SQLITE_DBSTATUS options], that 7522** determines the parameter to interrogate. The set of 7523** [SQLITE_DBSTATUS options] is likely 7524** to grow in future releases of SQLite. 7525** 7526** ^The current value of the requested parameter is written into *pCur 7527** and the highest instantaneous value is written into *pHiwtr. ^If 7528** the resetFlg is true, then the highest instantaneous value is 7529** reset back down to the current value. 7530** 7531** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7532** non-zero [error code] on failure. 7533** 7534** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7535*/ 7536int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7537 7538/* 7539** CAPI3REF: Status Parameters for database connections 7540** KEYWORDS: {SQLITE_DBSTATUS options} 7541** 7542** These constants are the available integer "verbs" that can be passed as 7543** the second argument to the [sqlite3_db_status()] interface. 7544** 7545** New verbs may be added in future releases of SQLite. Existing verbs 7546** might be discontinued. Applications should check the return code from 7547** [sqlite3_db_status()] to make sure that the call worked. 7548** The [sqlite3_db_status()] interface will return a non-zero error code 7549** if a discontinued or unsupported verb is invoked. 7550** 7551** <dl> 7552** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7553** <dd>This parameter returns the number of lookaside memory slots currently 7554** checked out.</dd>)^ 7555** 7556** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7557** <dd>This parameter returns the number malloc attempts that were 7558** satisfied using lookaside memory. Only the high-water value is meaningful; 7559** the current value is always zero.)^ 7560** 7561** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7562** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7563** <dd>This parameter returns the number malloc attempts that might have 7564** been satisfied using lookaside memory but failed due to the amount of 7565** memory requested being larger than the lookaside slot size. 7566** Only the high-water value is meaningful; 7567** the current value is always zero.)^ 7568** 7569** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7570** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7571** <dd>This parameter returns the number malloc attempts that might have 7572** been satisfied using lookaside memory but failed due to all lookaside 7573** memory already being in use. 7574** Only the high-water value is meaningful; 7575** the current value is always zero.)^ 7576** 7577** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7578** <dd>This parameter returns the approximate number of bytes of heap 7579** memory used by all pager caches associated with the database connection.)^ 7580** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7581** 7582** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7583** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7584** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7585** pager cache is shared between two or more connections the bytes of heap 7586** memory used by that pager cache is divided evenly between the attached 7587** connections.)^ In other words, if none of the pager caches associated 7588** with the database connection are shared, this request returns the same 7589** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7590** shared, the value returned by this call will be smaller than that returned 7591** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7592** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7593** 7594** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7595** <dd>This parameter returns the approximate number of bytes of heap 7596** memory used to store the schema for all databases associated 7597** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7598** ^The full amount of memory used by the schemas is reported, even if the 7599** schema memory is shared with other database connections due to 7600** [shared cache mode] being enabled. 7601** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7602** 7603** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7604** <dd>This parameter returns the approximate number of bytes of heap 7605** and lookaside memory used by all prepared statements associated with 7606** the database connection.)^ 7607** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7608** </dd> 7609** 7610** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7611** <dd>This parameter returns the number of pager cache hits that have 7612** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7613** is always 0. 7614** </dd> 7615** 7616** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7617** <dd>This parameter returns the number of pager cache misses that have 7618** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7619** is always 0. 7620** </dd> 7621** 7622** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7623** <dd>This parameter returns the number of dirty cache entries that have 7624** been written to disk. Specifically, the number of pages written to the 7625** wal file in wal mode databases, or the number of pages written to the 7626** database file in rollback mode databases. Any pages written as part of 7627** transaction rollback or database recovery operations are not included. 7628** If an IO or other error occurs while writing a page to disk, the effect 7629** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7630** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7631** </dd> 7632** 7633** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7634** <dd>This parameter returns the number of dirty cache entries that have 7635** been written to disk in the middle of a transaction due to the page 7636** cache overflowing. Transactions are more efficient if they are written 7637** to disk all at once. When pages spill mid-transaction, that introduces 7638** additional overhead. This parameter can be used help identify 7639** inefficiencies that can be resolve by increasing the cache size. 7640** </dd> 7641** 7642** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7643** <dd>This parameter returns zero for the current value if and only if 7644** all foreign key constraints (deferred or immediate) have been 7645** resolved.)^ ^The highwater mark is always 0. 7646** </dd> 7647** </dl> 7648*/ 7649#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7650#define SQLITE_DBSTATUS_CACHE_USED 1 7651#define SQLITE_DBSTATUS_SCHEMA_USED 2 7652#define SQLITE_DBSTATUS_STMT_USED 3 7653#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7654#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7655#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7656#define SQLITE_DBSTATUS_CACHE_HIT 7 7657#define SQLITE_DBSTATUS_CACHE_MISS 8 7658#define SQLITE_DBSTATUS_CACHE_WRITE 9 7659#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7660#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7661#define SQLITE_DBSTATUS_CACHE_SPILL 12 7662#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7663 7664 7665/* 7666** CAPI3REF: Prepared Statement Status 7667** METHOD: sqlite3_stmt 7668** 7669** ^(Each prepared statement maintains various 7670** [SQLITE_STMTSTATUS counters] that measure the number 7671** of times it has performed specific operations.)^ These counters can 7672** be used to monitor the performance characteristics of the prepared 7673** statements. For example, if the number of table steps greatly exceeds 7674** the number of table searches or result rows, that would tend to indicate 7675** that the prepared statement is using a full table scan rather than 7676** an index. 7677** 7678** ^(This interface is used to retrieve and reset counter values from 7679** a [prepared statement]. The first argument is the prepared statement 7680** object to be interrogated. The second argument 7681** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7682** to be interrogated.)^ 7683** ^The current value of the requested counter is returned. 7684** ^If the resetFlg is true, then the counter is reset to zero after this 7685** interface call returns. 7686** 7687** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7688*/ 7689int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7690 7691/* 7692** CAPI3REF: Status Parameters for prepared statements 7693** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7694** 7695** These preprocessor macros define integer codes that name counter 7696** values associated with the [sqlite3_stmt_status()] interface. 7697** The meanings of the various counters are as follows: 7698** 7699** <dl> 7700** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7701** <dd>^This is the number of times that SQLite has stepped forward in 7702** a table as part of a full table scan. Large numbers for this counter 7703** may indicate opportunities for performance improvement through 7704** careful use of indices.</dd> 7705** 7706** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7707** <dd>^This is the number of sort operations that have occurred. 7708** A non-zero value in this counter may indicate an opportunity to 7709** improvement performance through careful use of indices.</dd> 7710** 7711** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7712** <dd>^This is the number of rows inserted into transient indices that 7713** were created automatically in order to help joins run faster. 7714** A non-zero value in this counter may indicate an opportunity to 7715** improvement performance by adding permanent indices that do not 7716** need to be reinitialized each time the statement is run.</dd> 7717** 7718** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7719** <dd>^This is the number of virtual machine operations executed 7720** by the prepared statement if that number is less than or equal 7721** to 2147483647. The number of virtual machine operations can be 7722** used as a proxy for the total work done by the prepared statement. 7723** If the number of virtual machine operations exceeds 2147483647 7724** then the value returned by this statement status code is undefined. 7725** 7726** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7727** <dd>^This is the number of times that the prepare statement has been 7728** automatically regenerated due to schema changes or change to 7729** [bound parameters] that might affect the query plan. 7730** 7731** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7732** <dd>^This is the number of times that the prepared statement has 7733** been run. A single "run" for the purposes of this counter is one 7734** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7735** The counter is incremented on the first [sqlite3_step()] call of each 7736** cycle. 