1/* 2** 2001 September 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 an SHA1 118** hash of the entire source tree. 119** 120** See also: [sqlite3_libversion()], 121** [sqlite3_libversion_number()], [sqlite3_sourceid()], 122** [sqlite_version()] and [sqlite_source_id()]. 123*/ 124#define SQLITE_VERSION "--VERS--" 125#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 126#define SQLITE_SOURCE_ID "--SOURCE-ID--" 127 128/* 129** CAPI3REF: Run-Time Library Version Numbers 130** KEYWORDS: sqlite3_version sqlite3_sourceid 131** 132** These interfaces provide the same information as the [SQLITE_VERSION], 133** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 134** but are associated with the library instead of the header file. ^(Cautious 135** programmers might include assert() statements in their application to 136** verify that values returned by these interfaces match the macros in 137** the header, and thus ensure that the application is 138** compiled with matching library and header files. 139** 140** <blockquote><pre> 141** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 142** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 143** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 144** </pre></blockquote>)^ 145** 146** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 147** macro. ^The sqlite3_libversion() function returns a pointer to the 148** to the sqlite3_version[] string constant. The sqlite3_libversion() 149** function is provided for use in DLLs since DLL users usually do not have 150** direct access to string constants within the DLL. ^The 151** sqlite3_libversion_number() function returns an integer equal to 152** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 153** a pointer to a string constant whose value is the same as the 154** [SQLITE_SOURCE_ID] C preprocessor macro. 155** 156** See also: [sqlite_version()] and [sqlite_source_id()]. 157*/ 158SQLITE_EXTERN const char sqlite3_version[]; 159const char *sqlite3_libversion(void); 160const char *sqlite3_sourceid(void); 161int sqlite3_libversion_number(void); 162 163/* 164** CAPI3REF: Run-Time Library Compilation Options Diagnostics 165** 166** ^The sqlite3_compileoption_used() function returns 0 or 1 167** indicating whether the specified option was defined at 168** compile time. ^The SQLITE_ prefix may be omitted from the 169** option name passed to sqlite3_compileoption_used(). 170** 171** ^The sqlite3_compileoption_get() function allows iterating 172** over the list of options that were defined at compile time by 173** returning the N-th compile time option string. ^If N is out of range, 174** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 175** prefix is omitted from any strings returned by 176** sqlite3_compileoption_get(). 177** 178** ^Support for the diagnostic functions sqlite3_compileoption_used() 179** and sqlite3_compileoption_get() may be omitted by specifying the 180** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 181** 182** See also: SQL functions [sqlite_compileoption_used()] and 183** [sqlite_compileoption_get()] and the [compile_options pragma]. 184*/ 185#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 186int sqlite3_compileoption_used(const char *zOptName); 187const char *sqlite3_compileoption_get(int N); 188#endif 189 190/* 191** CAPI3REF: Test To See If The Library Is Threadsafe 192** 193** ^The sqlite3_threadsafe() function returns zero if and only if 194** SQLite was compiled with mutexing code omitted due to the 195** [SQLITE_THREADSAFE] compile-time option being set to 0. 196** 197** SQLite can be compiled with or without mutexes. When 198** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 199** are enabled and SQLite is threadsafe. When the 200** [SQLITE_THREADSAFE] macro is 0, 201** the mutexes are omitted. Without the mutexes, it is not safe 202** to use SQLite concurrently from more than one thread. 203** 204** Enabling mutexes incurs a measurable performance penalty. 205** So if speed is of utmost importance, it makes sense to disable 206** the mutexes. But for maximum safety, mutexes should be enabled. 207** ^The default behavior is for mutexes to be enabled. 208** 209** This interface can be used by an application to make sure that the 210** version of SQLite that it is linking against was compiled with 211** the desired setting of the [SQLITE_THREADSAFE] macro. 212** 213** This interface only reports on the compile-time mutex setting 214** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 215** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 216** can be fully or partially disabled using a call to [sqlite3_config()] 217** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 218** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 219** sqlite3_threadsafe() function shows only the compile-time setting of 220** thread safety, not any run-time changes to that setting made by 221** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 222** is unchanged by calls to sqlite3_config().)^ 223** 224** See the [threading mode] documentation for additional information. 225*/ 226int sqlite3_threadsafe(void); 227 228/* 229** CAPI3REF: Database Connection Handle 230** KEYWORDS: {database connection} {database connections} 231** 232** Each open SQLite database is represented by a pointer to an instance of 233** the opaque structure named "sqlite3". It is useful to think of an sqlite3 234** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 235** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 236** and [sqlite3_close_v2()] are its destructors. There are many other 237** interfaces (such as 238** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 239** [sqlite3_busy_timeout()] to name but three) that are methods on an 240** sqlite3 object. 241*/ 242typedef struct sqlite3 sqlite3; 243 244/* 245** CAPI3REF: 64-Bit Integer Types 246** KEYWORDS: sqlite_int64 sqlite_uint64 247** 248** Because there is no cross-platform way to specify 64-bit integer types 249** SQLite includes typedefs for 64-bit signed and unsigned integers. 250** 251** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 252** The sqlite_int64 and sqlite_uint64 types are supported for backwards 253** compatibility only. 254** 255** ^The sqlite3_int64 and sqlite_int64 types can store integer values 256** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 257** sqlite3_uint64 and sqlite_uint64 types can store integer values 258** between 0 and +18446744073709551615 inclusive. 259*/ 260#ifdef SQLITE_INT64_TYPE 261 typedef SQLITE_INT64_TYPE sqlite_int64; 262# ifdef SQLITE_UINT64_TYPE 263 typedef SQLITE_UINT64_TYPE sqlite_uint64; 264# else 265 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 266# endif 267#elif defined(_MSC_VER) || defined(__BORLANDC__) 268 typedef __int64 sqlite_int64; 269 typedef unsigned __int64 sqlite_uint64; 270#else 271 typedef long long int sqlite_int64; 272 typedef unsigned long long int sqlite_uint64; 273#endif 274typedef sqlite_int64 sqlite3_int64; 275typedef sqlite_uint64 sqlite3_uint64; 276 277/* 278** If compiling for a processor that lacks floating point support, 279** substitute integer for floating-point. 280*/ 281#ifdef SQLITE_OMIT_FLOATING_POINT 282# define double sqlite3_int64 283#endif 284 285/* 286** CAPI3REF: Closing A Database Connection 287** DESTRUCTOR: sqlite3 288** 289** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 290** for the [sqlite3] object. 291** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 292** the [sqlite3] object is successfully destroyed and all associated 293** resources are deallocated. 294** 295** ^If the database connection is associated with unfinalized prepared 296** statements or unfinished sqlite3_backup objects then sqlite3_close() 297** will leave the database connection open and return [SQLITE_BUSY]. 298** ^If sqlite3_close_v2() is called with unfinalized prepared statements 299** and/or unfinished sqlite3_backups, then the database connection becomes 300** an unusable "zombie" which will automatically be deallocated when the 301** last prepared statement is finalized or the last sqlite3_backup is 302** finished. The sqlite3_close_v2() interface is intended for use with 303** host languages that are garbage collected, and where the order in which 304** destructors are called is arbitrary. 305** 306** Applications should [sqlite3_finalize | finalize] all [prepared statements], 307** [sqlite3_blob_close | close] all [BLOB handles], and 308** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 309** with the [sqlite3] object prior to attempting to close the object. ^If 310** sqlite3_close_v2() is called on a [database connection] that still has 311** outstanding [prepared statements], [BLOB handles], and/or 312** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 313** of resources is deferred until all [prepared statements], [BLOB handles], 314** and [sqlite3_backup] objects are also destroyed. 315** 316** ^If an [sqlite3] object is destroyed while a transaction is open, 317** the transaction is automatically rolled back. 318** 319** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 320** must be either a NULL 321** pointer or an [sqlite3] object pointer obtained 322** from [sqlite3_open()], [sqlite3_open16()], or 323** [sqlite3_open_v2()], and not previously closed. 324** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 325** argument is a harmless no-op. 326*/ 327int sqlite3_close(sqlite3*); 328int sqlite3_close_v2(sqlite3*); 329 330/* 331** The type for a callback function. 332** This is legacy and deprecated. It is included for historical 333** compatibility and is not documented. 334*/ 335typedef int (*sqlite3_callback)(void*,int,char**, char**); 336 337/* 338** CAPI3REF: One-Step Query Execution Interface 339** METHOD: sqlite3 340** 341** The sqlite3_exec() interface is a convenience wrapper around 342** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 343** that allows an application to run multiple statements of SQL 344** without having to use a lot of C code. 345** 346** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 347** semicolon-separate SQL statements passed into its 2nd argument, 348** in the context of the [database connection] passed in as its 1st 349** argument. ^If the callback function of the 3rd argument to 350** sqlite3_exec() is not NULL, then it is invoked for each result row 351** coming out of the evaluated SQL statements. ^The 4th argument to 352** sqlite3_exec() is relayed through to the 1st argument of each 353** callback invocation. ^If the callback pointer to sqlite3_exec() 354** is NULL, then no callback is ever invoked and result rows are 355** ignored. 356** 357** ^If an error occurs while evaluating the SQL statements passed into 358** sqlite3_exec(), then execution of the current statement stops and 359** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 360** is not NULL then any error message is written into memory obtained 361** from [sqlite3_malloc()] and passed back through the 5th parameter. 362** To avoid memory leaks, the application should invoke [sqlite3_free()] 363** on error message strings returned through the 5th parameter of 364** sqlite3_exec() after the error message string is no longer needed. 365** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 366** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 367** NULL before returning. 368** 369** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 370** routine returns SQLITE_ABORT without invoking the callback again and 371** without running any subsequent SQL statements. 372** 373** ^The 2nd argument to the sqlite3_exec() callback function is the 374** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 375** callback is an array of pointers to strings obtained as if from 376** [sqlite3_column_text()], one for each column. ^If an element of a 377** result row is NULL then the corresponding string pointer for the 378** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 379** sqlite3_exec() callback is an array of pointers to strings where each 380** entry represents the name of corresponding result column as obtained 381** from [sqlite3_column_name()]. 382** 383** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 384** to an empty string, or a pointer that contains only whitespace and/or 385** SQL comments, then no SQL statements are evaluated and the database 386** is not changed. 387** 388** Restrictions: 389** 390** <ul> 391** <li> The application must ensure that the 1st parameter to sqlite3_exec() 392** is a valid and open [database connection]. 393** <li> The application must not close the [database connection] specified by 394** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 395** <li> The application must not modify the SQL statement text passed into 396** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 397** </ul> 398*/ 399int sqlite3_exec( 400 sqlite3*, /* An open database */ 401 const char *sql, /* SQL to be evaluated */ 402 int (*callback)(void*,int,char**,char**), /* Callback function */ 403 void *, /* 1st argument to callback */ 404 char **errmsg /* Error msg written here */ 405); 406 407/* 408** CAPI3REF: Result Codes 409** KEYWORDS: {result code definitions} 410** 411** Many SQLite functions return an integer result code from the set shown 412** here in order to indicate success or failure. 413** 414** New error codes may be added in future versions of SQLite. 415** 416** See also: [extended result code definitions] 417*/ 418#define SQLITE_OK 0 /* Successful result */ 419/* beginning-of-error-codes */ 420#define SQLITE_ERROR 1 /* SQL error or missing database */ 421#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 422#define SQLITE_PERM 3 /* Access permission denied */ 423#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 424#define SQLITE_BUSY 5 /* The database file is locked */ 425#define SQLITE_LOCKED 6 /* A table in the database is locked */ 426#define SQLITE_NOMEM 7 /* A malloc() failed */ 427#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 428#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 429#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 430#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 431#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 432#define SQLITE_FULL 13 /* Insertion failed because database is full */ 433#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 434#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 435#define SQLITE_EMPTY 16 /* Database is empty */ 436#define SQLITE_SCHEMA 17 /* The database schema changed */ 437#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 438#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 439#define SQLITE_MISMATCH 20 /* Data type mismatch */ 440#define SQLITE_MISUSE 21 /* Library used incorrectly */ 441#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 442#define SQLITE_AUTH 23 /* Authorization denied */ 443#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 444#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 445#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 446#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 447#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 448#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 449#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 450/* end-of-error-codes */ 451 452/* 453** CAPI3REF: Extended Result Codes 454** KEYWORDS: {extended result code definitions} 455** 456** In its default configuration, SQLite API routines return one of 30 integer 457** [result codes]. However, experience has shown that many of 458** these result codes are too coarse-grained. They do not provide as 459** much information about problems as programmers might like. In an effort to 460** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 461** and later) include 462** support for additional result codes that provide more detailed information 463** about errors. These [extended result codes] are enabled or disabled 464** on a per database connection basis using the 465** [sqlite3_extended_result_codes()] API. Or, the extended code for 466** the most recent error can be obtained using 467** [sqlite3_extended_errcode()]. 468*/ 469#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 470#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 471#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 472#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 473#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 474#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 475#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 476#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 477#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 478#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 479#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 480#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 481#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 482#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 483#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 484#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 485#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 486#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 487#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 488#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 489#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 490#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 491#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 492#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 493#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 494#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 495#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 496#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 497#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 498#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 499#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 500#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 501#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 502#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 503#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 504#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 505#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 506#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 507#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 508#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 509#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 510#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 511#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 512#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 513#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 514#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 515#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 516#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 517#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 518#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 519#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 520#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 521#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 522#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 523#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 524#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 525 526/* 527** CAPI3REF: Flags For File Open Operations 528** 529** These bit values are intended for use in the 530** 3rd parameter to the [sqlite3_open_v2()] interface and 531** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 532*/ 533#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 534#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 535#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 536#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 537#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 538#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 539#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 540#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 541#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 542#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 543#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 544#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 545#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 546#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 547#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 548#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 549#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 550#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 551#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 552#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 553 554/* Reserved: 0x00F00000 */ 555 556/* 557** CAPI3REF: Device Characteristics 558** 559** The xDeviceCharacteristics method of the [sqlite3_io_methods] 560** object returns an integer which is a vector of these 561** bit values expressing I/O characteristics of the mass storage 562** device that holds the file that the [sqlite3_io_methods] 563** refers to. 564** 565** The SQLITE_IOCAP_ATOMIC property means that all writes of 566** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 567** mean that writes of blocks that are nnn bytes in size and 568** are aligned to an address which is an integer multiple of 569** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 570** that when data is appended to a file, the data is appended 571** first then the size of the file is extended, never the other 572** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 573** information is written to disk in the same order as calls 574** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 575** after reboot following a crash or power loss, the only bytes in a 576** file that were written at the application level might have changed 577** and that adjacent bytes, even bytes within the same sector are 578** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 579** flag indicates that a file cannot be deleted when open. The 580** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 581** read-only media and cannot be changed even by processes with 582** elevated privileges. 583*/ 584#define SQLITE_IOCAP_ATOMIC 0x00000001 585#define SQLITE_IOCAP_ATOMIC512 0x00000002 586#define SQLITE_IOCAP_ATOMIC1K 0x00000004 587#define SQLITE_IOCAP_ATOMIC2K 0x00000008 588#define SQLITE_IOCAP_ATOMIC4K 0x00000010 589#define SQLITE_IOCAP_ATOMIC8K 0x00000020 590#define SQLITE_IOCAP_ATOMIC16K 0x00000040 591#define SQLITE_IOCAP_ATOMIC32K 0x00000080 592#define SQLITE_IOCAP_ATOMIC64K 0x00000100 593#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 594#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 595#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 596#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 597#define SQLITE_IOCAP_IMMUTABLE 0x00002000 598 599/* 600** CAPI3REF: File Locking Levels 601** 602** SQLite uses one of these integer values as the second 603** argument to calls it makes to the xLock() and xUnlock() methods 604** of an [sqlite3_io_methods] object. 605*/ 606#define SQLITE_LOCK_NONE 0 607#define SQLITE_LOCK_SHARED 1 608#define SQLITE_LOCK_RESERVED 2 609#define SQLITE_LOCK_PENDING 3 610#define SQLITE_LOCK_EXCLUSIVE 4 611 612/* 613** CAPI3REF: Synchronization Type Flags 614** 615** When SQLite invokes the xSync() method of an 616** [sqlite3_io_methods] object it uses a combination of 617** these integer values as the second argument. 618** 619** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 620** sync operation only needs to flush data to mass storage. Inode 621** information need not be flushed. If the lower four bits of the flag 622** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 623** If the lower four bits equal SQLITE_SYNC_FULL, that means 624** to use Mac OS X style fullsync instead of fsync(). 625** 626** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 627** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 628** settings. The [synchronous pragma] determines when calls to the 629** xSync VFS method occur and applies uniformly across all platforms. 630** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 631** energetic or rigorous or forceful the sync operations are and 632** only make a difference on Mac OSX for the default SQLite code. 633** (Third-party VFS implementations might also make the distinction 634** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 635** operating systems natively supported by SQLite, only Mac OSX 636** cares about the difference.) 637*/ 638#define SQLITE_SYNC_NORMAL 0x00002 639#define SQLITE_SYNC_FULL 0x00003 640#define SQLITE_SYNC_DATAONLY 0x00010 641 642/* 643** CAPI3REF: OS Interface Open File Handle 644** 645** An [sqlite3_file] object represents an open file in the 646** [sqlite3_vfs | OS interface layer]. Individual OS interface 647** implementations will 648** want to subclass this object by appending additional fields 649** for their own use. The pMethods entry is a pointer to an 650** [sqlite3_io_methods] object that defines methods for performing 651** I/O operations on the open file. 652*/ 653typedef struct sqlite3_file sqlite3_file; 654struct sqlite3_file { 655 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 656}; 657 658/* 659** CAPI3REF: OS Interface File Virtual Methods Object 660** 661** Every file opened by the [sqlite3_vfs.xOpen] method populates an 662** [sqlite3_file] object (or, more commonly, a subclass of the 663** [sqlite3_file] object) with a pointer to an instance of this object. 664** This object defines the methods used to perform various operations 665** against the open file represented by the [sqlite3_file] object. 666** 667** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 668** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 669** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 670** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 671** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 672** to NULL. 673** 674** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 675** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 676** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 677** flag may be ORed in to indicate that only the data of the file 678** and not its inode needs to be synced. 679** 680** The integer values to xLock() and xUnlock() are one of 681** <ul> 682** <li> [SQLITE_LOCK_NONE], 683** <li> [SQLITE_LOCK_SHARED], 684** <li> [SQLITE_LOCK_RESERVED], 685** <li> [SQLITE_LOCK_PENDING], or 686** <li> [SQLITE_LOCK_EXCLUSIVE]. 687** </ul> 688** xLock() increases the lock. xUnlock() decreases the lock. 689** The xCheckReservedLock() method checks whether any database connection, 690** either in this process or in some other process, is holding a RESERVED, 691** PENDING, or EXCLUSIVE lock on the file. It returns true 692** if such a lock exists and false otherwise. 693** 694** The xFileControl() method is a generic interface that allows custom 695** VFS implementations to directly control an open file using the 696** [sqlite3_file_control()] interface. The second "op" argument is an 697** integer opcode. The third argument is a generic pointer intended to 698** point to a structure that may contain arguments or space in which to 699** write return values. Potential uses for xFileControl() might be 700** functions to enable blocking locks with timeouts, to change the 701** locking strategy (for example to use dot-file locks), to inquire 702** about the status of a lock, or to break stale locks. The SQLite 703** core reserves all opcodes less than 100 for its own use. 704** A [file control opcodes | list of opcodes] less than 100 is available. 705** Applications that define a custom xFileControl method should use opcodes 706** greater than 100 to avoid conflicts. VFS implementations should 707** return [SQLITE_NOTFOUND] for file control opcodes that they do not 708** recognize. 709** 710** The xSectorSize() method returns the sector size of the 711** device that underlies the file. The sector size is the 712** minimum write that can be performed without disturbing 713** other bytes in the file. The xDeviceCharacteristics() 714** method returns a bit vector describing behaviors of the 715** underlying device: 716** 717** <ul> 718** <li> [SQLITE_IOCAP_ATOMIC] 719** <li> [SQLITE_IOCAP_ATOMIC512] 720** <li> [SQLITE_IOCAP_ATOMIC1K] 721** <li> [SQLITE_IOCAP_ATOMIC2K] 722** <li> [SQLITE_IOCAP_ATOMIC4K] 723** <li> [SQLITE_IOCAP_ATOMIC8K] 724** <li> [SQLITE_IOCAP_ATOMIC16K] 725** <li> [SQLITE_IOCAP_ATOMIC32K] 726** <li> [SQLITE_IOCAP_ATOMIC64K] 727** <li> [SQLITE_IOCAP_SAFE_APPEND] 728** <li> [SQLITE_IOCAP_SEQUENTIAL] 729** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 730** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 731** <li> [SQLITE_IOCAP_IMMUTABLE] 732** </ul> 733** 734** The SQLITE_IOCAP_ATOMIC property means that all writes of 735** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 736** mean that writes of blocks that are nnn bytes in size and 737** are aligned to an address which is an integer multiple of 738** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 739** that when data is appended to a file, the data is appended 740** first then the size of the file is extended, never the other 741** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 742** information is written to disk in the same order as calls 743** to xWrite(). 744** 745** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 746** in the unread portions of the buffer with zeros. A VFS that 747** fails to zero-fill short reads might seem to work. However, 748** failure to zero-fill short reads will eventually lead to 749** database corruption. 750*/ 751typedef struct sqlite3_io_methods sqlite3_io_methods; 752struct sqlite3_io_methods { 753 int iVersion; 754 int (*xClose)(sqlite3_file*); 755 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 756 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 757 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 758 int (*xSync)(sqlite3_file*, int flags); 759 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 760 int (*xLock)(sqlite3_file*, int); 761 int (*xUnlock)(sqlite3_file*, int); 762 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 763 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 764 int (*xSectorSize)(sqlite3_file*); 765 int (*xDeviceCharacteristics)(sqlite3_file*); 766 /* Methods above are valid for version 1 */ 767 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 768 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 769 void (*xShmBarrier)(sqlite3_file*); 770 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 771 /* Methods above are valid for version 2 */ 772 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 773 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 774 /* Methods above are valid for version 3 */ 775 /* Additional methods may be added in future releases */ 776}; 777 778/* 779** CAPI3REF: Standard File Control Opcodes 780** KEYWORDS: {file control opcodes} {file control opcode} 781** 782** These integer constants are opcodes for the xFileControl method 783** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 784** interface. 785** 786** <ul> 787** <li>[[SQLITE_FCNTL_LOCKSTATE]] 788** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 789** opcode causes the xFileControl method to write the current state of 790** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 791** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 792** into an integer that the pArg argument points to. This capability 793** is used during testing and is only available when the SQLITE_TEST 794** compile-time option is used. 795** 796** <li>[[SQLITE_FCNTL_SIZE_HINT]] 797** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 798** layer a hint of how large the database file will grow to be during the 799** current transaction. This hint is not guaranteed to be accurate but it 800** is often close. The underlying VFS might choose to preallocate database 801** file space based on this hint in order to help writes to the database 802** file run faster. 803** 804** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 805** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 806** extends and truncates the database file in chunks of a size specified 807** by the user. The fourth argument to [sqlite3_file_control()] should 808** point to an integer (type int) containing the new chunk-size to use 809** for the nominated database. Allocating database file space in large 810** chunks (say 1MB at a time), may reduce file-system fragmentation and 811** improve performance on some systems. 812** 813** <li>[[SQLITE_FCNTL_FILE_POINTER]] 814** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 815** to the [sqlite3_file] object associated with a particular database 816** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 817** 818** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 819** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 820** to the [sqlite3_file] object associated with the journal file (either 821** the [rollback journal] or the [write-ahead log]) for a particular database 822** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 823** 824** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 825** No longer in use. 826** 827** <li>[[SQLITE_FCNTL_SYNC]] 828** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 829** sent to the VFS immediately before the xSync method is invoked on a 830** database file descriptor. Or, if the xSync method is not invoked 831** because the user has configured SQLite with 832** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 833** of the xSync method. In most cases, the pointer argument passed with 834** this file-control is NULL. However, if the database file is being synced 835** as part of a multi-database commit, the argument points to a nul-terminated 836** string containing the transactions master-journal file name. VFSes that 837** do not need this signal should silently ignore this opcode. Applications 838** should not call [sqlite3_file_control()] with this opcode as doing so may 839** disrupt the operation of the specialized VFSes that do require it. 840** 841** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 842** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 843** and sent to the VFS after a transaction has been committed immediately 844** but before the database is unlocked. VFSes that do not need this signal 845** should silently ignore this opcode. Applications should not call 846** [sqlite3_file_control()] with this opcode as doing so may disrupt the 847** operation of the specialized VFSes that do require it. 848** 849** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 850** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 851** retry counts and intervals for certain disk I/O operations for the 852** windows [VFS] in order to provide robustness in the presence of 853** anti-virus programs. By default, the windows VFS will retry file read, 854** file write, and file delete operations up to 10 times, with a delay 855** of 25 milliseconds before the first retry and with the delay increasing 856** by an additional 25 milliseconds with each subsequent retry. This 857** opcode allows these two values (10 retries and 25 milliseconds of delay) 858** to be adjusted. The values are changed for all database connections 859** within the same process. The argument is a pointer to an array of two 860** integers where the first integer i the new retry count and the second 861** integer is the delay. If either integer is negative, then the setting 862** is not changed but instead the prior value of that setting is written 863** into the array entry, allowing the current retry settings to be 864** interrogated. The zDbName parameter is ignored. 865** 866** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 867** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 868** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 869** write ahead log and shared memory files used for transaction control 870** are automatically deleted when the latest connection to the database 871** closes. Setting persistent WAL mode causes those files to persist after 872** close. Persisting the files is useful when other processes that do not 873** have write permission on the directory containing the database file want 874** to read the database file, as the WAL and shared memory files must exist 875** in order for the database to be readable. The fourth parameter to 876** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 877** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 878** WAL mode. If the integer is -1, then it is overwritten with the current 879** WAL persistence setting. 880** 881** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 882** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 883** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 884** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 885** xDeviceCharacteristics methods. The fourth parameter to 886** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 887** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 888** mode. If the integer is -1, then it is overwritten with the current 889** zero-damage mode setting. 890** 891** <li>[[SQLITE_FCNTL_OVERWRITE]] 892** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 893** a write transaction to indicate that, unless it is rolled back for some 894** reason, the entire database file will be overwritten by the current 895** transaction. This is used by VACUUM operations. 896** 897** <li>[[SQLITE_FCNTL_VFSNAME]] 898** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 899** all [VFSes] in the VFS stack. The names are of all VFS shims and the 900** final bottom-level VFS are written into memory obtained from 901** [sqlite3_malloc()] and the result is stored in the char* variable 902** that the fourth parameter of [sqlite3_file_control()] points to. 903** The caller is responsible for freeing the memory when done. As with 904** all file-control actions, there is no guarantee that this will actually 905** do anything. Callers should initialize the char* variable to a NULL 906** pointer in case this file-control is not implemented. This file-control 907** is intended for diagnostic use only. 908** 909** <li>[[SQLITE_FCNTL_VFS_POINTER]] 910** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 911** [VFSes] currently in use. ^(The argument X in 912** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 913** of type "[sqlite3_vfs] **". This opcodes will set *X 914** to a pointer to the top-level VFS.)^ 915** ^When there are multiple VFS shims in the stack, this opcode finds the 916** upper-most shim only. 917** 918** <li>[[SQLITE_FCNTL_PRAGMA]] 919** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 920** file control is sent to the open [sqlite3_file] object corresponding 921** to the database file to which the pragma statement refers. ^The argument 922** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 923** pointers to strings (char**) in which the second element of the array 924** is the name of the pragma and the third element is the argument to the 925** pragma or NULL if the pragma has no argument. ^The handler for an 926** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 927** of the char** argument point to a string obtained from [sqlite3_mprintf()] 928** or the equivalent and that string will become the result of the pragma or 929** the error message if the pragma fails. ^If the 930** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 931** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 932** file control returns [SQLITE_OK], then the parser assumes that the 933** VFS has handled the PRAGMA itself and the parser generates a no-op 934** prepared statement if result string is NULL, or that returns a copy 935** of the result string if the string is non-NULL. 936** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 937** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 938** that the VFS encountered an error while handling the [PRAGMA] and the 939** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 940** file control occurs at the beginning of pragma statement analysis and so 941** it is able to override built-in [PRAGMA] statements. 942** 943** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 944** ^The [SQLITE_FCNTL_BUSYHANDLER] 945** file-control may be invoked by SQLite on the database file handle 946** shortly after it is opened in order to provide a custom VFS with access 947** to the connections busy-handler callback. The argument is of type (void **) 948** - an array of two (void *) values. The first (void *) actually points 949** to a function of type (int (*)(void *)). In order to invoke the connections 950** busy-handler, this function should be invoked with the second (void *) in 951** the array as the only argument. If it returns non-zero, then the operation 952** should be retried. If it returns zero, the custom VFS should abandon the 953** current operation. 954** 955** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 956** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 957** to have SQLite generate a 958** temporary filename using the same algorithm that is followed to generate 959** temporary filenames for TEMP tables and other internal uses. The 960** argument should be a char** which will be filled with the filename 961** written into memory obtained from [sqlite3_malloc()]. The caller should 962** invoke [sqlite3_free()] on the result to avoid a memory leak. 963** 964** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 965** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 966** maximum number of bytes that will be used for memory-mapped I/O. 967** The argument is a pointer to a value of type sqlite3_int64 that 968** is an advisory maximum number of bytes in the file to memory map. The 969** pointer is overwritten with the old value. The limit is not changed if 970** the value originally pointed to is negative, and so the current limit 971** can be queried by passing in a pointer to a negative number. This 972** file-control is used internally to implement [PRAGMA mmap_size]. 973** 974** <li>[[SQLITE_FCNTL_TRACE]] 975** The [SQLITE_FCNTL_TRACE] file control provides advisory information 976** to the VFS about what the higher layers of the SQLite stack are doing. 977** This file control is used by some VFS activity tracing [shims]. 978** The argument is a zero-terminated string. Higher layers in the 979** SQLite stack may generate instances of this file control if 980** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 981** 982** <li>[[SQLITE_FCNTL_HAS_MOVED]] 983** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 984** pointer to an integer and it writes a boolean into that integer depending 985** on whether or not the file has been renamed, moved, or deleted since it 986** was first opened. 987** 988** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 989** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 990** underlying native file handle associated with a file handle. This file 991** control interprets its argument as a pointer to a native file handle and 992** writes the resulting value there. 993** 994** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 995** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 996** opcode causes the xFileControl method to swap the file handle with the one 997** pointed to by the pArg argument. This capability is used during testing 998** and only needs to be supported when SQLITE_TEST is defined. 999** 1000** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1001** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1002** be advantageous to block on the next WAL lock if the lock is not immediately 1003** available. The WAL subsystem issues this signal during rare 1004** circumstances in order to fix a problem with priority inversion. 1005** Applications should <em>not</em> use this file-control. 1006** 1007** <li>[[SQLITE_FCNTL_ZIPVFS]] 1008** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1009** VFS should return SQLITE_NOTFOUND for this opcode. 1010** 1011** <li>[[SQLITE_FCNTL_RBU]] 1012** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1013** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1014** this opcode. 1015** </ul> 1016*/ 1017#define SQLITE_FCNTL_LOCKSTATE 1 1018#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1019#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1020#define SQLITE_FCNTL_LAST_ERRNO 4 1021#define SQLITE_FCNTL_SIZE_HINT 5 1022#define SQLITE_FCNTL_CHUNK_SIZE 6 1023#define SQLITE_FCNTL_FILE_POINTER 7 1024#define SQLITE_FCNTL_SYNC_OMITTED 8 1025#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1026#define SQLITE_FCNTL_PERSIST_WAL 10 1027#define SQLITE_FCNTL_OVERWRITE 11 1028#define SQLITE_FCNTL_VFSNAME 12 1029#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1030#define SQLITE_FCNTL_PRAGMA 14 1031#define SQLITE_FCNTL_BUSYHANDLER 15 1032#define SQLITE_FCNTL_TEMPFILENAME 16 1033#define SQLITE_FCNTL_MMAP_SIZE 18 1034#define SQLITE_FCNTL_TRACE 19 1035#define SQLITE_FCNTL_HAS_MOVED 20 1036#define SQLITE_FCNTL_SYNC 21 1037#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1038#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1039#define SQLITE_FCNTL_WAL_BLOCK 24 1040#define SQLITE_FCNTL_ZIPVFS 25 1041#define SQLITE_FCNTL_RBU 26 1042#define SQLITE_FCNTL_VFS_POINTER 27 1043#define SQLITE_FCNTL_JOURNAL_POINTER 28 1044#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1045#define SQLITE_FCNTL_PDB 30 1046 1047/* deprecated names */ 1048#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1049#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1050#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1051 1052 1053/* 1054** CAPI3REF: Mutex Handle 1055** 1056** The mutex module within SQLite defines [sqlite3_mutex] to be an 1057** abstract type for a mutex object. The SQLite core never looks 1058** at the internal representation of an [sqlite3_mutex]. It only 1059** deals with pointers to the [sqlite3_mutex] object. 1060** 1061** Mutexes are created using [sqlite3_mutex_alloc()]. 1062*/ 1063typedef struct sqlite3_mutex sqlite3_mutex; 1064 1065/* 1066** CAPI3REF: Loadable Extension Thunk 1067** 1068** A pointer to the opaque sqlite3_api_routines structure is passed as 1069** the third parameter to entry points of [loadable extensions]. This 1070** structure must be typedefed in order to work around compiler warnings 1071** on some platforms. 1072*/ 1073typedef struct sqlite3_api_routines sqlite3_api_routines; 1074 1075/* 1076** CAPI3REF: OS Interface Object 1077** 1078** An instance of the sqlite3_vfs object defines the interface between 1079** the SQLite core and the underlying operating system. The "vfs" 1080** in the name of the object stands for "virtual file system". See 1081** the [VFS | VFS documentation] for further information. 1082** 1083** The value of the iVersion field is initially 1 but may be larger in 1084** future versions of SQLite. Additional fields may be appended to this 1085** object when the iVersion value is increased. Note that the structure 1086** of the sqlite3_vfs object changes in the transaction between 1087** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1088** modified. 