7737** 7738** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7739** <dd>^This is the approximate number of bytes of heap memory 7740** used to store the prepared statement. ^This value is not actually 7741** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7742** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7743** </dd> 7744** </dl> 7745*/ 7746#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7747#define SQLITE_STMTSTATUS_SORT 2 7748#define SQLITE_STMTSTATUS_AUTOINDEX 3 7749#define SQLITE_STMTSTATUS_VM_STEP 4 7750#define SQLITE_STMTSTATUS_REPREPARE 5 7751#define SQLITE_STMTSTATUS_RUN 6 7752#define SQLITE_STMTSTATUS_MEMUSED 99 7753 7754/* 7755** CAPI3REF: Custom Page Cache Object 7756** 7757** The sqlite3_pcache type is opaque. It is implemented by 7758** the pluggable module. The SQLite core has no knowledge of 7759** its size or internal structure and never deals with the 7760** sqlite3_pcache object except by holding and passing pointers 7761** to the object. 7762** 7763** See [sqlite3_pcache_methods2] for additional information. 7764*/ 7765typedef struct sqlite3_pcache sqlite3_pcache; 7766 7767/* 7768** CAPI3REF: Custom Page Cache Object 7769** 7770** The sqlite3_pcache_page object represents a single page in the 7771** page cache. The page cache will allocate instances of this 7772** object. Various methods of the page cache use pointers to instances 7773** of this object as parameters or as their return value. 7774** 7775** See [sqlite3_pcache_methods2] for additional information. 7776*/ 7777typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7778struct sqlite3_pcache_page { 7779 void *pBuf; /* The content of the page */ 7780 void *pExtra; /* Extra information associated with the page */ 7781}; 7782 7783/* 7784** CAPI3REF: Application Defined Page Cache. 7785** KEYWORDS: {page cache} 7786** 7787** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7788** register an alternative page cache implementation by passing in an 7789** instance of the sqlite3_pcache_methods2 structure.)^ 7790** In many applications, most of the heap memory allocated by 7791** SQLite is used for the page cache. 7792** By implementing a 7793** custom page cache using this API, an application can better control 7794** the amount of memory consumed by SQLite, the way in which 7795** that memory is allocated and released, and the policies used to 7796** determine exactly which parts of a database file are cached and for 7797** how long. 7798** 7799** The alternative page cache mechanism is an 7800** extreme measure that is only needed by the most demanding applications. 7801** The built-in page cache is recommended for most uses. 7802** 7803** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7804** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7805** the application may discard the parameter after the call to 7806** [sqlite3_config()] returns.)^ 7807** 7808** [[the xInit() page cache method]] 7809** ^(The xInit() method is called once for each effective 7810** call to [sqlite3_initialize()])^ 7811** (usually only once during the lifetime of the process). ^(The xInit() 7812** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7813** The intent of the xInit() method is to set up global data structures 7814** required by the custom page cache implementation. 7815** ^(If the xInit() method is NULL, then the 7816** built-in default page cache is used instead of the application defined 7817** page cache.)^ 7818** 7819** [[the xShutdown() page cache method]] 7820** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7821** It can be used to clean up 7822** any outstanding resources before process shutdown, if required. 7823** ^The xShutdown() method may be NULL. 7824** 7825** ^SQLite automatically serializes calls to the xInit method, 7826** so the xInit method need not be threadsafe. ^The 7827** xShutdown method is only called from [sqlite3_shutdown()] so it does 7828** not need to be threadsafe either. All other methods must be threadsafe 7829** in multithreaded applications. 7830** 7831** ^SQLite will never invoke xInit() more than once without an intervening 7832** call to xShutdown(). 7833** 7834** [[the xCreate() page cache methods]] 7835** ^SQLite invokes the xCreate() method to construct a new cache instance. 7836** SQLite will typically create one cache instance for each open database file, 7837** though this is not guaranteed. ^The 7838** first parameter, szPage, is the size in bytes of the pages that must 7839** be allocated by the cache. ^szPage will always a power of two. ^The 7840** second parameter szExtra is a number of bytes of extra storage 7841** associated with each page cache entry. ^The szExtra parameter will 7842** a number less than 250. SQLite will use the 7843** extra szExtra bytes on each page to store metadata about the underlying 7844** database page on disk. The value passed into szExtra depends 7845** on the SQLite version, the target platform, and how SQLite was compiled. 7846** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7847** created will be used to cache database pages of a file stored on disk, or 7848** false if it is used for an in-memory database. The cache implementation 7849** does not have to do anything special based with the value of bPurgeable; 7850** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7851** never invoke xUnpin() except to deliberately delete a page. 7852** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7853** false will always have the "discard" flag set to true. 7854** ^Hence, a cache created with bPurgeable false will 7855** never contain any unpinned pages. 7856** 7857** [[the xCachesize() page cache method]] 7858** ^(The xCachesize() method may be called at any time by SQLite to set the 7859** suggested maximum cache-size (number of pages stored by) the cache 7860** instance passed as the first argument. This is the value configured using 7861** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7862** parameter, the implementation is not required to do anything with this 7863** value; it is advisory only. 7864** 7865** [[the xPagecount() page cache methods]] 7866** The xPagecount() method must return the number of pages currently 7867** stored in the cache, both pinned and unpinned. 7868** 7869** [[the xFetch() page cache methods]] 7870** The xFetch() method locates a page in the cache and returns a pointer to 7871** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7872** The pBuf element of the returned sqlite3_pcache_page object will be a 7873** pointer to a buffer of szPage bytes used to store the content of a 7874** single database page. The pExtra element of sqlite3_pcache_page will be 7875** a pointer to the szExtra bytes of extra storage that SQLite has requested 7876** for each entry in the page cache. 7877** 7878** The page to be fetched is determined by the key. ^The minimum key value 7879** is 1. After it has been retrieved using xFetch, the page is considered 7880** to be "pinned". 7881** 7882** If the requested page is already in the page cache, then the page cache 7883** implementation must return a pointer to the page buffer with its content 7884** intact. If the requested page is not already in the cache, then the 7885** cache implementation should use the value of the createFlag 7886** parameter to help it determined what action to take: 7887** 7888** <table border=1 width=85% align=center> 7889** <tr><th> createFlag <th> Behavior when page is not already in cache 7890** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7891** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7892** Otherwise return NULL. 7893** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7894** NULL if allocating a new page is effectively impossible. 7895** </table> 7896** 7897** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7898** will only use a createFlag of 2 after a prior call with a createFlag of 1 7899** failed.)^ In between the to xFetch() calls, SQLite may 7900** attempt to unpin one or more cache pages by spilling the content of 7901** pinned pages to disk and synching the operating system disk cache. 7902** 7903** [[the xUnpin() page cache method]] 7904** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7905** as its second argument. If the third parameter, discard, is non-zero, 7906** then the page must be evicted from the cache. 7907** ^If the discard parameter is 7908** zero, then the page may be discarded or retained at the discretion of 7909** page cache implementation. ^The page cache implementation 7910** may choose to evict unpinned pages at any time. 7911** 7912** The cache must not perform any reference counting. A single 7913** call to xUnpin() unpins the page regardless of the number of prior calls 7914** to xFetch(). 7915** 7916** [[the xRekey() page cache methods]] 7917** The xRekey() method is used to change the key value associated with the 7918** page passed as the second argument. If the cache 7919** previously contains an entry associated with newKey, it must be 7920** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7921** to be pinned. 7922** 7923** When SQLite calls the xTruncate() method, the cache must discard all 7924** existing cache entries with page numbers (keys) greater than or equal 7925** to the value of the iLimit parameter passed to xTruncate(). If any 7926** of these pages are pinned, they are implicitly unpinned, meaning that 7927** they can be safely discarded. 7928** 7929** [[the xDestroy() page cache method]] 7930** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7931** All resources associated with the specified cache should be freed. ^After 7932** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7933** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7934** functions. 