1089** 1090** The szOsFile field is the size of the subclassed [sqlite3_file] 1091** structure used by this VFS. mxPathname is the maximum length of 1092** a pathname in this VFS. 1093** 1094** Registered sqlite3_vfs objects are kept on a linked list formed by 1095** the pNext pointer. The [sqlite3_vfs_register()] 1096** and [sqlite3_vfs_unregister()] interfaces manage this list 1097** in a thread-safe way. The [sqlite3_vfs_find()] interface 1098** searches the list. Neither the application code nor the VFS 1099** implementation should use the pNext pointer. 1100** 1101** The pNext field is the only field in the sqlite3_vfs 1102** structure that SQLite will ever modify. SQLite will only access 1103** or modify this field while holding a particular static mutex. 1104** The application should never modify anything within the sqlite3_vfs 1105** object once the object has been registered. 1106** 1107** The zName field holds the name of the VFS module. The name must 1108** be unique across all VFS modules. 1109** 1110** [[sqlite3_vfs.xOpen]] 1111** ^SQLite guarantees that the zFilename parameter to xOpen 1112** is either a NULL pointer or string obtained 1113** from xFullPathname() with an optional suffix added. 1114** ^If a suffix is added to the zFilename parameter, it will 1115** consist of a single "-" character followed by no more than 1116** 11 alphanumeric and/or "-" characters. 1117** ^SQLite further guarantees that 1118** the string will be valid and unchanged until xClose() is 1119** called. Because of the previous sentence, 1120** the [sqlite3_file] can safely store a pointer to the 1121** filename if it needs to remember the filename for some reason. 1122** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1123** must invent its own temporary name for the file. ^Whenever the 1124** xFilename parameter is NULL it will also be the case that the 1125** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1126** 1127** The flags argument to xOpen() includes all bits set in 1128** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1129** or [sqlite3_open16()] is used, then flags includes at least 1130** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1131** If xOpen() opens a file read-only then it sets *pOutFlags to 1132** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1133** 1134** ^(SQLite will also add one of the following flags to the xOpen() 1135** call, depending on the object being opened: 1136** 1137** <ul> 1138** <li> [SQLITE_OPEN_MAIN_DB] 1139** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1140** <li> [SQLITE_OPEN_TEMP_DB] 1141** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1142** <li> [SQLITE_OPEN_TRANSIENT_DB] 1143** <li> [SQLITE_OPEN_SUBJOURNAL] 1144** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1145** <li> [SQLITE_OPEN_WAL] 1146** </ul>)^ 1147** 1148** The file I/O implementation can use the object type flags to 1149** change the way it deals with files. For example, an application 1150** that does not care about crash recovery or rollback might make 1151** the open of a journal file a no-op. Writes to this journal would 1152** also be no-ops, and any attempt to read the journal would return 1153** SQLITE_IOERR. Or the implementation might recognize that a database 1154** file will be doing page-aligned sector reads and writes in a random 1155** order and set up its I/O subsystem accordingly. 1156** 1157** SQLite might also add one of the following flags to the xOpen method: 1158** 1159** <ul> 1160** <li> [SQLITE_OPEN_DELETEONCLOSE] 1161** <li> [SQLITE_OPEN_EXCLUSIVE] 1162** </ul> 1163** 1164** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1165** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1166** will be set for TEMP databases and their journals, transient 1167** databases, and subjournals. 1168** 1169** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1170** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1171** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1172** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1173** SQLITE_OPEN_CREATE, is used to indicate that file should always 1174** be created, and that it is an error if it already exists. 1175** It is <i>not</i> used to indicate the file should be opened 1176** for exclusive access. 1177** 1178** ^At least szOsFile bytes of memory are allocated by SQLite 1179** to hold the [sqlite3_file] structure passed as the third 1180** argument to xOpen. The xOpen method does not have to 1181** allocate the structure; it should just fill it in. Note that 1182** the xOpen method must set the sqlite3_file.pMethods to either 1183** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1184** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1185** element will be valid after xOpen returns regardless of the success 1186** or failure of the xOpen call. 1187** 1188** [[sqlite3_vfs.xAccess]] 1189** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1190** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1191** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1192** to test whether a file is at least readable. The file can be a 1193** directory. 1194** 1195** ^SQLite will always allocate at least mxPathname+1 bytes for the 1196** output buffer xFullPathname. The exact size of the output buffer 1197** is also passed as a parameter to both methods. If the output buffer 1198** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1199** handled as a fatal error by SQLite, vfs implementations should endeavor 1200** to prevent this by setting mxPathname to a sufficiently large value. 1201** 1202** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1203** interfaces are not strictly a part of the filesystem, but they are 1204** included in the VFS structure for completeness. 1205** The xRandomness() function attempts to return nBytes bytes 1206** of good-quality randomness into zOut. The return value is 1207** the actual number of bytes of randomness obtained. 1208** The xSleep() method causes the calling thread to sleep for at 1209** least the number of microseconds given. ^The xCurrentTime() 1210** method returns a Julian Day Number for the current date and time as 1211** a floating point value. 1212** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1213** Day Number multiplied by 86400000 (the number of milliseconds in 1214** a 24-hour day). 1215** ^SQLite will use the xCurrentTimeInt64() method to get the current 1216** date and time if that method is available (if iVersion is 2 or 1217** greater and the function pointer is not NULL) and will fall back 1218** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1219** 1220** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1221** are not used by the SQLite core. These optional interfaces are provided 1222** by some VFSes to facilitate testing of the VFS code. By overriding 1223** system calls with functions under its control, a test program can 1224** simulate faults and error conditions that would otherwise be difficult 1225** or impossible to induce. The set of system calls that can be overridden 1226** varies from one VFS to another, and from one version of the same VFS to the 1227** next. Applications that use these interfaces must be prepared for any 1228** or all of these interfaces to be NULL or for their behavior to change 1229** from one release to the next. Applications must not attempt to access 1230** any of these methods if the iVersion of the VFS is less than 3. 1231*/ 1232typedef struct sqlite3_vfs sqlite3_vfs; 1233typedef void (*sqlite3_syscall_ptr)(void); 1234struct sqlite3_vfs { 1235 int iVersion; /* Structure version number (currently 3) */ 1236 int szOsFile; /* Size of subclassed sqlite3_file */ 1237 int mxPathname; /* Maximum file pathname length */ 1238 sqlite3_vfs *pNext; /* Next registered VFS */ 1239 const char *zName; /* Name of this virtual file system */ 1240 void *pAppData; /* Pointer to application-specific data */ 1241 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1242 int flags, int *pOutFlags); 1243 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1244 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1245 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1246 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1247 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1248 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1249 void (*xDlClose)(sqlite3_vfs*, void*); 1250 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1251 int (*xSleep)(sqlite3_vfs*, int microseconds); 1252 int (*xCurrentTime)(sqlite3_vfs*, double*); 1253 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1254 /* 1255 ** The methods above are in version 1 of the sqlite_vfs object 1256 ** definition. Those that follow are added in version 2 or later 1257 */ 1258 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1259 /* 1260 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1261 ** Those below are for version 3 and greater. 1262 */ 1263 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1264 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1265 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1266 /* 1267 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1268 ** New fields may be appended in future versions. The iVersion 1269 ** value will increment whenever this happens. 1270 */ 1271}; 1272 1273/* 1274** CAPI3REF: Flags for the xAccess VFS method 1275** 1276** These integer constants can be used as the third parameter to 1277** the xAccess method of an [sqlite3_vfs] object. They determine 1278** what kind of permissions the xAccess method is looking for. 1279** With SQLITE_ACCESS_EXISTS, the xAccess method 1280** simply checks whether the file exists. 1281** With SQLITE_ACCESS_READWRITE, the xAccess method 1282** checks whether the named directory is both readable and writable 1283** (in other words, if files can be added, removed, and renamed within 1284** the directory). 1285** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1286** [temp_store_directory pragma], though this could change in a future 1287** release of SQLite. 1288** With SQLITE_ACCESS_READ, the xAccess method 1289** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1290** currently unused, though it might be used in a future release of 1291** SQLite. 1292*/ 1293#define SQLITE_ACCESS_EXISTS 0 1294#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1295#define SQLITE_ACCESS_READ 2 /* Unused */ 1296 1297/* 1298** CAPI3REF: Flags for the xShmLock VFS method 1299** 1300** These integer constants define the various locking operations 1301** allowed by the xShmLock method of [sqlite3_io_methods]. The 1302** following are the only legal combinations of flags to the 1303** xShmLock method: 1304** 1305** <ul> 1306** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1307** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1308** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1309** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1310** </ul> 1311** 1312** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1313** was given on the corresponding lock. 1314** 1315** The xShmLock method can transition between unlocked and SHARED or 1316** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1317** and EXCLUSIVE. 1318*/ 1319#define SQLITE_SHM_UNLOCK 1 1320#define SQLITE_SHM_LOCK 2 1321#define SQLITE_SHM_SHARED 4 1322#define SQLITE_SHM_EXCLUSIVE 8 1323 1324/* 1325** CAPI3REF: Maximum xShmLock index 1326** 1327** The xShmLock method on [sqlite3_io_methods] may use values 1328** between 0 and this upper bound as its "offset" argument. 1329** The SQLite core will never attempt to acquire or release a 1330** lock outside of this range 1331*/ 1332#define SQLITE_SHM_NLOCK 8 1333 1334 1335/* 1336** CAPI3REF: Initialize The SQLite Library 1337** 1338** ^The sqlite3_initialize() routine initializes the 1339** SQLite library. ^The sqlite3_shutdown() routine 1340** deallocates any resources that were allocated by sqlite3_initialize(). 1341** These routines are designed to aid in process initialization and 1342** shutdown on embedded systems. Workstation applications using 1343** SQLite normally do not need to invoke either of these routines. 1344** 1345** A call to sqlite3_initialize() is an "effective" call if it is 1346** the first time sqlite3_initialize() is invoked during the lifetime of 1347** the process, or if it is the first time sqlite3_initialize() is invoked 1348** following a call to sqlite3_shutdown(). ^(Only an effective call 1349** of sqlite3_initialize() does any initialization. All other calls 1350** are harmless no-ops.)^ 1351** 1352** A call to sqlite3_shutdown() is an "effective" call if it is the first 1353** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1354** an effective call to sqlite3_shutdown() does any deinitialization. 1355** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1356** 1357** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1358** is not. The sqlite3_shutdown() interface must only be called from a 1359** single thread. All open [database connections] must be closed and all 1360** other SQLite resources must be deallocated prior to invoking 1361** sqlite3_shutdown(). 1362** 1363** Among other things, ^sqlite3_initialize() will invoke 1364** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1365** will invoke sqlite3_os_end(). 1366** 1367** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1368** ^If for some reason, sqlite3_initialize() is unable to initialize 1369** the library (perhaps it is unable to allocate a needed resource such 1370** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1371** 1372** ^The sqlite3_initialize() routine is called internally by many other 1373** SQLite interfaces so that an application usually does not need to 1374** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1375** calls sqlite3_initialize() so the SQLite library will be automatically 1376** initialized when [sqlite3_open()] is called if it has not be initialized 1377** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1378** compile-time option, then the automatic calls to sqlite3_initialize() 1379** are omitted and the application must call sqlite3_initialize() directly 1380** prior to using any other SQLite interface. For maximum portability, 1381** it is recommended that applications always invoke sqlite3_initialize() 1382** directly prior to using any other SQLite interface. Future releases 1383** of SQLite may require this. In other words, the behavior exhibited 1384** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1385** default behavior in some future release of SQLite. 1386** 1387** The sqlite3_os_init() routine does operating-system specific 1388** initialization of the SQLite library. The sqlite3_os_end() 1389** routine undoes the effect of sqlite3_os_init(). Typical tasks 1390** performed by these routines include allocation or deallocation 1391** of static resources, initialization of global variables, 1392** setting up a default [sqlite3_vfs] module, or setting up 1393** a default configuration using [sqlite3_config()]. 1394** 1395** The application should never invoke either sqlite3_os_init() 1396** or sqlite3_os_end() directly. The application should only invoke 1397** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1398** interface is called automatically by sqlite3_initialize() and 1399** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1400** implementations for sqlite3_os_init() and sqlite3_os_end() 1401** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1402** When [custom builds | built for other platforms] 1403** (using the [SQLITE_OS_OTHER=1] compile-time 1404** option) the application must supply a suitable implementation for 1405** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1406** implementation of sqlite3_os_init() or sqlite3_os_end() 1407** must return [SQLITE_OK] on success and some other [error code] upon 1408** failure. 1409*/ 1410int sqlite3_initialize(void); 1411int sqlite3_shutdown(void); 1412int sqlite3_os_init(void); 1413int sqlite3_os_end(void); 1414 1415/* 1416** CAPI3REF: Configuring The SQLite Library 1417** 1418** The sqlite3_config() interface is used to make global configuration 1419** changes to SQLite in order to tune SQLite to the specific needs of 1420** the application. The default configuration is recommended for most 1421** applications and so this routine is usually not necessary. It is 1422** provided to support rare applications with unusual needs. 1423** 1424** <b>The sqlite3_config() interface is not threadsafe. The application 1425** must ensure that no other SQLite interfaces are invoked by other 1426** threads while sqlite3_config() is running.</b> 1427** 1428** The sqlite3_config() interface 1429** may only be invoked prior to library initialization using 1430** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1431** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1432** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1433** Note, however, that ^sqlite3_config() can be called as part of the 1434** implementation of an application-defined [sqlite3_os_init()]. 1435** 1436** The first argument to sqlite3_config() is an integer 1437** [configuration option] that determines 1438** what property of SQLite is to be configured. Subsequent arguments 1439** vary depending on the [configuration option] 1440** in the first argument. 1441** 1442** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1443** ^If the option is unknown or SQLite is unable to set the option 1444** then this routine returns a non-zero [error code]. 1445*/ 1446int sqlite3_config(int, ...); 1447 1448/* 1449** CAPI3REF: Configure database connections 1450** METHOD: sqlite3 1451** 1452** The sqlite3_db_config() interface is used to make configuration 1453** changes to a [database connection]. The interface is similar to 1454** [sqlite3_config()] except that the changes apply to a single 1455** [database connection] (specified in the first argument). 1456** 1457** The second argument to sqlite3_db_config(D,V,...) is the 1458** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1459** that indicates what aspect of the [database connection] is being configured. 1460** Subsequent arguments vary depending on the configuration verb. 1461** 1462** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1463** the call is considered successful. 1464*/ 1465int sqlite3_db_config(sqlite3*, int op, ...); 1466 1467/* 1468** CAPI3REF: Memory Allocation Routines 1469** 1470** An instance of this object defines the interface between SQLite 1471** and low-level memory allocation routines. 1472** 1473** This object is used in only one place in the SQLite interface. 1474** A pointer to an instance of this object is the argument to 1475** [sqlite3_config()] when the configuration option is 1476** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1477** By creating an instance of this object 1478** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1479** during configuration, an application can specify an alternative 1480** memory allocation subsystem for SQLite to use for all of its 1481** dynamic memory needs. 1482** 1483** Note that SQLite comes with several [built-in memory allocators] 1484** that are perfectly adequate for the overwhelming majority of applications 1485** and that this object is only useful to a tiny minority of applications 1486** with specialized memory allocation requirements. This object is 1487** also used during testing of SQLite in order to specify an alternative 1488** memory allocator that simulates memory out-of-memory conditions in 1489** order to verify that SQLite recovers gracefully from such 1490** conditions. 1491** 1492** The xMalloc, xRealloc, and xFree methods must work like the 1493** malloc(), realloc() and free() functions from the standard C library. 1494** ^SQLite guarantees that the second argument to 1495** xRealloc is always a value returned by a prior call to xRoundup. 1496** 1497** xSize should return the allocated size of a memory allocation 1498** previously obtained from xMalloc or xRealloc. The allocated size 1499** is always at least as big as the requested size but may be larger. 1500** 1501** The xRoundup method returns what would be the allocated size of 1502** a memory allocation given a particular requested size. Most memory 1503** allocators round up memory allocations at least to the next multiple 1504** of 8. Some allocators round up to a larger multiple or to a power of 2. 1505** Every memory allocation request coming in through [sqlite3_malloc()] 1506** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1507** that causes the corresponding memory allocation to fail. 1508** 1509** The xInit method initializes the memory allocator. For example, 1510** it might allocate any require mutexes or initialize internal data 1511** structures. The xShutdown method is invoked (indirectly) by 1512** [sqlite3_shutdown()] and should deallocate any resources acquired 1513** by xInit. The pAppData pointer is used as the only parameter to 1514** xInit and xShutdown. 1515** 1516** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1517** the xInit method, so the xInit method need not be threadsafe. The 1518** xShutdown method is only called from [sqlite3_shutdown()] so it does 1519** not need to be threadsafe either. For all other methods, SQLite 1520** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1521** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1522** it is by default) and so the methods are automatically serialized. 1523** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1524** methods must be threadsafe or else make their own arrangements for 1525** serialization. 1526** 1527** SQLite will never invoke xInit() more than once without an intervening 1528** call to xShutdown(). 1529*/ 1530typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1531struct sqlite3_mem_methods { 1532 void *(*xMalloc)(int); /* Memory allocation function */ 1533 void (*xFree)(void*); /* Free a prior allocation */ 1534 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1535 int (*xSize)(void*); /* Return the size of an allocation */ 1536 int (*xRoundup)(int); /* Round up request size to allocation size */ 1537 int (*xInit)(void*); /* Initialize the memory allocator */ 1538 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1539 void *pAppData; /* Argument to xInit() and xShutdown() */ 1540}; 1541 1542/* 1543** CAPI3REF: Configuration Options 1544** KEYWORDS: {configuration option} 1545** 1546** These constants are the available integer configuration options that 1547** can be passed as the first argument to the [sqlite3_config()] interface. 1548** 1549** New configuration options may be added in future releases of SQLite. 1550** Existing configuration options might be discontinued. Applications 1551** should check the return code from [sqlite3_config()] to make sure that 1552** the call worked. The [sqlite3_config()] interface will return a 1553** non-zero [error code] if a discontinued or unsupported configuration option 1554** is invoked. 1555** 1556** <dl> 1557** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1558** <dd>There are no arguments to this option. ^This option sets the 1559** [threading mode] to Single-thread. In other words, it disables 1560** all mutexing and puts SQLite into a mode where it can only be used 1561** by a single thread. ^If SQLite is compiled with 1562** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1563** it is not possible to change the [threading mode] from its default 1564** value of Single-thread and so [sqlite3_config()] will return 1565** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1566** configuration option.</dd> 1567** 1568** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1569** <dd>There are no arguments to this option. ^This option sets the 1570** [threading mode] to Multi-thread. In other words, it disables 1571** mutexing on [database connection] and [prepared statement] objects. 1572** The application is responsible for serializing access to 1573** [database connections] and [prepared statements]. But other mutexes 1574** are enabled so that SQLite will be safe to use in a multi-threaded 1575** environment as long as no two threads attempt to use the same 1576** [database connection] at the same time. ^If SQLite is compiled with 1577** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1578** it is not possible to set the Multi-thread [threading mode] and 1579** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1580** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1581** 1582** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1583** <dd>There are no arguments to this option. ^This option sets the 1584** [threading mode] to Serialized. In other words, this option enables 1585** all mutexes including the recursive 1586** mutexes on [database connection] and [prepared statement] objects. 1587** In this mode (which is the default when SQLite is compiled with 1588** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1589** to [database connections] and [prepared statements] so that the 1590** application is free to use the same [database connection] or the 1591** same [prepared statement] in different threads at the same time. 1592** ^If SQLite is compiled with 1593** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1594** it is not possible to set the Serialized [threading mode] and 1595** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1596** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1597** 1598** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1599** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1600** a pointer to an instance of the [sqlite3_mem_methods] structure. 1601** The argument specifies 1602** alternative low-level memory allocation routines to be used in place of 1603** the memory allocation routines built into SQLite.)^ ^SQLite makes 1604** its own private copy of the content of the [sqlite3_mem_methods] structure 1605** before the [sqlite3_config()] call returns.</dd> 1606** 1607** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1608** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1609** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1610** The [sqlite3_mem_methods] 1611** structure is filled with the currently defined memory allocation routines.)^ 1612** This option can be used to overload the default memory allocation 1613** routines with a wrapper that simulations memory allocation failure or 1614** tracks memory usage, for example. </dd> 1615** 1616** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1617** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1618** interpreted as a boolean, which enables or disables the collection of 1619** memory allocation statistics. ^(When memory allocation statistics are 1620** disabled, the following SQLite interfaces become non-operational: 1621** <ul> 1622** <li> [sqlite3_memory_used()] 1623** <li> [sqlite3_memory_highwater()] 1624** <li> [sqlite3_soft_heap_limit64()] 1625** <li> [sqlite3_status64()] 1626** </ul>)^ 1627** ^Memory allocation statistics are enabled by default unless SQLite is 1628** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1629** allocation statistics are disabled by default. 1630** </dd> 1631** 1632** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1633** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer 1634** that SQLite can use for scratch memory. ^(There are three arguments 1635** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte 1636** aligned memory buffer from which the scratch allocations will be 1637** drawn, the size of each scratch allocation (sz), 1638** and the maximum number of scratch allocations (N).)^ 1639** The first argument must be a pointer to an 8-byte aligned buffer 1640** of at least sz*N bytes of memory. 1641** ^SQLite will not use more than one scratch buffers per thread. 1642** ^SQLite will never request a scratch buffer that is more than 6 1643** times the database page size. 1644** ^If SQLite needs needs additional 1645** scratch memory beyond what is provided by this configuration option, then 1646** [sqlite3_malloc()] will be used to obtain the memory needed.<p> 1647** ^When the application provides any amount of scratch memory using 1648** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large 1649** [sqlite3_malloc|heap allocations]. 1650** This can help [Robson proof|prevent memory allocation failures] due to heap 1651** fragmentation in low-memory embedded systems. 1652** </dd> 1653** 1654** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1655** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1656** that SQLite can use for the database page cache with the default page 1657** cache implementation. 1658** This configuration option is a no-op if an application-define page 1659** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1660** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1661** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1662** and the number of cache lines (N). 1663** The sz argument should be the size of the largest database page 1664** (a power of two between 512 and 65536) plus some extra bytes for each 1665** page header. ^The number of extra bytes needed by the page header 1666** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1667** ^It is harmless, apart from the wasted memory, 1668** for the sz parameter to be larger than necessary. The pMem 1669** argument must be either a NULL pointer or a pointer to an 8-byte 1670** aligned block of memory of at least sz*N bytes, otherwise 1671** subsequent behavior is undefined. 1672** ^When pMem is not NULL, SQLite will strive to use the memory provided 1673** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1674** a page cache line is larger than sz bytes or if all of the pMem buffer 1675** is exhausted. 1676** ^If pMem is NULL and N is non-zero, then each database connection 1677** does an initial bulk allocation for page cache memory 1678** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1679** of -1024*N bytes if N is negative, . ^If additional 1680** page cache memory is needed beyond what is provided by the initial 1681** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1682** additional cache line. </dd> 1683** 1684** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1685** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1686** that SQLite will use for all of its dynamic memory allocation needs 1687** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and 1688** [SQLITE_CONFIG_PAGECACHE]. 1689** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1690** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1691** [SQLITE_ERROR] if invoked otherwise. 1692** ^There are three arguments to SQLITE_CONFIG_HEAP: 1693** An 8-byte aligned pointer to the memory, 1694** the number of bytes in the memory buffer, and the minimum allocation size. 1695** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1696** to using its default memory allocator (the system malloc() implementation), 1697** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1698** memory pointer is not NULL then the alternative memory 1699** allocator is engaged to handle all of SQLites memory allocation needs. 1700** The first pointer (the memory pointer) must be aligned to an 8-byte 1701** boundary or subsequent behavior of SQLite will be undefined. 1702** The minimum allocation size is capped at 2**12. Reasonable values 1703** for the minimum allocation size are 2**5 through 2**8.</dd> 1704** 1705** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1706** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1707** pointer to an instance of the [sqlite3_mutex_methods] structure. 1708** The argument specifies alternative low-level mutex routines to be used 1709** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1710** the content of the [sqlite3_mutex_methods] structure before the call to 1711** [sqlite3_config()] returns. ^If SQLite is compiled with 1712** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1713** the entire mutexing subsystem is omitted from the build and hence calls to 1714** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1715** return [SQLITE_ERROR].</dd> 1716** 1717** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1718** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1719** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1720** [sqlite3_mutex_methods] 1721** structure is filled with the currently defined mutex routines.)^ 1722** This option can be used to overload the default mutex allocation 1723** routines with a wrapper used to track mutex usage for performance 1724** profiling or testing, for example. ^If SQLite is compiled with 1725** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1726** the entire mutexing subsystem is omitted from the build and hence calls to 1727** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1728** return [SQLITE_ERROR].</dd> 1729** 1730** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1731** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1732** the default size of lookaside memory on each [database connection]. 1733** The first argument is the 1734** size of each lookaside buffer slot and the second is the number of 1735** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1736** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1737** option to [sqlite3_db_config()] can be used to change the lookaside 1738** configuration on individual connections.)^ </dd> 1739** 1740** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1741** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1742** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1743** the interface to a custom page cache implementation.)^ 1744** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1745** 1746** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1747** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1748** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1749** the current page cache implementation into that object.)^ </dd> 1750** 1751** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1752** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1753** global [error log]. 1754** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1755** function with a call signature of void(*)(void*,int,const char*), 1756** and a pointer to void. ^If the function pointer is not NULL, it is 1757** invoked by [sqlite3_log()] to process each logging event. ^If the 1758** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1759** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1760** passed through as the first parameter to the application-defined logger 1761** function whenever that function is invoked. ^The second parameter to 1762** the logger function is a copy of the first parameter to the corresponding 1763** [sqlite3_log()] call and is intended to be a [result code] or an 1764** [extended result code]. ^The third parameter passed to the logger is 1765** log message after formatting via [sqlite3_snprintf()]. 1766** The SQLite logging interface is not reentrant; the logger function 1767** supplied by the application must not invoke any SQLite interface. 1768** In a multi-threaded application, the application-defined logger 1769** function must be threadsafe. </dd> 1770** 1771** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1772** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1773** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1774** then URI handling is globally disabled.)^ ^If URI handling is globally 1775** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1776** [sqlite3_open16()] or 1777** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1778** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1779** connection is opened. ^If it is globally disabled, filenames are 1780** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1781** database connection is opened. ^(By default, URI handling is globally 1782** disabled. The default value may be changed by compiling with the 1783** [SQLITE_USE_URI] symbol defined.)^ 1784** 1785** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1786** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1787** argument which is interpreted as a boolean in order to enable or disable 1788** the use of covering indices for full table scans in the query optimizer. 1789** ^The default setting is determined 1790** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1791** if that compile-time option is omitted. 1792** The ability to disable the use of covering indices for full table scans 1793** is because some incorrectly coded legacy applications might malfunction 1794** when the optimization is enabled. Providing the ability to 1795** disable the optimization allows the older, buggy application code to work 1796** without change even with newer versions of SQLite. 1797** 1798** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1799** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1800** <dd> These options are obsolete and should not be used by new code. 1801** They are retained for backwards compatibility but are now no-ops. 1802** </dd> 1803** 1804** [[SQLITE_CONFIG_SQLLOG]] 1805** <dt>SQLITE_CONFIG_SQLLOG 1806** <dd>This option is only available if sqlite is compiled with the 1807** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1808** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1809** The second should be of type (void*). The callback is invoked by the library 1810** in three separate circumstances, identified by the value passed as the 1811** fourth parameter. If the fourth parameter is 0, then the database connection 1812** passed as the second argument has just been opened. The third argument 1813** points to a buffer containing the name of the main database file. If the 1814** fourth parameter is 1, then the SQL statement that the third parameter 1815** points to has just been executed. Or, if the fourth parameter is 2, then 1816** the connection being passed as the second parameter is being closed. The 1817** third parameter is passed NULL In this case. An example of using this 1818** configuration option can be seen in the "test_sqllog.c" source file in 1819** the canonical SQLite source tree.</dd> 1820** 1821** [[SQLITE_CONFIG_MMAP_SIZE]] 1822** <dt>SQLITE_CONFIG_MMAP_SIZE 1823** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1824** that are the default mmap size limit (the default setting for 1825** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1826** ^The default setting can be overridden by each database connection using 1827** either the [PRAGMA mmap_size] command, or by using the 1828** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1829** will be silently truncated if necessary so that it does not exceed the 1830** compile-time maximum mmap size set by the 1831** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1832** ^If either argument to this option is negative, then that argument is 1833** changed to its compile-time default. 1834** 1835** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1836** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1837** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1838** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1839** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1840** that specifies the maximum size of the created heap. 1841** 1842** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1843** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1844** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1845** is a pointer to an integer and writes into that integer the number of extra 1846** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1847** The amount of extra space required can change depending on the compiler, 1848** target platform, and SQLite version. 1849** 1850** [[SQLITE_CONFIG_PMASZ]] 1851** <dt>SQLITE_CONFIG_PMASZ 1852** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1853** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1854** sorter to that integer. The default minimum PMA Size is set by the 1855** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1856** to help with sort operations when multithreaded sorting 1857** is enabled (using the [PRAGMA threads] command) and the amount of content 1858** to be sorted exceeds the page size times the minimum of the 1859** [PRAGMA cache_size] setting and this value. 1860** 1861** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1862** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1863** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1864** becomes the [statement journal] spill-to-disk threshold. 1865** [Statement journals] are held in memory until their size (in bytes) 1866** exceeds this threshold, at which point they are written to disk. 1867** Or if the threshold is -1, statement journals are always held 1868** exclusively in memory. 1869** Since many statement journals never become large, setting the spill 1870** threshold to a value such as 64KiB can greatly reduce the amount of 1871** I/O required to support statement rollback. 1872** The default value for this setting is controlled by the 1873** [SQLITE_STMTJRNL_SPILL] compile-time option. 1874** </dl> 1875*/ 1876#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1877#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1878#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1879#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1880#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1881#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1882#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1883#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1884#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1885#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1886#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1887/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1888#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1889#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1890#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1891#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1892#define SQLITE_CONFIG_URI 17 /* int */ 1893#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1894#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1895#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1896#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1897#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1898#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1899#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 1900#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 1901#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 1902 1903/* 1904** CAPI3REF: Database Connection Configuration Options 1905** 1906** These constants are the available integer configuration options that 1907** can be passed as the second argument to the [sqlite3_db_config()] interface. 1908** 1909** New configuration options may be added in future releases of SQLite. 1910** Existing configuration options might be discontinued. Applications 1911** should check the return code from [sqlite3_db_config()] to make sure that 1912** the call worked. ^The [sqlite3_db_config()] interface will return a 1913** non-zero [error code] if a discontinued or unsupported configuration option 1914** is invoked. 1915** 1916** <dl> 1917** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1918** <dd> ^This option takes three additional arguments that determine the 1919** [lookaside memory allocator] configuration for the [database connection]. 1920** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1921** pointer to a memory buffer to use for lookaside memory. 1922** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1923** may be NULL in which case SQLite will allocate the 1924** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1925** size of each lookaside buffer slot. ^The third argument is the number of 1926** slots. The size of the buffer in the first argument must be greater than 1927** or equal to the product of the second and third arguments. The buffer 1928** must be aligned to an 8-byte boundary. ^If the second argument to 1929** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1930** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1931** configuration for a database connection can only be changed when that 1932** connection is not currently using lookaside memory, or in other words 1933** when the "current value" returned by 1934** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1935** Any attempt to change the lookaside memory configuration when lookaside 1936** memory is in use leaves the configuration unchanged and returns 1937** [SQLITE_BUSY].)^</dd> 1938** 1939** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1940** <dd> ^This option is used to enable or disable the enforcement of 1941** [foreign key constraints]. There should be two additional arguments. 1942** The first argument is an integer which is 0 to disable FK enforcement, 1943** positive to enable FK enforcement or negative to leave FK enforcement 1944** unchanged. The second parameter is a pointer to an integer into which 1945** is written 0 or 1 to indicate whether FK enforcement is off or on 1946** following this call. The second parameter may be a NULL pointer, in 1947** which case the FK enforcement setting is not reported back. </dd> 1948** 1949** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1950** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1951** There should be two additional arguments. 1952** The first argument is an integer which is 0 to disable triggers, 1953** positive to enable triggers or negative to leave the setting unchanged. 1954** The second parameter is a pointer to an integer into which 1955** is written 0 or 1 to indicate whether triggers are disabled or enabled 1956** following this call. The second parameter may be a NULL pointer, in 1957** which case the trigger setting is not reported back. </dd> 1958** 1959** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 1960** <dd> ^This option is used to enable or disable the two-argument 1961** version of the [fts3_tokenizer()] function which is part of the 1962** [FTS3] full-text search engine extension. 1963** There should be two additional arguments. 1964** The first argument is an integer which is 0 to disable fts3_tokenizer() or 1965** positive to enable fts3_tokenizer() or negative to leave the setting 1966** unchanged. 1967** The second parameter is a pointer to an integer into which 1968** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 1969** following this call. The second parameter may be a NULL pointer, in 1970** which case the new setting is not reported back. </dd> 1971** 1972** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 1973** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 1974** interface independently of the [load_extension()] SQL function. 1975** The [sqlite3_enable_load_extension()] API enables or disables both the 1976** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 1977** There should be two additional arguments. 1978** When the first argument to this interface is 1, then only the C-API is 1979** enabled and the SQL function remains disabled. If the first argument to 1980** this interface is 0, then both the C-API and the SQL function are disabled. 1981** If the first argument is -1, then no changes are made to state of either the 1982** C-API or the SQL function. 1983** The second parameter is a pointer to an integer into which 1984** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 1985** is disabled or enabled following this call. The second parameter may 1986** be a NULL pointer, in which case the new setting is not reported back. 1987** </dd> 1988** 1989** <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 1990** <dd> ^This option is used to change the name of the "main" database 1991** schema. ^The sole argument is a pointer to a constant UTF8 string 1992** which will become the new schema name in place of "main". ^SQLite 1993** does not make a copy of the new main schema name string, so the application 1994** must ensure that the argument passed into this DBCONFIG option is unchanged 1995** until after the database connection closes. 1996** </dd> 1997** 1998** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 1999** <dd> Usually, when a database in wal mode is closed or detached from a 2000** database handle, SQLite checks if this will mean that there are now no 2001** connections at all to the database. If so, it performs a checkpoint 2002** operation before closing the connection. This option may be used to 2003** override this behaviour. The first parameter passed to this operation 2004** is an integer - non-zero to disable checkpoints-on-close, or zero (the 2005** default) to enable them. The second parameter is a pointer to an integer 2006** into which is written 0 or 1 to indicate whether checkpoints-on-close 2007** have been disabled - 0 if they are not disabled, 1 if they are. 2008** </dd> 2009** 2010** </dl> 2011*/ 2012#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2013#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2014#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2015#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2016#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2017#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2018#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2019 2020 2021/* 2022** CAPI3REF: Enable Or Disable Extended Result Codes 2023** METHOD: sqlite3 2024** 2025** ^The sqlite3_extended_result_codes() routine enables or disables the 2026** [extended result codes] feature of SQLite. ^The extended result 2027** codes are disabled by default for historical compatibility. 2028*/ 2029int sqlite3_extended_result_codes(sqlite3*, int onoff); 2030 2031/* 2032** CAPI3REF: Last Insert Rowid 2033** METHOD: sqlite3 2034** 2035** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2036** has a unique 64-bit signed 2037** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2038** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2039** names are not also used by explicitly declared columns. ^If 2040** the table has a column of type [INTEGER PRIMARY KEY] then that column 2041** is another alias for the rowid. 2042** 2043** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 2044** most recent successful [INSERT] into a rowid table or [virtual table] 2045** on database connection D. 2046** ^Inserts into [WITHOUT ROWID] tables are not recorded. 2047** ^If no successful [INSERT]s into rowid tables 2048** have ever occurred on the database connection D, 2049** then sqlite3_last_insert_rowid(D) returns zero. 2050** 2051** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 2052** method, then this routine will return the [rowid] of the inserted 2053** row as long as the trigger or virtual table method is running. 2054** But once the trigger or virtual table method ends, the value returned 2055** by this routine reverts to what it was before the trigger or virtual 2056** table method began.)^ 2057** 2058** ^An [INSERT] that fails due to a constraint violation is not a 2059** successful [INSERT] and does not change the value returned by this 2060** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2061** and INSERT OR ABORT make no changes to the return value of this 2062** routine when their insertion fails. ^(When INSERT OR REPLACE 2063** encounters a constraint violation, it does not fail. The 2064** INSERT continues to completion after deleting rows that caused 2065** the constraint problem so INSERT OR REPLACE will always change 2066** the return value of this interface.)^ 2067** 2068** ^For the purposes of this routine, an [INSERT] is considered to 2069** be successful even if it is subsequently rolled back. 2070** 2071** This function is accessible to SQL statements via the 2072** [last_insert_rowid() SQL function]. 2073** 2074** If a separate thread performs a new [INSERT] on the same 2075** database connection while the [sqlite3_last_insert_rowid()] 2076** function is running and thus changes the last insert [rowid], 2077** then the value returned by [sqlite3_last_insert_rowid()] is 2078** unpredictable and might not equal either the old or the new 2079** last insert [rowid]. 2080*/ 2081sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2082 2083/* 2084** CAPI3REF: Count The Number Of Rows Modified 2085** METHOD: sqlite3 2086** 2087** ^This function returns the number of rows modified, inserted or 2088** deleted by the most recently completed INSERT, UPDATE or DELETE 2089** statement on the database connection specified by the only parameter. 2090** ^Executing any other type of SQL statement does not modify the value 2091** returned by this function. 2092** 2093** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2094** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2095** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2096** 2097** Changes to a view that are intercepted by 2098** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2099** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2100** DELETE statement run on a view is always zero. Only changes made to real 2101** tables are counted. 2102** 2103** Things are more complicated if the sqlite3_changes() function is 2104** executed while a trigger program is running. This may happen if the 2105** program uses the [changes() SQL function], or if some other callback 2106** function invokes sqlite3_changes() directly. Essentially: 2107** 2108** <ul> 2109** <li> ^(Before entering a trigger program the value returned by 2110** sqlite3_changes() function is saved. After the trigger program 2111** has finished, the original value is restored.)^ 2112** 2113** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2114** statement sets the value returned by sqlite3_changes() 2115** upon completion as normal. Of course, this value will not include 2116** any changes performed by sub-triggers, as the sqlite3_changes() 2117** value will be saved and restored after each sub-trigger has run.)^ 2118** </ul> 2119** 2120** ^This means that if the changes() SQL function (or similar) is used 2121** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2122** returns the value as set when the calling statement began executing. 2123** ^If it is used by the second or subsequent such statement within a trigger 2124** program, the value returned reflects the number of rows modified by the 2125** previous INSERT, UPDATE or DELETE statement within the same trigger. 2126** 2127** See also the [sqlite3_total_changes()] interface, the 2128** [count_changes pragma], and the [changes() SQL function]. 2129** 2130** If a separate thread makes changes on the same database connection 2131** while [sqlite3_changes()] is running then the value returned 2132** is unpredictable and not meaningful. 2133*/ 2134int sqlite3_changes(sqlite3*); 2135 2136/* 2137** CAPI3REF: Total Number Of Rows Modified 2138** METHOD: sqlite3 2139** 2140** ^This function returns the total number of rows inserted, modified or 2141** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2142** since the database connection was opened, including those executed as 2143** part of trigger programs. ^Executing any other type of SQL statement 2144** does not affect the value returned by sqlite3_total_changes(). 2145** 2146** ^Changes made as part of [foreign key actions] are included in the 2147** count, but those made as part of REPLACE constraint resolution are 2148** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2149** are not counted. 2150** 2151** See also the [sqlite3_changes()] interface, the 2152** [count_changes pragma], and the [total_changes() SQL function]. 2153** 2154** If a separate thread makes changes on the same database connection 2155** while [sqlite3_total_changes()] is running then the value 2156** returned is unpredictable and not meaningful. 2157*/ 2158int sqlite3_total_changes(sqlite3*); 2159 2160/* 2161** CAPI3REF: Interrupt A Long-Running Query 2162** METHOD: sqlite3 2163** 2164** ^This function causes any pending database operation to abort and 2165** return at its earliest opportunity. This routine is typically 2166** called in response to a user action such as pressing "Cancel" 2167** or Ctrl-C where the user wants a long query operation to halt 2168** immediately. 2169** 2170** ^It is safe to call this routine from a thread different from the 2171** thread that is currently running the database operation. But it 2172** is not safe to call this routine with a [database connection] that 2173** is closed or might close before sqlite3_interrupt() returns. 2174** 2175** ^If an SQL operation is very nearly finished at the time when 2176** sqlite3_interrupt() is called, then it might not have an opportunity 2177** to be interrupted and might continue to completion. 2178** 2179** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2180** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2181** that is inside an explicit transaction, then the entire transaction 2182** will be rolled back automatically. 2183** 2184** ^The sqlite3_interrupt(D) call is in effect until all currently running 2185** SQL statements on [database connection] D complete. ^Any new SQL statements 2186** that are started after the sqlite3_interrupt() call and before the 2187** running statements reaches zero are interrupted as if they had been 2188** running prior to the sqlite3_interrupt() call. ^New SQL statements 2189** that are started after the running statement count reaches zero are 2190** not effected by the sqlite3_interrupt(). 2191** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2192** SQL statements is a no-op and has no effect on SQL statements 2193** that are started after the sqlite3_interrupt() call returns. 2194** 2195** If the database connection closes while [sqlite3_interrupt()] 2196** is running then bad things will likely happen. 2197*/ 2198void sqlite3_interrupt(sqlite3*); 2199 2200/* 2201** CAPI3REF: Determine If An SQL Statement Is Complete 2202** 2203** These routines are useful during command-line input to determine if the 2204** currently entered text seems to form a complete SQL statement or 2205** if additional input is needed before sending the text into 2206** SQLite for parsing. ^These routines return 1 if the input string 2207** appears to be a complete SQL statement. ^A statement is judged to be 2208** complete if it ends with a semicolon token and is not a prefix of a 2209** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2210** string literals or quoted identifier names or comments are not 2211** independent tokens (they are part of the token in which they are 2212** embedded) and thus do not count as a statement terminator. ^Whitespace 2213** and comments that follow the final semicolon are ignored. 2214** 2215** ^These routines return 0 if the statement is incomplete. ^If a 2216** memory allocation fails, then SQLITE_NOMEM is returned. 2217** 2218** ^These routines do not parse the SQL statements thus 2219** will not detect syntactically incorrect SQL. 2220** 2221** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2222** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2223** automatically by sqlite3_complete16(). If that initialization fails, 2224** then the return value from sqlite3_complete16() will be non-zero 2225** regardless of whether or not the input SQL is complete.)^ 2226** 2227** The input to [sqlite3_complete()] must be a zero-terminated 2228** UTF-8 string. 2229** 2230** The input to [sqlite3_complete16()] must be a zero-terminated 2231** UTF-16 string in native byte order. 2232*/ 2233int sqlite3_complete(const char *sql); 2234int sqlite3_complete16(const void *sql); 2235 2236/* 2237** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2238** KEYWORDS: {busy-handler callback} {busy handler} 2239** METHOD: sqlite3 2240** 2241** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2242** that might be invoked with argument P whenever 2243** an attempt is made to access a database table associated with 2244** [database connection] D when another thread 2245** or process has the table locked. 2246** The sqlite3_busy_handler() interface is used to implement 2247** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2248** 2249** ^If the busy callback is NULL, then [SQLITE_BUSY] 2250** is returned immediately upon encountering the lock. ^If the busy callback 2251** is not NULL, then the callback might be invoked with two arguments. 2252** 2253** ^The first argument to the busy handler is a copy of the void* pointer which 2254** is the third argument to sqlite3_busy_handler(). ^The second argument to 2255** the busy handler callback is the number of times that the busy handler has 2256** been invoked previously for the same locking event. ^If the 2257** busy callback returns 0, then no additional attempts are made to 2258** access the database and [SQLITE_BUSY] is returned 2259** to the application. 2260** ^If the callback returns non-zero, then another attempt 2261** is made to access the database and the cycle repeats. 2262** 2263** The presence of a busy handler does not guarantee that it will be invoked 2264** when there is lock contention. ^If SQLite determines that invoking the busy 2265** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2266** to the application instead of invoking the 2267** busy handler. 2268** Consider a scenario where one process is holding a read lock that 2269** it is trying to promote to a reserved lock and 2270** a second process is holding a reserved lock that it is trying 2271** to promote to an exclusive lock. The first process cannot proceed 2272** because it is blocked by the second and the second process cannot 2273** proceed because it is blocked by the first. If both processes 2274** invoke the busy handlers, neither will make any progress. Therefore, 2275** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2276** will induce the first process to release its read lock and allow 2277** the second process to proceed. 2278** 2279** ^The default busy callback is NULL. 2280** 2281** ^(There can only be a single busy handler defined for each 2282** [database connection]. Setting a new busy handler clears any 2283** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2284** or evaluating [PRAGMA busy_timeout=N] will change the 2285** busy handler and thus clear any previously set busy handler. 2286** 2287** The busy callback should not take any actions which modify the 2288** database connection that invoked the busy handler. In other words, 2289** the busy handler is not reentrant. Any such actions 2290** result in undefined behavior. 2291** 2292** A busy handler must not close the database connection 2293** or [prepared statement] that invoked the busy handler. 2294*/ 2295int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2296 2297/* 2298** CAPI3REF: Set A Busy Timeout 2299** METHOD: sqlite3 2300** 2301** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2302** for a specified amount of time when a table is locked. ^The handler 2303** will sleep multiple times until at least "ms" milliseconds of sleeping 2304** have accumulated. ^After at least "ms" milliseconds of sleeping, 2305** the handler returns 0 which causes [sqlite3_step()] to return 2306** [SQLITE_BUSY]. 2307** 2308** ^Calling this routine with an argument less than or equal to zero 2309** turns off all busy handlers. 2310** 2311** ^(There can only be a single busy handler for a particular 2312** [database connection] at any given moment. If another busy handler 2313** was defined (using [sqlite3_busy_handler()]) prior to calling 2314** this routine, that other busy handler is cleared.)^ 2315** 2316** See also: [PRAGMA busy_timeout] 2317*/ 2318int sqlite3_busy_timeout(sqlite3*, int ms); 2319 2320/* 2321** CAPI3REF: Convenience Routines For Running Queries 2322** METHOD: sqlite3 2323** 2324** This is a legacy interface that is preserved for backwards compatibility. 2325** Use of this interface is not recommended. 2326** 2327** Definition: A <b>result table</b> is memory data structure created by the 2328** [sqlite3_get_table()] interface. A result table records the 2329** complete query results from one or more queries. 2330** 2331** The table conceptually has a number of rows and columns. But 2332** these numbers are not part of the result table itself. These 2333** numbers are obtained separately. Let N be the number of rows 2334** and M be the number of columns. 2335** 2336** A result table is an array of pointers to zero-terminated UTF-8 strings. 2337** There are (N+1)*M elements in the array. The first M pointers point 2338** to zero-terminated strings that contain the names of the columns. 2339** The remaining entries all point to query results. NULL values result 2340** in NULL pointers. All other values are in their UTF-8 zero-terminated 2341** string representation as returned by [sqlite3_column_text()]. 2342** 2343** A result table might consist of one or more memory allocations. 2344** It is not safe to pass a result table directly to [sqlite3_free()]. 2345** A result table should be deallocated using [sqlite3_free_table()]. 2346** 2347** ^(As an example of the result table format, suppose a query result 2348** is as follows: 2349** 2350** <blockquote><pre> 2351** Name | Age 2352** ----------------------- 2353** Alice | 43 2354** Bob | 28 2355** Cindy | 21 2356** </pre></blockquote> 2357** 2358** There are two column (M==2) and three rows (N==3). Thus the 2359** result table has 8 entries. Suppose the result table is stored 2360** in an array names azResult. Then azResult holds this content: 2361** 2362** <blockquote><pre> 2363** azResult[0] = "Name"; 2364** azResult[1] = "Age"; 2365** azResult[2] = "Alice"; 2366** azResult[3] = "43"; 2367** azResult[4] = "Bob"; 2368** azResult[5] = "28"; 2369** azResult[6] = "Cindy"; 2370** azResult[7] = "21"; 2371** </pre></blockquote>)^ 2372** 2373** ^The sqlite3_get_table() function evaluates one or more 2374** semicolon-separated SQL statements in the zero-terminated UTF-8 2375** string of its 2nd parameter and returns a result table to the 2376** pointer given in its 3rd parameter. 2377** 2378** After the application has finished with the result from sqlite3_get_table(), 2379** it must pass the result table pointer to sqlite3_free_table() in order to 2380** release the memory that was malloced. Because of the way the 2381** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2382** function must not try to call [sqlite3_free()] directly. Only 2383** [sqlite3_free_table()] is able to release the memory properly and safely. 2384** 2385** The sqlite3_get_table() interface is implemented as a wrapper around 2386** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2387** to any internal data structures of SQLite. It uses only the public 2388** interface defined here. As a consequence, errors that occur in the 2389** wrapper layer outside of the internal [sqlite3_exec()] call are not 2390** reflected in subsequent calls to [sqlite3_errcode()] or 2391** [sqlite3_errmsg()]. 2392*/ 2393int sqlite3_get_table( 2394 sqlite3 *db, /* An open database */ 2395 const char *zSql, /* SQL to be evaluated */ 2396 char ***pazResult, /* Results of the query */ 2397 int *pnRow, /* Number of result rows written here */ 2398 int *pnColumn, /* Number of result columns written here */ 2399 char **pzErrmsg /* Error msg written here */ 2400); 2401void sqlite3_free_table(char **result); 2402 2403/* 2404** CAPI3REF: Formatted String Printing Functions 2405** 2406** These routines are work-alikes of the "printf()" family of functions 2407** from the standard C library. 2408** These routines understand most of the common K&R formatting options, 2409** plus some additional non-standard formats, detailed below. 2410** Note that some of the more obscure formatting options from recent 2411** C-library standards are omitted from this implementation. 2412** 2413** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2414** results into memory obtained from [sqlite3_malloc()]. 2415** The strings returned by these two routines should be 2416** released by [sqlite3_free()]. ^Both routines return a 2417** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2418** memory to hold the resulting string. 2419** 2420** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2421** the standard C library. The result is written into the 2422** buffer supplied as the second parameter whose size is given by 2423** the first parameter. Note that the order of the 2424** first two parameters is reversed from snprintf().)^ This is an 2425** historical accident that cannot be fixed without breaking 2426** backwards compatibility. ^(Note also that sqlite3_snprintf() 2427** returns a pointer to its buffer instead of the number of 2428** characters actually written into the buffer.)^ We admit that 2429** the number of characters written would be a more useful return 2430** value but we cannot change the implementation of sqlite3_snprintf() 2431** now without breaking compatibility. 2432** 2433** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2434** guarantees that the buffer is always zero-terminated. ^The first 2435** parameter "n" is the total size of the buffer, including space for 2436** the zero terminator. So the longest string that can be completely 2437** written will be n-1 characters. 2438** 2439** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2440** 2441** These routines all implement some additional formatting 2442** options that are useful for constructing SQL statements. 2443** All of the usual printf() formatting options apply. In addition, there 2444** is are "%q", "%Q", "%w" and "%z" options. 2445** 2446** ^(The %q option works like %s in that it substitutes a nul-terminated 2447** string from the argument list. But %q also doubles every '\'' character. 2448** %q is designed for use inside a string literal.)^ By doubling each '\'' 2449** character it escapes that character and allows it to be inserted into 2450** the string. 2451** 2452** For example, assume the string variable zText contains text as follows: 2453** 2454** <blockquote><pre> 2455** char *zText = "It's a happy day!"; 2456** </pre></blockquote> 2457** 2458** One can use this text in an SQL statement as follows: 2459** 2460** <blockquote><pre> 2461** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2462** sqlite3_exec(db, zSQL, 0, 0, 0); 2463** sqlite3_free(zSQL); 2464** </pre></blockquote> 2465** 2466** Because the %q format string is used, the '\'' character in zText 2467** is escaped and the SQL generated is as follows: 2468** 2469** <blockquote><pre> 2470** INSERT INTO table1 VALUES('It''s a happy day!') 2471** </pre></blockquote> 2472** 2473** This is correct. Had we used %s instead of %q, the generated SQL 2474** would have looked like this: 2475** 2476** <blockquote><pre> 2477** INSERT INTO table1 VALUES('It's a happy day!'); 2478** </pre></blockquote> 2479** 2480** This second example is an SQL syntax error. As a general rule you should 2481** always use %q instead of %s when inserting text into a string literal. 2482** 2483** ^(The %Q option works like %q except it also adds single quotes around 2484** the outside of the total string. Additionally, if the parameter in the 2485** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2486** single quotes).)^ So, for example, one could say: 2487** 2488** <blockquote><pre> 2489** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2490** sqlite3_exec(db, zSQL, 0, 0, 0); 2491** sqlite3_free(zSQL); 2492** </pre></blockquote> 2493** 2494** The code above will render a correct SQL statement in the zSQL 2495** variable even if the zText variable is a NULL pointer. 2496** 2497** ^(The "%w" formatting option is like "%q" except that it expects to 2498** be contained within double-quotes instead of single quotes, and it 2499** escapes the double-quote character instead of the single-quote 2500** character.)^ The "%w" formatting option is intended for safely inserting 2501** table and column names into a constructed SQL statement. 2502** 2503** ^(The "%z" formatting option works like "%s" but with the 2504** addition that after the string has been read and copied into 2505** the result, [sqlite3_free()] is called on the input string.)^ 2506*/ 2507char *sqlite3_mprintf(const char*,...); 2508char *sqlite3_vmprintf(const char*, va_list); 2509char *sqlite3_snprintf(int,char*,const char*, ...); 2510char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2511 2512/* 2513** CAPI3REF: Memory Allocation Subsystem 2514** 2515** The SQLite core uses these three routines for all of its own 2516** internal memory allocation needs. "Core" in the previous sentence 2517** does not include operating-system specific VFS implementation. The 2518** Windows VFS uses native malloc() and free() for some operations. 2519** 2520** ^The sqlite3_malloc() routine returns a pointer to a block 2521** of memory at least N bytes in length, where N is the parameter. 2522** ^If sqlite3_malloc() is unable to obtain sufficient free 2523** memory, it returns a NULL pointer. ^If the parameter N to 2524** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2525** a NULL pointer. 2526** 2527** ^The sqlite3_malloc64(N) routine works just like 2528** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2529** of a signed 32-bit integer. 2530** 2531** ^Calling sqlite3_free() with a pointer previously returned 2532** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2533** that it might be reused. ^The sqlite3_free() routine is 2534** a no-op if is called with a NULL pointer. Passing a NULL pointer 2535** to sqlite3_free() is harmless. After being freed, memory 2536** should neither be read nor written. Even reading previously freed 2537** memory might result in a segmentation fault or other severe error. 2538** Memory corruption, a segmentation fault, or other severe error 2539** might result if sqlite3_free() is called with a non-NULL pointer that 2540** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2541** 2542** ^The sqlite3_realloc(X,N) interface attempts to resize a 2543** prior memory allocation X to be at least N bytes. 2544** ^If the X parameter to sqlite3_realloc(X,N) 2545** is a NULL pointer then its behavior is identical to calling 2546** sqlite3_malloc(N). 2547** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2548** negative then the behavior is exactly the same as calling 2549** sqlite3_free(X). 2550** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2551** of at least N bytes in size or NULL if insufficient memory is available. 2552** ^If M is the size of the prior allocation, then min(N,M) bytes 2553** of the prior allocation are copied into the beginning of buffer returned 2554** by sqlite3_realloc(X,N) and the prior allocation is freed. 2555** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2556** prior allocation is not freed. 2557** 2558** ^The sqlite3_realloc64(X,N) interfaces works the same as 2559** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2560** of a 32-bit signed integer. 2561** 2562** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2563** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2564** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2565** ^The value returned by sqlite3_msize(X) might be larger than the number 2566** of bytes requested when X was allocated. ^If X is a NULL pointer then 2567** sqlite3_msize(X) returns zero. If X points to something that is not 2568** the beginning of memory allocation, or if it points to a formerly 2569** valid memory allocation that has now been freed, then the behavior 2570** of sqlite3_msize(X) is undefined and possibly harmful. 2571** 2572** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2573** sqlite3_malloc64(), and sqlite3_realloc64() 2574** is always aligned to at least an 8 byte boundary, or to a 2575** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2576** option is used. 2577** 2578** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2579** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2580** implementation of these routines to be omitted. That capability 2581** is no longer provided. Only built-in memory allocators can be used. 2582** 2583** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2584** the system malloc() and free() directly when converting 2585** filenames between the UTF-8 encoding used by SQLite 2586** and whatever filename encoding is used by the particular Windows 2587** installation. Memory allocation errors were detected, but 2588** they were reported back as [SQLITE_CANTOPEN] or 2589** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2590** 2591** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2592** must be either NULL or else pointers obtained from a prior 2593** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2594** not yet been released. 2595** 2596** The application must not read or write any part of 2597** a block of memory after it has been released using 2598** [sqlite3_free()] or [sqlite3_realloc()]. 2599*/ 2600void *sqlite3_malloc(int); 2601void *sqlite3_malloc64(sqlite3_uint64); 2602void *sqlite3_realloc(void*, int); 2603void *sqlite3_realloc64(void*, sqlite3_uint64); 2604void sqlite3_free(void*); 2605sqlite3_uint64 sqlite3_msize(void*); 2606 2607/* 2608** CAPI3REF: Memory Allocator Statistics 2609** 2610** SQLite provides these two interfaces for reporting on the status 2611** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2612** routines, which form the built-in memory allocation subsystem. 2613** 2614** ^The [sqlite3_memory_used()] routine returns the number of bytes 2615** of memory currently outstanding (malloced but not freed). 2616** ^The [sqlite3_memory_highwater()] routine returns the maximum 2617** value of [sqlite3_memory_used()] since the high-water mark 2618** was last reset. ^The values returned by [sqlite3_memory_used()] and 2619** [sqlite3_memory_highwater()] include any overhead 2620** added by SQLite in its implementation of [sqlite3_malloc()], 2621** but not overhead added by the any underlying system library 2622** routines that [sqlite3_malloc()] may call. 2623** 2624** ^The memory high-water mark is reset to the current value of 2625** [sqlite3_memory_used()] if and only if the parameter to 2626** [sqlite3_memory_highwater()] is true. ^The value returned 2627** by [sqlite3_memory_highwater(1)] is the high-water mark 2628** prior to the reset. 2629*/ 2630sqlite3_int64 sqlite3_memory_used(void); 2631sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2632 2633/* 2634** CAPI3REF: Pseudo-Random Number Generator 2635** 2636** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2637** select random [ROWID | ROWIDs] when inserting new records into a table that 2638** already uses the largest possible [ROWID]. The PRNG is also used for 2639** the build-in random() and randomblob() SQL functions. This interface allows 2640** applications to access the same PRNG for other purposes. 2641** 2642** ^A call to this routine stores N bytes of randomness into buffer P. 2643** ^The P parameter can be a NULL pointer. 2644** 2645** ^If this routine has not been previously called or if the previous 2646** call had N less than one or a NULL pointer for P, then the PRNG is 2647** seeded using randomness obtained from the xRandomness method of 2648** the default [sqlite3_vfs] object. 2649** ^If the previous call to this routine had an N of 1 or more and a 2650** non-NULL P then the pseudo-randomness is generated 2651** internally and without recourse to the [sqlite3_vfs] xRandomness 2652** method. 2653*/ 2654void sqlite3_randomness(int N, void *P); 2655 2656/* 2657** CAPI3REF: Compile-Time Authorization Callbacks 2658** METHOD: sqlite3 2659** 2660** ^This routine registers an authorizer callback with a particular 2661** [database connection], supplied in the first argument. 2662** ^The authorizer callback is invoked as SQL statements are being compiled 2663** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2664** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2665** points during the compilation process, as logic is being created 2666** to perform various actions, the authorizer callback is invoked to 2667** see if those actions are allowed. ^The authorizer callback should 2668** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2669** specific action but allow the SQL statement to continue to be 2670** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2671** rejected with an error. ^If the authorizer callback returns 2672** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2673** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2674** the authorizer will fail with an error message. 2675** 2676** When the callback returns [SQLITE_OK], that means the operation 2677** requested is ok. ^When the callback returns [SQLITE_DENY], the 2678** [sqlite3_prepare_v2()] or equivalent call that triggered the 2679** authorizer will fail with an error message explaining that 2680** access is denied. 2681** 2682** ^The first parameter to the authorizer callback is a copy of the third 2683** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2684** to the callback is an integer [SQLITE_COPY | action code] that specifies 2685** the particular action to be authorized. ^The third through sixth parameters 2686** to the callback are zero-terminated strings that contain additional 2687** details about the action to be authorized. 2688** 2689** ^If the action code is [SQLITE_READ] 2690** and the callback returns [SQLITE_IGNORE] then the 2691** [prepared statement] statement is constructed to substitute 2692** a NULL value in place of the table column that would have 2693** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2694** return can be used to deny an untrusted user access to individual 2695** columns of a table. 2696** ^If the action code is [SQLITE_DELETE] and the callback returns 2697** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2698** [truncate optimization] is disabled and all rows are deleted individually. 2699** 2700** An authorizer is used when [sqlite3_prepare | preparing] 2701** SQL statements from an untrusted source, to ensure that the SQL statements 2702** do not try to access data they are not allowed to see, or that they do not 2703** try to execute malicious statements that damage the database. For 2704** example, an application may allow a user to enter arbitrary 2705** SQL queries for evaluation by a database. But the application does 2706** not want the user to be able to make arbitrary changes to the 2707** database. An authorizer could then be put in place while the 2708** user-entered SQL is being [sqlite3_prepare | prepared] that 2709** disallows everything except [SELECT] statements. 2710** 2711** Applications that need to process SQL from untrusted sources 2712** might also consider lowering resource limits using [sqlite3_limit()] 2713** and limiting database size using the [max_page_count] [PRAGMA] 2714** in addition to using an authorizer. 2715** 2716** ^(Only a single authorizer can be in place on a database connection 2717** at a time. Each call to sqlite3_set_authorizer overrides the 2718** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2719** The authorizer is disabled by default. 2720** 2721** The authorizer callback must not do anything that will modify 2722** the database connection that invoked the authorizer callback. 2723** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2724** database connections for the meaning of "modify" in this paragraph. 2725** 2726** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2727** statement might be re-prepared during [sqlite3_step()] due to a 2728** schema change. Hence, the application should ensure that the 2729** correct authorizer callback remains in place during the [sqlite3_step()]. 2730** 2731** ^Note that the authorizer callback is invoked only during 2732** [sqlite3_prepare()] or its variants. Authorization is not 2733** performed during statement evaluation in [sqlite3_step()], unless 2734** as stated in the previous paragraph, sqlite3_step() invokes 2735** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2736*/ 2737int sqlite3_set_authorizer( 2738 sqlite3*, 2739 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2740 void *pUserData 2741); 2742 2743/* 2744** CAPI3REF: Authorizer Return Codes 2745** 2746** The [sqlite3_set_authorizer | authorizer callback function] must 2747** return either [SQLITE_OK] or one of these two constants in order 2748** to signal SQLite whether or not the action is permitted. See the 2749** [sqlite3_set_authorizer | authorizer documentation] for additional 2750** information. 2751** 2752** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2753** returned from the [sqlite3_vtab_on_conflict()] interface. 2754*/ 2755#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2756#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2757 2758/* 2759** CAPI3REF: Authorizer Action Codes 2760** 2761** The [sqlite3_set_authorizer()] interface registers a callback function 2762** that is invoked to authorize certain SQL statement actions. The 2763** second parameter to the callback is an integer code that specifies 2764** what action is being authorized. These are the integer action codes that 2765** the authorizer callback may be passed. 2766** 2767** These action code values signify what kind of operation is to be 2768** authorized. The 3rd and 4th parameters to the authorization 2769** callback function will be parameters or NULL depending on which of these 2770** codes is used as the second parameter. ^(The 5th parameter to the 2771** authorizer callback is the name of the database ("main", "temp", 2772** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2773** is the name of the inner-most trigger or view that is responsible for 2774** the access attempt or NULL if this access attempt is directly from 2775** top-level SQL code. 2776*/ 2777/******************************************* 3rd ************ 4th ***********/ 2778#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2779#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2780#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2781#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2782#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2783#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2784#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2785#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2786#define SQLITE_DELETE 9 /* Table Name NULL */ 2787#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2788#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2789#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2790#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2791#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2792#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2793#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2794#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2795#define SQLITE_INSERT 18 /* Table Name NULL */ 2796#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2797#define SQLITE_READ 20 /* Table Name Column Name */ 2798#define SQLITE_SELECT 21 /* NULL NULL */ 2799#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2800#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2801#define SQLITE_ATTACH 24 /* Filename NULL */ 2802#define SQLITE_DETACH 25 /* Database Name NULL */ 2803#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2804#define SQLITE_REINDEX 27 /* Index Name NULL */ 2805#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2806#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2807#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2808#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2809#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2810#define SQLITE_COPY 0 /* No longer used */ 2811#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2812 2813/* 2814** CAPI3REF: Tracing And Profiling Functions 2815** METHOD: sqlite3 2816** 2817** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 2818** instead of the routines described here. 2819** 2820** These routines register callback functions that can be used for 2821** tracing and profiling the execution of SQL statements. 2822** 2823** ^The callback function registered by sqlite3_trace() is invoked at 2824** various times when an SQL statement is being run by [sqlite3_step()]. 2825** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2826** SQL statement text as the statement first begins executing. 2827** ^(Additional sqlite3_trace() callbacks might occur 2828** as each triggered subprogram is entered. The callbacks for triggers 2829** contain a UTF-8 SQL comment that identifies the trigger.)^ 2830** 2831** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2832** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2833** 2834** ^The callback function registered by sqlite3_profile() is invoked 2835** as each SQL statement finishes. ^The profile callback contains 2836** the original statement text and an estimate of wall-clock time 2837** of how long that statement took to run. ^The profile callback 2838** time is in units of nanoseconds, however the current implementation 2839** is only capable of millisecond resolution so the six least significant 2840** digits in the time are meaningless. Future versions of SQLite 2841** might provide greater resolution on the profiler callback. The 2842** sqlite3_profile() function is considered experimental and is 2843** subject to change in future versions of SQLite. 2844*/ 2845SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 2846 void(*xTrace)(void*,const char*), void*); 2847SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 2848 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2849 2850/* 2851** CAPI3REF: SQL Trace Event Codes 2852** KEYWORDS: SQLITE_TRACE 2853** 2854** These constants identify classes of events that can be monitored 2855** using the [sqlite3_trace_v2()] tracing logic. The third argument 2856** to [sqlite3_trace_v2()] is an OR-ed combination of one or more of 2857** the following constants. ^The first argument to the trace callback 2858** is one of the following constants. 2859** 2860** New tracing constants may be added in future releases. 2861** 2862** ^A trace callback has four arguments: xCallback(T,C,P,X). 2863** ^The T argument is one of the integer type codes above. 2864** ^The C argument is a copy of the context pointer passed in as the 2865** fourth argument to [sqlite3_trace_v2()]. 2866** The P and X arguments are pointers whose meanings depend on T. 2867** 2868** <dl> 2869** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 2870** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 2871** first begins running and possibly at other times during the 2872** execution of the prepared statement, such as at the start of each 2873** trigger subprogram. ^The P argument is a pointer to the 2874** [prepared statement]. ^The X argument is a pointer to a string which 2875** is the unexpanded SQL text of the prepared statement or an SQL comment 2876** that indicates the invocation of a trigger. ^The callback can compute 2877** the same text that would have been returned by the legacy [sqlite3_trace()] 2878** interface by using the X argument when X begins with "--" and invoking 2879** [sqlite3_expanded_sql(P)] otherwise. 2880** 2881** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 2882** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 2883** information as is provided by the [sqlite3_profile()] callback. 2884** ^The P argument is a pointer to the [prepared statement] and the 2885** X argument points to a 64-bit integer which is the estimated of 2886** the number of nanosecond that the prepared statement took to run. 2887** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 2888** 2889** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 2890** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 2891** statement generates a single row of result. 2892** ^The P argument is a pointer to the [prepared statement] and the 2893** X argument is unused. 2894** 2895** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 2896** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 2897** connection closes. 2898** ^The P argument is a pointer to the [database connection] object 2899** and the X argument is unused. 2900** </dl> 2901*/ 2902#define SQLITE_TRACE_STMT 0x01 2903#define SQLITE_TRACE_PROFILE 0x02 2904#define SQLITE_TRACE_ROW 0x04 2905#define SQLITE_TRACE_CLOSE 0x08 2906 2907/* 2908** CAPI3REF: SQL Trace Hook 2909** METHOD: sqlite3 2910** 2911** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 2912** function X against [database connection] D, using property mask M 2913** and context pointer P. ^If the X callback is 2914** NULL or if the M mask is zero, then tracing is disabled. The 2915** M argument should be the bitwise OR-ed combination of 2916** zero or more [SQLITE_TRACE] constants. 2917** 2918** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 2919** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 2920** 2921** ^The X callback is invoked whenever any of the events identified by 2922** mask M occur. ^The integer return value from the callback is currently 2923** ignored, though this may change in future releases. Callback 2924** implementations should return zero to ensure future compatibility. 2925** 2926** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 2927** ^The T argument is one of the [SQLITE_TRACE] 2928** constants to indicate why the callback was invoked. 2929** ^The C argument is a copy of the context pointer. 2930** The P and X arguments are pointers whose meanings depend on T. 2931** 2932** The sqlite3_trace_v2() interface is intended to replace the legacy 2933** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 2934** are deprecated. 2935*/ 2936int sqlite3_trace_v2( 2937 sqlite3*, 2938 unsigned uMask, 2939 int(*xCallback)(unsigned,void*,void*,void*), 2940 void *pCtx 2941); 2942 2943/* 2944** CAPI3REF: Query Progress Callbacks 2945** METHOD: sqlite3 2946** 2947** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2948** function X to be invoked periodically during long running calls to 2949** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2950** database connection D. An example use for this 2951** interface is to keep a GUI updated during a large query. 2952** 2953** ^The parameter P is passed through as the only parameter to the 2954** callback function X. ^The parameter N is the approximate number of 2955** [virtual machine instructions] that are evaluated between successive 2956** invocations of the callback X. ^If N is less than one then the progress 2957** handler is disabled. 