7935** 7936** [[the xShrink() page cache method]] 7937** ^SQLite invokes the xShrink() method when it wants the page cache to 7938** free up as much of heap memory as possible. The page cache implementation 7939** is not obligated to free any memory, but well-behaved implementations should 7940** do their best. 7941*/ 7942typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7943struct sqlite3_pcache_methods2 { 7944 int iVersion; 7945 void *pArg; 7946 int (*xInit)(void*); 7947 void (*xShutdown)(void*); 7948 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7949 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7950 int (*xPagecount)(sqlite3_pcache*); 7951 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7952 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7953 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7954 unsigned oldKey, unsigned newKey); 7955 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7956 void (*xDestroy)(sqlite3_pcache*); 7957 void (*xShrink)(sqlite3_pcache*); 7958}; 7959 7960/* 7961** This is the obsolete pcache_methods object that has now been replaced 7962** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7963** retained in the header file for backwards compatibility only. 7964*/ 7965typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7966struct sqlite3_pcache_methods { 7967 void *pArg; 7968 int (*xInit)(void*); 7969 void (*xShutdown)(void*); 7970 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7971 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7972 int (*xPagecount)(sqlite3_pcache*); 7973 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7974 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7975 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7976 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7977 void (*xDestroy)(sqlite3_pcache*); 7978}; 7979 7980 7981/* 7982** CAPI3REF: Online Backup Object 7983** 7984** The sqlite3_backup object records state information about an ongoing 7985** online backup operation. ^The sqlite3_backup object is created by 7986** a call to [sqlite3_backup_init()] and is destroyed by a call to 7987** [sqlite3_backup_finish()]. 7988** 7989** See Also: [Using the SQLite Online Backup API] 7990*/ 7991typedef struct sqlite3_backup sqlite3_backup; 7992 7993/* 7994** CAPI3REF: Online Backup API. 7995** 7996** The backup API copies the content of one database into another. 7997** It is useful either for creating backups of databases or 7998** for copying in-memory databases to or from persistent files. 7999** 8000** See Also: [Using the SQLite Online Backup API] 8001** 8002** ^SQLite holds a write transaction open on the destination database file 8003** for the duration of the backup operation. 8004** ^The source database is read-locked only while it is being read; 8005** it is not locked continuously for the entire backup operation. 8006** ^Thus, the backup may be performed on a live source database without 8007** preventing other database connections from 8008** reading or writing to the source database while the backup is underway. 8009** 8010** ^(To perform a backup operation: 8011** <ol> 8012** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8013** backup, 8014** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8015** the data between the two databases, and finally 8016** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8017** associated with the backup operation. 8018** </ol>)^ 8019** There should be exactly one call to sqlite3_backup_finish() for each 8020** successful call to sqlite3_backup_init(). 8021** 8022** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8023** 8024** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8025** [database connection] associated with the destination database 8026** and the database name, respectively. 8027** ^The database name is "main" for the main database, "temp" for the 8028** temporary database, or the name specified after the AS keyword in 8029** an [ATTACH] statement for an attached database. 8030** ^The S and M arguments passed to 8031** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8032** and database name of the source database, respectively. 8033** ^The source and destination [database connections] (parameters S and D) 8034** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8035** an error. 8036** 8037** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8038** there is already a read or read-write transaction open on the 8039** destination database. 8040** 8041** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8042** returned and an error code and error message are stored in the 8043** destination [database connection] D. 8044** ^The error code and message for the failed call to sqlite3_backup_init() 8045** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8046** [sqlite3_errmsg16()] functions. 8047** ^A successful call to sqlite3_backup_init() returns a pointer to an 8048** [sqlite3_backup] object. 8049** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8050** sqlite3_backup_finish() functions to perform the specified backup 8051** operation. 8052** 8053** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8054** 8055** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8056** the source and destination databases specified by [sqlite3_backup] object B. 8057** ^If N is negative, all remaining source pages are copied. 8058** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8059** are still more pages to be copied, then the function returns [SQLITE_OK]. 8060** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8061** from source to destination, then it returns [SQLITE_DONE]. 8062** ^If an error occurs while running sqlite3_backup_step(B,N), 8063** then an [error code] is returned. ^As well as [SQLITE_OK] and 8064** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8065** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8066** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8067** 8068** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8069** <ol> 8070** <li> the destination database was opened read-only, or 8071** <li> the destination database is using write-ahead-log journaling 8072** and the destination and source page sizes differ, or 8073** <li> the destination database is an in-memory database and the 8074** destination and source page sizes differ. 8075** </ol>)^ 8076** 8077** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8078** the [sqlite3_busy_handler | busy-handler function] 8079** is invoked (if one is specified). ^If the 8080** busy-handler returns non-zero before the lock is available, then 8081** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8082** sqlite3_backup_step() can be retried later. ^If the source 8083** [database connection] 8084** is being used to write to the source database when sqlite3_backup_step() 8085** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8086** case the call to sqlite3_backup_step() can be retried later on. ^(If 8087** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8088** [SQLITE_READONLY] is returned, then 8089** there is no point in retrying the call to sqlite3_backup_step(). These 8090** errors are considered fatal.)^ The application must accept 8091** that the backup operation has failed and pass the backup operation handle 8092** to the sqlite3_backup_finish() to release associated resources. 8093** 8094** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8095** on the destination file. ^The exclusive lock is not released until either 8096** sqlite3_backup_finish() is called or the backup operation is complete 8097** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8098** sqlite3_backup_step() obtains a [shared lock] on the source database that 8099** lasts for the duration of the sqlite3_backup_step() call. 8100** ^Because the source database is not locked between calls to 8101** sqlite3_backup_step(), the source database may be modified mid-way 8102** through the backup process. ^If the source database is modified by an 8103** external process or via a database connection other than the one being 8104** used by the backup operation, then the backup will be automatically 8105** restarted by the next call to sqlite3_backup_step(). ^If the source 8106** database is modified by the using the same database connection as is used 8107** by the backup operation, then the backup database is automatically 8108** updated at the same time. 8109** 8110** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8111** 8112** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8113** application wishes to abandon the backup operation, the application 8114** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8115** ^The sqlite3_backup_finish() interfaces releases all 8116** resources associated with the [sqlite3_backup] object. 8117** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8118** active write-transaction on the destination database is rolled back. 8119** The [sqlite3_backup] object is invalid 8120** and may not be used following a call to sqlite3_backup_finish(). 8121** 8122** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8123** sqlite3_backup_step() errors occurred, regardless or whether or not 8124** sqlite3_backup_step() completed. 8125** ^If an out-of-memory condition or IO error occurred during any prior 8126** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8127** sqlite3_backup_finish() returns the corresponding [error code]. 8128** 8129** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8130** is not a permanent error and does not affect the return value of 8131** sqlite3_backup_finish(). 8132** 8133** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8134** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8135** 8136** ^The sqlite3_backup_remaining() routine returns the number of pages still 8137** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8138** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8139** in the source database at the conclusion of the most recent 8140** sqlite3_backup_step(). 8141** ^(The values returned by these functions are only updated by 8142** sqlite3_backup_step(). If the source database is modified in a way that 8143** changes the size of the source database or the number of pages remaining, 8144** those changes are not reflected in the output of sqlite3_backup_pagecount() 8145** and sqlite3_backup_remaining() until after the next 8146** sqlite3_backup_step().)^ 8147** 8148** <b>Concurrent Usage of Database Handles</b> 8149** 8150** ^The source [database connection] may be used by the application for other 8151** purposes while a backup operation is underway or being initialized. 8152** ^If SQLite is compiled and configured to support threadsafe database 8153** connections, then the source database connection may be used concurrently 8154** from within other threads. 8155** 8156** However, the application must guarantee that the destination 8157** [database connection] is not passed to any other API (by any thread) after 8158** sqlite3_backup_init() is called and before the corresponding call to 8159** sqlite3_backup_finish(). SQLite does not currently check to see 8160** if the application incorrectly accesses the destination [database connection] 8161** and so no error code is reported, but the operations may malfunction 8162** nevertheless. Use of the destination database connection while a 8163** backup is in progress might also also cause a mutex deadlock. 