2958** 2959** ^Only a single progress handler may be defined at one time per 2960** [database connection]; setting a new progress handler cancels the 2961** old one. ^Setting parameter X to NULL disables the progress handler. 2962** ^The progress handler is also disabled by setting N to a value less 2963** than 1. 2964** 2965** ^If the progress callback returns non-zero, the operation is 2966** interrupted. This feature can be used to implement a 2967** "Cancel" button on a GUI progress dialog box. 2968** 2969** The progress handler callback must not do anything that will modify 2970** the database connection that invoked the progress handler. 2971** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2972** database connections for the meaning of "modify" in this paragraph. 2973** 2974*/ 2975void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2976 2977/* 2978** CAPI3REF: Opening A New Database Connection 2979** CONSTRUCTOR: sqlite3 2980** 2981** ^These routines open an SQLite database file as specified by the 2982** filename argument. ^The filename argument is interpreted as UTF-8 for 2983** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2984** order for sqlite3_open16(). ^(A [database connection] handle is usually 2985** returned in *ppDb, even if an error occurs. The only exception is that 2986** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2987** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2988** object.)^ ^(If the database is opened (and/or created) successfully, then 2989** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2990** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2991** an English language description of the error following a failure of any 2992** of the sqlite3_open() routines. 2993** 2994** ^The default encoding will be UTF-8 for databases created using 2995** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 2996** created using sqlite3_open16() will be UTF-16 in the native byte order. 2997** 2998** Whether or not an error occurs when it is opened, resources 2999** associated with the [database connection] handle should be released by 3000** passing it to [sqlite3_close()] when it is no longer required. 3001** 3002** The sqlite3_open_v2() interface works like sqlite3_open() 3003** except that it accepts two additional parameters for additional control 3004** over the new database connection. ^(The flags parameter to 3005** sqlite3_open_v2() can take one of 3006** the following three values, optionally combined with the 3007** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3008** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3009** 3010** <dl> 3011** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3012** <dd>The database is opened in read-only mode. If the database does not 3013** already exist, an error is returned.</dd>)^ 3014** 3015** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3016** <dd>The database is opened for reading and writing if possible, or reading 3017** only if the file is write protected by the operating system. In either 3018** case the database must already exist, otherwise an error is returned.</dd>)^ 3019** 3020** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3021** <dd>The database is opened for reading and writing, and is created if 3022** it does not already exist. This is the behavior that is always used for 3023** sqlite3_open() and sqlite3_open16().</dd>)^ 3024** </dl> 3025** 3026** If the 3rd parameter to sqlite3_open_v2() is not one of the 3027** combinations shown above optionally combined with other 3028** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3029** then the behavior is undefined. 3030** 3031** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3032** opens in the multi-thread [threading mode] as long as the single-thread 3033** mode has not been set at compile-time or start-time. ^If the 3034** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3035** in the serialized [threading mode] unless single-thread was 3036** previously selected at compile-time or start-time. 3037** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3038** eligible to use [shared cache mode], regardless of whether or not shared 3039** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3040** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3041** participate in [shared cache mode] even if it is enabled. 3042** 3043** ^The fourth parameter to sqlite3_open_v2() is the name of the 3044** [sqlite3_vfs] object that defines the operating system interface that 3045** the new database connection should use. ^If the fourth parameter is 3046** a NULL pointer then the default [sqlite3_vfs] object is used. 3047** 3048** ^If the filename is ":memory:", then a private, temporary in-memory database 3049** is created for the connection. ^This in-memory database will vanish when 3050** the database connection is closed. Future versions of SQLite might 3051** make use of additional special filenames that begin with the ":" character. 3052** It is recommended that when a database filename actually does begin with 3053** a ":" character you should prefix the filename with a pathname such as 3054** "./" to avoid ambiguity. 3055** 3056** ^If the filename is an empty string, then a private, temporary 3057** on-disk database will be created. ^This private database will be 3058** automatically deleted as soon as the database connection is closed. 3059** 3060** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3061** 3062** ^If [URI filename] interpretation is enabled, and the filename argument 3063** begins with "file:", then the filename is interpreted as a URI. ^URI 3064** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3065** set in the fourth argument to sqlite3_open_v2(), or if it has 3066** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3067** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3068** As of SQLite version 3.7.7, URI filename interpretation is turned off 3069** by default, but future releases of SQLite might enable URI filename 3070** interpretation by default. See "[URI filenames]" for additional 3071** information. 3072** 3073** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3074** authority, then it must be either an empty string or the string 3075** "localhost". ^If the authority is not an empty string or "localhost", an 3076** error is returned to the caller. ^The fragment component of a URI, if 3077** present, is ignored. 3078** 3079** ^SQLite uses the path component of the URI as the name of the disk file 3080** which contains the database. ^If the path begins with a '/' character, 3081** then it is interpreted as an absolute path. ^If the path does not begin 3082** with a '/' (meaning that the authority section is omitted from the URI) 3083** then the path is interpreted as a relative path. 3084** ^(On windows, the first component of an absolute path 3085** is a drive specification (e.g. "C:").)^ 3086** 3087** [[core URI query parameters]] 3088** The query component of a URI may contain parameters that are interpreted 3089** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3090** SQLite and its built-in [VFSes] interpret the 3091** following query parameters: 3092** 3093** <ul> 3094** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3095** a VFS object that provides the operating system interface that should 3096** be used to access the database file on disk. ^If this option is set to 3097** an empty string the default VFS object is used. ^Specifying an unknown 3098** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3099** present, then the VFS specified by the option takes precedence over 3100** the value passed as the fourth parameter to sqlite3_open_v2(). 3101** 3102** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3103** "rwc", or "memory". Attempting to set it to any other value is 3104** an error)^. 3105** ^If "ro" is specified, then the database is opened for read-only 3106** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3107** third argument to sqlite3_open_v2(). ^If the mode option is set to 3108** "rw", then the database is opened for read-write (but not create) 3109** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3110** been set. ^Value "rwc" is equivalent to setting both 3111** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3112** set to "memory" then a pure [in-memory database] that never reads 3113** or writes from disk is used. ^It is an error to specify a value for 3114** the mode parameter that is less restrictive than that specified by 3115** the flags passed in the third parameter to sqlite3_open_v2(). 3116** 3117** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3118** "private". ^Setting it to "shared" is equivalent to setting the 3119** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3120** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3121** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3122** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3123** a URI filename, its value overrides any behavior requested by setting 3124** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3125** 3126** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3127** [powersafe overwrite] property does or does not apply to the 3128** storage media on which the database file resides. 3129** 3130** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3131** which if set disables file locking in rollback journal modes. This 3132** is useful for accessing a database on a filesystem that does not 3133** support locking. Caution: Database corruption might result if two 3134** or more processes write to the same database and any one of those 3135** processes uses nolock=1. 3136** 3137** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3138** parameter that indicates that the database file is stored on 3139** read-only media. ^When immutable is set, SQLite assumes that the 3140** database file cannot be changed, even by a process with higher 3141** privilege, and so the database is opened read-only and all locking 3142** and change detection is disabled. Caution: Setting the immutable 3143** property on a database file that does in fact change can result 3144** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3145** See also: [SQLITE_IOCAP_IMMUTABLE]. 3146** 3147** </ul> 3148** 3149** ^Specifying an unknown parameter in the query component of a URI is not an 3150** error. Future versions of SQLite might understand additional query 3151** parameters. See "[query parameters with special meaning to SQLite]" for 3152** additional information. 3153** 3154** [[URI filename examples]] <h3>URI filename examples</h3> 3155** 3156** <table border="1" align=center cellpadding=5> 3157** <tr><th> URI filenames <th> Results 3158** <tr><td> file:data.db <td> 3159** Open the file "data.db" in the current directory. 3160** <tr><td> file:/home/fred/data.db<br> 3161** file:///home/fred/data.db <br> 3162** file://localhost/home/fred/data.db <br> <td> 3163** Open the database file "/home/fred/data.db". 3164** <tr><td> file://darkstar/home/fred/data.db <td> 3165** An error. "darkstar" is not a recognized authority. 3166** <tr><td style="white-space:nowrap"> 3167** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3168** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3169** C:. Note that the %20 escaping in this example is not strictly 3170** necessary - space characters can be used literally 3171** in URI filenames. 3172** <tr><td> file:data.db?mode=ro&cache=private <td> 3173** Open file "data.db" in the current directory for read-only access. 3174** Regardless of whether or not shared-cache mode is enabled by 3175** default, use a private cache. 3176** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3177** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3178** that uses dot-files in place of posix advisory locking. 3179** <tr><td> file:data.db?mode=readonly <td> 3180** An error. "readonly" is not a valid option for the "mode" parameter. 3181** </table> 3182** 3183** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3184** query components of a URI. A hexadecimal escape sequence consists of a 3185** percent sign - "%" - followed by exactly two hexadecimal digits 3186** specifying an octet value. ^Before the path or query components of a 3187** URI filename are interpreted, they are encoded using UTF-8 and all 3188** hexadecimal escape sequences replaced by a single byte containing the 3189** corresponding octet. If this process generates an invalid UTF-8 encoding, 3190** the results are undefined. 3191** 3192** <b>Note to Windows users:</b> The encoding used for the filename argument 3193** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3194** codepage is currently defined. Filenames containing international 3195** characters must be converted to UTF-8 prior to passing them into 3196** sqlite3_open() or sqlite3_open_v2(). 3197** 3198** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3199** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3200** features that require the use of temporary files may fail. 3201** 3202** See also: [sqlite3_temp_directory] 3203*/ 3204int sqlite3_open( 3205 const char *filename, /* Database filename (UTF-8) */ 3206 sqlite3 **ppDb /* OUT: SQLite db handle */ 3207); 3208int sqlite3_open16( 3209 const void *filename, /* Database filename (UTF-16) */ 3210 sqlite3 **ppDb /* OUT: SQLite db handle */ 3211); 3212int sqlite3_open_v2( 3213 const char *filename, /* Database filename (UTF-8) */ 3214 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3215 int flags, /* Flags */ 3216 const char *zVfs /* Name of VFS module to use */ 3217); 3218 3219/* 3220** CAPI3REF: Obtain Values For URI Parameters 3221** 3222** These are utility routines, useful to VFS implementations, that check 3223** to see if a database file was a URI that contained a specific query 3224** parameter, and if so obtains the value of that query parameter. 3225** 3226** If F is the database filename pointer passed into the xOpen() method of 3227** a VFS implementation when the flags parameter to xOpen() has one or 3228** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3229** P is the name of the query parameter, then 3230** sqlite3_uri_parameter(F,P) returns the value of the P 3231** parameter if it exists or a NULL pointer if P does not appear as a 3232** query parameter on F. If P is a query parameter of F 3233** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3234** a pointer to an empty string. 3235** 3236** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3237** parameter and returns true (1) or false (0) according to the value 3238** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3239** value of query parameter P is one of "yes", "true", or "on" in any 3240** case or if the value begins with a non-zero number. The 3241** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3242** query parameter P is one of "no", "false", or "off" in any case or 3243** if the value begins with a numeric zero. If P is not a query 3244** parameter on F or if the value of P is does not match any of the 3245** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3246** 3247** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3248** 64-bit signed integer and returns that integer, or D if P does not 3249** exist. If the value of P is something other than an integer, then 3250** zero is returned. 3251** 3252** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3253** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3254** is not a database file pathname pointer that SQLite passed into the xOpen 3255** VFS method, then the behavior of this routine is undefined and probably 3256** undesirable. 3257*/ 3258const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3259int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3260sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3261 3262 3263/* 3264** CAPI3REF: Error Codes And Messages 3265** METHOD: sqlite3 3266** 3267** ^If the most recent sqlite3_* API call associated with 3268** [database connection] D failed, then the sqlite3_errcode(D) interface 3269** returns the numeric [result code] or [extended result code] for that 3270** API call. 3271** If the most recent API call was successful, 3272** then the return value from sqlite3_errcode() is undefined. 3273** ^The sqlite3_extended_errcode() 3274** interface is the same except that it always returns the 3275** [extended result code] even when extended result codes are 3276** disabled. 3277** 3278** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3279** text that describes the error, as either UTF-8 or UTF-16 respectively. 3280** ^(Memory to hold the error message string is managed internally. 3281** The application does not need to worry about freeing the result. 3282** However, the error string might be overwritten or deallocated by 3283** subsequent calls to other SQLite interface functions.)^ 3284** 3285** ^The sqlite3_errstr() interface returns the English-language text 3286** that describes the [result code], as UTF-8. 3287** ^(Memory to hold the error message string is managed internally 3288** and must not be freed by the application)^. 3289** 3290** When the serialized [threading mode] is in use, it might be the 3291** case that a second error occurs on a separate thread in between 3292** the time of the first error and the call to these interfaces. 3293** When that happens, the second error will be reported since these 3294** interfaces always report the most recent result. To avoid 3295** this, each thread can obtain exclusive use of the [database connection] D 3296** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3297** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3298** all calls to the interfaces listed here are completed. 3299** 3300** If an interface fails with SQLITE_MISUSE, that means the interface 3301** was invoked incorrectly by the application. In that case, the 3302** error code and message may or may not be set. 3303*/ 3304int sqlite3_errcode(sqlite3 *db); 3305int sqlite3_extended_errcode(sqlite3 *db); 3306const char *sqlite3_errmsg(sqlite3*); 3307const void *sqlite3_errmsg16(sqlite3*); 3308const char *sqlite3_errstr(int); 3309 3310/* 3311** CAPI3REF: Prepared Statement Object 3312** KEYWORDS: {prepared statement} {prepared statements} 3313** 3314** An instance of this object represents a single SQL statement that 3315** has been compiled into binary form and is ready to be evaluated. 3316** 3317** Think of each SQL statement as a separate computer program. The 3318** original SQL text is source code. A prepared statement object 3319** is the compiled object code. All SQL must be converted into a 3320** prepared statement before it can be run. 3321** 3322** The life-cycle of a prepared statement object usually goes like this: 3323** 3324** <ol> 3325** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3326** <li> Bind values to [parameters] using the sqlite3_bind_*() 3327** interfaces. 3328** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3329** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3330** to step 2. Do this zero or more times. 3331** <li> Destroy the object using [sqlite3_finalize()]. 3332** </ol> 3333*/ 3334typedef struct sqlite3_stmt sqlite3_stmt; 3335 3336/* 3337** CAPI3REF: Run-time Limits 3338** METHOD: sqlite3 3339** 3340** ^(This interface allows the size of various constructs to be limited 3341** on a connection by connection basis. The first parameter is the 3342** [database connection] whose limit is to be set or queried. The 3343** second parameter is one of the [limit categories] that define a 3344** class of constructs to be size limited. The third parameter is the 3345** new limit for that construct.)^ 3346** 3347** ^If the new limit is a negative number, the limit is unchanged. 3348** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3349** [limits | hard upper bound] 3350** set at compile-time by a C preprocessor macro called 3351** [limits | SQLITE_MAX_<i>NAME</i>]. 3352** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3353** ^Attempts to increase a limit above its hard upper bound are 3354** silently truncated to the hard upper bound. 3355** 3356** ^Regardless of whether or not the limit was changed, the 3357** [sqlite3_limit()] interface returns the prior value of the limit. 3358** ^Hence, to find the current value of a limit without changing it, 3359** simply invoke this interface with the third parameter set to -1. 3360** 3361** Run-time limits are intended for use in applications that manage 3362** both their own internal database and also databases that are controlled 3363** by untrusted external sources. An example application might be a 3364** web browser that has its own databases for storing history and 3365** separate databases controlled by JavaScript applications downloaded 3366** off the Internet. The internal databases can be given the 3367** large, default limits. Databases managed by external sources can 3368** be given much smaller limits designed to prevent a denial of service 3369** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3370** interface to further control untrusted SQL. The size of the database 3371** created by an untrusted script can be contained using the 3372** [max_page_count] [PRAGMA]. 3373** 3374** New run-time limit categories may be added in future releases. 3375*/ 3376int sqlite3_limit(sqlite3*, int id, int newVal); 3377 3378/* 3379** CAPI3REF: Run-Time Limit Categories 3380** KEYWORDS: {limit category} {*limit categories} 3381** 3382** These constants define various performance limits 3383** that can be lowered at run-time using [sqlite3_limit()]. 3384** The synopsis of the meanings of the various limits is shown below. 3385** Additional information is available at [limits | Limits in SQLite]. 3386** 3387** <dl> 3388** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3389** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3390** 3391** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3392** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3393** 3394** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3395** <dd>The maximum number of columns in a table definition or in the 3396** result set of a [SELECT] or the maximum number of columns in an index 3397** or in an ORDER BY or GROUP BY clause.</dd>)^ 3398** 3399** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3400** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3401** 3402** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3403** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3404** 3405** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3406** <dd>The maximum number of instructions in a virtual machine program 3407** used to implement an SQL statement. This limit is not currently 3408** enforced, though that might be added in some future release of 3409** SQLite.</dd>)^ 3410** 3411** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3412** <dd>The maximum number of arguments on a function.</dd>)^ 3413** 3414** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3415** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3416** 3417** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3418** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3419** <dd>The maximum length of the pattern argument to the [LIKE] or 3420** [GLOB] operators.</dd>)^ 3421** 3422** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3423** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3424** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3425** 3426** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3427** <dd>The maximum depth of recursion for triggers.</dd>)^ 3428** 3429** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3430** <dd>The maximum number of auxiliary worker threads that a single 3431** [prepared statement] may start.</dd>)^ 3432** </dl> 3433*/ 3434#define SQLITE_LIMIT_LENGTH 0 3435#define SQLITE_LIMIT_SQL_LENGTH 1 3436#define SQLITE_LIMIT_COLUMN 2 3437#define SQLITE_LIMIT_EXPR_DEPTH 3 3438#define SQLITE_LIMIT_COMPOUND_SELECT 4 3439#define SQLITE_LIMIT_VDBE_OP 5 3440#define SQLITE_LIMIT_FUNCTION_ARG 6 3441#define SQLITE_LIMIT_ATTACHED 7 3442#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3443#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3444#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3445#define SQLITE_LIMIT_WORKER_THREADS 11 3446 3447/* 3448** CAPI3REF: Compiling An SQL Statement 3449** KEYWORDS: {SQL statement compiler} 3450** METHOD: sqlite3 3451** CONSTRUCTOR: sqlite3_stmt 3452** 3453** To execute an SQL query, it must first be compiled into a byte-code 3454** program using one of these routines. 3455** 3456** The first argument, "db", is a [database connection] obtained from a 3457** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3458** [sqlite3_open16()]. The database connection must not have been closed. 3459** 3460** The second argument, "zSql", is the statement to be compiled, encoded 3461** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3462** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3463** use UTF-16. 3464** 3465** ^If the nByte argument is negative, then zSql is read up to the 3466** first zero terminator. ^If nByte is positive, then it is the 3467** number of bytes read from zSql. ^If nByte is zero, then no prepared 3468** statement is generated. 3469** If the caller knows that the supplied string is nul-terminated, then 3470** there is a small performance advantage to passing an nByte parameter that 3471** is the number of bytes in the input string <i>including</i> 3472** the nul-terminator. 3473** 3474** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3475** past the end of the first SQL statement in zSql. These routines only 3476** compile the first statement in zSql, so *pzTail is left pointing to 3477** what remains uncompiled. 3478** 3479** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3480** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3481** to NULL. ^If the input text contains no SQL (if the input is an empty 3482** string or a comment) then *ppStmt is set to NULL. 3483** The calling procedure is responsible for deleting the compiled 3484** SQL statement using [sqlite3_finalize()] after it has finished with it. 3485** ppStmt may not be NULL. 3486** 3487** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3488** otherwise an [error code] is returned. 3489** 3490** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3491** recommended for all new programs. The two older interfaces are retained 3492** for backwards compatibility, but their use is discouraged. 3493** ^In the "v2" interfaces, the prepared statement 3494** that is returned (the [sqlite3_stmt] object) contains a copy of the 3495** original SQL text. This causes the [sqlite3_step()] interface to 3496** behave differently in three ways: 3497** 3498** <ol> 3499** <li> 3500** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3501** always used to do, [sqlite3_step()] will automatically recompile the SQL 3502** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3503** retries will occur before sqlite3_step() gives up and returns an error. 3504** </li> 3505** 3506** <li> 3507** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3508** [error codes] or [extended error codes]. ^The legacy behavior was that 3509** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3510** and the application would have to make a second call to [sqlite3_reset()] 3511** in order to find the underlying cause of the problem. With the "v2" prepare 3512** interfaces, the underlying reason for the error is returned immediately. 3513** </li> 3514** 3515** <li> 3516** ^If the specific value bound to [parameter | host parameter] in the 3517** WHERE clause might influence the choice of query plan for a statement, 3518** then the statement will be automatically recompiled, as if there had been 3519** a schema change, on the first [sqlite3_step()] call following any change 3520** to the [sqlite3_bind_text | bindings] of that [parameter]. 3521** ^The specific value of WHERE-clause [parameter] might influence the 3522** choice of query plan if the parameter is the left-hand side of a [LIKE] 3523** or [GLOB] operator or if the parameter is compared to an indexed column 3524** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3525** </li> 3526** </ol> 3527*/ 3528int sqlite3_prepare( 3529 sqlite3 *db, /* Database handle */ 3530 const char *zSql, /* SQL statement, UTF-8 encoded */ 3531 int nByte, /* Maximum length of zSql in bytes. */ 3532 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3533 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3534); 3535int sqlite3_prepare_v2( 3536 sqlite3 *db, /* Database handle */ 3537 const char *zSql, /* SQL statement, UTF-8 encoded */ 3538 int nByte, /* Maximum length of zSql in bytes. */ 3539 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3540 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3541); 3542int sqlite3_prepare16( 3543 sqlite3 *db, /* Database handle */ 3544 const void *zSql, /* SQL statement, UTF-16 encoded */ 3545 int nByte, /* Maximum length of zSql in bytes. */ 3546 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3547 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3548); 3549int sqlite3_prepare16_v2( 3550 sqlite3 *db, /* Database handle */ 3551 const void *zSql, /* SQL statement, UTF-16 encoded */ 3552 int nByte, /* Maximum length of zSql in bytes. */ 3553 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3554 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3555); 3556 3557/* 3558** CAPI3REF: Retrieving Statement SQL 3559** METHOD: sqlite3_stmt 3560** 3561** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3562** SQL text used to create [prepared statement] P if P was 3563** created by either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3564** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3565** string containing the SQL text of prepared statement P with 3566** [bound parameters] expanded. 3567** 3568** ^(For example, if a prepared statement is created using the SQL 3569** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3570** and parameter :xyz is unbound, then sqlite3_sql() will return 3571** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3572** will return "SELECT 2345,NULL".)^ 3573** 3574** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3575** is available to hold the result, or if the result would exceed the 3576** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3577** 3578** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3579** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3580** option causes sqlite3_expanded_sql() to always return NULL. 3581** 3582** ^The string returned by sqlite3_sql(P) is managed by SQLite and is 3583** automatically freed when the prepared statement is finalized. 3584** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3585** is obtained from [sqlite3_malloc()] and must be free by the application 3586** by passing it to [sqlite3_free()]. 3587*/ 3588const char *sqlite3_sql(sqlite3_stmt *pStmt); 3589char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3590 3591/* 3592** CAPI3REF: Determine If An SQL Statement Writes The Database 3593** METHOD: sqlite3_stmt 3594** 3595** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3596** and only if the [prepared statement] X makes no direct changes to 3597** the content of the database file. 3598** 3599** Note that [application-defined SQL functions] or 3600** [virtual tables] might change the database indirectly as a side effect. 3601** ^(For example, if an application defines a function "eval()" that 3602** calls [sqlite3_exec()], then the following SQL statement would 3603** change the database file through side-effects: 3604** 3605** <blockquote><pre> 3606** SELECT eval('DELETE FROM t1') FROM t2; 3607** </pre></blockquote> 3608** 3609** But because the [SELECT] statement does not change the database file 3610** directly, sqlite3_stmt_readonly() would still return true.)^ 3611** 3612** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3613** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3614** since the statements themselves do not actually modify the database but 3615** rather they control the timing of when other statements modify the 3616** database. ^The [ATTACH] and [DETACH] statements also cause 3617** sqlite3_stmt_readonly() to return true since, while those statements 3618** change the configuration of a database connection, they do not make 3619** changes to the content of the database files on disk. 3620** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3621** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3622** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3623** sqlite3_stmt_readonly() returns false for those commands. 3624*/ 3625int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3626 3627/* 3628** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3629** METHOD: sqlite3_stmt 3630** 3631** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3632** [prepared statement] S has been stepped at least once using 3633** [sqlite3_step(S)] but has neither run to completion (returned 3634** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3635** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3636** interface returns false if S is a NULL pointer. If S is not a 3637** NULL pointer and is not a pointer to a valid [prepared statement] 3638** object, then the behavior is undefined and probably undesirable. 3639** 3640** This interface can be used in combination [sqlite3_next_stmt()] 3641** to locate all prepared statements associated with a database 3642** connection that are in need of being reset. This can be used, 3643** for example, in diagnostic routines to search for prepared 3644** statements that are holding a transaction open. 3645*/ 3646int sqlite3_stmt_busy(sqlite3_stmt*); 3647 3648/* 3649** CAPI3REF: Dynamically Typed Value Object 3650** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3651** 3652** SQLite uses the sqlite3_value object to represent all values 3653** that can be stored in a database table. SQLite uses dynamic typing 3654** for the values it stores. ^Values stored in sqlite3_value objects 3655** can be integers, floating point values, strings, BLOBs, or NULL. 3656** 3657** An sqlite3_value object may be either "protected" or "unprotected". 3658** Some interfaces require a protected sqlite3_value. Other interfaces 3659** will accept either a protected or an unprotected sqlite3_value. 3660** Every interface that accepts sqlite3_value arguments specifies 3661** whether or not it requires a protected sqlite3_value. The 3662** [sqlite3_value_dup()] interface can be used to construct a new 3663** protected sqlite3_value from an unprotected sqlite3_value. 3664** 3665** The terms "protected" and "unprotected" refer to whether or not 3666** a mutex is held. An internal mutex is held for a protected 3667** sqlite3_value object but no mutex is held for an unprotected 3668** sqlite3_value object. If SQLite is compiled to be single-threaded 3669** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3670** or if SQLite is run in one of reduced mutex modes 3671** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3672** then there is no distinction between protected and unprotected 3673** sqlite3_value objects and they can be used interchangeably. However, 3674** for maximum code portability it is recommended that applications 3675** still make the distinction between protected and unprotected 3676** sqlite3_value objects even when not strictly required. 3677** 3678** ^The sqlite3_value objects that are passed as parameters into the 3679** implementation of [application-defined SQL functions] are protected. 3680** ^The sqlite3_value object returned by 3681** [sqlite3_column_value()] is unprotected. 3682** Unprotected sqlite3_value objects may only be used with 3683** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3684** The [sqlite3_value_blob | sqlite3_value_type()] family of 3685** interfaces require protected sqlite3_value objects. 3686*/ 3687typedef struct Mem sqlite3_value; 3688 3689/* 3690** CAPI3REF: SQL Function Context Object 3691** 3692** The context in which an SQL function executes is stored in an 3693** sqlite3_context object. ^A pointer to an sqlite3_context object 3694** is always first parameter to [application-defined SQL functions]. 3695** The application-defined SQL function implementation will pass this 3696** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3697** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3698** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3699** and/or [sqlite3_set_auxdata()]. 3700*/ 3701typedef struct sqlite3_context sqlite3_context; 3702 3703/* 3704** CAPI3REF: Binding Values To Prepared Statements 3705** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3706** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3707** METHOD: sqlite3_stmt 3708** 3709** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3710** literals may be replaced by a [parameter] that matches one of following 3711** templates: 3712** 3713** <ul> 3714** <li> ? 3715** <li> ?NNN 3716** <li> :VVV 3717** <li> @VVV 3718** <li> $VVV 3719** </ul> 3720** 3721** In the templates above, NNN represents an integer literal, 3722** and VVV represents an alphanumeric identifier.)^ ^The values of these 3723** parameters (also called "host parameter names" or "SQL parameters") 3724** can be set using the sqlite3_bind_*() routines defined here. 3725** 3726** ^The first argument to the sqlite3_bind_*() routines is always 3727** a pointer to the [sqlite3_stmt] object returned from 3728** [sqlite3_prepare_v2()] or its variants. 3729** 3730** ^The second argument is the index of the SQL parameter to be set. 3731** ^The leftmost SQL parameter has an index of 1. ^When the same named 3732** SQL parameter is used more than once, second and subsequent 3733** occurrences have the same index as the first occurrence. 3734** ^The index for named parameters can be looked up using the 3735** [sqlite3_bind_parameter_index()] API if desired. ^The index 3736** for "?NNN" parameters is the value of NNN. 3737** ^The NNN value must be between 1 and the [sqlite3_limit()] 3738** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3739** 3740** ^The third argument is the value to bind to the parameter. 3741** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3742** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3743** is ignored and the end result is the same as sqlite3_bind_null(). 3744** 3745** ^(In those routines that have a fourth argument, its value is the 3746** number of bytes in the parameter. To be clear: the value is the 3747** number of <u>bytes</u> in the value, not the number of characters.)^ 3748** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3749** is negative, then the length of the string is 3750** the number of bytes up to the first zero terminator. 3751** If the fourth parameter to sqlite3_bind_blob() is negative, then 3752** the behavior is undefined. 3753** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3754** or sqlite3_bind_text16() or sqlite3_bind_text64() then 3755** that parameter must be the byte offset 3756** where the NUL terminator would occur assuming the string were NUL 3757** terminated. If any NUL characters occur at byte offsets less than 3758** the value of the fourth parameter then the resulting string value will 3759** contain embedded NULs. The result of expressions involving strings 3760** with embedded NULs is undefined. 3761** 3762** ^The fifth argument to the BLOB and string binding interfaces 3763** is a destructor used to dispose of the BLOB or 3764** string after SQLite has finished with it. ^The destructor is called 3765** to dispose of the BLOB or string even if the call to bind API fails. 3766** ^If the fifth argument is 3767** the special value [SQLITE_STATIC], then SQLite assumes that the 3768** information is in static, unmanaged space and does not need to be freed. 3769** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3770** SQLite makes its own private copy of the data immediately, before 3771** the sqlite3_bind_*() routine returns. 3772** 3773** ^The sixth argument to sqlite3_bind_text64() must be one of 3774** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 3775** to specify the encoding of the text in the third parameter. If 3776** the sixth argument to sqlite3_bind_text64() is not one of the 3777** allowed values shown above, or if the text encoding is different 3778** from the encoding specified by the sixth parameter, then the behavior 3779** is undefined. 3780** 3781** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3782** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3783** (just an integer to hold its size) while it is being processed. 3784** Zeroblobs are intended to serve as placeholders for BLOBs whose 3785** content is later written using 3786** [sqlite3_blob_open | incremental BLOB I/O] routines. 3787** ^A negative value for the zeroblob results in a zero-length BLOB. 3788** 3789** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3790** for the [prepared statement] or with a prepared statement for which 3791** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3792** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3793** routine is passed a [prepared statement] that has been finalized, the 3794** result is undefined and probably harmful. 3795** 3796** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3797** ^Unbound parameters are interpreted as NULL. 3798** 3799** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3800** [error code] if anything goes wrong. 3801** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 3802** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 3803** [SQLITE_MAX_LENGTH]. 3804** ^[SQLITE_RANGE] is returned if the parameter 3805** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3806** 3807** See also: [sqlite3_bind_parameter_count()], 3808** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3809*/ 3810int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3811int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 3812 void(*)(void*)); 3813int sqlite3_bind_double(sqlite3_stmt*, int, double); 3814int sqlite3_bind_int(sqlite3_stmt*, int, int); 3815int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3816int sqlite3_bind_null(sqlite3_stmt*, int); 3817int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 3818int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3819int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 3820 void(*)(void*), unsigned char encoding); 3821int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3822int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3823int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 3824 3825/* 3826** CAPI3REF: Number Of SQL Parameters 3827** METHOD: sqlite3_stmt 3828** 3829** ^This routine can be used to find the number of [SQL parameters] 3830** in a [prepared statement]. SQL parameters are tokens of the 3831** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3832** placeholders for values that are [sqlite3_bind_blob | bound] 3833** to the parameters at a later time. 3834** 3835** ^(This routine actually returns the index of the largest (rightmost) 3836** parameter. For all forms except ?NNN, this will correspond to the 3837** number of unique parameters. If parameters of the ?NNN form are used, 3838** there may be gaps in the list.)^ 3839** 3840** See also: [sqlite3_bind_blob|sqlite3_bind()], 3841** [sqlite3_bind_parameter_name()], and 3842** [sqlite3_bind_parameter_index()]. 3843*/ 3844int sqlite3_bind_parameter_count(sqlite3_stmt*); 3845 3846/* 3847** CAPI3REF: Name Of A Host Parameter 3848** METHOD: sqlite3_stmt 3849** 3850** ^The sqlite3_bind_parameter_name(P,N) interface returns 3851** the name of the N-th [SQL parameter] in the [prepared statement] P. 3852** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3853** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3854** respectively. 3855** In other words, the initial ":" or "$" or "@" or "?" 3856** is included as part of the name.)^ 3857** ^Parameters of the form "?" without a following integer have no name 3858** and are referred to as "nameless" or "anonymous parameters". 3859** 3860** ^The first host parameter has an index of 1, not 0. 3861** 3862** ^If the value N is out of range or if the N-th parameter is 3863** nameless, then NULL is returned. ^The returned string is 3864** always in UTF-8 encoding even if the named parameter was 3865** originally specified as UTF-16 in [sqlite3_prepare16()] or 3866** [sqlite3_prepare16_v2()]. 3867** 3868** See also: [sqlite3_bind_blob|sqlite3_bind()], 3869** [sqlite3_bind_parameter_count()], and 3870** [sqlite3_bind_parameter_index()]. 3871*/ 3872const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3873 3874/* 3875** CAPI3REF: Index Of A Parameter With A Given Name 3876** METHOD: sqlite3_stmt 3877** 3878** ^Return the index of an SQL parameter given its name. ^The 3879** index value returned is suitable for use as the second 3880** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3881** is returned if no matching parameter is found. ^The parameter 3882** name must be given in UTF-8 even if the original statement 3883** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3884** 3885** See also: [sqlite3_bind_blob|sqlite3_bind()], 3886** [sqlite3_bind_parameter_count()], and 3887** [sqlite3_bind_parameter_name()]. 3888*/ 3889int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3890 3891/* 3892** CAPI3REF: Reset All Bindings On A Prepared Statement 3893** METHOD: sqlite3_stmt 3894** 3895** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3896** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3897** ^Use this routine to reset all host parameters to NULL. 3898*/ 3899int sqlite3_clear_bindings(sqlite3_stmt*); 3900 3901/* 3902** CAPI3REF: Number Of Columns In A Result Set 3903** METHOD: sqlite3_stmt 3904** 3905** ^Return the number of columns in the result set returned by the 3906** [prepared statement]. ^If this routine returns 0, that means the 3907** [prepared statement] returns no data (for example an [UPDATE]). 3908** ^However, just because this routine returns a positive number does not 3909** mean that one or more rows of data will be returned. ^A SELECT statement 3910** will always have a positive sqlite3_column_count() but depending on the 3911** WHERE clause constraints and the table content, it might return no rows. 3912** 3913** See also: [sqlite3_data_count()] 3914*/ 3915int sqlite3_column_count(sqlite3_stmt *pStmt); 3916 3917/* 3918** CAPI3REF: Column Names In A Result Set 3919** METHOD: sqlite3_stmt 3920** 3921** ^These routines return the name assigned to a particular column 3922** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3923** interface returns a pointer to a zero-terminated UTF-8 string 3924** and sqlite3_column_name16() returns a pointer to a zero-terminated 3925** UTF-16 string. ^The first parameter is the [prepared statement] 3926** that implements the [SELECT] statement. ^The second parameter is the 3927** column number. ^The leftmost column is number 0. 