8164** 8165** If running in [shared cache mode], the application must 8166** guarantee that the shared cache used by the destination database 8167** is not accessed while the backup is running. In practice this means 8168** that the application must guarantee that the disk file being 8169** backed up to is not accessed by any connection within the process, 8170** not just the specific connection that was passed to sqlite3_backup_init(). 8171** 8172** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8173** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8174** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8175** APIs are not strictly speaking threadsafe. If they are invoked at the 8176** same time as another thread is invoking sqlite3_backup_step() it is 8177** possible that they return invalid values. 8178*/ 8179sqlite3_backup *sqlite3_backup_init( 8180 sqlite3 *pDest, /* Destination database handle */ 8181 const char *zDestName, /* Destination database name */ 8182 sqlite3 *pSource, /* Source database handle */ 8183 const char *zSourceName /* Source database name */ 8184); 8185int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8186int sqlite3_backup_finish(sqlite3_backup *p); 8187int sqlite3_backup_remaining(sqlite3_backup *p); 8188int sqlite3_backup_pagecount(sqlite3_backup *p); 8189 8190/* 8191** CAPI3REF: Unlock Notification 8192** METHOD: sqlite3 8193** 8194** ^When running in shared-cache mode, a database operation may fail with 8195** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8196** individual tables within the shared-cache cannot be obtained. See 8197** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8198** ^This API may be used to register a callback that SQLite will invoke 8199** when the connection currently holding the required lock relinquishes it. 8200** ^This API is only available if the library was compiled with the 8201** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8202** 8203** See Also: [Using the SQLite Unlock Notification Feature]. 8204** 8205** ^Shared-cache locks are released when a database connection concludes 8206** its current transaction, either by committing it or rolling it back. 8207** 8208** ^When a connection (known as the blocked connection) fails to obtain a 8209** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8210** identity of the database connection (the blocking connection) that 8211** has locked the required resource is stored internally. ^After an 8212** application receives an SQLITE_LOCKED error, it may call the 8213** sqlite3_unlock_notify() method with the blocked connection handle as 8214** the first argument to register for a callback that will be invoked 8215** when the blocking connections current transaction is concluded. ^The 8216** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8217** call that concludes the blocking connections transaction. 8218** 8219** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8220** there is a chance that the blocking connection will have already 8221** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8222** If this happens, then the specified callback is invoked immediately, 8223** from within the call to sqlite3_unlock_notify().)^ 8224** 8225** ^If the blocked connection is attempting to obtain a write-lock on a 8226** shared-cache table, and more than one other connection currently holds 8227** a read-lock on the same table, then SQLite arbitrarily selects one of 8228** the other connections to use as the blocking connection. 8229** 8230** ^(There may be at most one unlock-notify callback registered by a 8231** blocked connection. If sqlite3_unlock_notify() is called when the 8232** blocked connection already has a registered unlock-notify callback, 8233** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8234** called with a NULL pointer as its second argument, then any existing 8235** unlock-notify callback is canceled. ^The blocked connections 8236** unlock-notify callback may also be canceled by closing the blocked 8237** connection using [sqlite3_close()]. 8238** 8239** The unlock-notify callback is not reentrant. If an application invokes 8240** any sqlite3_xxx API functions from within an unlock-notify callback, a 8241** crash or deadlock may be the result. 8242** 8243** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8244** returns SQLITE_OK. 8245** 8246** <b>Callback Invocation Details</b> 8247** 8248** When an unlock-notify callback is registered, the application provides a 8249** single void* pointer that is passed to the callback when it is invoked. 8250** However, the signature of the callback function allows SQLite to pass 8251** it an array of void* context pointers. The first argument passed to 8252** an unlock-notify callback is a pointer to an array of void* pointers, 8253** and the second is the number of entries in the array. 8254** 8255** When a blocking connections transaction is concluded, there may be 8256** more than one blocked connection that has registered for an unlock-notify 8257** callback. ^If two or more such blocked connections have specified the 8258** same callback function, then instead of invoking the callback function 8259** multiple times, it is invoked once with the set of void* context pointers 8260** specified by the blocked connections bundled together into an array. 8261** This gives the application an opportunity to prioritize any actions 8262** related to the set of unblocked database connections. 8263** 8264** <b>Deadlock Detection</b> 8265** 8266** Assuming that after registering for an unlock-notify callback a 8267** database waits for the callback to be issued before taking any further 8268** action (a reasonable assumption), then using this API may cause the 8269** application to deadlock. For example, if connection X is waiting for 8270** connection Y's transaction to be concluded, and similarly connection 8271** Y is waiting on connection X's transaction, then neither connection 8272** will proceed and the system may remain deadlocked indefinitely. 8273** 8274** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8275** detection. ^If a given call to sqlite3_unlock_notify() would put the 8276** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8277** unlock-notify callback is registered. The system is said to be in 8278** a deadlocked state if connection A has registered for an unlock-notify 8279** callback on the conclusion of connection B's transaction, and connection 8280** B has itself registered for an unlock-notify callback when connection 8281** A's transaction is concluded. ^Indirect deadlock is also detected, so 8282** the system is also considered to be deadlocked if connection B has 8283** registered for an unlock-notify callback on the conclusion of connection 8284** C's transaction, where connection C is waiting on connection A. ^Any 8285** number of levels of indirection are allowed. 8286** 8287** <b>The "DROP TABLE" Exception</b> 8288** 8289** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8290** always appropriate to call sqlite3_unlock_notify(). There is however, 8291** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8292** SQLite checks if there are any currently executing SELECT statements 8293** that belong to the same connection. If there are, SQLITE_LOCKED is 8294** returned. In this case there is no "blocking connection", so invoking 8295** sqlite3_unlock_notify() results in the unlock-notify callback being 8296** invoked immediately. If the application then re-attempts the "DROP TABLE" 8297** or "DROP INDEX" query, an infinite loop might be the result. 8298** 8299** One way around this problem is to check the extended error code returned 8300** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8301** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8302** the special "DROP TABLE/INDEX" case, the extended error code is just 8303** SQLITE_LOCKED.)^ 8304*/ 8305int sqlite3_unlock_notify( 8306 sqlite3 *pBlocked, /* Waiting connection */ 8307 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8308 void *pNotifyArg /* Argument to pass to xNotify */ 8309); 8310 8311 8312/* 8313** CAPI3REF: String Comparison 8314** 8315** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8316** and extensions to compare the contents of two buffers containing UTF-8 8317** strings in a case-independent fashion, using the same definition of "case 8318** independence" that SQLite uses internally when comparing identifiers. 8319*/ 8320int sqlite3_stricmp(const char *, const char *); 8321int sqlite3_strnicmp(const char *, const char *, int); 8322 8323/* 8324** CAPI3REF: String Globbing 8325* 8326** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8327** string X matches the [GLOB] pattern P. 8328** ^The definition of [GLOB] pattern matching used in 8329** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8330** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8331** is case sensitive. 8332** 8333** Note that this routine returns zero on a match and non-zero if the strings 8334** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8335** 8336** See also: [sqlite3_strlike()]. 8337*/ 8338int sqlite3_strglob(const char *zGlob, const char *zStr); 8339 8340/* 8341** CAPI3REF: String LIKE Matching 8342* 8343** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8344** string X matches the [LIKE] pattern P with escape character E. 8345** ^The definition of [LIKE] pattern matching used in 8346** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8347** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8348** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8349** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8350** insensitive - equivalent upper and lower case ASCII characters match 8351** one another. 8352** 8353** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8354** only ASCII characters are case folded. 8355** 8356** Note that this routine returns zero on a match and non-zero if the strings 8357** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8358** 8359** See also: [sqlite3_strglob()]. 8360*/ 8361int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8362 8363/* 8364** CAPI3REF: Error Logging Interface 8365** 8366** ^The [sqlite3_log()] interface writes a message into the [error log] 8367** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8368** ^If logging is enabled, the zFormat string and subsequent arguments are 8369** used with [sqlite3_snprintf()] to generate the final output string. 8370** 8371** The sqlite3_log() interface is intended for use by extensions such as 8372** virtual tables, collating functions, and SQL functions. While there is 8373** nothing to prevent an application from calling sqlite3_log(), doing so 8374** is considered bad form. 8375** 8376** The zFormat string must not be NULL. 8377** 8378** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8379** will not use dynamically allocated memory. The log message is stored in 8380** a fixed-length buffer on the stack. If the log message is longer than 8381** a few hundred characters, it will be truncated to the length of the 8382** buffer. 