3928** 3929** ^The returned string pointer is valid until either the [prepared statement] 3930** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3931** reprepared by the first call to [sqlite3_step()] for a particular run 3932** or until the next call to 3933** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3934** 3935** ^If sqlite3_malloc() fails during the processing of either routine 3936** (for example during a conversion from UTF-8 to UTF-16) then a 3937** NULL pointer is returned. 3938** 3939** ^The name of a result column is the value of the "AS" clause for 3940** that column, if there is an AS clause. If there is no AS clause 3941** then the name of the column is unspecified and may change from 3942** one release of SQLite to the next. 3943*/ 3944const char *sqlite3_column_name(sqlite3_stmt*, int N); 3945const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3946 3947/* 3948** CAPI3REF: Source Of Data In A Query Result 3949** METHOD: sqlite3_stmt 3950** 3951** ^These routines provide a means to determine the database, table, and 3952** table column that is the origin of a particular result column in 3953** [SELECT] statement. 3954** ^The name of the database or table or column can be returned as 3955** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3956** the database name, the _table_ routines return the table name, and 3957** the origin_ routines return the column name. 3958** ^The returned string is valid until the [prepared statement] is destroyed 3959** using [sqlite3_finalize()] or until the statement is automatically 3960** reprepared by the first call to [sqlite3_step()] for a particular run 3961** or until the same information is requested 3962** again in a different encoding. 3963** 3964** ^The names returned are the original un-aliased names of the 3965** database, table, and column. 3966** 3967** ^The first argument to these interfaces is a [prepared statement]. 3968** ^These functions return information about the Nth result column returned by 3969** the statement, where N is the second function argument. 3970** ^The left-most column is column 0 for these routines. 3971** 3972** ^If the Nth column returned by the statement is an expression or 3973** subquery and is not a column value, then all of these functions return 3974** NULL. ^These routine might also return NULL if a memory allocation error 3975** occurs. ^Otherwise, they return the name of the attached database, table, 3976** or column that query result column was extracted from. 3977** 3978** ^As with all other SQLite APIs, those whose names end with "16" return 3979** UTF-16 encoded strings and the other functions return UTF-8. 3980** 3981** ^These APIs are only available if the library was compiled with the 3982** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3983** 3984** If two or more threads call one or more of these routines against the same 3985** prepared statement and column at the same time then the results are 3986** undefined. 3987** 3988** If two or more threads call one or more 3989** [sqlite3_column_database_name | column metadata interfaces] 3990** for the same [prepared statement] and result column 3991** at the same time then the results are undefined. 3992*/ 3993const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3994const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3995const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3996const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3997const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3998const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3999 4000/* 4001** CAPI3REF: Declared Datatype Of A Query Result 4002** METHOD: sqlite3_stmt 4003** 4004** ^(The first parameter is a [prepared statement]. 4005** If this statement is a [SELECT] statement and the Nth column of the 4006** returned result set of that [SELECT] is a table column (not an 4007** expression or subquery) then the declared type of the table 4008** column is returned.)^ ^If the Nth column of the result set is an 4009** expression or subquery, then a NULL pointer is returned. 4010** ^The returned string is always UTF-8 encoded. 4011** 4012** ^(For example, given the database schema: 4013** 4014** CREATE TABLE t1(c1 VARIANT); 4015** 4016** and the following statement to be compiled: 4017** 4018** SELECT c1 + 1, c1 FROM t1; 4019** 4020** this routine would return the string "VARIANT" for the second result 4021** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4022** 4023** ^SQLite uses dynamic run-time typing. ^So just because a column 4024** is declared to contain a particular type does not mean that the 4025** data stored in that column is of the declared type. SQLite is 4026** strongly typed, but the typing is dynamic not static. ^Type 4027** is associated with individual values, not with the containers 4028** used to hold those values. 4029*/ 4030const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4031const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4032 4033/* 4034** CAPI3REF: Evaluate An SQL Statement 4035** METHOD: sqlite3_stmt 4036** 4037** After a [prepared statement] has been prepared using either 4038** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 4039** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4040** must be called one or more times to evaluate the statement. 4041** 4042** The details of the behavior of the sqlite3_step() interface depend 4043** on whether the statement was prepared using the newer "v2" interface 4044** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 4045** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4046** new "v2" interface is recommended for new applications but the legacy 4047** interface will continue to be supported. 4048** 4049** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4050** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4051** ^With the "v2" interface, any of the other [result codes] or 4052** [extended result codes] might be returned as well. 4053** 4054** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4055** database locks it needs to do its job. ^If the statement is a [COMMIT] 4056** or occurs outside of an explicit transaction, then you can retry the 4057** statement. If the statement is not a [COMMIT] and occurs within an 4058** explicit transaction then you should rollback the transaction before 4059** continuing. 4060** 4061** ^[SQLITE_DONE] means that the statement has finished executing 4062** successfully. sqlite3_step() should not be called again on this virtual 4063** machine without first calling [sqlite3_reset()] to reset the virtual 4064** machine back to its initial state. 4065** 4066** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4067** is returned each time a new row of data is ready for processing by the 4068** caller. The values may be accessed using the [column access functions]. 4069** sqlite3_step() is called again to retrieve the next row of data. 4070** 4071** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4072** violation) has occurred. sqlite3_step() should not be called again on 4073** the VM. More information may be found by calling [sqlite3_errmsg()]. 4074** ^With the legacy interface, a more specific error code (for example, 4075** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4076** can be obtained by calling [sqlite3_reset()] on the 4077** [prepared statement]. ^In the "v2" interface, 4078** the more specific error code is returned directly by sqlite3_step(). 4079** 4080** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4081** Perhaps it was called on a [prepared statement] that has 4082** already been [sqlite3_finalize | finalized] or on one that had 4083** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4084** be the case that the same database connection is being used by two or 4085** more threads at the same moment in time. 4086** 4087** For all versions of SQLite up to and including 3.6.23.1, a call to 4088** [sqlite3_reset()] was required after sqlite3_step() returned anything 4089** other than [SQLITE_ROW] before any subsequent invocation of 4090** sqlite3_step(). Failure to reset the prepared statement using 4091** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4092** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4093** sqlite3_step() began 4094** calling [sqlite3_reset()] automatically in this circumstance rather 4095** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4096** break because any application that ever receives an SQLITE_MISUSE error 4097** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4098** can be used to restore the legacy behavior. 4099** 4100** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4101** API always returns a generic error code, [SQLITE_ERROR], following any 4102** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4103** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4104** specific [error codes] that better describes the error. 4105** We admit that this is a goofy design. The problem has been fixed 4106** with the "v2" interface. If you prepare all of your SQL statements 4107** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 4108** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4109** then the more specific [error codes] are returned directly 4110** by sqlite3_step(). The use of the "v2" interface is recommended. 4111*/ 4112int sqlite3_step(sqlite3_stmt*); 4113 4114/* 4115** CAPI3REF: Number of columns in a result set 4116** METHOD: sqlite3_stmt 4117** 4118** ^The sqlite3_data_count(P) interface returns the number of columns in the 4119** current row of the result set of [prepared statement] P. 4120** ^If prepared statement P does not have results ready to return 4121** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4122** interfaces) then sqlite3_data_count(P) returns 0. 4123** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4124** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4125** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4126** will return non-zero if previous call to [sqlite3_step](P) returned 4127** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4128** where it always returns zero since each step of that multi-step 4129** pragma returns 0 columns of data. 4130** 4131** See also: [sqlite3_column_count()] 4132*/ 4133int sqlite3_data_count(sqlite3_stmt *pStmt); 4134 4135/* 4136** CAPI3REF: Fundamental Datatypes 4137** KEYWORDS: SQLITE_TEXT 4138** 4139** ^(Every value in SQLite has one of five fundamental datatypes: 4140** 4141** <ul> 4142** <li> 64-bit signed integer 4143** <li> 64-bit IEEE floating point number 4144** <li> string 4145** <li> BLOB 4146** <li> NULL 4147** </ul>)^ 4148** 4149** These constants are codes for each of those types. 4150** 4151** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4152** for a completely different meaning. Software that links against both 4153** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4154** SQLITE_TEXT. 4155*/ 4156#define SQLITE_INTEGER 1 4157#define SQLITE_FLOAT 2 4158#define SQLITE_BLOB 4 4159#define SQLITE_NULL 5 4160#ifdef SQLITE_TEXT 4161# undef SQLITE_TEXT 4162#else 4163# define SQLITE_TEXT 3 4164#endif 4165#define SQLITE3_TEXT 3 4166 4167/* 4168** CAPI3REF: Result Values From A Query 4169** KEYWORDS: {column access functions} 4170** METHOD: sqlite3_stmt 4171** 4172** ^These routines return information about a single column of the current 4173** result row of a query. ^In every case the first argument is a pointer 4174** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4175** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4176** and the second argument is the index of the column for which information 4177** should be returned. ^The leftmost column of the result set has the index 0. 4178** ^The number of columns in the result can be determined using 4179** [sqlite3_column_count()]. 4180** 4181** If the SQL statement does not currently point to a valid row, or if the 4182** column index is out of range, the result is undefined. 4183** These routines may only be called when the most recent call to 4184** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4185** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4186** If any of these routines are called after [sqlite3_reset()] or 4187** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4188** something other than [SQLITE_ROW], the results are undefined. 4189** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4190** are called from a different thread while any of these routines 4191** are pending, then the results are undefined. 4192** 4193** ^The sqlite3_column_type() routine returns the 4194** [SQLITE_INTEGER | datatype code] for the initial data type 4195** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4196** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 4197** returned by sqlite3_column_type() is only meaningful if no type 4198** conversions have occurred as described below. After a type conversion, 4199** the value returned by sqlite3_column_type() is undefined. Future 4200** versions of SQLite may change the behavior of sqlite3_column_type() 4201** following a type conversion. 4202** 4203** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4204** routine returns the number of bytes in that BLOB or string. 4205** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4206** the string to UTF-8 and then returns the number of bytes. 4207** ^If the result is a numeric value then sqlite3_column_bytes() uses 4208** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4209** the number of bytes in that string. 4210** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4211** 4212** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4213** routine returns the number of bytes in that BLOB or string. 4214** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4215** the string to UTF-16 and then returns the number of bytes. 4216** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4217** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4218** the number of bytes in that string. 4219** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4220** 4221** ^The values returned by [sqlite3_column_bytes()] and 4222** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4223** of the string. ^For clarity: the values returned by 4224** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4225** bytes in the string, not the number of characters. 4226** 4227** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4228** even empty strings, are always zero-terminated. ^The return 4229** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4230** 4231** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4232** [unprotected sqlite3_value] object. In a multithreaded environment, 4233** an unprotected sqlite3_value object may only be used safely with 4234** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4235** If the [unprotected sqlite3_value] object returned by 4236** [sqlite3_column_value()] is used in any other way, including calls 4237** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4238** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4239** 4240** These routines attempt to convert the value where appropriate. ^For 4241** example, if the internal representation is FLOAT and a text result 4242** is requested, [sqlite3_snprintf()] is used internally to perform the 4243** conversion automatically. ^(The following table details the conversions 4244** that are applied: 4245** 4246** <blockquote> 4247** <table border="1"> 4248** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4249** 4250** <tr><td> NULL <td> INTEGER <td> Result is 0 4251** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4252** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4253** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4254** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4255** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4256** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4257** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4258** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4259** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4260** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4261** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4262** <tr><td> TEXT <td> BLOB <td> No change 4263** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4264** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4265** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4266** </table> 4267** </blockquote>)^ 4268** 4269** Note that when type conversions occur, pointers returned by prior 4270** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4271** sqlite3_column_text16() may be invalidated. 4272** Type conversions and pointer invalidations might occur 4273** in the following cases: 4274** 4275** <ul> 4276** <li> The initial content is a BLOB and sqlite3_column_text() or 4277** sqlite3_column_text16() is called. A zero-terminator might 4278** need to be added to the string.</li> 4279** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4280** sqlite3_column_text16() is called. The content must be converted 4281** to UTF-16.</li> 4282** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4283** sqlite3_column_text() is called. The content must be converted 4284** to UTF-8.</li> 4285** </ul> 4286** 4287** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4288** not invalidate a prior pointer, though of course the content of the buffer 4289** that the prior pointer references will have been modified. Other kinds 4290** of conversion are done in place when it is possible, but sometimes they 4291** are not possible and in those cases prior pointers are invalidated. 4292** 4293** The safest policy is to invoke these routines 4294** in one of the following ways: 4295** 4296** <ul> 4297** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4298** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4299** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4300** </ul> 4301** 4302** In other words, you should call sqlite3_column_text(), 4303** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4304** into the desired format, then invoke sqlite3_column_bytes() or 4305** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4306** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4307** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4308** with calls to sqlite3_column_bytes(). 4309** 4310** ^The pointers returned are valid until a type conversion occurs as 4311** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4312** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4313** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned 4314** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4315** [sqlite3_free()]. 4316** 4317** ^(If a memory allocation error occurs during the evaluation of any 4318** of these routines, a default value is returned. The default value 4319** is either the integer 0, the floating point number 0.0, or a NULL 4320** pointer. Subsequent calls to [sqlite3_errcode()] will return 4321** [SQLITE_NOMEM].)^ 4322*/ 4323const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4324int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4325int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4326double sqlite3_column_double(sqlite3_stmt*, int iCol); 4327int sqlite3_column_int(sqlite3_stmt*, int iCol); 4328sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4329const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4330const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4331int sqlite3_column_type(sqlite3_stmt*, int iCol); 4332sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4333 4334/* 4335** CAPI3REF: Destroy A Prepared Statement Object 4336** DESTRUCTOR: sqlite3_stmt 4337** 4338** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4339** ^If the most recent evaluation of the statement encountered no errors 4340** or if the statement is never been evaluated, then sqlite3_finalize() returns 4341** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4342** sqlite3_finalize(S) returns the appropriate [error code] or 4343** [extended error code]. 4344** 4345** ^The sqlite3_finalize(S) routine can be called at any point during 4346** the life cycle of [prepared statement] S: 4347** before statement S is ever evaluated, after 4348** one or more calls to [sqlite3_reset()], or after any call 4349** to [sqlite3_step()] regardless of whether or not the statement has 4350** completed execution. 4351** 4352** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4353** 4354** The application must finalize every [prepared statement] in order to avoid 4355** resource leaks. It is a grievous error for the application to try to use 4356** a prepared statement after it has been finalized. Any use of a prepared 4357** statement after it has been finalized can result in undefined and 4358** undesirable behavior such as segfaults and heap corruption. 4359*/ 4360int sqlite3_finalize(sqlite3_stmt *pStmt); 4361 4362/* 4363** CAPI3REF: Reset A Prepared Statement Object 4364** METHOD: sqlite3_stmt 4365** 4366** The sqlite3_reset() function is called to reset a [prepared statement] 4367** object back to its initial state, ready to be re-executed. 4368** ^Any SQL statement variables that had values bound to them using 4369** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4370** Use [sqlite3_clear_bindings()] to reset the bindings. 4371** 4372** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4373** back to the beginning of its program. 4374** 4375** ^If the most recent call to [sqlite3_step(S)] for the 4376** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4377** or if [sqlite3_step(S)] has never before been called on S, 4378** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4379** 4380** ^If the most recent call to [sqlite3_step(S)] for the 4381** [prepared statement] S indicated an error, then 4382** [sqlite3_reset(S)] returns an appropriate [error code]. 4383** 4384** ^The [sqlite3_reset(S)] interface does not change the values 4385** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4386*/ 4387int sqlite3_reset(sqlite3_stmt *pStmt); 4388 4389/* 4390** CAPI3REF: Create Or Redefine SQL Functions 4391** KEYWORDS: {function creation routines} 4392** KEYWORDS: {application-defined SQL function} 4393** KEYWORDS: {application-defined SQL functions} 4394** METHOD: sqlite3 4395** 4396** ^These functions (collectively known as "function creation routines") 4397** are used to add SQL functions or aggregates or to redefine the behavior 4398** of existing SQL functions or aggregates. The only differences between 4399** these routines are the text encoding expected for 4400** the second parameter (the name of the function being created) 4401** and the presence or absence of a destructor callback for 4402** the application data pointer. 4403** 4404** ^The first parameter is the [database connection] to which the SQL 4405** function is to be added. ^If an application uses more than one database 4406** connection then application-defined SQL functions must be added 4407** to each database connection separately. 4408** 4409** ^The second parameter is the name of the SQL function to be created or 4410** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4411** representation, exclusive of the zero-terminator. ^Note that the name 4412** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4413** ^Any attempt to create a function with a longer name 4414** will result in [SQLITE_MISUSE] being returned. 4415** 4416** ^The third parameter (nArg) 4417** is the number of arguments that the SQL function or 4418** aggregate takes. ^If this parameter is -1, then the SQL function or 4419** aggregate may take any number of arguments between 0 and the limit 4420** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4421** parameter is less than -1 or greater than 127 then the behavior is 4422** undefined. 4423** 4424** ^The fourth parameter, eTextRep, specifies what 4425** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4426** its parameters. The application should set this parameter to 4427** [SQLITE_UTF16LE] if the function implementation invokes 4428** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4429** implementation invokes [sqlite3_value_text16be()] on an input, or 4430** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4431** otherwise. ^The same SQL function may be registered multiple times using 4432** different preferred text encodings, with different implementations for 4433** each encoding. 4434** ^When multiple implementations of the same function are available, SQLite 4435** will pick the one that involves the least amount of data conversion. 4436** 4437** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4438** to signal that the function will always return the same result given 4439** the same inputs within a single SQL statement. Most SQL functions are 4440** deterministic. The built-in [random()] SQL function is an example of a 4441** function that is not deterministic. The SQLite query planner is able to 4442** perform additional optimizations on deterministic functions, so use 4443** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4444** 4445** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4446** function can gain access to this pointer using [sqlite3_user_data()].)^ 4447** 4448** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4449** pointers to C-language functions that implement the SQL function or 4450** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4451** callback only; NULL pointers must be passed as the xStep and xFinal 4452** parameters. ^An aggregate SQL function requires an implementation of xStep 4453** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4454** SQL function or aggregate, pass NULL pointers for all three function 4455** callbacks. 4456** 4457** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4458** then it is destructor for the application data pointer. 4459** The destructor is invoked when the function is deleted, either by being 4460** overloaded or when the database connection closes.)^ 4461** ^The destructor is also invoked if the call to 4462** sqlite3_create_function_v2() fails. 4463** ^When the destructor callback of the tenth parameter is invoked, it 4464** is passed a single argument which is a copy of the application data 4465** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4466** 4467** ^It is permitted to register multiple implementations of the same 4468** functions with the same name but with either differing numbers of 4469** arguments or differing preferred text encodings. ^SQLite will use 4470** the implementation that most closely matches the way in which the 4471** SQL function is used. ^A function implementation with a non-negative 4472** nArg parameter is a better match than a function implementation with 4473** a negative nArg. ^A function where the preferred text encoding 4474** matches the database encoding is a better 4475** match than a function where the encoding is different. 4476** ^A function where the encoding difference is between UTF16le and UTF16be 4477** is a closer match than a function where the encoding difference is 4478** between UTF8 and UTF16. 4479** 4480** ^Built-in functions may be overloaded by new application-defined functions. 4481** 4482** ^An application-defined function is permitted to call other 4483** SQLite interfaces. However, such calls must not 4484** close the database connection nor finalize or reset the prepared 4485** statement in which the function is running. 4486*/ 4487int sqlite3_create_function( 4488 sqlite3 *db, 4489 const char *zFunctionName, 4490 int nArg, 4491 int eTextRep, 4492 void *pApp, 4493 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4494 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4495 void (*xFinal)(sqlite3_context*) 4496); 4497int sqlite3_create_function16( 4498 sqlite3 *db, 4499 const void *zFunctionName, 4500 int nArg, 4501 int eTextRep, 4502 void *pApp, 4503 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4504 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4505 void (*xFinal)(sqlite3_context*) 4506); 4507int sqlite3_create_function_v2( 4508 sqlite3 *db, 4509 const char *zFunctionName, 4510 int nArg, 4511 int eTextRep, 4512 void *pApp, 4513 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4514 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4515 void (*xFinal)(sqlite3_context*), 4516 void(*xDestroy)(void*) 4517); 4518 4519/* 4520** CAPI3REF: Text Encodings 4521** 4522** These constant define integer codes that represent the various 4523** text encodings supported by SQLite. 4524*/ 4525#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4526#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4527#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4528#define SQLITE_UTF16 4 /* Use native byte order */ 4529#define SQLITE_ANY 5 /* Deprecated */ 4530#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4531 4532/* 4533** CAPI3REF: Function Flags 4534** 4535** These constants may be ORed together with the 4536** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4537** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4538** [sqlite3_create_function_v2()]. 4539*/ 4540#define SQLITE_DETERMINISTIC 0x800 4541 4542/* 4543** CAPI3REF: Deprecated Functions 4544** DEPRECATED 4545** 4546** These functions are [deprecated]. In order to maintain 4547** backwards compatibility with older code, these functions continue 4548** to be supported. However, new applications should avoid 4549** the use of these functions. To encourage programmers to avoid 4550** these functions, we will not explain what they do. 4551*/ 4552#ifndef SQLITE_OMIT_DEPRECATED 4553SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4554SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4555SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4556SQLITE_DEPRECATED int sqlite3_global_recover(void); 4557SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4558SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4559 void*,sqlite3_int64); 4560#endif 4561 4562/* 4563** CAPI3REF: Obtaining SQL Values 4564** METHOD: sqlite3_value 4565** 4566** The C-language implementation of SQL functions and aggregates uses 4567** this set of interface routines to access the parameter values on 4568** the function or aggregate. 4569** 4570** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4571** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4572** define callbacks that implement the SQL functions and aggregates. 4573** The 3rd parameter to these callbacks is an array of pointers to 4574** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4575** each parameter to the SQL function. These routines are used to 4576** extract values from the [sqlite3_value] objects. 4577** 4578** These routines work only with [protected sqlite3_value] objects. 4579** Any attempt to use these routines on an [unprotected sqlite3_value] 4580** object results in undefined behavior. 4581** 4582** ^These routines work just like the corresponding [column access functions] 4583** except that these routines take a single [protected sqlite3_value] object 4584** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4585** 4586** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4587** in the native byte-order of the host machine. ^The 4588** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4589** extract UTF-16 strings as big-endian and little-endian respectively. 4590** 4591** ^(The sqlite3_value_numeric_type() interface attempts to apply 4592** numeric affinity to the value. This means that an attempt is 4593** made to convert the value to an integer or floating point. If 4594** such a conversion is possible without loss of information (in other 4595** words, if the value is a string that looks like a number) 4596** then the conversion is performed. Otherwise no conversion occurs. 4597** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4598** 4599** Please pay particular attention to the fact that the pointer returned 4600** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4601** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4602** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4603** or [sqlite3_value_text16()]. 4604** 4605** These routines must be called from the same thread as 4606** the SQL function that supplied the [sqlite3_value*] parameters. 4607*/ 4608const void *sqlite3_value_blob(sqlite3_value*); 4609int sqlite3_value_bytes(sqlite3_value*); 4610int sqlite3_value_bytes16(sqlite3_value*); 4611double sqlite3_value_double(sqlite3_value*); 4612int sqlite3_value_int(sqlite3_value*); 4613sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4614const unsigned char *sqlite3_value_text(sqlite3_value*); 4615const void *sqlite3_value_text16(sqlite3_value*); 4616const void *sqlite3_value_text16le(sqlite3_value*); 4617const void *sqlite3_value_text16be(sqlite3_value*); 4618int sqlite3_value_type(sqlite3_value*); 4619int sqlite3_value_numeric_type(sqlite3_value*); 4620 4621/* 4622** CAPI3REF: Finding The Subtype Of SQL Values 4623** METHOD: sqlite3_value 4624** 4625** The sqlite3_value_subtype(V) function returns the subtype for 4626** an [application-defined SQL function] argument V. The subtype 4627** information can be used to pass a limited amount of context from 4628** one SQL function to another. Use the [sqlite3_result_subtype()] 4629** routine to set the subtype for the return value of an SQL function. 4630** 4631** SQLite makes no use of subtype itself. It merely passes the subtype 4632** from the result of one [application-defined SQL function] into the 4633** input of another. 4634*/ 4635unsigned int sqlite3_value_subtype(sqlite3_value*); 4636 4637/* 4638** CAPI3REF: Copy And Free SQL Values 4639** METHOD: sqlite3_value 4640** 4641** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 4642** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 4643** is a [protected sqlite3_value] object even if the input is not. 4644** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 4645** memory allocation fails. 4646** 4647** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 4648** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 4649** then sqlite3_value_free(V) is a harmless no-op. 4650*/ 4651sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 4652void sqlite3_value_free(sqlite3_value*); 4653 4654/* 4655** CAPI3REF: Obtain Aggregate Function Context 4656** METHOD: sqlite3_context 4657** 4658** Implementations of aggregate SQL functions use this 4659** routine to allocate memory for storing their state. 4660** 4661** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4662** for a particular aggregate function, SQLite 4663** allocates N of memory, zeroes out that memory, and returns a pointer 4664** to the new memory. ^On second and subsequent calls to 4665** sqlite3_aggregate_context() for the same aggregate function instance, 4666** the same buffer is returned. Sqlite3_aggregate_context() is normally 4667** called once for each invocation of the xStep callback and then one 4668** last time when the xFinal callback is invoked. ^(When no rows match 4669** an aggregate query, the xStep() callback of the aggregate function 4670** implementation is never called and xFinal() is called exactly once. 4671** In those cases, sqlite3_aggregate_context() might be called for the 4672** first time from within xFinal().)^ 4673** 4674** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4675** when first called if N is less than or equal to zero or if a memory 4676** allocate error occurs. 4677** 4678** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4679** determined by the N parameter on first successful call. Changing the 4680** value of N in subsequent call to sqlite3_aggregate_context() within 4681** the same aggregate function instance will not resize the memory 4682** allocation.)^ Within the xFinal callback, it is customary to set 4683** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4684** pointless memory allocations occur. 4685** 4686** ^SQLite automatically frees the memory allocated by 4687** sqlite3_aggregate_context() when the aggregate query concludes. 4688** 4689** The first parameter must be a copy of the 4690** [sqlite3_context | SQL function context] that is the first parameter 4691** to the xStep or xFinal callback routine that implements the aggregate 4692** function. 4693** 4694** This routine must be called from the same thread in which 4695** the aggregate SQL function is running. 4696*/ 4697void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4698 4699/* 4700** CAPI3REF: User Data For Functions 4701** METHOD: sqlite3_context 4702** 4703** ^The sqlite3_user_data() interface returns a copy of 4704** the pointer that was the pUserData parameter (the 5th parameter) 4705** of the [sqlite3_create_function()] 4706** and [sqlite3_create_function16()] routines that originally 4707** registered the application defined function. 4708** 4709** This routine must be called from the same thread in which 4710** the application-defined function is running. 4711*/ 4712void *sqlite3_user_data(sqlite3_context*); 4713 4714/* 4715** CAPI3REF: Database Connection For Functions 4716** METHOD: sqlite3_context 4717** 4718** ^The sqlite3_context_db_handle() interface returns a copy of 4719** the pointer to the [database connection] (the 1st parameter) 4720** of the [sqlite3_create_function()] 4721** and [sqlite3_create_function16()] routines that originally 4722** registered the application defined function. 4723*/ 4724sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4725 4726/* 4727** CAPI3REF: Function Auxiliary Data 4728** METHOD: sqlite3_context 4729** 4730** These functions may be used by (non-aggregate) SQL functions to 4731** associate metadata with argument values. If the same value is passed to 4732** multiple invocations of the same SQL function during query execution, under 4733** some circumstances the associated metadata may be preserved. An example 4734** of where this might be useful is in a regular-expression matching 4735** function. The compiled version of the regular expression can be stored as 4736** metadata associated with the pattern string. 4737** Then as long as the pattern string remains the same, 4738** the compiled regular expression can be reused on multiple 4739** invocations of the same function. 4740** 4741** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4742** associated by the sqlite3_set_auxdata() function with the Nth argument 4743** value to the application-defined function. ^If there is no metadata 4744** associated with the function argument, this sqlite3_get_auxdata() interface 4745** returns a NULL pointer. 4746** 4747** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4748** argument of the application-defined function. ^Subsequent 4749** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4750** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4751** NULL if the metadata has been discarded. 4752** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4753** SQLite will invoke the destructor function X with parameter P exactly 4754** once, when the metadata is discarded. 4755** SQLite is free to discard the metadata at any time, including: <ul> 4756** <li> ^(when the corresponding function parameter changes)^, or 4757** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4758** SQL statement)^, or 4759** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 4760** parameter)^, or 4761** <li> ^(during the original sqlite3_set_auxdata() call when a memory 4762** allocation error occurs.)^ </ul> 4763** 4764** Note the last bullet in particular. The destructor X in 4765** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4766** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4767** should be called near the end of the function implementation and the 4768** function implementation should not make any use of P after 4769** sqlite3_set_auxdata() has been called. 4770** 4771** ^(In practice, metadata is preserved between function calls for 4772** function parameters that are compile-time constants, including literal 4773** values and [parameters] and expressions composed from the same.)^ 4774** 4775** These routines must be called from the same thread in which 4776** the SQL function is running. 4777*/ 4778void *sqlite3_get_auxdata(sqlite3_context*, int N); 4779void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4780 4781 4782/* 4783** CAPI3REF: Constants Defining Special Destructor Behavior 4784** 4785** These are special values for the destructor that is passed in as the 4786** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4787** argument is SQLITE_STATIC, it means that the content pointer is constant 4788** and will never change. It does not need to be destroyed. ^The 4789** SQLITE_TRANSIENT value means that the content will likely change in 4790** the near future and that SQLite should make its own private copy of 4791** the content before returning. 4792** 4793** The typedef is necessary to work around problems in certain 4794** C++ compilers. 4795*/ 4796typedef void (*sqlite3_destructor_type)(void*); 4797#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4798#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4799 4800/* 4801** CAPI3REF: Setting The Result Of An SQL Function 4802** METHOD: sqlite3_context 4803** 4804** These routines are used by the xFunc or xFinal callbacks that 4805** implement SQL functions and aggregates. See 4806** [sqlite3_create_function()] and [sqlite3_create_function16()] 4807** for additional information. 4808** 4809** These functions work very much like the [parameter binding] family of 4810** functions used to bind values to host parameters in prepared statements. 4811** Refer to the [SQL parameter] documentation for additional information. 4812** 4813** ^The sqlite3_result_blob() interface sets the result from 4814** an application-defined function to be the BLOB whose content is pointed 4815** to by the second parameter and which is N bytes long where N is the 4816** third parameter. 4817** 4818** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 4819** interfaces set the result of the application-defined function to be 4820** a BLOB containing all zero bytes and N bytes in size. 4821** 4822** ^The sqlite3_result_double() interface sets the result from 4823** an application-defined function to be a floating point value specified 4824** by its 2nd argument. 4825** 4826** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4827** cause the implemented SQL function to throw an exception. 4828** ^SQLite uses the string pointed to by the 4829** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4830** as the text of an error message. ^SQLite interprets the error 4831** message string from sqlite3_result_error() as UTF-8. ^SQLite 4832** interprets the string from sqlite3_result_error16() as UTF-16 in native 4833** byte order. ^If the third parameter to sqlite3_result_error() 4834** or sqlite3_result_error16() is negative then SQLite takes as the error 4835** message all text up through the first zero character. 4836** ^If the third parameter to sqlite3_result_error() or 4837** sqlite3_result_error16() is non-negative then SQLite takes that many 4838** bytes (not characters) from the 2nd parameter as the error message. 4839** ^The sqlite3_result_error() and sqlite3_result_error16() 4840** routines make a private copy of the error message text before 4841** they return. Hence, the calling function can deallocate or 4842** modify the text after they return without harm. 4843** ^The sqlite3_result_error_code() function changes the error code 4844** returned by SQLite as a result of an error in a function. ^By default, 4845** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4846** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4847** 4848** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4849** error indicating that a string or BLOB is too long to represent. 4850** 4851** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4852** error indicating that a memory allocation failed. 4853** 4854** ^The sqlite3_result_int() interface sets the return value 4855** of the application-defined function to be the 32-bit signed integer 4856** value given in the 2nd argument. 4857** ^The sqlite3_result_int64() interface sets the return value 4858** of the application-defined function to be the 64-bit signed integer 4859** value given in the 2nd argument. 4860** 4861** ^The sqlite3_result_null() interface sets the return value 4862** of the application-defined function to be NULL. 4863** 4864** ^The sqlite3_result_text(), sqlite3_result_text16(), 4865** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4866** set the return value of the application-defined function to be 4867** a text string which is represented as UTF-8, UTF-16 native byte order, 4868** UTF-16 little endian, or UTF-16 big endian, respectively. 4869** ^The sqlite3_result_text64() interface sets the return value of an 4870** application-defined function to be a text string in an encoding 4871** specified by the fifth (and last) parameter, which must be one 4872** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 4873** ^SQLite takes the text result from the application from 4874** the 2nd parameter of the sqlite3_result_text* interfaces. 4875** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4876** is negative, then SQLite takes result text from the 2nd parameter 4877** through the first zero character. 4878** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4879** is non-negative, then as many bytes (not characters) of the text 4880** pointed to by the 2nd parameter are taken as the application-defined 4881** function result. If the 3rd parameter is non-negative, then it 4882** must be the byte offset into the string where the NUL terminator would 4883** appear if the string where NUL terminated. If any NUL characters occur 4884** in the string at a byte offset that is less than the value of the 3rd 4885** parameter, then the resulting string will contain embedded NULs and the 4886** result of expressions operating on strings with embedded NULs is undefined. 4887** ^If the 4th parameter to the sqlite3_result_text* interfaces 4888** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4889** function as the destructor on the text or BLOB result when it has 4890** finished using that result. 4891** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4892** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4893** assumes that the text or BLOB result is in constant space and does not 4894** copy the content of the parameter nor call a destructor on the content 4895** when it has finished using that result. 4896** ^If the 4th parameter to the sqlite3_result_text* interfaces 4897** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4898** then SQLite makes a copy of the result into space obtained from 4899** from [sqlite3_malloc()] before it returns. 4900** 4901** ^The sqlite3_result_value() interface sets the result of 4902** the application-defined function to be a copy of the 4903** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4904** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4905** so that the [sqlite3_value] specified in the parameter may change or 4906** be deallocated after sqlite3_result_value() returns without harm. 4907** ^A [protected sqlite3_value] object may always be used where an 4908** [unprotected sqlite3_value] object is required, so either 4909** kind of [sqlite3_value] object can be used with this interface. 