8383*/ 8384void sqlite3_log(int iErrCode, const char *zFormat, ...); 8385 8386/* 8387** CAPI3REF: Write-Ahead Log Commit Hook 8388** METHOD: sqlite3 8389** 8390** ^The [sqlite3_wal_hook()] function is used to register a callback that 8391** is invoked each time data is committed to a database in wal mode. 8392** 8393** ^(The callback is invoked by SQLite after the commit has taken place and 8394** the associated write-lock on the database released)^, so the implementation 8395** may read, write or [checkpoint] the database as required. 8396** 8397** ^The first parameter passed to the callback function when it is invoked 8398** is a copy of the third parameter passed to sqlite3_wal_hook() when 8399** registering the callback. ^The second is a copy of the database handle. 8400** ^The third parameter is the name of the database that was written to - 8401** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8402** is the number of pages currently in the write-ahead log file, 8403** including those that were just committed. 8404** 8405** The callback function should normally return [SQLITE_OK]. ^If an error 8406** code is returned, that error will propagate back up through the 8407** SQLite code base to cause the statement that provoked the callback 8408** to report an error, though the commit will have still occurred. If the 8409** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8410** that does not correspond to any valid SQLite error code, the results 8411** are undefined. 8412** 8413** A single database handle may have at most a single write-ahead log callback 8414** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8415** previously registered write-ahead log callback. ^Note that the 8416** [sqlite3_wal_autocheckpoint()] interface and the 8417** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8418** overwrite any prior [sqlite3_wal_hook()] settings. 8419*/ 8420void *sqlite3_wal_hook( 8421 sqlite3*, 8422 int(*)(void *,sqlite3*,const char*,int), 8423 void* 8424); 8425 8426/* 8427** CAPI3REF: Configure an auto-checkpoint 8428** METHOD: sqlite3 8429** 8430** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8431** [sqlite3_wal_hook()] that causes any database on [database connection] D 8432** to automatically [checkpoint] 8433** after committing a transaction if there are N or 8434** more frames in the [write-ahead log] file. ^Passing zero or 8435** a negative value as the nFrame parameter disables automatic 8436** checkpoints entirely. 8437** 8438** ^The callback registered by this function replaces any existing callback 8439** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8440** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8441** configured by this function. 8442** 8443** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8444** from SQL. 8445** 8446** ^Checkpoints initiated by this mechanism are 8447** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8448** 8449** ^Every new [database connection] defaults to having the auto-checkpoint 8450** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8451** pages. The use of this interface 8452** is only necessary if the default setting is found to be suboptimal 8453** for a particular application. 8454*/ 8455int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8456 8457/* 8458** CAPI3REF: Checkpoint a database 8459** METHOD: sqlite3 8460** 8461** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8462** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8463** 8464** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8465** [write-ahead log] for database X on [database connection] D to be 8466** transferred into the database file and for the write-ahead log to 8467** be reset. See the [checkpointing] documentation for addition 8468** information. 8469** 8470** This interface used to be the only way to cause a checkpoint to 8471** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8472** interface was added. This interface is retained for backwards 8473** compatibility and as a convenience for applications that need to manually 8474** start a callback but which do not need the full power (and corresponding 8475** complication) of [sqlite3_wal_checkpoint_v2()]. 8476*/ 8477int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8478 8479/* 8480** CAPI3REF: Checkpoint a database 8481** METHOD: sqlite3 8482** 8483** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8484** operation on database X of [database connection] D in mode M. Status 8485** information is written back into integers pointed to by L and C.)^ 8486** ^(The M parameter must be a valid [checkpoint mode]:)^ 8487** 8488** <dl> 8489** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8490** ^Checkpoint as many frames as possible without waiting for any database 8491** readers or writers to finish, then sync the database file if all frames 8492** in the log were checkpointed. ^The [busy-handler callback] 8493** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8494** ^On the other hand, passive mode might leave the checkpoint unfinished 8495** if there are concurrent readers or writers. 8496** 8497** <dt>SQLITE_CHECKPOINT_FULL<dd> 8498** ^This mode blocks (it invokes the 8499** [sqlite3_busy_handler|busy-handler callback]) until there is no 8500** database writer and all readers are reading from the most recent database 8501** snapshot. ^It then checkpoints all frames in the log file and syncs the 8502** database file. ^This mode blocks new database writers while it is pending, 8503** but new database readers are allowed to continue unimpeded. 8504** 8505** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8506** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8507** that after checkpointing the log file it blocks (calls the 8508** [busy-handler callback]) 8509** until all readers are reading from the database file only. ^This ensures 8510** that the next writer will restart the log file from the beginning. 8511** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8512** database writer attempts while it is pending, but does not impede readers. 8513** 8514** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8515** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8516** addition that it also truncates the log file to zero bytes just prior 8517** to a successful return. 8518** </dl> 8519** 8520** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8521** the log file or to -1 if the checkpoint could not run because 8522** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8523** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8524** log file (including any that were already checkpointed before the function 8525** was called) or to -1 if the checkpoint could not run due to an error or 8526** because the database is not in WAL mode. ^Note that upon successful 8527** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8528** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8529** 8530** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8531** any other process is running a checkpoint operation at the same time, the 8532** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8533** busy-handler configured, it will not be invoked in this case. 8534** 8535** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8536** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8537** obtained immediately, and a busy-handler is configured, it is invoked and 8538** the writer lock retried until either the busy-handler returns 0 or the lock 8539** is successfully obtained. ^The busy-handler is also invoked while waiting for 8540** database readers as described above. ^If the busy-handler returns 0 before 8541** the writer lock is obtained or while waiting for database readers, the 8542** checkpoint operation proceeds from that point in the same way as 8543** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8544** without blocking any further. ^SQLITE_BUSY is returned in this case. 8545** 8546** ^If parameter zDb is NULL or points to a zero length string, then the 8547** specified operation is attempted on all WAL databases [attached] to 8548** [database connection] db. In this case the 8549** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8550** an SQLITE_BUSY error is encountered when processing one or more of the 8551** attached WAL databases, the operation is still attempted on any remaining 8552** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8553** error occurs while processing an attached database, processing is abandoned 8554** and the error code is returned to the caller immediately. ^If no error 8555** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8556** databases, SQLITE_OK is returned. 8557** 8558** ^If database zDb is the name of an attached database that is not in WAL 8559** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8560** zDb is not NULL (or a zero length string) and is not the name of any 8561** attached database, SQLITE_ERROR is returned to the caller. 8562** 8563** ^Unless it returns SQLITE_MISUSE, 8564** the sqlite3_wal_checkpoint_v2() interface 8565** sets the error information that is queried by 8566** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8567** 8568** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8569** from SQL. 8570*/ 8571int sqlite3_wal_checkpoint_v2( 8572 sqlite3 *db, /* Database handle */ 8573 const char *zDb, /* Name of attached database (or NULL) */ 8574 int eMode, /* SQLITE_CHECKPOINT_* value */ 8575 int *pnLog, /* OUT: Size of WAL log in frames */ 8576 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8577); 8578 8579/* 8580** CAPI3REF: Checkpoint Mode Values 8581** KEYWORDS: {checkpoint mode} 8582** 8583** These constants define all valid values for the "checkpoint mode" passed 8584** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8585** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8586** meaning of each of these checkpoint modes. 8587*/ 8588#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8589#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8590#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8591#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8592 8593/* 8594** CAPI3REF: Virtual Table Interface Configuration 8595** 8596** This function may be called by either the [xConnect] or [xCreate] method 8597** of a [virtual table] implementation to configure 8598** various facets of the virtual table interface. 8599** 8600** If this interface is invoked outside the context of an xConnect or 8601** xCreate virtual table method then the behavior is undefined. 8602** 8603** At present, there is only one option that may be configured using 8604** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8605** may be added in the future. 8606*/ 8607int sqlite3_vtab_config(sqlite3*, int op, ...); 8608 8609/* 8610** CAPI3REF: Virtual Table Configuration Options 8611** 8612** These macros define the various options to the 8613** [sqlite3_vtab_config()] interface that [virtual table] implementations 8614** can use to customize and optimize their behavior. 8615** 8616** <dl> 8617** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8618** <dd>Calls of the form 8619** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8620** where X is an integer. If X is zero, then the [virtual table] whose 8621** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8622** support constraints. In this configuration (which is the default) if 8623** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8624** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8625** specified as part of the users SQL statement, regardless of the actual 8626** ON CONFLICT mode specified. 8627** 8628** If X is non-zero, then the virtual table implementation guarantees 8629** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8630** any modifications to internal or persistent data structures have been made. 8631** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8632** is able to roll back a statement or database transaction, and abandon 8633** or continue processing the current SQL statement as appropriate. 8634** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8635** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8636** had been ABORT. 8637** 8638** Virtual table implementations that are required to handle OR REPLACE 8639** must do so within the [xUpdate] method. If a call to the 8640** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8641** CONFLICT policy is REPLACE, the virtual table implementation should 8642** silently replace the appropriate rows within the xUpdate callback and 8643** return SQLITE_OK. Or, if this is not possible, it may return 8644** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8645** constraint handling. 8646** </dl> 8647*/ 8648#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8649 8650/* 8651** CAPI3REF: Determine The Virtual Table Conflict Policy 8652** 8653** This function may only be called from within a call to the [xUpdate] method 8654** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8655** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8656** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8657** of the SQL statement that triggered the call to the [xUpdate] method of the 8658** [virtual table]. 8659*/ 8660int sqlite3_vtab_on_conflict(sqlite3 *); 8661 8662/* 8663** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8664** 8665** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8666** method of a [virtual table], then it returns true if and only if the 8667** column is being fetched as part of an UPDATE operation during which the 8668** column value will not change. Applications might use this to substitute 8669** a return value that is less expensive to compute and that the corresponding 8670** [xUpdate] method understands as a "no-change" value. 8671** 8672** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8673** the column is not changed by the UPDATE statement, then the xColumn 8674** method can optionally return without setting a result, without calling 8675** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8676** In that case, [sqlite3_value_nochange(X)] will return true for the 8677** same column in the [xUpdate] method. 8678*/ 8679int sqlite3_vtab_nochange(sqlite3_context*); 8680 8681/* 8682** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8683** 8684** This function may only be called from within a call to the [xBestIndex] 8685** method of a [virtual table]. 8686** 8687** The first argument must be the sqlite3_index_info object that is the 8688** first parameter to the xBestIndex() method. The second argument must be 8689** an index into the aConstraint[] array belonging to the sqlite3_index_info 8690** structure passed to xBestIndex. This function returns a pointer to a buffer 8691** containing the name of the collation sequence for the corresponding 8692** constraint. 8693*/ 8694SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8695 8696/* 8697** CAPI3REF: Conflict resolution modes 8698** KEYWORDS: {conflict resolution mode} 8699** 8700** These constants are returned by [sqlite3_vtab_on_conflict()] to 8701** inform a [virtual table] implementation what the [ON CONFLICT] mode 8702** is for the SQL statement being evaluated. 8703** 8704** Note that the [SQLITE_IGNORE] constant is also used as a potential 8705** return value from the [sqlite3_set_authorizer()] callback and that 8706** [SQLITE_ABORT] is also a [result code]. 8707*/ 8708#define SQLITE_ROLLBACK 1 8709/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8710#define SQLITE_FAIL 3 8711/* #define SQLITE_ABORT 4 // Also an error code */ 8712#define SQLITE_REPLACE 5 8713 8714/* 8715** CAPI3REF: Prepared Statement Scan Status Opcodes 8716** KEYWORDS: {scanstatus options} 8717** 8718** The following constants can be used for the T parameter to the 8719** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8720** different metric for sqlite3_stmt_scanstatus() to return. 8721** 8722** When the value returned to V is a string, space to hold that string is 8723** managed by the prepared statement S and will be automatically freed when 8724** S is finalized. 8725** 8726** <dl> 8727** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8728** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8729** set to the total number of times that the X-th loop has run.</dd> 8730** 8731** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8732** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8733** to the total number of rows examined by all iterations of the X-th loop.</dd> 8734** 8735** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8736** <dd>^The "double" variable pointed to by the T parameter will be set to the 8737** query planner's estimate for the average number of rows output from each 8738** iteration of the X-th loop. If the query planner's estimates was accurate, 8739** then this value will approximate the quotient NVISIT/NLOOP and the 8740** product of this value for all prior loops with the same SELECTID will 8741** be the NLOOP value for the current loop. 8742** 8743** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8744** <dd>^The "const char *" variable pointed to by the T parameter will be set 8745** to a zero-terminated UTF-8 string containing the name of the index or table 8746** used for the X-th loop. 8747** 8748** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8749** <dd>^The "const char *" variable pointed to by the T parameter will be set 8750** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8751** description for the X-th loop. 8752** 8753** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8754** <dd>^The "int" variable pointed to by the T parameter will be set to the 8755** "select-id" for the X-th loop. The select-id identifies which query or 8756** subquery the loop is part of. The main query has a select-id of zero. 8757** The select-id is the same value as is output in the first column 8758** of an [EXPLAIN QUERY PLAN] query. 8759** </dl> 8760*/ 8761#define SQLITE_SCANSTAT_NLOOP 0 8762#define SQLITE_SCANSTAT_NVISIT 1 8763#define SQLITE_SCANSTAT_EST 2 8764#define SQLITE_SCANSTAT_NAME 3 8765#define SQLITE_SCANSTAT_EXPLAIN 4 8766#define SQLITE_SCANSTAT_SELECTID 5 8767 8768/* 8769** CAPI3REF: Prepared Statement Scan Status 8770** METHOD: sqlite3_stmt 8771** 8772** This interface returns information about the predicted and measured 8773** performance for pStmt. Advanced applications can use this 8774** interface to compare the predicted and the measured performance and 8775** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8776** 8777** Since this interface is expected to be rarely used, it is only 8778** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8779** compile-time option. 8780** 8781** The "iScanStatusOp" parameter determines which status information to return. 8782** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8783** of this interface is undefined. 8784** ^The requested measurement is written into a variable pointed to by 8785** the "pOut" parameter. 8786** Parameter "idx" identifies the specific loop to retrieve statistics for. 8787** Loops are numbered starting from zero. ^If idx is out of range - less than 8788** zero or greater than or equal to the total number of loops used to implement 8789** the statement - a non-zero value is returned and the variable that pOut 8790** points to is unchanged. 8791** 8792** ^Statistics might not be available for all loops in all statements. ^In cases 8793** where there exist loops with no available statistics, this function behaves 8794** as if the loop did not exist - it returns non-zero and leave the variable 8795** that pOut points to unchanged. 8796** 8797** See also: [sqlite3_stmt_scanstatus_reset()] 8798*/ 8799int sqlite3_stmt_scanstatus( 8800 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8801 int idx, /* Index of loop to report on */ 8802 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8803 void *pOut /* Result written here */ 8804); 8805 8806/* 8807** CAPI3REF: Zero Scan-Status Counters 8808** METHOD: sqlite3_stmt 8809** 8810** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8811** 8812** This API is only available if the library is built with pre-processor 8813** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8814*/ 8815void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8816 8817/* 8818** CAPI3REF: Flush caches to disk mid-transaction 8819** 8820** ^If a write-transaction is open on [database connection] D when the 8821** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8822** pages in the pager-cache that are not currently in use are written out 8823** to disk. A dirty page may be in use if a database cursor created by an 8824** active SQL statement is reading from it, or if it is page 1 of a database 8825** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8826** interface flushes caches for all schemas - "main", "temp", and 8827** any [attached] databases. 