4910** 4911** If these routines are called from within the different thread 4912** than the one containing the application-defined function that received 4913** the [sqlite3_context] pointer, the results are undefined. 4914*/ 4915void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4916void sqlite3_result_blob64(sqlite3_context*,const void*, 4917 sqlite3_uint64,void(*)(void*)); 4918void sqlite3_result_double(sqlite3_context*, double); 4919void sqlite3_result_error(sqlite3_context*, const char*, int); 4920void sqlite3_result_error16(sqlite3_context*, const void*, int); 4921void sqlite3_result_error_toobig(sqlite3_context*); 4922void sqlite3_result_error_nomem(sqlite3_context*); 4923void sqlite3_result_error_code(sqlite3_context*, int); 4924void sqlite3_result_int(sqlite3_context*, int); 4925void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4926void sqlite3_result_null(sqlite3_context*); 4927void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4928void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 4929 void(*)(void*), unsigned char encoding); 4930void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4931void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4932void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4933void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4934void sqlite3_result_zeroblob(sqlite3_context*, int n); 4935int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 4936 4937 4938/* 4939** CAPI3REF: Setting The Subtype Of An SQL Function 4940** METHOD: sqlite3_context 4941** 4942** The sqlite3_result_subtype(C,T) function causes the subtype of 4943** the result from the [application-defined SQL function] with 4944** [sqlite3_context] C to be the value T. Only the lower 8 bits 4945** of the subtype T are preserved in current versions of SQLite; 4946** higher order bits are discarded. 4947** The number of subtype bytes preserved by SQLite might increase 4948** in future releases of SQLite. 4949*/ 4950void sqlite3_result_subtype(sqlite3_context*,unsigned int); 4951 4952/* 4953** CAPI3REF: Define New Collating Sequences 4954** METHOD: sqlite3 4955** 4956** ^These functions add, remove, or modify a [collation] associated 4957** with the [database connection] specified as the first argument. 4958** 4959** ^The name of the collation is a UTF-8 string 4960** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4961** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4962** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4963** considered to be the same name. 4964** 4965** ^(The third argument (eTextRep) must be one of the constants: 4966** <ul> 4967** <li> [SQLITE_UTF8], 4968** <li> [SQLITE_UTF16LE], 4969** <li> [SQLITE_UTF16BE], 4970** <li> [SQLITE_UTF16], or 4971** <li> [SQLITE_UTF16_ALIGNED]. 4972** </ul>)^ 4973** ^The eTextRep argument determines the encoding of strings passed 4974** to the collating function callback, xCallback. 4975** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4976** force strings to be UTF16 with native byte order. 4977** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4978** on an even byte address. 4979** 4980** ^The fourth argument, pArg, is an application data pointer that is passed 4981** through as the first argument to the collating function callback. 4982** 4983** ^The fifth argument, xCallback, is a pointer to the collating function. 4984** ^Multiple collating functions can be registered using the same name but 4985** with different eTextRep parameters and SQLite will use whichever 4986** function requires the least amount of data transformation. 4987** ^If the xCallback argument is NULL then the collating function is 4988** deleted. ^When all collating functions having the same name are deleted, 4989** that collation is no longer usable. 4990** 4991** ^The collating function callback is invoked with a copy of the pArg 4992** application data pointer and with two strings in the encoding specified 4993** by the eTextRep argument. The collating function must return an 4994** integer that is negative, zero, or positive 4995** if the first string is less than, equal to, or greater than the second, 4996** respectively. A collating function must always return the same answer 4997** given the same inputs. If two or more collating functions are registered 4998** to the same collation name (using different eTextRep values) then all 4999** must give an equivalent answer when invoked with equivalent strings. 5000** The collating function must obey the following properties for all 5001** strings A, B, and C: 5002** 5003** <ol> 5004** <li> If A==B then B==A. 5005** <li> If A==B and B==C then A==C. 5006** <li> If A<B THEN B>A. 5007** <li> If A<B and B<C then A<C. 5008** </ol> 5009** 5010** If a collating function fails any of the above constraints and that 5011** collating function is registered and used, then the behavior of SQLite 5012** is undefined. 5013** 5014** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5015** with the addition that the xDestroy callback is invoked on pArg when 5016** the collating function is deleted. 5017** ^Collating functions are deleted when they are overridden by later 5018** calls to the collation creation functions or when the 5019** [database connection] is closed using [sqlite3_close()]. 5020** 5021** ^The xDestroy callback is <u>not</u> called if the 5022** sqlite3_create_collation_v2() function fails. Applications that invoke 5023** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5024** check the return code and dispose of the application data pointer 5025** themselves rather than expecting SQLite to deal with it for them. 5026** This is different from every other SQLite interface. The inconsistency 5027** is unfortunate but cannot be changed without breaking backwards 5028** compatibility. 5029** 5030** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5031*/ 5032int sqlite3_create_collation( 5033 sqlite3*, 5034 const char *zName, 5035 int eTextRep, 5036 void *pArg, 5037 int(*xCompare)(void*,int,const void*,int,const void*) 5038); 5039int sqlite3_create_collation_v2( 5040 sqlite3*, 5041 const char *zName, 5042 int eTextRep, 5043 void *pArg, 5044 int(*xCompare)(void*,int,const void*,int,const void*), 5045 void(*xDestroy)(void*) 5046); 5047int sqlite3_create_collation16( 5048 sqlite3*, 5049 const void *zName, 5050 int eTextRep, 5051 void *pArg, 5052 int(*xCompare)(void*,int,const void*,int,const void*) 5053); 5054 5055/* 5056** CAPI3REF: Collation Needed Callbacks 5057** METHOD: sqlite3 5058** 5059** ^To avoid having to register all collation sequences before a database 5060** can be used, a single callback function may be registered with the 5061** [database connection] to be invoked whenever an undefined collation 5062** sequence is required. 5063** 5064** ^If the function is registered using the sqlite3_collation_needed() API, 5065** then it is passed the names of undefined collation sequences as strings 5066** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5067** the names are passed as UTF-16 in machine native byte order. 5068** ^A call to either function replaces the existing collation-needed callback. 5069** 5070** ^(When the callback is invoked, the first argument passed is a copy 5071** of the second argument to sqlite3_collation_needed() or 5072** sqlite3_collation_needed16(). The second argument is the database 5073** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5074** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5075** sequence function required. The fourth parameter is the name of the 5076** required collation sequence.)^ 5077** 5078** The callback function should register the desired collation using 5079** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5080** [sqlite3_create_collation_v2()]. 5081*/ 5082int sqlite3_collation_needed( 5083 sqlite3*, 5084 void*, 5085 void(*)(void*,sqlite3*,int eTextRep,const char*) 5086); 5087int sqlite3_collation_needed16( 5088 sqlite3*, 5089 void*, 5090 void(*)(void*,sqlite3*,int eTextRep,const void*) 5091); 5092 5093#ifdef SQLITE_HAS_CODEC 5094/* 5095** Specify the key for an encrypted database. This routine should be 5096** called right after sqlite3_open(). 5097** 5098** The code to implement this API is not available in the public release 5099** of SQLite. 5100*/ 5101int sqlite3_key( 5102 sqlite3 *db, /* Database to be rekeyed */ 5103 const void *pKey, int nKey /* The key */ 5104); 5105int sqlite3_key_v2( 5106 sqlite3 *db, /* Database to be rekeyed */ 5107 const char *zDbName, /* Name of the database */ 5108 const void *pKey, int nKey /* The key */ 5109); 5110 5111/* 5112** Change the key on an open database. If the current database is not 5113** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5114** database is decrypted. 5115** 5116** The code to implement this API is not available in the public release 5117** of SQLite. 5118*/ 5119int sqlite3_rekey( 5120 sqlite3 *db, /* Database to be rekeyed */ 5121 const void *pKey, int nKey /* The new key */ 5122); 5123int sqlite3_rekey_v2( 5124 sqlite3 *db, /* Database to be rekeyed */ 5125 const char *zDbName, /* Name of the database */ 5126 const void *pKey, int nKey /* The new key */ 5127); 5128 5129/* 5130** Specify the activation key for a SEE database. Unless 5131** activated, none of the SEE routines will work. 5132*/ 5133void sqlite3_activate_see( 5134 const char *zPassPhrase /* Activation phrase */ 5135); 5136#endif 5137 5138#ifdef SQLITE_ENABLE_CEROD 5139/* 5140** Specify the activation key for a CEROD database. Unless 5141** activated, none of the CEROD routines will work. 5142*/ 5143void sqlite3_activate_cerod( 5144 const char *zPassPhrase /* Activation phrase */ 5145); 5146#endif 5147 5148/* 5149** CAPI3REF: Suspend Execution For A Short Time 5150** 5151** The sqlite3_sleep() function causes the current thread to suspend execution 5152** for at least a number of milliseconds specified in its parameter. 5153** 5154** If the operating system does not support sleep requests with 5155** millisecond time resolution, then the time will be rounded up to 5156** the nearest second. The number of milliseconds of sleep actually 5157** requested from the operating system is returned. 5158** 5159** ^SQLite implements this interface by calling the xSleep() 5160** method of the default [sqlite3_vfs] object. If the xSleep() method 5161** of the default VFS is not implemented correctly, or not implemented at 5162** all, then the behavior of sqlite3_sleep() may deviate from the description 5163** in the previous paragraphs. 5164*/ 5165int sqlite3_sleep(int); 5166 5167/* 5168** CAPI3REF: Name Of The Folder Holding Temporary Files 5169** 5170** ^(If this global variable is made to point to a string which is 5171** the name of a folder (a.k.a. directory), then all temporary files 5172** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5173** will be placed in that directory.)^ ^If this variable 5174** is a NULL pointer, then SQLite performs a search for an appropriate 5175** temporary file directory. 5176** 5177** Applications are strongly discouraged from using this global variable. 5178** It is required to set a temporary folder on Windows Runtime (WinRT). 5179** But for all other platforms, it is highly recommended that applications 5180** neither read nor write this variable. This global variable is a relic 5181** that exists for backwards compatibility of legacy applications and should 5182** be avoided in new projects. 5183** 5184** It is not safe to read or modify this variable in more than one 5185** thread at a time. It is not safe to read or modify this variable 5186** if a [database connection] is being used at the same time in a separate 5187** thread. 5188** It is intended that this variable be set once 5189** as part of process initialization and before any SQLite interface 5190** routines have been called and that this variable remain unchanged 5191** thereafter. 5192** 5193** ^The [temp_store_directory pragma] may modify this variable and cause 5194** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5195** the [temp_store_directory pragma] always assumes that any string 5196** that this variable points to is held in memory obtained from 5197** [sqlite3_malloc] and the pragma may attempt to free that memory 5198** using [sqlite3_free]. 5199** Hence, if this variable is modified directly, either it should be 5200** made NULL or made to point to memory obtained from [sqlite3_malloc] 5201** or else the use of the [temp_store_directory pragma] should be avoided. 5202** Except when requested by the [temp_store_directory pragma], SQLite 5203** does not free the memory that sqlite3_temp_directory points to. If 5204** the application wants that memory to be freed, it must do 5205** so itself, taking care to only do so after all [database connection] 5206** objects have been destroyed. 5207** 5208** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5209** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5210** features that require the use of temporary files may fail. Here is an 5211** example of how to do this using C++ with the Windows Runtime: 5212** 5213** <blockquote><pre> 5214** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5215** TemporaryFolder->Path->Data(); 5216** char zPathBuf[MAX_PATH + 1]; 5217** memset(zPathBuf, 0, sizeof(zPathBuf)); 5218** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5219** NULL, NULL); 5220** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5221** </pre></blockquote> 5222*/ 5223SQLITE_EXTERN char *sqlite3_temp_directory; 5224 5225/* 5226** CAPI3REF: Name Of The Folder Holding Database Files 5227** 5228** ^(If this global variable is made to point to a string which is 5229** the name of a folder (a.k.a. directory), then all database files 5230** specified with a relative pathname and created or accessed by 5231** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5232** to be relative to that directory.)^ ^If this variable is a NULL 5233** pointer, then SQLite assumes that all database files specified 5234** with a relative pathname are relative to the current directory 5235** for the process. Only the windows VFS makes use of this global 5236** variable; it is ignored by the unix VFS. 5237** 5238** Changing the value of this variable while a database connection is 5239** open can result in a corrupt database. 5240** 5241** It is not safe to read or modify this variable in more than one 5242** thread at a time. It is not safe to read or modify this variable 5243** if a [database connection] is being used at the same time in a separate 5244** thread. 5245** It is intended that this variable be set once 5246** as part of process initialization and before any SQLite interface 5247** routines have been called and that this variable remain unchanged 5248** thereafter. 5249** 5250** ^The [data_store_directory pragma] may modify this variable and cause 5251** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5252** the [data_store_directory pragma] always assumes that any string 5253** that this variable points to is held in memory obtained from 5254** [sqlite3_malloc] and the pragma may attempt to free that memory 5255** using [sqlite3_free]. 5256** Hence, if this variable is modified directly, either it should be 5257** made NULL or made to point to memory obtained from [sqlite3_malloc] 5258** or else the use of the [data_store_directory pragma] should be avoided. 5259*/ 5260SQLITE_EXTERN char *sqlite3_data_directory; 5261 5262/* 5263** CAPI3REF: Test For Auto-Commit Mode 5264** KEYWORDS: {autocommit mode} 5265** METHOD: sqlite3 5266** 5267** ^The sqlite3_get_autocommit() interface returns non-zero or 5268** zero if the given database connection is or is not in autocommit mode, 5269** respectively. ^Autocommit mode is on by default. 5270** ^Autocommit mode is disabled by a [BEGIN] statement. 5271** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5272** 5273** If certain kinds of errors occur on a statement within a multi-statement 5274** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5275** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5276** transaction might be rolled back automatically. The only way to 5277** find out whether SQLite automatically rolled back the transaction after 5278** an error is to use this function. 5279** 5280** If another thread changes the autocommit status of the database 5281** connection while this routine is running, then the return value 5282** is undefined. 5283*/ 5284int sqlite3_get_autocommit(sqlite3*); 5285 5286/* 5287** CAPI3REF: Find The Database Handle Of A Prepared Statement 5288** METHOD: sqlite3_stmt 5289** 5290** ^The sqlite3_db_handle interface returns the [database connection] handle 5291** to which a [prepared statement] belongs. ^The [database connection] 5292** returned by sqlite3_db_handle is the same [database connection] 5293** that was the first argument 5294** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5295** create the statement in the first place. 5296*/ 5297sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5298 5299/* 5300** CAPI3REF: Return The Filename For A Database Connection 5301** METHOD: sqlite3 5302** 5303** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5304** associated with database N of connection D. ^The main database file 5305** has the name "main". If there is no attached database N on the database 5306** connection D, or if database N is a temporary or in-memory database, then 5307** a NULL pointer is returned. 5308** 5309** ^The filename returned by this function is the output of the 5310** xFullPathname method of the [VFS]. ^In other words, the filename 5311** will be an absolute pathname, even if the filename used 5312** to open the database originally was a URI or relative pathname. 5313*/ 5314const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5315 5316/* 5317** CAPI3REF: Determine if a database is read-only 5318** METHOD: sqlite3 5319** 5320** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5321** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5322** the name of a database on connection D. 5323*/ 5324int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5325 5326/* 5327** CAPI3REF: Find the next prepared statement 5328** METHOD: sqlite3 5329** 5330** ^This interface returns a pointer to the next [prepared statement] after 5331** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5332** then this interface returns a pointer to the first prepared statement 5333** associated with the database connection pDb. ^If no prepared statement 5334** satisfies the conditions of this routine, it returns NULL. 5335** 5336** The [database connection] pointer D in a call to 5337** [sqlite3_next_stmt(D,S)] must refer to an open database 5338** connection and in particular must not be a NULL pointer. 5339*/ 5340sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5341 5342/* 5343** CAPI3REF: Commit And Rollback Notification Callbacks 5344** METHOD: sqlite3 5345** 5346** ^The sqlite3_commit_hook() interface registers a callback 5347** function to be invoked whenever a transaction is [COMMIT | committed]. 5348** ^Any callback set by a previous call to sqlite3_commit_hook() 5349** for the same database connection is overridden. 5350** ^The sqlite3_rollback_hook() interface registers a callback 5351** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5352** ^Any callback set by a previous call to sqlite3_rollback_hook() 5353** for the same database connection is overridden. 5354** ^The pArg argument is passed through to the callback. 5355** ^If the callback on a commit hook function returns non-zero, 5356** then the commit is converted into a rollback. 5357** 5358** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5359** return the P argument from the previous call of the same function 5360** on the same [database connection] D, or NULL for 5361** the first call for each function on D. 5362** 5363** The commit and rollback hook callbacks are not reentrant. 5364** The callback implementation must not do anything that will modify 5365** the database connection that invoked the callback. Any actions 5366** to modify the database connection must be deferred until after the 5367** completion of the [sqlite3_step()] call that triggered the commit 5368** or rollback hook in the first place. 5369** Note that running any other SQL statements, including SELECT statements, 5370** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5371** the database connections for the meaning of "modify" in this paragraph. 5372** 5373** ^Registering a NULL function disables the callback. 5374** 5375** ^When the commit hook callback routine returns zero, the [COMMIT] 5376** operation is allowed to continue normally. ^If the commit hook 5377** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5378** ^The rollback hook is invoked on a rollback that results from a commit 5379** hook returning non-zero, just as it would be with any other rollback. 5380** 5381** ^For the purposes of this API, a transaction is said to have been 5382** rolled back if an explicit "ROLLBACK" statement is executed, or 5383** an error or constraint causes an implicit rollback to occur. 5384** ^The rollback callback is not invoked if a transaction is 5385** automatically rolled back because the database connection is closed. 5386** 5387** See also the [sqlite3_update_hook()] interface. 5388*/ 5389void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5390void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5391 5392/* 5393** CAPI3REF: Data Change Notification Callbacks 5394** METHOD: sqlite3 5395** 5396** ^The sqlite3_update_hook() interface registers a callback function 5397** with the [database connection] identified by the first argument 5398** to be invoked whenever a row is updated, inserted or deleted in 5399** a [rowid table]. 5400** ^Any callback set by a previous call to this function 5401** for the same database connection is overridden. 5402** 5403** ^The second argument is a pointer to the function to invoke when a 5404** row is updated, inserted or deleted in a rowid table. 5405** ^The first argument to the callback is a copy of the third argument 5406** to sqlite3_update_hook(). 5407** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5408** or [SQLITE_UPDATE], depending on the operation that caused the callback 5409** to be invoked. 5410** ^The third and fourth arguments to the callback contain pointers to the 5411** database and table name containing the affected row. 5412** ^The final callback parameter is the [rowid] of the row. 5413** ^In the case of an update, this is the [rowid] after the update takes place. 5414** 5415** ^(The update hook is not invoked when internal system tables are 5416** modified (i.e. sqlite_master and sqlite_sequence).)^ 5417** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5418** 5419** ^In the current implementation, the update hook 5420** is not invoked when duplication rows are deleted because of an 5421** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5422** invoked when rows are deleted using the [truncate optimization]. 5423** The exceptions defined in this paragraph might change in a future 5424** release of SQLite. 5425** 5426** The update hook implementation must not do anything that will modify 5427** the database connection that invoked the update hook. Any actions 5428** to modify the database connection must be deferred until after the 5429** completion of the [sqlite3_step()] call that triggered the update hook. 5430** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5431** database connections for the meaning of "modify" in this paragraph. 5432** 5433** ^The sqlite3_update_hook(D,C,P) function 5434** returns the P argument from the previous call 5435** on the same [database connection] D, or NULL for 5436** the first call on D. 5437** 5438** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 5439** and [sqlite3_preupdate_hook()] interfaces. 5440*/ 5441void *sqlite3_update_hook( 5442 sqlite3*, 5443 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5444 void* 5445); 5446 5447/* 5448** CAPI3REF: Enable Or Disable Shared Pager Cache 5449** 5450** ^(This routine enables or disables the sharing of the database cache 5451** and schema data structures between [database connection | connections] 5452** to the same database. Sharing is enabled if the argument is true 5453** and disabled if the argument is false.)^ 5454** 5455** ^Cache sharing is enabled and disabled for an entire process. 5456** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 5457** In prior versions of SQLite, 5458** sharing was enabled or disabled for each thread separately. 5459** 5460** ^(The cache sharing mode set by this interface effects all subsequent 5461** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5462** Existing database connections continue use the sharing mode 5463** that was in effect at the time they were opened.)^ 5464** 5465** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5466** successfully. An [error code] is returned otherwise.)^ 5467** 5468** ^Shared cache is disabled by default. But this might change in 5469** future releases of SQLite. Applications that care about shared 5470** cache setting should set it explicitly. 5471** 5472** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 5473** and will always return SQLITE_MISUSE. On those systems, 5474** shared cache mode should be enabled per-database connection via 5475** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 5476** 5477** This interface is threadsafe on processors where writing a 5478** 32-bit integer is atomic. 5479** 5480** See Also: [SQLite Shared-Cache Mode] 5481*/ 5482int sqlite3_enable_shared_cache(int); 5483 5484/* 5485** CAPI3REF: Attempt To Free Heap Memory 5486** 5487** ^The sqlite3_release_memory() interface attempts to free N bytes 5488** of heap memory by deallocating non-essential memory allocations 5489** held by the database library. Memory used to cache database 5490** pages to improve performance is an example of non-essential memory. 5491** ^sqlite3_release_memory() returns the number of bytes actually freed, 5492** which might be more or less than the amount requested. 5493** ^The sqlite3_release_memory() routine is a no-op returning zero 5494** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5495** 5496** See also: [sqlite3_db_release_memory()] 5497*/ 5498int sqlite3_release_memory(int); 5499 5500/* 5501** CAPI3REF: Free Memory Used By A Database Connection 5502** METHOD: sqlite3 5503** 5504** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5505** memory as possible from database connection D. Unlike the 5506** [sqlite3_release_memory()] interface, this interface is in effect even 5507** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5508** omitted. 5509** 5510** See also: [sqlite3_release_memory()] 5511*/ 5512int sqlite3_db_release_memory(sqlite3*); 5513 5514/* 5515** CAPI3REF: Impose A Limit On Heap Size 5516** 5517** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5518** soft limit on the amount of heap memory that may be allocated by SQLite. 5519** ^SQLite strives to keep heap memory utilization below the soft heap 5520** limit by reducing the number of pages held in the page cache 5521** as heap memory usages approaches the limit. 5522** ^The soft heap limit is "soft" because even though SQLite strives to stay 5523** below the limit, it will exceed the limit rather than generate 5524** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5525** is advisory only. 5526** 5527** ^The return value from sqlite3_soft_heap_limit64() is the size of 5528** the soft heap limit prior to the call, or negative in the case of an 5529** error. ^If the argument N is negative 5530** then no change is made to the soft heap limit. Hence, the current 5531** size of the soft heap limit can be determined by invoking 5532** sqlite3_soft_heap_limit64() with a negative argument. 5533** 5534** ^If the argument N is zero then the soft heap limit is disabled. 5535** 5536** ^(The soft heap limit is not enforced in the current implementation 5537** if one or more of following conditions are true: 5538** 5539** <ul> 5540** <li> The soft heap limit is set to zero. 5541** <li> Memory accounting is disabled using a combination of the 5542** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5543** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5544** <li> An alternative page cache implementation is specified using 5545** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5546** <li> The page cache allocates from its own memory pool supplied 5547** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5548** from the heap. 5549** </ul>)^ 5550** 5551** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 5552** the soft heap limit is enforced 5553** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5554** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5555** the soft heap limit is enforced on every memory allocation. Without 5556** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5557** when memory is allocated by the page cache. Testing suggests that because 5558** the page cache is the predominate memory user in SQLite, most 5559** applications will achieve adequate soft heap limit enforcement without 5560** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5561** 5562** The circumstances under which SQLite will enforce the soft heap limit may 5563** changes in future releases of SQLite. 5564*/ 5565sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5566 5567/* 5568** CAPI3REF: Deprecated Soft Heap Limit Interface 5569** DEPRECATED 5570** 5571** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5572** interface. This routine is provided for historical compatibility 5573** only. All new applications should use the 5574** [sqlite3_soft_heap_limit64()] interface rather than this one. 5575*/ 5576SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5577 5578 5579/* 5580** CAPI3REF: Extract Metadata About A Column Of A Table 5581** METHOD: sqlite3 5582** 5583** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 5584** information about column C of table T in database D 5585** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 5586** interface returns SQLITE_OK and fills in the non-NULL pointers in 5587** the final five arguments with appropriate values if the specified 5588** column exists. ^The sqlite3_table_column_metadata() interface returns 5589** SQLITE_ERROR and if the specified column does not exist. 5590** ^If the column-name parameter to sqlite3_table_column_metadata() is a 5591** NULL pointer, then this routine simply checks for the existence of the 5592** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 5593** does not. 5594** 5595** ^The column is identified by the second, third and fourth parameters to 5596** this function. ^(The second parameter is either the name of the database 5597** (i.e. "main", "temp", or an attached database) containing the specified 5598** table or NULL.)^ ^If it is NULL, then all attached databases are searched 5599** for the table using the same algorithm used by the database engine to 5600** resolve unqualified table references. 5601** 5602** ^The third and fourth parameters to this function are the table and column 5603** name of the desired column, respectively. 5604** 5605** ^Metadata is returned by writing to the memory locations passed as the 5th 5606** and subsequent parameters to this function. ^Any of these arguments may be 5607** NULL, in which case the corresponding element of metadata is omitted. 5608** 5609** ^(<blockquote> 5610** <table border="1"> 5611** <tr><th> Parameter <th> Output<br>Type <th> Description 5612** 5613** <tr><td> 5th <td> const char* <td> Data type 5614** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5615** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5616** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5617** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5618** </table> 5619** </blockquote>)^ 5620** 5621** ^The memory pointed to by the character pointers returned for the 5622** declaration type and collation sequence is valid until the next 5623** call to any SQLite API function. 5624** 5625** ^If the specified table is actually a view, an [error code] is returned. 5626** 5627** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 5628** is not a [WITHOUT ROWID] table and an 5629** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5630** parameters are set for the explicitly declared column. ^(If there is no 5631** [INTEGER PRIMARY KEY] column, then the outputs 5632** for the [rowid] are set as follows: 5633** 5634** <pre> 5635** data type: "INTEGER" 5636** collation sequence: "BINARY" 5637** not null: 0 5638** primary key: 1 5639** auto increment: 0 5640** </pre>)^ 5641** 5642** ^This function causes all database schemas to be read from disk and 5643** parsed, if that has not already been done, and returns an error if 5644** any errors are encountered while loading the schema. 5645*/ 5646int sqlite3_table_column_metadata( 5647 sqlite3 *db, /* Connection handle */ 5648 const char *zDbName, /* Database name or NULL */ 5649 const char *zTableName, /* Table name */ 5650 const char *zColumnName, /* Column name */ 5651 char const **pzDataType, /* OUTPUT: Declared data type */ 5652 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5653 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5654 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5655 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5656); 5657 5658/* 5659** CAPI3REF: Load An Extension 5660** METHOD: sqlite3 5661** 5662** ^This interface loads an SQLite extension library from the named file. 5663** 5664** ^The sqlite3_load_extension() interface attempts to load an 5665** [SQLite extension] library contained in the file zFile. If 5666** the file cannot be loaded directly, attempts are made to load 5667** with various operating-system specific extensions added. 5668** So for example, if "samplelib" cannot be loaded, then names like 5669** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5670** be tried also. 5671** 5672** ^The entry point is zProc. 5673** ^(zProc may be 0, in which case SQLite will try to come up with an 5674** entry point name on its own. It first tries "sqlite3_extension_init". 5675** If that does not work, it constructs a name "sqlite3_X_init" where the 5676** X is consists of the lower-case equivalent of all ASCII alphabetic 5677** characters in the filename from the last "/" to the first following 5678** "." and omitting any initial "lib".)^ 5679** ^The sqlite3_load_extension() interface returns 5680** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5681** ^If an error occurs and pzErrMsg is not 0, then the 5682** [sqlite3_load_extension()] interface shall attempt to 5683** fill *pzErrMsg with error message text stored in memory 5684** obtained from [sqlite3_malloc()]. The calling function 5685** should free this memory by calling [sqlite3_free()]. 5686** 5687** ^Extension loading must be enabled using 5688** [sqlite3_enable_load_extension()] or 5689** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 5690** prior to calling this API, 5691** otherwise an error will be returned. 5692** 5693** <b>Security warning:</b> It is recommended that the 5694** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 5695** interface. The use of the [sqlite3_enable_load_extension()] interface 5696** should be avoided. This will keep the SQL function [load_extension()] 5697** disabled and prevent SQL injections from giving attackers 5698** access to extension loading capabilities. 5699** 5700** See also the [load_extension() SQL function]. 5701*/ 5702int sqlite3_load_extension( 5703 sqlite3 *db, /* Load the extension into this database connection */ 5704 const char *zFile, /* Name of the shared library containing extension */ 5705 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5706 char **pzErrMsg /* Put error message here if not 0 */ 5707); 5708 5709/* 5710** CAPI3REF: Enable Or Disable Extension Loading 5711** METHOD: sqlite3 5712** 5713** ^So as not to open security holes in older applications that are 5714** unprepared to deal with [extension loading], and as a means of disabling 5715** [extension loading] while evaluating user-entered SQL, the following API 5716** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5717** 5718** ^Extension loading is off by default. 5719** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5720** to turn extension loading on and call it with onoff==0 to turn 5721** it back off again. 5722** 5723** ^This interface enables or disables both the C-API 5724** [sqlite3_load_extension()] and the SQL function [load_extension()]. 5725** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 5726** to enable or disable only the C-API.)^ 5727** 5728** <b>Security warning:</b> It is recommended that extension loading 5729** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 5730** rather than this interface, so the [load_extension()] SQL function 5731** remains disabled. This will prevent SQL injections from giving attackers 5732** access to extension loading capabilities. 5733*/ 5734int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5735 5736/* 5737** CAPI3REF: Automatically Load Statically Linked Extensions 5738** 5739** ^This interface causes the xEntryPoint() function to be invoked for 5740** each new [database connection] that is created. The idea here is that 5741** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5742** that is to be automatically loaded into all new database connections. 5743** 5744** ^(Even though the function prototype shows that xEntryPoint() takes 5745** no arguments and returns void, SQLite invokes xEntryPoint() with three 5746** arguments and expects an integer result as if the signature of the 5747** entry point where as follows: 5748** 5749** <blockquote><pre> 5750** int xEntryPoint( 5751** sqlite3 *db, 5752** const char **pzErrMsg, 5753** const struct sqlite3_api_routines *pThunk 5754** ); 5755** </pre></blockquote>)^ 5756** 5757** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5758** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5759** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5760** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5761** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5762** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5763** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5764** 5765** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5766** on the list of automatic extensions is a harmless no-op. ^No entry point 5767** will be called more than once for each database connection that is opened. 5768** 5769** See also: [sqlite3_reset_auto_extension()] 5770** and [sqlite3_cancel_auto_extension()] 5771*/ 5772int sqlite3_auto_extension(void(*xEntryPoint)(void)); 5773 5774/* 5775** CAPI3REF: Cancel Automatic Extension Loading 5776** 5777** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5778** initialization routine X that was registered using a prior call to 5779** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5780** routine returns 1 if initialization routine X was successfully 5781** unregistered and it returns 0 if X was not on the list of initialization 5782** routines. 5783*/ 5784int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 5785 5786/* 5787** CAPI3REF: Reset Automatic Extension Loading 5788** 5789** ^This interface disables all automatic extensions previously 5790** registered using [sqlite3_auto_extension()]. 5791*/ 5792void sqlite3_reset_auto_extension(void); 5793 5794/* 5795** The interface to the virtual-table mechanism is currently considered 5796** to be experimental. The interface might change in incompatible ways. 5797** If this is a problem for you, do not use the interface at this time. 5798** 5799** When the virtual-table mechanism stabilizes, we will declare the 5800** interface fixed, support it indefinitely, and remove this comment. 5801*/ 5802 5803/* 5804** Structures used by the virtual table interface 5805*/ 5806typedef struct sqlite3_vtab sqlite3_vtab; 5807typedef struct sqlite3_index_info sqlite3_index_info; 5808typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5809typedef struct sqlite3_module sqlite3_module; 5810 5811/* 5812** CAPI3REF: Virtual Table Object 5813** KEYWORDS: sqlite3_module {virtual table module} 5814** 5815** This structure, sometimes called a "virtual table module", 5816** defines the implementation of a [virtual tables]. 5817** This structure consists mostly of methods for the module. 5818** 5819** ^A virtual table module is created by filling in a persistent 5820** instance of this structure and passing a pointer to that instance 5821** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5822** ^The registration remains valid until it is replaced by a different 5823** module or until the [database connection] closes. The content 5824** of this structure must not change while it is registered with 5825** any database connection. 5826*/ 5827struct sqlite3_module { 5828 int iVersion; 5829 int (*xCreate)(sqlite3*, void *pAux, 5830 int argc, const char *const*argv, 5831 sqlite3_vtab **ppVTab, char**); 5832 int (*xConnect)(sqlite3*, void *pAux, 5833 int argc, const char *const*argv, 5834 sqlite3_vtab **ppVTab, char**); 5835 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5836 int (*xDisconnect)(sqlite3_vtab *pVTab); 5837 int (*xDestroy)(sqlite3_vtab *pVTab); 5838 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5839 int (*xClose)(sqlite3_vtab_cursor*); 5840 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5841 int argc, sqlite3_value **argv); 5842 int (*xNext)(sqlite3_vtab_cursor*); 5843 int (*xEof)(sqlite3_vtab_cursor*); 5844 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5845 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5846 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5847 int (*xBegin)(sqlite3_vtab *pVTab); 5848 int (*xSync)(sqlite3_vtab *pVTab); 5849 int (*xCommit)(sqlite3_vtab *pVTab); 5850 int (*xRollback)(sqlite3_vtab *pVTab); 5851 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5852 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5853 void **ppArg); 5854 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5855 /* The methods above are in version 1 of the sqlite_module object. Those 5856 ** below are for version 2 and greater. */ 5857 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5858 int (*xRelease)(sqlite3_vtab *pVTab, int); 5859 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5860}; 5861 5862/* 5863** CAPI3REF: Virtual Table Indexing Information 5864** KEYWORDS: sqlite3_index_info 5865** 5866** The sqlite3_index_info structure and its substructures is used as part 5867** of the [virtual table] interface to 5868** pass information into and receive the reply from the [xBestIndex] 5869** method of a [virtual table module]. The fields under **Inputs** are the 5870** inputs to xBestIndex and are read-only. xBestIndex inserts its 5871** results into the **Outputs** fields. 5872** 5873** ^(The aConstraint[] array records WHERE clause constraints of the form: 5874** 5875** <blockquote>column OP expr</blockquote> 5876** 5877** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5878** stored in aConstraint[].op using one of the 5879** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5880** ^(The index of the column is stored in 5881** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5882** expr on the right-hand side can be evaluated (and thus the constraint 5883** is usable) and false if it cannot.)^ 5884** 5885** ^The optimizer automatically inverts terms of the form "expr OP column" 5886** and makes other simplifications to the WHERE clause in an attempt to 5887** get as many WHERE clause terms into the form shown above as possible. 5888** ^The aConstraint[] array only reports WHERE clause terms that are 5889** relevant to the particular virtual table being queried. 5890** 5891** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5892** ^Each term of aOrderBy records a column of the ORDER BY clause. 5893** 5894** The colUsed field indicates which columns of the virtual table may be 5895** required by the current scan. Virtual table columns are numbered from 5896** zero in the order in which they appear within the CREATE TABLE statement 5897** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 5898** the corresponding bit is set within the colUsed mask if the column may be 5899** required by SQLite. If the table has at least 64 columns and any column 5900** to the right of the first 63 is required, then bit 63 of colUsed is also 5901** set. In other words, column iCol may be required if the expression 5902** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 5903** non-zero. 5904** 5905** The [xBestIndex] method must fill aConstraintUsage[] with information 5906** about what parameters to pass to xFilter. ^If argvIndex>0 then 5907** the right-hand side of the corresponding aConstraint[] is evaluated 5908** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5909** is true, then the constraint is assumed to be fully handled by the 5910** virtual table and is not checked again by SQLite.)^ 5911** 5912** ^The idxNum and idxPtr values are recorded and passed into the 5913** [xFilter] method. 5914** ^[sqlite3_free()] is used to free idxPtr if and only if 5915** needToFreeIdxPtr is true. 5916** 5917** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5918** the correct order to satisfy the ORDER BY clause so that no separate 5919** sorting step is required. 5920** 5921** ^The estimatedCost value is an estimate of the cost of a particular 5922** strategy. A cost of N indicates that the cost of the strategy is similar 5923** to a linear scan of an SQLite table with N rows. A cost of log(N) 5924** indicates that the expense of the operation is similar to that of a 5925** binary search on a unique indexed field of an SQLite table with N rows. 5926** 5927** ^The estimatedRows value is an estimate of the number of rows that 5928** will be returned by the strategy. 5929** 5930** The xBestIndex method may optionally populate the idxFlags field with a 5931** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 5932** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 5933** assumes that the strategy may visit at most one row. 5934** 5935** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 5936** SQLite also assumes that if a call to the xUpdate() method is made as 5937** part of the same statement to delete or update a virtual table row and the 5938** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 5939** any database changes. In other words, if the xUpdate() returns 5940** SQLITE_CONSTRAINT, the database contents must be exactly as they were 5941** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 5942** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 5943** the xUpdate method are automatically rolled back by SQLite. 5944** 5945** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5946** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 5947** If a virtual table extension is 5948** used with an SQLite version earlier than 3.8.2, the results of attempting 5949** to read or write the estimatedRows field are undefined (but are likely 5950** to included crashing the application). The estimatedRows field should 5951** therefore only be used if [sqlite3_libversion_number()] returns a 5952** value greater than or equal to 3008002. Similarly, the idxFlags field 5953** was added for [version 3.9.0] ([dateof:3.9.0]). 5954** It may therefore only be used if 5955** sqlite3_libversion_number() returns a value greater than or equal to 5956** 3009000. 5957*/ 5958struct sqlite3_index_info { 5959 /* Inputs */ 5960 int nConstraint; /* Number of entries in aConstraint */ 5961 struct sqlite3_index_constraint { 5962 int iColumn; /* Column constrained. -1 for ROWID */ 5963 unsigned char op; /* Constraint operator */ 5964 unsigned char usable; /* True if this constraint is usable */ 5965 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5966 } *aConstraint; /* Table of WHERE clause constraints */ 5967 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5968 struct sqlite3_index_orderby { 5969 int iColumn; /* Column number */ 5970 unsigned char desc; /* True for DESC. False for ASC. */ 5971 } *aOrderBy; /* The ORDER BY clause */ 5972 /* Outputs */ 5973 struct sqlite3_index_constraint_usage { 5974 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5975 unsigned char omit; /* Do not code a test for this constraint */ 5976 } *aConstraintUsage; 5977 int idxNum; /* Number used to identify the index */ 5978 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5979 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5980 int orderByConsumed; /* True if output is already ordered */ 5981 double estimatedCost; /* Estimated cost of using this index */ 5982 /* Fields below are only available in SQLite 3.8.2 and later */ 5983 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5984 /* Fields below are only available in SQLite 3.9.0 and later */ 5985 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 5986 /* Fields below are only available in SQLite 3.10.0 and later */ 5987 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 5988}; 5989 5990/* 5991** CAPI3REF: Virtual Table Scan Flags 5992*/ 5993#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 5994 5995/* 5996** CAPI3REF: Virtual Table Constraint Operator Codes 5997** 5998** These macros defined the allowed values for the 5999** [sqlite3_index_info].aConstraint[].op field. Each value represents 6000** an operator that is part of a constraint term in the wHERE clause of 6001** a query that uses a [virtual table]. 6002*/ 6003#define SQLITE_INDEX_CONSTRAINT_EQ 2 6004#define SQLITE_INDEX_CONSTRAINT_GT 4 6005#define SQLITE_INDEX_CONSTRAINT_LE 8 6006#define SQLITE_INDEX_CONSTRAINT_LT 16 6007#define SQLITE_INDEX_CONSTRAINT_GE 32 6008#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6009#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6010#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6011#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6012 6013/* 6014** CAPI3REF: Register A Virtual Table Implementation 6015** METHOD: sqlite3 6016** 6017** ^These routines are used to register a new [virtual table module] name. 6018** ^Module names must be registered before 6019** creating a new [virtual table] using the module and before using a 6020** preexisting [virtual table] for the module. 6021** 6022** ^The module name is registered on the [database connection] specified 6023** by the first parameter. ^The name of the module is given by the 6024** second parameter. ^The third parameter is a pointer to 6025** the implementation of the [virtual table module]. ^The fourth 6026** parameter is an arbitrary client data pointer that is passed through 6027** into the [xCreate] and [xConnect] methods of the virtual table module 6028** when a new virtual table is be being created or reinitialized. 6029** 6030** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6031** is a pointer to a destructor for the pClientData. ^SQLite will 6032** invoke the destructor function (if it is not NULL) when SQLite 6033** no longer needs the pClientData pointer. ^The destructor will also 6034** be invoked if the call to sqlite3_create_module_v2() fails. 6035** ^The sqlite3_create_module() 6036** interface is equivalent to sqlite3_create_module_v2() with a NULL 6037** destructor. 6038*/ 6039int sqlite3_create_module( 6040 sqlite3 *db, /* SQLite connection to register module with */ 6041 const char *zName, /* Name of the module */ 6042 const sqlite3_module *p, /* Methods for the module */ 6043 void *pClientData /* Client data for xCreate/xConnect */ 6044); 6045int sqlite3_create_module_v2( 6046 sqlite3 *db, /* SQLite connection to register module with */ 6047 const char *zName, /* Name of the module */ 6048 const sqlite3_module *p, /* Methods for the module */ 6049 void *pClientData, /* Client data for xCreate/xConnect */ 6050 void(*xDestroy)(void*) /* Module destructor function */ 6051); 6052 6053/* 6054** CAPI3REF: Virtual Table Instance Object 6055** KEYWORDS: sqlite3_vtab 6056** 6057** Every [virtual table module] implementation uses a subclass 6058** of this object to describe a particular instance 6059** of the [virtual table]. Each subclass will 6060** be tailored to the specific needs of the module implementation. 6061** The purpose of this superclass is to define certain fields that are 6062** common to all module implementations. 6063** 6064** ^Virtual tables methods can set an error message by assigning a 6065** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6066** take care that any prior string is freed by a call to [sqlite3_free()] 6067** prior to assigning a new string to zErrMsg. ^After the error message 6068** is delivered up to the client application, the string will be automatically 6069** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6070*/ 6071struct sqlite3_vtab { 6072 const sqlite3_module *pModule; /* The module for this virtual table */ 6073 int nRef; /* Number of open cursors */ 6074 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6075 /* Virtual table implementations will typically add additional fields */ 6076}; 6077 6078/* 6079** CAPI3REF: Virtual Table Cursor Object 6080** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6081** 6082** Every [virtual table module] implementation uses a subclass of the 6083** following structure to describe cursors that point into the 6084** [virtual table] and are used 6085** to loop through the virtual table. Cursors are created using the 6086** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6087** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6088** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6089** of the module. Each module implementation will define 6090** the content of a cursor structure to suit its own needs. 6091** 6092** This superclass exists in order to define fields of the cursor that 6093** are common to all implementations. 6094*/ 6095struct sqlite3_vtab_cursor { 6096 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6097 /* Virtual table implementations will typically add additional fields */ 6098}; 6099 6100/* 6101** CAPI3REF: Declare The Schema Of A Virtual Table 6102** 6103** ^The [xCreate] and [xConnect] methods of a 6104** [virtual table module] call this interface 6105** to declare the format (the names and datatypes of the columns) of 6106** the virtual tables they implement. 6107*/ 6108int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6109 6110/* 6111** CAPI3REF: Overload A Function For A Virtual Table 6112** METHOD: sqlite3 6113** 6114** ^(Virtual tables can provide alternative implementations of functions 6115** using the [xFindFunction] method of the [virtual table module]. 6116** But global versions of those functions 6117** must exist in order to be overloaded.)^ 6118** 6119** ^(This API makes sure a global version of a function with a particular 6120** name and number of parameters exists. If no such function exists 6121** before this API is called, a new function is created.)^ ^The implementation 6122** of the new function always causes an exception to be thrown. So 6123** the new function is not good for anything by itself. Its only 6124** purpose is to be a placeholder function that can be overloaded 6125** by a [virtual table]. 6126*/ 6127int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6128 6129/* 6130** The interface to the virtual-table mechanism defined above (back up 6131** to a comment remarkably similar to this one) is currently considered 6132** to be experimental. The interface might change in incompatible ways. 6133** If this is a problem for you, do not use the interface at this time. 6134** 6135** When the virtual-table mechanism stabilizes, we will declare the 6136** interface fixed, support it indefinitely, and remove this comment. 6137*/ 6138 6139/* 6140** CAPI3REF: A Handle To An Open BLOB 6141** KEYWORDS: {BLOB handle} {BLOB handles} 6142** 6143** An instance of this object represents an open BLOB on which 6144** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6145** ^Objects of this type are created by [sqlite3_blob_open()] 6146** and destroyed by [sqlite3_blob_close()]. 6147** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6148** can be used to read or write small subsections of the BLOB. 6149** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6150*/ 6151typedef struct sqlite3_blob sqlite3_blob; 6152 6153/* 6154** CAPI3REF: Open A BLOB For Incremental I/O 6155** METHOD: sqlite3 6156** CONSTRUCTOR: sqlite3_blob 6157** 6158** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6159** in row iRow, column zColumn, table zTable in database zDb; 6160** in other words, the same BLOB that would be selected by: 6161** 6162** <pre> 6163** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6164** </pre>)^ 6165** 6166** ^(Parameter zDb is not the filename that contains the database, but 6167** rather the symbolic name of the database. For attached databases, this is 6168** the name that appears after the AS keyword in the [ATTACH] statement. 6169** For the main database file, the database name is "main". For TEMP 6170** tables, the database name is "temp".)^ 6171** 6172** ^If the flags parameter is non-zero, then the BLOB is opened for read 6173** and write access. ^If the flags parameter is zero, the BLOB is opened for 6174** read-only access. 6175** 6176** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6177** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6178** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6179** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6180** on *ppBlob after this function it returns. 6181** 6182** This function fails with SQLITE_ERROR if any of the following are true: 6183** <ul> 6184** <li> ^(Database zDb does not exist)^, 6185** <li> ^(Table zTable does not exist within database zDb)^, 6186** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6187** <li> ^(Column zColumn does not exist)^, 6188** <li> ^(Row iRow is not present in the table)^, 6189** <li> ^(The specified column of row iRow contains a value that is not 6190** a TEXT or BLOB value)^, 6191** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6192** constraint and the blob is being opened for read/write access)^, 6193** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6194** column zColumn is part of a [child key] definition and the blob is 6195** being opened for read/write access)^. 6196** </ul> 6197** 6198** ^Unless it returns SQLITE_MISUSE, this function sets the 6199** [database connection] error code and message accessible via 6200** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6201** 6202** 6203** ^(If the row that a BLOB handle points to is modified by an 6204** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6205** then the BLOB handle is marked as "expired". 6206** This is true if any column of the row is changed, even a column 6207** other than the one the BLOB handle is open on.)^ 6208** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6209** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6210** ^(Changes written into a BLOB prior to the BLOB expiring are not 6211** rolled back by the expiration of the BLOB. Such changes will eventually 6212** commit if the transaction continues to completion.)^ 6213** 6214** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6215** the opened blob. ^The size of a blob may not be changed by this 6216** interface. Use the [UPDATE] SQL command to change the size of a 6217** blob. 6218** 6219** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6220** and the built-in [zeroblob] SQL function may be used to create a 6221** zero-filled blob to read or write using the incremental-blob interface. 6222** 6223** To avoid a resource leak, every open [BLOB handle] should eventually 6224** be released by a call to [sqlite3_blob_close()]. 6225*/ 6226int sqlite3_blob_open( 6227 sqlite3*, 6228 const char *zDb, 6229 const char *zTable, 6230 const char *zColumn, 6231 sqlite3_int64 iRow, 6232 int flags, 6233 sqlite3_blob **ppBlob 6234); 6235 6236/* 6237** CAPI3REF: Move a BLOB Handle to a New Row 6238** METHOD: sqlite3_blob 6239** 6240** ^This function is used to move an existing blob handle so that it points 6241** to a different row of the same database table. ^The new row is identified 6242** by the rowid value passed as the second argument. Only the row can be 6243** changed. ^The database, table and column on which the blob handle is open 6244** remain the same. Moving an existing blob handle to a new row can be 6245** faster than closing the existing handle and opening a new one. 6246** 6247** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6248** it must exist and there must be either a blob or text value stored in 6249** the nominated column.)^ ^If the new row is not present in the table, or if 6250** it does not contain a blob or text value, or if another error occurs, an 6251** SQLite error code is returned and the blob handle is considered aborted. 6252** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6253** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6254** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6255** always returns zero. 6256** 6257** ^This function sets the database handle error code and message. 6258*/ 6259int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6260 6261/* 6262** CAPI3REF: Close A BLOB Handle 6263** DESTRUCTOR: sqlite3_blob 6264** 6265** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6266** unconditionally. Even if this routine returns an error code, the 6267** handle is still closed.)^ 6268** 6269** ^If the blob handle being closed was opened for read-write access, and if 6270** the database is in auto-commit mode and there are no other open read-write 6271** blob handles or active write statements, the current transaction is 6272** committed. ^If an error occurs while committing the transaction, an error 6273** code is returned and the transaction rolled back. 6274** 6275** Calling this function with an argument that is not a NULL pointer or an 6276** open blob handle results in undefined behaviour. ^Calling this routine 6277** with a null pointer (such as would be returned by a failed call to 6278** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6279** is passed a valid open blob handle, the values returned by the 6280** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6281*/ 6282int sqlite3_blob_close(sqlite3_blob *); 6283 6284/* 6285** CAPI3REF: Return The Size Of An Open BLOB 6286** METHOD: sqlite3_blob 6287** 6288** ^Returns the size in bytes of the BLOB accessible via the 6289** successfully opened [BLOB handle] in its only argument. ^The 6290** incremental blob I/O routines can only read or overwriting existing 6291** blob content; they cannot change the size of a blob. 6292** 6293** This routine only works on a [BLOB handle] which has been created 6294** by a prior successful call to [sqlite3_blob_open()] and which has not 6295** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6296** to this routine results in undefined and probably undesirable behavior. 6297*/ 6298int sqlite3_blob_bytes(sqlite3_blob *); 6299 6300/* 6301** CAPI3REF: Read Data From A BLOB Incrementally 6302** METHOD: sqlite3_blob 6303** 6304** ^(This function is used to read data from an open [BLOB handle] into a 6305** caller-supplied buffer. N bytes of data are copied into buffer Z 6306** from the open BLOB, starting at offset iOffset.)^ 6307** 6308** ^If offset iOffset is less than N bytes from the end of the BLOB, 6309** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6310** less than zero, [SQLITE_ERROR] is returned and no data is read. 6311** ^The size of the blob (and hence the maximum value of N+iOffset) 6312** can be determined using the [sqlite3_blob_bytes()] interface. 6313** 6314** ^An attempt to read from an expired [BLOB handle] fails with an 6315** error code of [SQLITE_ABORT]. 6316** 6317** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6318** Otherwise, an [error code] or an [extended error code] is returned.)^ 6319** 6320** This routine only works on a [BLOB handle] which has been created 6321** by a prior successful call to [sqlite3_blob_open()] and which has not 6322** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6323** to this routine results in undefined and probably undesirable behavior. 6324** 6325** See also: [sqlite3_blob_write()]. 6326*/ 6327int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6328 6329/* 6330** CAPI3REF: Write Data Into A BLOB Incrementally 6331** METHOD: sqlite3_blob 6332** 6333** ^(This function is used to write data into an open [BLOB handle] from a 6334** caller-supplied buffer. N bytes of data are copied from the buffer Z 6335** into the open BLOB, starting at offset iOffset.)^ 6336** 6337** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6338** Otherwise, an [error code] or an [extended error code] is returned.)^ 6339** ^Unless SQLITE_MISUSE is returned, this function sets the 6340** [database connection] error code and message accessible via 6341** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6342** 6343** ^If the [BLOB handle] passed as the first argument was not opened for 6344** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6345** this function returns [SQLITE_READONLY]. 6346** 6347** This function may only modify the contents of the BLOB; it is 6348** not possible to increase the size of a BLOB using this API. 6349** ^If offset iOffset is less than N bytes from the end of the BLOB, 6350** [SQLITE_ERROR] is returned and no data is written. The size of the 6351** BLOB (and hence the maximum value of N+iOffset) can be determined 6352** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6353** than zero [SQLITE_ERROR] is returned and no data is written. 6354** 6355** ^An attempt to write to an expired [BLOB handle] fails with an 6356** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6357** before the [BLOB handle] expired are not rolled back by the 6358** expiration of the handle, though of course those changes might 6359** have been overwritten by the statement that expired the BLOB handle 6360** or by other independent statements. 6361** 6362** This routine only works on a [BLOB handle] which has been created 6363** by a prior successful call to [sqlite3_blob_open()] and which has not 6364** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6365** to this routine results in undefined and probably undesirable behavior. 6366** 6367** See also: [sqlite3_blob_read()]. 6368*/ 6369int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 6370 6371/* 6372** CAPI3REF: Virtual File System Objects 6373** 6374** A virtual filesystem (VFS) is an [sqlite3_vfs] object 6375** that SQLite uses to interact 6376** with the underlying operating system. Most SQLite builds come with a 6377** single default VFS that is appropriate for the host computer. 6378** New VFSes can be registered and existing VFSes can be unregistered. 6379** The following interfaces are provided. 6380** 6381** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 6382** ^Names are case sensitive. 6383** ^Names are zero-terminated UTF-8 strings. 6384** ^If there is no match, a NULL pointer is returned. 6385** ^If zVfsName is NULL then the default VFS is returned. 6386** 6387** ^New VFSes are registered with sqlite3_vfs_register(). 6388** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 6389** ^The same VFS can be registered multiple times without injury. 6390** ^To make an existing VFS into the default VFS, register it again 6391** with the makeDflt flag set. If two different VFSes with the 6392** same name are registered, the behavior is undefined. If a 6393** VFS is registered with a name that is NULL or an empty string, 6394** then the behavior is undefined. 6395** 6396** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 6397** ^(If the default VFS is unregistered, another VFS is chosen as 6398** the default. The choice for the new VFS is arbitrary.)^ 6399*/ 6400sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 6401int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 6402int sqlite3_vfs_unregister(sqlite3_vfs*); 6403 6404/* 6405** CAPI3REF: Mutexes 6406** 6407** The SQLite core uses these routines for thread 6408** synchronization. Though they are intended for internal 6409** use by SQLite, code that links against SQLite is 6410** permitted to use any of these routines. 6411** 6412** The SQLite source code contains multiple implementations 6413** of these mutex routines. An appropriate implementation 6414** is selected automatically at compile-time. The following 6415** implementations are available in the SQLite core: 6416** 6417** <ul> 6418** <li> SQLITE_MUTEX_PTHREADS 6419** <li> SQLITE_MUTEX_W32 6420** <li> SQLITE_MUTEX_NOOP 6421** </ul> 6422** 6423** The SQLITE_MUTEX_NOOP implementation is a set of routines 6424** that does no real locking and is appropriate for use in 6425** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 6426** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 6427** and Windows. 6428** 6429** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 6430** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 6431** implementation is included with the library. In this case the 6432** application must supply a custom mutex implementation using the 6433** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 6434** before calling sqlite3_initialize() or any other public sqlite3_ 6435** function that calls sqlite3_initialize(). 6436** 6437** ^The sqlite3_mutex_alloc() routine allocates a new 6438** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 6439** routine returns NULL if it is unable to allocate the requested 6440** mutex. The argument to sqlite3_mutex_alloc() must one of these 6441** integer constants: 6442** 6443** <ul> 6444** <li> SQLITE_MUTEX_FAST 6445** <li> SQLITE_MUTEX_RECURSIVE 6446** <li> SQLITE_MUTEX_STATIC_MASTER 6447** <li> SQLITE_MUTEX_STATIC_MEM 6448** <li> SQLITE_MUTEX_STATIC_OPEN 6449** <li> SQLITE_MUTEX_STATIC_PRNG 6450** <li> SQLITE_MUTEX_STATIC_LRU 6451** <li> SQLITE_MUTEX_STATIC_PMEM 6452** <li> SQLITE_MUTEX_STATIC_APP1 6453** <li> SQLITE_MUTEX_STATIC_APP2 6454** <li> SQLITE_MUTEX_STATIC_APP3 6455** <li> SQLITE_MUTEX_STATIC_VFS1 6456** <li> SQLITE_MUTEX_STATIC_VFS2 6457** <li> SQLITE_MUTEX_STATIC_VFS3 6458** </ul> 6459** 6460** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 6461** cause sqlite3_mutex_alloc() to create 6462** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 6463** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 6464** The mutex implementation does not need to make a distinction 6465** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 6466** not want to. SQLite will only request a recursive mutex in 6467** cases where it really needs one. If a faster non-recursive mutex 6468** implementation is available on the host platform, the mutex subsystem 6469** might return such a mutex in response to SQLITE_MUTEX_FAST. 6470** 6471** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 6472** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 6473** a pointer to a static preexisting mutex. ^Nine static mutexes are 6474** used by the current version of SQLite. Future versions of SQLite 6475** may add additional static mutexes. Static mutexes are for internal 6476** use by SQLite only. Applications that use SQLite mutexes should 6477** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6478** SQLITE_MUTEX_RECURSIVE. 6479** 6480** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6481** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6482** returns a different mutex on every call. ^For the static 6483** mutex types, the same mutex is returned on every call that has 6484** the same type number. 6485** 6486** ^The sqlite3_mutex_free() routine deallocates a previously 6487** allocated dynamic mutex. Attempting to deallocate a static 6488** mutex results in undefined behavior. 6489** 6490** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6491** to enter a mutex. ^If another thread is already within the mutex, 6492** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6493** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6494** upon successful entry. ^(Mutexes created using 6495** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6496** In such cases, the 6497** mutex must be exited an equal number of times before another thread 6498** can enter.)^ If the same thread tries to enter any mutex other 6499** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 6500** 6501** ^(Some systems (for example, Windows 95) do not support the operation 6502** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6503** will always return SQLITE_BUSY. The SQLite core only ever uses 6504** sqlite3_mutex_try() as an optimization so this is acceptable 6505** behavior.)^ 6506** 6507** ^The sqlite3_mutex_leave() routine exits a mutex that was 6508** previously entered by the same thread. The behavior 6509** is undefined if the mutex is not currently entered by the 6510** calling thread or is not currently allocated. 6511** 6512** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6513** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6514** behave as no-ops. 6515** 6516** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6517*/ 6518sqlite3_mutex *sqlite3_mutex_alloc(int); 6519void sqlite3_mutex_free(sqlite3_mutex*); 6520void sqlite3_mutex_enter(sqlite3_mutex*); 6521int sqlite3_mutex_try(sqlite3_mutex*); 6522void sqlite3_mutex_leave(sqlite3_mutex*); 6523 6524/* 6525** CAPI3REF: Mutex Methods Object 6526** 6527** An instance of this structure defines the low-level routines 6528** used to allocate and use mutexes. 6529** 6530** Usually, the default mutex implementations provided by SQLite are 6531** sufficient, however the application has the option of substituting a custom 6532** implementation for specialized deployments or systems for which SQLite 6533** does not provide a suitable implementation. In this case, the application 6534** creates and populates an instance of this structure to pass 6535** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6536** Additionally, an instance of this structure can be used as an 6537** output variable when querying the system for the current mutex 6538** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6539** 6540** ^The xMutexInit method defined by this structure is invoked as 6541** part of system initialization by the sqlite3_initialize() function. 6542** ^The xMutexInit routine is called by SQLite exactly once for each 6543** effective call to [sqlite3_initialize()]. 6544** 6545** ^The xMutexEnd method defined by this structure is invoked as 6546** part of system shutdown by the sqlite3_shutdown() function. The 6547** implementation of this method is expected to release all outstanding 6548** resources obtained by the mutex methods implementation, especially 6549** those obtained by the xMutexInit method. ^The xMutexEnd() 6550** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6551** 6552** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6553** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6554** xMutexNotheld) implement the following interfaces (respectively): 6555** 6556** <ul> 6557** <li> [sqlite3_mutex_alloc()] </li> 6558** <li> [sqlite3_mutex_free()] </li> 6559** <li> [sqlite3_mutex_enter()] </li> 6560** <li> [sqlite3_mutex_try()] </li> 6561** <li> [sqlite3_mutex_leave()] </li> 6562** <li> [sqlite3_mutex_held()] </li> 6563** <li> [sqlite3_mutex_notheld()] </li> 6564** </ul>)^ 6565** 6566** The only difference is that the public sqlite3_XXX functions enumerated 6567** above silently ignore any invocations that pass a NULL pointer instead 6568** of a valid mutex handle. The implementations of the methods defined 6569** by this structure are not required to handle this case, the results 6570** of passing a NULL pointer instead of a valid mutex handle are undefined 6571** (i.e. it is acceptable to provide an implementation that segfaults if 6572** it is passed a NULL pointer). 6573** 6574** The xMutexInit() method must be threadsafe. It must be harmless to 6575** invoke xMutexInit() multiple times within the same process and without 6576** intervening calls to xMutexEnd(). Second and subsequent calls to 6577** xMutexInit() must be no-ops. 6578** 6579** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6580** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 6581** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6582** memory allocation for a fast or recursive mutex. 6583** 6584** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6585** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6586** If xMutexInit fails in any way, it is expected to clean up after itself 6587** prior to returning. 6588*/ 6589typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6590struct sqlite3_mutex_methods { 6591 int (*xMutexInit)(void); 6592 int (*xMutexEnd)(void); 6593 sqlite3_mutex *(*xMutexAlloc)(int); 6594 void (*xMutexFree)(sqlite3_mutex *); 6595 void (*xMutexEnter)(sqlite3_mutex *); 6596 int (*xMutexTry)(sqlite3_mutex *); 6597 void (*xMutexLeave)(sqlite3_mutex *); 6598 int (*xMutexHeld)(sqlite3_mutex *); 6599 int (*xMutexNotheld)(sqlite3_mutex *); 6600}; 6601 6602/* 6603** CAPI3REF: Mutex Verification Routines 6604** 6605** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6606** are intended for use inside assert() statements. The SQLite core 6607** never uses these routines except inside an assert() and applications 6608** are advised to follow the lead of the core. The SQLite core only 6609** provides implementations for these routines when it is compiled 6610** with the SQLITE_DEBUG flag. External mutex implementations 6611** are only required to provide these routines if SQLITE_DEBUG is 6612** defined and if NDEBUG is not defined. 6613** 6614** These routines should return true if the mutex in their argument 6615** is held or not held, respectively, by the calling thread. 6616** 6617** The implementation is not required to provide versions of these 6618** routines that actually work. If the implementation does not provide working 6619** versions of these routines, it should at least provide stubs that always 6620** return true so that one does not get spurious assertion failures. 6621** 6622** If the argument to sqlite3_mutex_held() is a NULL pointer then 6623** the routine should return 1. This seems counter-intuitive since 6624** clearly the mutex cannot be held if it does not exist. But 6625** the reason the mutex does not exist is because the build is not 6626** using mutexes. And we do not want the assert() containing the 6627** call to sqlite3_mutex_held() to fail, so a non-zero return is 6628** the appropriate thing to do. The sqlite3_mutex_notheld() 6629** interface should also return 1 when given a NULL pointer. 6630*/ 6631#ifndef NDEBUG 6632int sqlite3_mutex_held(sqlite3_mutex*); 6633int sqlite3_mutex_notheld(sqlite3_mutex*); 6634#endif 6635 6636/* 6637** CAPI3REF: Mutex Types 6638** 6639** The [sqlite3_mutex_alloc()] interface takes a single argument 6640** which is one of these integer constants. 6641** 6642** The set of static mutexes may change from one SQLite release to the 6643** next. Applications that override the built-in mutex logic must be 6644** prepared to accommodate additional static mutexes. 6645*/ 6646#define SQLITE_MUTEX_FAST 0 6647#define SQLITE_MUTEX_RECURSIVE 1 6648#define SQLITE_MUTEX_STATIC_MASTER 2 6649#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6650#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6651#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6652#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 6653#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6654#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6655#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6656#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6657#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6658#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6659#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 6660#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 6661#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 6662 6663/* 6664** CAPI3REF: Retrieve the mutex for a database connection 6665** METHOD: sqlite3 6666** 6667** ^This interface returns a pointer the [sqlite3_mutex] object that 6668** serializes access to the [database connection] given in the argument 6669** when the [threading mode] is Serialized. 6670** ^If the [threading mode] is Single-thread or Multi-thread then this 6671** routine returns a NULL pointer. 6672*/ 6673sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6674 6675/* 6676** CAPI3REF: Low-Level Control Of Database Files 6677** METHOD: sqlite3 6678** 6679** ^The [sqlite3_file_control()] interface makes a direct call to the 6680** xFileControl method for the [sqlite3_io_methods] object associated 6681** with a particular database identified by the second argument. ^The 6682** name of the database is "main" for the main database or "temp" for the 6683** TEMP database, or the name that appears after the AS keyword for 6684** databases that are added using the [ATTACH] SQL command. 6685** ^A NULL pointer can be used in place of "main" to refer to the 6686** main database file. 6687** ^The third and fourth parameters to this routine 6688** are passed directly through to the second and third parameters of 6689** the xFileControl method. ^The return value of the xFileControl 6690** method becomes the return value of this routine. 6691** 6692** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6693** a pointer to the underlying [sqlite3_file] object to be written into 6694** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6695** case is a short-circuit path which does not actually invoke the 6696** underlying sqlite3_io_methods.xFileControl method. 6697** 6698** ^If the second parameter (zDbName) does not match the name of any 6699** open database file, then SQLITE_ERROR is returned. ^This error 6700** code is not remembered and will not be recalled by [sqlite3_errcode()] 6701** or [sqlite3_errmsg()]. The underlying xFileControl method might 6702** also return SQLITE_ERROR. There is no way to distinguish between 6703** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6704** xFileControl method. 6705** 6706** See also: [SQLITE_FCNTL_LOCKSTATE] 6707*/ 6708int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6709 6710/* 6711** CAPI3REF: Testing Interface 6712** 6713** ^The sqlite3_test_control() interface is used to read out internal 6714** state of SQLite and to inject faults into SQLite for testing 6715** purposes. ^The first parameter is an operation code that determines 6716** the number, meaning, and operation of all subsequent parameters. 6717** 6718** This interface is not for use by applications. It exists solely 6719** for verifying the correct operation of the SQLite library. Depending 6720** on how the SQLite library is compiled, this interface might not exist. 6721** 6722** The details of the operation codes, their meanings, the parameters 6723** they take, and what they do are all subject to change without notice. 6724** Unlike most of the SQLite API, this function is not guaranteed to 6725** operate consistently from one release to the next. 6726*/ 6727int sqlite3_test_control(int op, ...); 6728 6729/* 6730** CAPI3REF: Testing Interface Operation Codes 6731** 6732** These constants are the valid operation code parameters used 6733** as the first argument to [sqlite3_test_control()]. 6734** 6735** These parameters and their meanings are subject to change 6736** without notice. These values are for testing purposes only. 6737** Applications should not use any of these parameters or the 6738** [sqlite3_test_control()] interface. 6739*/ 6740#define SQLITE_TESTCTRL_FIRST 5 6741#define SQLITE_TESTCTRL_PRNG_SAVE 5 6742#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6743#define SQLITE_TESTCTRL_PRNG_RESET 7 6744#define SQLITE_TESTCTRL_BITVEC_TEST 8 6745#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6746#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6747#define SQLITE_TESTCTRL_PENDING_BYTE 11 6748#define SQLITE_TESTCTRL_ASSERT 12 6749#define SQLITE_TESTCTRL_ALWAYS 13 6750#define SQLITE_TESTCTRL_RESERVE 14 6751#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6752#define SQLITE_TESTCTRL_ISKEYWORD 16 6753#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6754#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6755#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 6756#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 6757#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6758#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6759#define SQLITE_TESTCTRL_BYTEORDER 22 6760#define SQLITE_TESTCTRL_ISINIT 23 6761#define SQLITE_TESTCTRL_SORTER_MMAP 24 6762#define SQLITE_TESTCTRL_IMPOSTER 25 6763#define SQLITE_TESTCTRL_LAST 25 6764 6765/* 6766** CAPI3REF: SQLite Runtime Status 6767** 6768** ^These interfaces are used to retrieve runtime status information 6769** about the performance of SQLite, and optionally to reset various 6770** highwater marks. ^The first argument is an integer code for 6771** the specific parameter to measure. ^(Recognized integer codes 6772** are of the form [status parameters | SQLITE_STATUS_...].)^ 6773** ^The current value of the parameter is returned into *pCurrent. 6774** ^The highest recorded value is returned in *pHighwater. ^If the 6775** resetFlag is true, then the highest record value is reset after 6776** *pHighwater is written. ^(Some parameters do not record the highest 6777** value. For those parameters 6778** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6779** ^(Other parameters record only the highwater mark and not the current 6780** value. For these latter parameters nothing is written into *pCurrent.)^ 6781** 6782** ^The sqlite3_status() and sqlite3_status64() routines return 6783** SQLITE_OK on success and a non-zero [error code] on failure. 6784** 6785** If either the current value or the highwater mark is too large to 6786** be represented by a 32-bit integer, then the values returned by 6787** sqlite3_status() are undefined. 6788** 6789** See also: [sqlite3_db_status()] 6790*/ 6791int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6792int sqlite3_status64( 6793 int op, 6794 sqlite3_int64 *pCurrent, 6795 sqlite3_int64 *pHighwater, 6796 int resetFlag 6797); 6798 6799 6800/* 6801** CAPI3REF: Status Parameters 6802** KEYWORDS: {status parameters} 6803** 6804** These integer constants designate various run-time status parameters 6805** that can be returned by [sqlite3_status()]. 6806** 6807** <dl> 6808** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6809** <dd>This parameter is the current amount of memory checked out 6810** using [sqlite3_malloc()], either directly or indirectly. The 6811** figure includes calls made to [sqlite3_malloc()] by the application 6812** and internal memory usage by the SQLite library. Scratch memory 6813** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6814** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6815** this parameter. The amount returned is the sum of the allocation 6816** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6817** 6818** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6819** <dd>This parameter records the largest memory allocation request 6820** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6821** internal equivalents). Only the value returned in the 6822** *pHighwater parameter to [sqlite3_status()] is of interest. 6823** The value written into the *pCurrent parameter is undefined.</dd>)^ 6824** 6825** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6826** <dd>This parameter records the number of separate memory allocations 6827** currently checked out.</dd>)^ 6828** 6829** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6830** <dd>This parameter returns the number of pages used out of the 6831** [pagecache memory allocator] that was configured using 6832** [SQLITE_CONFIG_PAGECACHE]. The 6833** value returned is in pages, not in bytes.</dd>)^ 6834** 6835** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6836** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6837** <dd>This parameter returns the number of bytes of page cache 6838** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6839** buffer and where forced to overflow to [sqlite3_malloc()]. The 6840** returned value includes allocations that overflowed because they 6841** where too large (they were larger than the "sz" parameter to 6842** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6843** no space was left in the page cache.</dd>)^ 6844** 6845** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6846** <dd>This parameter records the largest memory allocation request 6847** handed to [pagecache memory allocator]. Only the value returned in the 6848** *pHighwater parameter to [sqlite3_status()] is of interest. 6849** The value written into the *pCurrent parameter is undefined.</dd>)^ 6850** 6851** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6852** <dd>This parameter returns the number of allocations used out of the 6853** [scratch memory allocator] configured using 6854** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6855** in bytes. Since a single thread may only have one scratch allocation 6856** outstanding at time, this parameter also reports the number of threads 6857** using scratch memory at the same time.</dd>)^ 6858** 6859** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6860** <dd>This parameter returns the number of bytes of scratch memory 6861** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6862** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6863** returned include overflows because the requested allocation was too 6864** larger (that is, because the requested allocation was larger than the 6865** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6866** slots were available. 6867** </dd>)^ 6868** 6869** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6870** <dd>This parameter records the largest memory allocation request 6871** handed to [scratch memory allocator]. Only the value returned in the 6872** *pHighwater parameter to [sqlite3_status()] is of interest. 6873** The value written into the *pCurrent parameter is undefined.</dd>)^ 6874** 6875** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6876** <dd>The *pHighwater parameter records the deepest parser stack. 6877** The *pCurrent value is undefined. The *pHighwater value is only 6878** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6879** </dl> 6880** 6881** New status parameters may be added from time to time. 6882*/ 6883#define SQLITE_STATUS_MEMORY_USED 0 6884#define SQLITE_STATUS_PAGECACHE_USED 1 6885#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6886#define SQLITE_STATUS_SCRATCH_USED 3 6887#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6888#define SQLITE_STATUS_MALLOC_SIZE 5 6889#define SQLITE_STATUS_PARSER_STACK 6 6890#define SQLITE_STATUS_PAGECACHE_SIZE 7 6891#define SQLITE_STATUS_SCRATCH_SIZE 8 6892#define SQLITE_STATUS_MALLOC_COUNT 9 6893 6894/* 6895** CAPI3REF: Database Connection Status 6896** METHOD: sqlite3 6897** 6898** ^This interface is used to retrieve runtime status information 6899** about a single [database connection]. ^The first argument is the 6900** database connection object to be interrogated. ^The second argument 6901** is an integer constant, taken from the set of 6902** [SQLITE_DBSTATUS options], that 6903** determines the parameter to interrogate. The set of 6904** [SQLITE_DBSTATUS options] is likely 6905** to grow in future releases of SQLite. 6906** 6907** ^The current value of the requested parameter is written into *pCur 6908** and the highest instantaneous value is written into *pHiwtr. ^If 6909** the resetFlg is true, then the highest instantaneous value is 6910** reset back down to the current value. 6911** 6912** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6913** non-zero [error code] on failure. 6914** 6915** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6916*/ 6917int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6918 6919/* 6920** CAPI3REF: Status Parameters for database connections 6921** KEYWORDS: {SQLITE_DBSTATUS options} 6922** 6923** These constants are the available integer "verbs" that can be passed as 6924** the second argument to the [sqlite3_db_status()] interface. 6925** 6926** New verbs may be added in future releases of SQLite. Existing verbs 6927** might be discontinued. Applications should check the return code from 6928** [sqlite3_db_status()] to make sure that the call worked. 6929** The [sqlite3_db_status()] interface will return a non-zero error code 6930** if a discontinued or unsupported verb is invoked. 6931** 6932** <dl> 6933** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6934** <dd>This parameter returns the number of lookaside memory slots currently 6935** checked out.</dd>)^ 6936** 6937** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6938** <dd>This parameter returns the number malloc attempts that were 6939** satisfied using lookaside memory. Only the high-water value is meaningful; 6940** the current value is always zero.)^ 6941** 6942** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6943** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6944** <dd>This parameter returns the number malloc attempts that might have 6945** been satisfied using lookaside memory but failed due to the amount of 6946** memory requested being larger than the lookaside slot size. 6947** Only the high-water value is meaningful; 6948** the current value is always zero.)^ 6949** 6950** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6951** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6952** <dd>This parameter returns the number malloc attempts that might have 6953** been satisfied using lookaside memory but failed due to all lookaside 6954** memory already being in use. 6955** Only the high-water value is meaningful; 6956** the current value is always zero.)^ 6957** 6958** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6959** <dd>This parameter returns the approximate number of bytes of heap 6960** memory used by all pager caches associated with the database connection.)^ 6961** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6962** 6963** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 6964** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 6965** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 6966** pager cache is shared between two or more connections the bytes of heap 6967** memory used by that pager cache is divided evenly between the attached 6968** connections.)