8828** 8829** ^If this function needs to obtain extra database locks before dirty pages 8830** can be flushed to disk, it does so. ^If those locks cannot be obtained 8831** immediately and there is a busy-handler callback configured, it is invoked 8832** in the usual manner. ^If the required lock still cannot be obtained, then 8833** the database is skipped and an attempt made to flush any dirty pages 8834** belonging to the next (if any) database. ^If any databases are skipped 8835** because locks cannot be obtained, but no other error occurs, this 8836** function returns SQLITE_BUSY. 8837** 8838** ^If any other error occurs while flushing dirty pages to disk (for 8839** example an IO error or out-of-memory condition), then processing is 8840** abandoned and an SQLite [error code] is returned to the caller immediately. 8841** 8842** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8843** 8844** ^This function does not set the database handle error code or message 8845** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8846*/ 8847int sqlite3_db_cacheflush(sqlite3*); 8848 8849/* 8850** CAPI3REF: The pre-update hook. 8851** 8852** ^These interfaces are only available if SQLite is compiled using the 8853** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8854** 8855** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8856** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8857** on a database table. 8858** ^At most one preupdate hook may be registered at a time on a single 8859** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8860** the previous setting. 8861** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8862** with a NULL pointer as the second parameter. 8863** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8864** the first parameter to callbacks. 8865** 8866** ^The preupdate hook only fires for changes to real database tables; the 8867** preupdate hook is not invoked for changes to [virtual tables] or to 8868** system tables like sqlite_master or sqlite_stat1. 8869** 8870** ^The second parameter to the preupdate callback is a pointer to 8871** the [database connection] that registered the preupdate hook. 8872** ^The third parameter to the preupdate callback is one of the constants 8873** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8874** kind of update operation that is about to occur. 8875** ^(The fourth parameter to the preupdate callback is the name of the 8876** database within the database connection that is being modified. This 8877** will be "main" for the main database or "temp" for TEMP tables or 8878** the name given after the AS keyword in the [ATTACH] statement for attached 8879** databases.)^ 8880** ^The fifth parameter to the preupdate callback is the name of the 8881** table that is being modified. 8882** 8883** For an UPDATE or DELETE operation on a [rowid table], the sixth 8884** parameter passed to the preupdate callback is the initial [rowid] of the 8885** row being modified or deleted. For an INSERT operation on a rowid table, 8886** or any operation on a WITHOUT ROWID table, the value of the sixth 8887** parameter is undefined. For an INSERT or UPDATE on a rowid table the 8888** seventh parameter is the final rowid value of the row being inserted 8889** or updated. The value of the seventh parameter passed to the callback 8890** function is not defined for operations on WITHOUT ROWID tables, or for 8891** INSERT operations on rowid tables. 8892** 8893** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8894** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8895** provide additional information about a preupdate event. These routines 8896** may only be called from within a preupdate callback. Invoking any of 8897** these routines from outside of a preupdate callback or with a 8898** [database connection] pointer that is different from the one supplied 8899** to the preupdate callback results in undefined and probably undesirable 8900** behavior. 8901** 8902** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8903** in the row that is being inserted, updated, or deleted. 8904** 8905** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8906** a [protected sqlite3_value] that contains the value of the Nth column of 8907** the table row before it is updated. The N parameter must be between 0 8908** and one less than the number of columns or the behavior will be 8909** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8910** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8911** behavior is undefined. The [sqlite3_value] that P points to 8912** will be destroyed when the preupdate callback returns. 8913** 8914** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8915** a [protected sqlite3_value] that contains the value of the Nth column of 8916** the table row after it is updated. The N parameter must be between 0 8917** and one less than the number of columns or the behavior will be 8918** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8919** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8920** behavior is undefined. The [sqlite3_value] that P points to 8921** will be destroyed when the preupdate callback returns. 8922** 8923** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8924** callback was invoked as a result of a direct insert, update, or delete 8925** operation; or 1 for inserts, updates, or deletes invoked by top-level 8926** triggers; or 2 for changes resulting from triggers called by top-level 8927** triggers; and so forth. 8928** 8929** See also: [sqlite3_update_hook()] 8930*/ 8931#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8932void *sqlite3_preupdate_hook( 8933 sqlite3 *db, 8934 void(*xPreUpdate)( 8935 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8936 sqlite3 *db, /* Database handle */ 8937 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8938 char const *zDb, /* Database name */ 8939 char const *zName, /* Table name */ 8940 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8941 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8942 ), 8943 void* 8944); 8945int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8946int sqlite3_preupdate_count(sqlite3 *); 8947int sqlite3_preupdate_depth(sqlite3 *); 8948int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8949#endif 8950 8951/* 8952** CAPI3REF: Low-level system error code 8953** 8954** ^Attempt to return the underlying operating system error code or error 8955** number that caused the most recent I/O error or failure to open a file. 8956** The return value is OS-dependent. For example, on unix systems, after 8957** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8958** called to get back the underlying "errno" that caused the problem, such 8959** as ENOSPC, EAUTH, EISDIR, and so forth. 8960*/ 8961int sqlite3_system_errno(sqlite3*); 8962 8963/* 8964** CAPI3REF: Database Snapshot 8965** KEYWORDS: {snapshot} {sqlite3_snapshot} 8966** 8967** An instance of the snapshot object records the state of a [WAL mode] 8968** database for some specific point in history. 8969** 8970** In [WAL mode], multiple [database connections] that are open on the 8971** same database file can each be reading a different historical version 8972** of the database file. When a [database connection] begins a read 8973** transaction, that connection sees an unchanging copy of the database 8974** as it existed for the point in time when the transaction first started. 8975** Subsequent changes to the database from other connections are not seen 8976** by the reader until a new read transaction is started. 8977** 8978** The sqlite3_snapshot object records state information about an historical 8979** version of the database file so that it is possible to later open a new read 8980** transaction that sees that historical version of the database rather than 8981** the most recent version. 8982*/ 8983typedef struct sqlite3_snapshot { 8984 unsigned char hidden[48]; 8985} sqlite3_snapshot; 8986 8987/* 8988** CAPI3REF: Record A Database Snapshot 8989** CONSTRUCTOR: sqlite3_snapshot 8990** 8991** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8992** new [sqlite3_snapshot] object that records the current state of 8993** schema S in database connection D. ^On success, the 8994** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8995** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8996** If there is not already a read-transaction open on schema S when 8997** this function is called, one is opened automatically. 8998** 8999** The following must be true for this function to succeed. If any of 9000** the following statements are false when sqlite3_snapshot_get() is 9001** called, SQLITE_ERROR is returned. The final value of *P is undefined 9002** in this case. 9003** 9004** <ul> 9005** <li> The database handle must not be in [autocommit mode]. 9006** 9007** <li> Schema S of [database connection] D must be a [WAL mode] database. 9008** 9009** <li> There must not be a write transaction open on schema S of database 9010** connection D. 9011** 9012** <li> One or more transactions must have been written to the current wal 9013** file since it was created on disk (by any connection). This means 9014** that a snapshot cannot be taken on a wal mode database with no wal 9015** file immediately after it is first opened. At least one transaction 9016** must be written to it first. 9017** </ul> 9018** 9019** This function may also return SQLITE_NOMEM. If it is called with the 9020** database handle in autocommit mode but fails for some other reason, 9021** whether or not a read transaction is opened on schema S is undefined. 9022** 9023** The [sqlite3_snapshot] object returned from a successful call to 9024** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9025** to avoid a memory leak. 9026** 9027** The [sqlite3_snapshot_get()] interface is only available when the 9028** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9029*/ 9030SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9031 sqlite3 *db, 9032 const char *zSchema, 9033 sqlite3_snapshot **ppSnapshot 9034); 9035 9036/* 9037** CAPI3REF: Start a read transaction on an historical snapshot 9038** METHOD: sqlite3_snapshot 9039** 9040** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9041** transaction or upgrades an existing one for schema S of 9042** [database connection] D such that the read transaction refers to 9043** historical [snapshot] P, rather than the most recent change to the 9044** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9045** on success or an appropriate [error code] if it fails. 9046** 9047** ^In order to succeed, the database connection must not be in 9048** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9049** is already a read transaction open on schema S, then the database handle 9050** must have no active statements (SELECT statements that have been passed 9051** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9052** SQLITE_ERROR is returned if either of these conditions is violated, or 9053** if schema S does not exist, or if the snapshot object is invalid. 9054** 9055** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9056** snapshot has been overwritten by a [checkpoint]. In this case 9057** SQLITE_ERROR_SNAPSHOT is returned. 9058** 9059** If there is already a read transaction open when this function is 9060** invoked, then the same read transaction remains open (on the same 9061** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9062** is returned. If another error code - for example SQLITE_PROTOCOL or an 9063** SQLITE_IOERR error code - is returned, then the final state of the 9064** read transaction is undefined. If SQLITE_OK is returned, then the 9065** read transaction is now open on database snapshot P. 9066** 9067** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9068** database connection D does not know that the database file for 9069** schema S is in [WAL mode]. A database connection might not know 9070** that the database file is in [WAL mode] if there has been no prior 9071** I/O on that database connection, or if the database entered [WAL mode] 9072** after the most recent I/O on the database connection.)^ 9073** (Hint: Run "[PRAGMA application_id]" against a newly opened 9074** database connection in order to make it ready to use snapshots.) 9075** 9076** The [sqlite3_snapshot_open()] interface is only available when the 9077** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9078*/ 9079SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9080 sqlite3 *db, 9081 const char *zSchema, 9082 sqlite3_snapshot *pSnapshot 9083); 9084 9085/* 9086** CAPI3REF: Destroy a snapshot 9087** DESTRUCTOR: sqlite3_snapshot 9088** 9089** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9090** The application must eventually free every [sqlite3_snapshot] object 9091** using this routine to avoid a memory leak. 9092** 9093** The [sqlite3_snapshot_free()] interface is only available when the 9094** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9095*/ 9096SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9097 9098/* 9099** CAPI3REF: Compare the ages of two snapshot handles. 9100** METHOD: sqlite3_snapshot 9101** 9102** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9103** of two valid snapshot handles. 9104** 9105** If the two snapshot handles are not associated with the same database 9106** file, the result of the comparison is undefined. 9107** 9108** Additionally, the result of the comparison is only valid if both of the 9109** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9110** last time the wal file was deleted. The wal file is deleted when the 9111** database is changed back to rollback mode or when the number of database 9112** clients drops to zero. If either snapshot handle was obtained before the 9113** wal file was last deleted, the value returned by this function 9114** is undefined. 9115** 9116** Otherwise, this API returns a negative value if P1 refers to an older 9117** snapshot than P2, zero if the two handles refer to the same database 9118** snapshot, and a positive value if P1 is a newer snapshot than P2. 9119** 9120** This interface is only available if SQLite is compiled with the 9121** [SQLITE_ENABLE_SNAPSHOT] option. 9122*/ 9123SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9124 sqlite3_snapshot *p1, 9125 sqlite3_snapshot *p2 9126); 9127 9128/* 9129** CAPI3REF: Recover snapshots from a wal file 9130** METHOD: sqlite3_snapshot 9131** 9132** If a [WAL file] remains on disk after all database connections close 9133** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9134** or because the last process to have the database opened exited without 9135** calling [sqlite3_close()]) and a new connection is subsequently opened 9136** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9137** will only be able to open the last transaction added to the WAL file 9138** even though the WAL file contains other valid transactions. 9139** 9140** This function attempts to scan the WAL file associated with database zDb 9141** of database handle db and make all valid snapshots available to 9142** sqlite3_snapshot_open(). It is an error if there is already a read 9143** transaction open on the database, or if the database is not a WAL mode 9144** database. 9145** 9146** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9147** 9148** This interface is only available if SQLite is compiled with the 9149** [SQLITE_ENABLE_SNAPSHOT] option. 9150*/ 9151SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9152 9153/* 9154** CAPI3REF: Serialize a database 9155** 9156** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9157** that is a serialization of the S database on [database connection] D. 9158** If P is not a NULL pointer, then the size of the database in bytes 9159** is written into *P. 9160** 9161** For an ordinary on-disk database file, the serialization is just a 9162** copy of the disk file. For an in-memory database or a "TEMP" database, 9163** the serialization is the same sequence of bytes which would be written 9164** to disk if that database where backed up to disk. 9165** 9166** The usual case is that sqlite3_serialize() copies the serialization of 9167** the database into memory obtained from [sqlite3_malloc64()] and returns 9168** a pointer to that memory. The caller is responsible for freeing the 9169** returned value to avoid a memory leak. However, if the F argument 9170** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9171** are made, and the sqlite3_serialize() function will return a pointer 9172** to the contiguous memory representation of the database that SQLite 9173** is currently using for that database, or NULL if the no such contiguous 9174** memory representation of the database exists. A contiguous memory 9175** representation of the database will usually only exist if there has 9176** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9177** values of D and S. 9178** The size of the database is written into *P even if the 9179** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9180** of the database exists. 9181** 9182** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9183** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9184** allocation error occurs. 9185** 9186** This interface is only available if SQLite is compiled with the 9187** [SQLITE_ENABLE_DESERIALIZE] option. 9188*/ 9189unsigned char *sqlite3_serialize( 9190 sqlite3 *db, /* The database connection */ 9191 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9192 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9193 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9194); 9195 9196/* 9197** CAPI3REF: Flags for sqlite3_serialize 9198** 9199** Zero or more of the following constants can be OR-ed together for 9200** the F argument to [sqlite3_serialize(D,S,P,F)]. 9201** 9202** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9203** a pointer to contiguous in-memory database that it is currently using, 9204** without making a copy of the database. If SQLite is not currently using 9205** a contiguous in-memory database, then this option causes 9206** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9207** using a contiguous in-memory database if it has been initialized by a 9208** prior call to [sqlite3_deserialize()]. 9209*/ 9210#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9211 9212/* 9213** CAPI3REF: Deserialize a database 9214** 9215** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9216** [database connection] D to disconnect from database S and then 9217** reopen S as an in-memory database based on the serialization contained 9218** in P. The serialized database P is N bytes in size. M is the size of 9219** the buffer P, which might be larger than N. If M is larger than N, and 9220** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9221** permitted to add content to the in-memory database as long as the total 9222** size does not exceed M bytes. 9223** 9224** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9225** invoke sqlite3_free() on the serialization buffer when the database 9226** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9227** SQLite will try to increase the buffer size using sqlite3_realloc64() 9228** if writes on the database cause it to grow larger than M bytes. 9229** 9230** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9231** database is currently in a read transaction or is involved in a backup 9232** operation. 9233** 9234** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9235** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9236** [sqlite3_free()] is invoked on argument P prior to returning. 9237** 9238** This interface is only available if SQLite is compiled with the 9239** [SQLITE_ENABLE_DESERIALIZE] option. 9240*/ 9241int sqlite3_deserialize( 9242 sqlite3 *db, /* The database connection */ 9243 const char *zSchema, /* Which DB to reopen with the deserialization */ 9244 unsigned char *pData, /* The serialized database content */ 9245 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9246 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9247 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9248); 9249 9250/* 9251** CAPI3REF: Flags for sqlite3_deserialize() 9252** 9253** The following are allowed values for 6th argument (the F argument) to 9254** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9255** 9256** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9257** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9258** and that SQLite should take ownership of this memory and automatically 9259** free it when it has finished using it. Without this flag, the caller 9260** is resposible for freeing any dynamically allocated memory. 9261** 9262** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9263** grow the size of the database using calls to [sqlite3_realloc64()]. This 9264** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9265** Without this flag, the deserialized database cannot increase in size beyond 9266** the number of bytes specified by the M parameter. 9267** 9268** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9269** should be treated as read-only. 9270*/ 9271#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9272#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9273#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9274 9275/* 9276** Undo the hack that converts floating point types to integer for 9277** builds on processors without floating point support. 9278*/ 9279#ifdef SQLITE_OMIT_FLOATING_POINT 9280# undef double 9281#endif 9282 9283#ifdef __cplusplus 9284} /* End of the 'extern "C"' block */ 9285#endif 9286#endif /* SQLITE3_H */ 9287