^ In other words, if none of the pager caches associated 6969** with the database connection are shared, this request returns the same 6970** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 6971** shared, the value returned by this call will be smaller than that returned 6972** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 6973** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 6974** 6975** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6976** <dd>This parameter returns the approximate number of bytes of heap 6977** memory used to store the schema for all databases associated 6978** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6979** ^The full amount of memory used by the schemas is reported, even if the 6980** schema memory is shared with other database connections due to 6981** [shared cache mode] being enabled. 6982** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6983** 6984** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6985** <dd>This parameter returns the approximate number of bytes of heap 6986** and lookaside memory used by all prepared statements associated with 6987** the database connection.)^ 6988** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6989** </dd> 6990** 6991** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6992** <dd>This parameter returns the number of pager cache hits that have 6993** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6994** is always 0. 6995** </dd> 6996** 6997** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6998** <dd>This parameter returns the number of pager cache misses that have 6999** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7000** is always 0. 7001** </dd> 7002** 7003** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7004** <dd>This parameter returns the number of dirty cache entries that have 7005** been written to disk. Specifically, the number of pages written to the 7006** wal file in wal mode databases, or the number of pages written to the 7007** database file in rollback mode databases. Any pages written as part of 7008** transaction rollback or database recovery operations are not included. 7009** If an IO or other error occurs while writing a page to disk, the effect 7010** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7011** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7012** </dd> 7013** 7014** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7015** <dd>This parameter returns zero for the current value if and only if 7016** all foreign key constraints (deferred or immediate) have been 7017** resolved.)^ ^The highwater mark is always 0. 7018** </dd> 7019** </dl> 7020*/ 7021#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7022#define SQLITE_DBSTATUS_CACHE_USED 1 7023#define SQLITE_DBSTATUS_SCHEMA_USED 2 7024#define SQLITE_DBSTATUS_STMT_USED 3 7025#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7026#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7027#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7028#define SQLITE_DBSTATUS_CACHE_HIT 7 7029#define SQLITE_DBSTATUS_CACHE_MISS 8 7030#define SQLITE_DBSTATUS_CACHE_WRITE 9 7031#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7032#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7033#define SQLITE_DBSTATUS_MAX 11 /* Largest defined DBSTATUS */ 7034 7035 7036/* 7037** CAPI3REF: Prepared Statement Status 7038** METHOD: sqlite3_stmt 7039** 7040** ^(Each prepared statement maintains various 7041** [SQLITE_STMTSTATUS counters] that measure the number 7042** of times it has performed specific operations.)^ These counters can 7043** be used to monitor the performance characteristics of the prepared 7044** statements. For example, if the number of table steps greatly exceeds 7045** the number of table searches or result rows, that would tend to indicate 7046** that the prepared statement is using a full table scan rather than 7047** an index. 7048** 7049** ^(This interface is used to retrieve and reset counter values from 7050** a [prepared statement]. The first argument is the prepared statement 7051** object to be interrogated. The second argument 7052** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7053** to be interrogated.)^ 7054** ^The current value of the requested counter is returned. 7055** ^If the resetFlg is true, then the counter is reset to zero after this 7056** interface call returns. 7057** 7058** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7059*/ 7060int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7061 7062/* 7063** CAPI3REF: Status Parameters for prepared statements 7064** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7065** 7066** These preprocessor macros define integer codes that name counter 7067** values associated with the [sqlite3_stmt_status()] interface. 7068** The meanings of the various counters are as follows: 7069** 7070** <dl> 7071** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7072** <dd>^This is the number of times that SQLite has stepped forward in 7073** a table as part of a full table scan. Large numbers for this counter 7074** may indicate opportunities for performance improvement through 7075** careful use of indices.</dd> 7076** 7077** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7078** <dd>^This is the number of sort operations that have occurred. 7079** A non-zero value in this counter may indicate an opportunity to 7080** improvement performance through careful use of indices.</dd> 7081** 7082** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7083** <dd>^This is the number of rows inserted into transient indices that 7084** were created automatically in order to help joins run faster. 7085** A non-zero value in this counter may indicate an opportunity to 7086** improvement performance by adding permanent indices that do not 7087** need to be reinitialized each time the statement is run.</dd> 7088** 7089** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7090** <dd>^This is the number of virtual machine operations executed 7091** by the prepared statement if that number is less than or equal 7092** to 2147483647. The number of virtual machine operations can be 7093** used as a proxy for the total work done by the prepared statement. 7094** If the number of virtual machine operations exceeds 2147483647 7095** then the value returned by this statement status code is undefined. 7096** </dd> 7097** </dl> 7098*/ 7099#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7100#define SQLITE_STMTSTATUS_SORT 2 7101#define SQLITE_STMTSTATUS_AUTOINDEX 3 7102#define SQLITE_STMTSTATUS_VM_STEP 4 7103 7104/* 7105** CAPI3REF: Custom Page Cache Object 7106** 7107** The sqlite3_pcache type is opaque. It is implemented by 7108** the pluggable module. The SQLite core has no knowledge of 7109** its size or internal structure and never deals with the 7110** sqlite3_pcache object except by holding and passing pointers 7111** to the object. 7112** 7113** See [sqlite3_pcache_methods2] for additional information. 7114*/ 7115typedef struct sqlite3_pcache sqlite3_pcache; 7116 7117/* 7118** CAPI3REF: Custom Page Cache Object 7119** 7120** The sqlite3_pcache_page object represents a single page in the 7121** page cache. The page cache will allocate instances of this 7122** object. Various methods of the page cache use pointers to instances 7123** of this object as parameters or as their return value. 7124** 7125** See [sqlite3_pcache_methods2] for additional information. 7126*/ 7127typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7128struct sqlite3_pcache_page { 7129 void *pBuf; /* The content of the page */ 7130 void *pExtra; /* Extra information associated with the page */ 7131}; 7132 7133/* 7134** CAPI3REF: Application Defined Page Cache. 7135** KEYWORDS: {page cache} 7136** 7137** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7138** register an alternative page cache implementation by passing in an 7139** instance of the sqlite3_pcache_methods2 structure.)^ 7140** In many applications, most of the heap memory allocated by 7141** SQLite is used for the page cache. 7142** By implementing a 7143** custom page cache using this API, an application can better control 7144** the amount of memory consumed by SQLite, the way in which 7145** that memory is allocated and released, and the policies used to 7146** determine exactly which parts of a database file are cached and for 7147** how long. 7148** 7149** The alternative page cache mechanism is an 7150** extreme measure that is only needed by the most demanding applications. 7151** The built-in page cache is recommended for most uses. 7152** 7153** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7154** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7155** the application may discard the parameter after the call to 7156** [sqlite3_config()] returns.)^ 7157** 7158** [[the xInit() page cache method]] 7159** ^(The xInit() method is called once for each effective 7160** call to [sqlite3_initialize()])^ 7161** (usually only once during the lifetime of the process). ^(The xInit() 7162** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 7163** The intent of the xInit() method is to set up global data structures 7164** required by the custom page cache implementation. 7165** ^(If the xInit() method is NULL, then the 7166** built-in default page cache is used instead of the application defined 7167** page cache.)^ 7168** 7169** [[the xShutdown() page cache method]] 7170** ^The xShutdown() method is called by [sqlite3_shutdown()]. 7171** It can be used to clean up 7172** any outstanding resources before process shutdown, if required. 7173** ^The xShutdown() method may be NULL. 7174** 7175** ^SQLite automatically serializes calls to the xInit method, 7176** so the xInit method need not be threadsafe. ^The 7177** xShutdown method is only called from [sqlite3_shutdown()] so it does 7178** not need to be threadsafe either. All other methods must be threadsafe 7179** in multithreaded applications. 7180** 7181** ^SQLite will never invoke xInit() more than once without an intervening 7182** call to xShutdown(). 7183** 7184** [[the xCreate() page cache methods]] 7185** ^SQLite invokes the xCreate() method to construct a new cache instance. 7186** SQLite will typically create one cache instance for each open database file, 7187** though this is not guaranteed. ^The 7188** first parameter, szPage, is the size in bytes of the pages that must 7189** be allocated by the cache. ^szPage will always a power of two. ^The 7190** second parameter szExtra is a number of bytes of extra storage 7191** associated with each page cache entry. ^The szExtra parameter will 7192** a number less than 250. SQLite will use the 7193** extra szExtra bytes on each page to store metadata about the underlying 7194** database page on disk. The value passed into szExtra depends 7195** on the SQLite version, the target platform, and how SQLite was compiled. 7196** ^The third argument to xCreate(), bPurgeable, is true if the cache being 7197** created will be used to cache database pages of a file stored on disk, or 7198** false if it is used for an in-memory database. The cache implementation 7199** does not have to do anything special based with the value of bPurgeable; 7200** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 7201** never invoke xUnpin() except to deliberately delete a page. 7202** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 7203** false will always have the "discard" flag set to true. 7204** ^Hence, a cache created with bPurgeable false will 7205** never contain any unpinned pages. 7206** 7207** [[the xCachesize() page cache method]] 7208** ^(The xCachesize() method may be called at any time by SQLite to set the 7209** suggested maximum cache-size (number of pages stored by) the cache 7210** instance passed as the first argument. This is the value configured using 7211** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 7212** parameter, the implementation is not required to do anything with this 7213** value; it is advisory only. 7214** 7215** [[the xPagecount() page cache methods]] 7216** The xPagecount() method must return the number of pages currently 7217** stored in the cache, both pinned and unpinned. 7218** 7219** [[the xFetch() page cache methods]] 7220** The xFetch() method locates a page in the cache and returns a pointer to 7221** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 7222** The pBuf element of the returned sqlite3_pcache_page object will be a 7223** pointer to a buffer of szPage bytes used to store the content of a 7224** single database page. The pExtra element of sqlite3_pcache_page will be 7225** a pointer to the szExtra bytes of extra storage that SQLite has requested 7226** for each entry in the page cache. 7227** 7228** The page to be fetched is determined by the key. ^The minimum key value 7229** is 1. After it has been retrieved using xFetch, the page is considered 7230** to be "pinned". 7231** 7232** If the requested page is already in the page cache, then the page cache 7233** implementation must return a pointer to the page buffer with its content 7234** intact. If the requested page is not already in the cache, then the 7235** cache implementation should use the value of the createFlag 7236** parameter to help it determined what action to take: 7237** 7238** <table border=1 width=85% align=center> 7239** <tr><th> createFlag <th> Behavior when page is not already in cache 7240** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 7241** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 7242** Otherwise return NULL. 7243** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 7244** NULL if allocating a new page is effectively impossible. 7245** </table> 7246** 7247** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 7248** will only use a createFlag of 2 after a prior call with a createFlag of 1 7249** failed.)^ In between the to xFetch() calls, SQLite may 7250** attempt to unpin one or more cache pages by spilling the content of 7251** pinned pages to disk and synching the operating system disk cache. 7252** 7253** [[the xUnpin() page cache method]] 7254** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 7255** as its second argument. If the third parameter, discard, is non-zero, 7256** then the page must be evicted from the cache. 7257** ^If the discard parameter is 7258** zero, then the page may be discarded or retained at the discretion of 7259** page cache implementation. ^The page cache implementation 7260** may choose to evict unpinned pages at any time. 7261** 7262** The cache must not perform any reference counting. A single 7263** call to xUnpin() unpins the page regardless of the number of prior calls 7264** to xFetch(). 7265** 7266** [[the xRekey() page cache methods]] 7267** The xRekey() method is used to change the key value associated with the 7268** page passed as the second argument. If the cache 7269** previously contains an entry associated with newKey, it must be 7270** discarded. ^Any prior cache entry associated with newKey is guaranteed not 7271** to be pinned. 7272** 7273** When SQLite calls the xTruncate() method, the cache must discard all 7274** existing cache entries with page numbers (keys) greater than or equal 7275** to the value of the iLimit parameter passed to xTruncate(). If any 7276** of these pages are pinned, they are implicitly unpinned, meaning that 7277** they can be safely discarded. 7278** 7279** [[the xDestroy() page cache method]] 7280** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 7281** All resources associated with the specified cache should be freed. ^After 7282** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 7283** handle invalid, and will not use it with any other sqlite3_pcache_methods2 7284** functions. 7285** 7286** [[the xShrink() page cache method]] 7287** ^SQLite invokes the xShrink() method when it wants the page cache to 7288** free up as much of heap memory as possible. The page cache implementation 7289** is not obligated to free any memory, but well-behaved implementations should 7290** do their best. 7291*/ 7292typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 7293struct sqlite3_pcache_methods2 { 7294 int iVersion; 7295 void *pArg; 7296 int (*xInit)(void*); 7297 void (*xShutdown)(void*); 7298 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 7299 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7300 int (*xPagecount)(sqlite3_pcache*); 7301 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7302 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 7303 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 7304 unsigned oldKey, unsigned newKey); 7305 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7306 void (*xDestroy)(sqlite3_pcache*); 7307 void (*xShrink)(sqlite3_pcache*); 7308}; 7309 7310/* 7311** This is the obsolete pcache_methods object that has now been replaced 7312** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 7313** retained in the header file for backwards compatibility only. 7314*/ 7315typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 7316struct sqlite3_pcache_methods { 7317 void *pArg; 7318 int (*xInit)(void*); 7319 void (*xShutdown)(void*); 7320 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 7321 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 7322 int (*xPagecount)(sqlite3_pcache*); 7323 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 7324 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 7325 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 7326 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 7327 void (*xDestroy)(sqlite3_pcache*); 7328}; 7329 7330 7331/* 7332** CAPI3REF: Online Backup Object 7333** 7334** The sqlite3_backup object records state information about an ongoing 7335** online backup operation. ^The sqlite3_backup object is created by 7336** a call to [sqlite3_backup_init()] and is destroyed by a call to 7337** [sqlite3_backup_finish()]. 7338** 7339** See Also: [Using the SQLite Online Backup API] 7340*/ 7341typedef struct sqlite3_backup sqlite3_backup; 7342 7343/* 7344** CAPI3REF: Online Backup API. 7345** 7346** The backup API copies the content of one database into another. 7347** It is useful either for creating backups of databases or 7348** for copying in-memory databases to or from persistent files. 7349** 7350** See Also: [Using the SQLite Online Backup API] 7351** 7352** ^SQLite holds a write transaction open on the destination database file 7353** for the duration of the backup operation. 7354** ^The source database is read-locked only while it is being read; 7355** it is not locked continuously for the entire backup operation. 7356** ^Thus, the backup may be performed on a live source database without 7357** preventing other database connections from 7358** reading or writing to the source database while the backup is underway. 7359** 7360** ^(To perform a backup operation: 7361** <ol> 7362** <li><b>sqlite3_backup_init()</b> is called once to initialize the 7363** backup, 7364** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 7365** the data between the two databases, and finally 7366** <li><b>sqlite3_backup_finish()</b> is called to release all resources 7367** associated with the backup operation. 7368** </ol>)^ 7369** There should be exactly one call to sqlite3_backup_finish() for each 7370** successful call to sqlite3_backup_init(). 7371** 7372** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 7373** 7374** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 7375** [database connection] associated with the destination database 7376** and the database name, respectively. 7377** ^The database name is "main" for the main database, "temp" for the 7378** temporary database, or the name specified after the AS keyword in 7379** an [ATTACH] statement for an attached database. 7380** ^The S and M arguments passed to 7381** sqlite3_backup_init(D,N,S,M) identify the [database connection] 7382** and database name of the source database, respectively. 7383** ^The source and destination [database connections] (parameters S and D) 7384** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 7385** an error. 7386** 7387** ^A call to sqlite3_backup_init() will fail, returning NULL, if 7388** there is already a read or read-write transaction open on the 7389** destination database. 7390** 7391** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 7392** returned and an error code and error message are stored in the 7393** destination [database connection] D. 7394** ^The error code and message for the failed call to sqlite3_backup_init() 7395** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 7396** [sqlite3_errmsg16()] functions. 7397** ^A successful call to sqlite3_backup_init() returns a pointer to an 7398** [sqlite3_backup] object. 7399** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 7400** sqlite3_backup_finish() functions to perform the specified backup 7401** operation. 7402** 7403** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 7404** 7405** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 7406** the source and destination databases specified by [sqlite3_backup] object B. 7407** ^If N is negative, all remaining source pages are copied. 7408** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 7409** are still more pages to be copied, then the function returns [SQLITE_OK]. 7410** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 7411** from source to destination, then it returns [SQLITE_DONE]. 7412** ^If an error occurs while running sqlite3_backup_step(B,N), 7413** then an [error code] is returned. ^As well as [SQLITE_OK] and 7414** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 7415** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 7416** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 7417** 7418** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 7419** <ol> 7420** <li> the destination database was opened read-only, or 7421** <li> the destination database is using write-ahead-log journaling 7422** and the destination and source page sizes differ, or 7423** <li> the destination database is an in-memory database and the 7424** destination and source page sizes differ. 7425** </ol>)^ 7426** 7427** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 7428** the [sqlite3_busy_handler | busy-handler function] 7429** is invoked (if one is specified). ^If the 7430** busy-handler returns non-zero before the lock is available, then 7431** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 7432** sqlite3_backup_step() can be retried later. ^If the source 7433** [database connection] 7434** is being used to write to the source database when sqlite3_backup_step() 7435** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 7436** case the call to sqlite3_backup_step() can be retried later on. ^(If 7437** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 7438** [SQLITE_READONLY] is returned, then 7439** there is no point in retrying the call to sqlite3_backup_step(). These 7440** errors are considered fatal.)^ The application must accept 7441** that the backup operation has failed and pass the backup operation handle 7442** to the sqlite3_backup_finish() to release associated resources. 7443** 7444** ^The first call to sqlite3_backup_step() obtains an exclusive lock 7445** on the destination file. ^The exclusive lock is not released until either 7446** sqlite3_backup_finish() is called or the backup operation is complete 7447** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 7448** sqlite3_backup_step() obtains a [shared lock] on the source database that 7449** lasts for the duration of the sqlite3_backup_step() call. 7450** ^Because the source database is not locked between calls to 7451** sqlite3_backup_step(), the source database may be modified mid-way 7452** through the backup process. ^If the source database is modified by an 7453** external process or via a database connection other than the one being 7454** used by the backup operation, then the backup will be automatically 7455** restarted by the next call to sqlite3_backup_step(). ^If the source 7456** database is modified by the using the same database connection as is used 7457** by the backup operation, then the backup database is automatically 7458** updated at the same time. 7459** 7460** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 7461** 7462** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 7463** application wishes to abandon the backup operation, the application 7464** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 7465** ^The sqlite3_backup_finish() interfaces releases all 7466** resources associated with the [sqlite3_backup] object. 7467** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 7468** active write-transaction on the destination database is rolled back. 7469** The [sqlite3_backup] object is invalid 7470** and may not be used following a call to sqlite3_backup_finish(). 7471** 7472** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 7473** sqlite3_backup_step() errors occurred, regardless or whether or not 7474** sqlite3_backup_step() completed. 7475** ^If an out-of-memory condition or IO error occurred during any prior 7476** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 7477** sqlite3_backup_finish() returns the corresponding [error code]. 7478** 7479** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 7480** is not a permanent error and does not affect the return value of 7481** sqlite3_backup_finish(). 7482** 7483** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 7484** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 7485** 7486** ^The sqlite3_backup_remaining() routine returns the number of pages still 7487** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 7488** ^The sqlite3_backup_pagecount() routine returns the total number of pages 7489** in the source database at the conclusion of the most recent 7490** sqlite3_backup_step(). 7491** ^(The values returned by these functions are only updated by 7492** sqlite3_backup_step(). If the source database is modified in a way that 7493** changes the size of the source database or the number of pages remaining, 7494** those changes are not reflected in the output of sqlite3_backup_pagecount() 7495** and sqlite3_backup_remaining() until after the next 7496** sqlite3_backup_step().)^ 7497** 7498** <b>Concurrent Usage of Database Handles</b> 7499** 7500** ^The source [database connection] may be used by the application for other 7501** purposes while a backup operation is underway or being initialized. 7502** ^If SQLite is compiled and configured to support threadsafe database 7503** connections, then the source database connection may be used concurrently 7504** from within other threads. 7505** 7506** However, the application must guarantee that the destination 7507** [database connection] is not passed to any other API (by any thread) after 7508** sqlite3_backup_init() is called and before the corresponding call to 7509** sqlite3_backup_finish(). SQLite does not currently check to see 7510** if the application incorrectly accesses the destination [database connection] 7511** and so no error code is reported, but the operations may malfunction 7512** nevertheless. Use of the destination database connection while a 7513** backup is in progress might also also cause a mutex deadlock. 7514** 7515** If running in [shared cache mode], the application must 7516** guarantee that the shared cache used by the destination database 7517** is not accessed while the backup is running. In practice this means 7518** that the application must guarantee that the disk file being 7519** backed up to is not accessed by any connection within the process, 7520** not just the specific connection that was passed to sqlite3_backup_init(). 7521** 7522** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7523** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7524** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7525** APIs are not strictly speaking threadsafe. If they are invoked at the 7526** same time as another thread is invoking sqlite3_backup_step() it is 7527** possible that they return invalid values. 7528*/ 7529sqlite3_backup *sqlite3_backup_init( 7530 sqlite3 *pDest, /* Destination database handle */ 7531 const char *zDestName, /* Destination database name */ 7532 sqlite3 *pSource, /* Source database handle */ 7533 const char *zSourceName /* Source database name */ 7534); 7535int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7536int sqlite3_backup_finish(sqlite3_backup *p); 7537int sqlite3_backup_remaining(sqlite3_backup *p); 7538int sqlite3_backup_pagecount(sqlite3_backup *p); 7539 7540/* 7541** CAPI3REF: Unlock Notification 7542** METHOD: sqlite3 7543** 7544** ^When running in shared-cache mode, a database operation may fail with 7545** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7546** individual tables within the shared-cache cannot be obtained. See 7547** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7548** ^This API may be used to register a callback that SQLite will invoke 7549** when the connection currently holding the required lock relinquishes it. 7550** ^This API is only available if the library was compiled with the 7551** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7552** 7553** See Also: [Using the SQLite Unlock Notification Feature]. 7554** 7555** ^Shared-cache locks are released when a database connection concludes 7556** its current transaction, either by committing it or rolling it back. 7557** 7558** ^When a connection (known as the blocked connection) fails to obtain a 7559** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7560** identity of the database connection (the blocking connection) that 7561** has locked the required resource is stored internally. ^After an 7562** application receives an SQLITE_LOCKED error, it may call the 7563** sqlite3_unlock_notify() method with the blocked connection handle as 7564** the first argument to register for a callback that will be invoked 7565** when the blocking connections current transaction is concluded. ^The 7566** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7567** call that concludes the blocking connections transaction. 7568** 7569** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7570** there is a chance that the blocking connection will have already 7571** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7572** If this happens, then the specified callback is invoked immediately, 7573** from within the call to sqlite3_unlock_notify().)^ 7574** 7575** ^If the blocked connection is attempting to obtain a write-lock on a 7576** shared-cache table, and more than one other connection currently holds 7577** a read-lock on the same table, then SQLite arbitrarily selects one of 7578** the other connections to use as the blocking connection. 7579** 7580** ^(There may be at most one unlock-notify callback registered by a 7581** blocked connection. If sqlite3_unlock_notify() is called when the 7582** blocked connection already has a registered unlock-notify callback, 7583** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7584** called with a NULL pointer as its second argument, then any existing 7585** unlock-notify callback is canceled. ^The blocked connections 7586** unlock-notify callback may also be canceled by closing the blocked 7587** connection using [sqlite3_close()]. 7588** 7589** The unlock-notify callback is not reentrant. If an application invokes 7590** any sqlite3_xxx API functions from within an unlock-notify callback, a 7591** crash or deadlock may be the result. 7592** 7593** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7594** returns SQLITE_OK. 7595** 7596** <b>Callback Invocation Details</b> 7597** 7598** When an unlock-notify callback is registered, the application provides a 7599** single void* pointer that is passed to the callback when it is invoked. 7600** However, the signature of the callback function allows SQLite to pass 7601** it an array of void* context pointers. The first argument passed to 7602** an unlock-notify callback is a pointer to an array of void* pointers, 7603** and the second is the number of entries in the array. 7604** 7605** When a blocking connections transaction is concluded, there may be 7606** more than one blocked connection that has registered for an unlock-notify 7607** callback. ^If two or more such blocked connections have specified the 7608** same callback function, then instead of invoking the callback function 7609** multiple times, it is invoked once with the set of void* context pointers 7610** specified by the blocked connections bundled together into an array. 7611** This gives the application an opportunity to prioritize any actions 7612** related to the set of unblocked database connections. 7613** 7614** <b>Deadlock Detection</b> 7615** 7616** Assuming that after registering for an unlock-notify callback a 7617** database waits for the callback to be issued before taking any further 7618** action (a reasonable assumption), then using this API may cause the 7619** application to deadlock. For example, if connection X is waiting for 7620** connection Y's transaction to be concluded, and similarly connection 7621** Y is waiting on connection X's transaction, then neither connection 7622** will proceed and the system may remain deadlocked indefinitely. 7623** 7624** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7625** detection. ^If a given call to sqlite3_unlock_notify() would put the 7626** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7627** unlock-notify callback is registered. The system is said to be in 7628** a deadlocked state if connection A has registered for an unlock-notify 7629** callback on the conclusion of connection B's transaction, and connection 7630** B has itself registered for an unlock-notify callback when connection 7631** A's transaction is concluded. ^Indirect deadlock is also detected, so 7632** the system is also considered to be deadlocked if connection B has 7633** registered for an unlock-notify callback on the conclusion of connection 7634** C's transaction, where connection C is waiting on connection A. ^Any 7635** number of levels of indirection are allowed. 7636** 7637** <b>The "DROP TABLE" Exception</b> 7638** 7639** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7640** always appropriate to call sqlite3_unlock_notify(). There is however, 7641** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7642** SQLite checks if there are any currently executing SELECT statements 7643** that belong to the same connection. If there are, SQLITE_LOCKED is 7644** returned. In this case there is no "blocking connection", so invoking 7645** sqlite3_unlock_notify() results in the unlock-notify callback being 7646** invoked immediately. If the application then re-attempts the "DROP TABLE" 7647** or "DROP INDEX" query, an infinite loop might be the result. 7648** 7649** One way around this problem is to check the extended error code returned 7650** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7651** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7652** the special "DROP TABLE/INDEX" case, the extended error code is just 7653** SQLITE_LOCKED.)^ 7654*/ 7655int sqlite3_unlock_notify( 7656 sqlite3 *pBlocked, /* Waiting connection */ 7657 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7658 void *pNotifyArg /* Argument to pass to xNotify */ 7659); 7660 7661 7662/* 7663** CAPI3REF: String Comparison 7664** 7665** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7666** and extensions to compare the contents of two buffers containing UTF-8 7667** strings in a case-independent fashion, using the same definition of "case 7668** independence" that SQLite uses internally when comparing identifiers. 7669*/ 7670int sqlite3_stricmp(const char *, const char *); 7671int sqlite3_strnicmp(const char *, const char *, int); 7672 7673/* 7674** CAPI3REF: String Globbing 7675* 7676** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 7677** string X matches the [GLOB] pattern P. 7678** ^The definition of [GLOB] pattern matching used in 7679** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7680** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 7681** is case sensitive. 7682** 7683** Note that this routine returns zero on a match and non-zero if the strings 7684** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7685** 7686** See also: [sqlite3_strlike()]. 7687*/ 7688int sqlite3_strglob(const char *zGlob, const char *zStr); 7689 7690/* 7691** CAPI3REF: String LIKE Matching 7692* 7693** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 7694** string X matches the [LIKE] pattern P with escape character E. 7695** ^The definition of [LIKE] pattern matching used in 7696** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 7697** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 7698** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 7699** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 7700** insensitive - equivalent upper and lower case ASCII characters match 7701** one another. 7702** 7703** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 7704** only ASCII characters are case folded. 7705** 7706** Note that this routine returns zero on a match and non-zero if the strings 7707** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7708** 7709** See also: [sqlite3_strglob()]. 7710*/ 7711int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 7712 7713/* 7714** CAPI3REF: Error Logging Interface 7715** 7716** ^The [sqlite3_log()] interface writes a message into the [error log] 7717** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7718** ^If logging is enabled, the zFormat string and subsequent arguments are 7719** used with [sqlite3_snprintf()] to generate the final output string. 7720** 7721** The sqlite3_log() interface is intended for use by extensions such as 7722** virtual tables, collating functions, and SQL functions. While there is 7723** nothing to prevent an application from calling sqlite3_log(), doing so 7724** is considered bad form. 7725** 7726** The zFormat string must not be NULL. 7727** 7728** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7729** will not use dynamically allocated memory. The log message is stored in 7730** a fixed-length buffer on the stack. If the log message is longer than 7731** a few hundred characters, it will be truncated to the length of the 7732** buffer. 7733*/ 7734void sqlite3_log(int iErrCode, const char *zFormat, ...); 7735 7736/* 7737** CAPI3REF: Write-Ahead Log Commit Hook 7738** METHOD: sqlite3 7739** 7740** ^The [sqlite3_wal_hook()] function is used to register a callback that 7741** is invoked each time data is committed to a database in wal mode. 7742** 7743** ^(The callback is invoked by SQLite after the commit has taken place and 7744** the associated write-lock on the database released)^, so the implementation 7745** may read, write or [checkpoint] the database as required. 7746** 7747** ^The first parameter passed to the callback function when it is invoked 7748** is a copy of the third parameter passed to sqlite3_wal_hook() when 7749** registering the callback. ^The second is a copy of the database handle. 7750** ^The third parameter is the name of the database that was written to - 7751** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7752** is the number of pages currently in the write-ahead log file, 7753** including those that were just committed. 7754** 7755** The callback function should normally return [SQLITE_OK]. ^If an error 7756** code is returned, that error will propagate back up through the 7757** SQLite code base to cause the statement that provoked the callback 7758** to report an error, though the commit will have still occurred. If the 7759** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7760** that does not correspond to any valid SQLite error code, the results 7761** are undefined. 7762** 7763** A single database handle may have at most a single write-ahead log callback 7764** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7765** previously registered write-ahead log callback. ^Note that the 7766** [sqlite3_wal_autocheckpoint()] interface and the 7767** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7768** overwrite any prior [sqlite3_wal_hook()] settings. 7769*/ 7770void *sqlite3_wal_hook( 7771 sqlite3*, 7772 int(*)(void *,sqlite3*,const char*,int), 7773 void* 7774); 7775 7776/* 7777** CAPI3REF: Configure an auto-checkpoint 7778** METHOD: sqlite3 7779** 7780** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7781** [sqlite3_wal_hook()] that causes any database on [database connection] D 7782** to automatically [checkpoint] 7783** after committing a transaction if there are N or 7784** more frames in the [write-ahead log] file. ^Passing zero or 7785** a negative value as the nFrame parameter disables automatic 7786** checkpoints entirely. 7787** 7788** ^The callback registered by this function replaces any existing callback 7789** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7790** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7791** configured by this function. 7792** 7793** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7794** from SQL. 7795** 7796** ^Checkpoints initiated by this mechanism are 7797** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7798** 7799** ^Every new [database connection] defaults to having the auto-checkpoint 7800** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7801** pages. The use of this interface 7802** is only necessary if the default setting is found to be suboptimal 7803** for a particular application. 7804*/ 7805int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7806 7807/* 7808** CAPI3REF: Checkpoint a database 7809** METHOD: sqlite3 7810** 7811** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 7812** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 7813** 7814** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 7815** [write-ahead log] for database X on [database connection] D to be 7816** transferred into the database file and for the write-ahead log to 7817** be reset. See the [checkpointing] documentation for addition 7818** information. 7819** 7820** This interface used to be the only way to cause a checkpoint to 7821** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 7822** interface was added. This interface is retained for backwards 7823** compatibility and as a convenience for applications that need to manually 7824** start a callback but which do not need the full power (and corresponding 7825** complication) of [sqlite3_wal_checkpoint_v2()]. 7826*/ 7827int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7828 7829/* 7830** CAPI3REF: Checkpoint a database 7831** METHOD: sqlite3 7832** 7833** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 7834** operation on database X of [database connection] D in mode M. Status 7835** information is written back into integers pointed to by L and C.)^ 7836** ^(The M parameter must be a valid [checkpoint mode]:)^ 7837** 7838** <dl> 7839** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7840** ^Checkpoint as many frames as possible without waiting for any database 7841** readers or writers to finish, then sync the database file if all frames 7842** in the log were checkpointed. ^The [busy-handler callback] 7843** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 7844** ^On the other hand, passive mode might leave the checkpoint unfinished 7845** if there are concurrent readers or writers. 7846** 7847** <dt>SQLITE_CHECKPOINT_FULL<dd> 7848** ^This mode blocks (it invokes the 7849** [sqlite3_busy_handler|busy-handler callback]) until there is no 7850** database writer and all readers are reading from the most recent database 7851** snapshot. ^It then checkpoints all frames in the log file and syncs the 7852** database file. ^This mode blocks new database writers while it is pending, 7853** but new database readers are allowed to continue unimpeded. 7854** 7855** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7856** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 7857** that after checkpointing the log file it blocks (calls the 7858** [busy-handler callback]) 7859** until all readers are reading from the database file only. ^This ensures 7860** that the next writer will restart the log file from the beginning. 7861** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 7862** database writer attempts while it is pending, but does not impede readers. 7863** 7864** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 7865** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 7866** addition that it also truncates the log file to zero bytes just prior 7867** to a successful return. 7868** </dl> 7869** 7870** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 7871** the log file or to -1 if the checkpoint could not run because 7872** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 7873** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 7874** log file (including any that were already checkpointed before the function 7875** was called) or to -1 if the checkpoint could not run due to an error or 7876** because the database is not in WAL mode. ^Note that upon successful 7877** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 7878** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 7879** 7880** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 7881** any other process is running a checkpoint operation at the same time, the 7882** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 7883** busy-handler configured, it will not be invoked in this case. 7884** 7885** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 7886** exclusive "writer" lock on the database file. ^If the writer lock cannot be 7887** obtained immediately, and a busy-handler is configured, it is invoked and 7888** the writer lock retried until either the busy-handler returns 0 or the lock 7889** is successfully obtained. ^The busy-handler is also invoked while waiting for 7890** database readers as described above. ^If the busy-handler returns 0 before 7891** the writer lock is obtained or while waiting for database readers, the 7892** checkpoint operation proceeds from that point in the same way as 7893** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7894** without blocking any further. ^SQLITE_BUSY is returned in this case. 7895** 7896** ^If parameter zDb is NULL or points to a zero length string, then the 7897** specified operation is attempted on all WAL databases [attached] to 7898** [database connection] db. In this case the 7899** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 7900** an SQLITE_BUSY error is encountered when processing one or more of the 7901** attached WAL databases, the operation is still attempted on any remaining 7902** attached databases and SQLITE_BUSY is returned at the end. ^If any other 7903** error occurs while processing an attached database, processing is abandoned 7904** and the error code is returned to the caller immediately. ^If no error 7905** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7906** databases, SQLITE_OK is returned. 7907** 7908** ^If database zDb is the name of an attached database that is not in WAL 7909** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 7910** zDb is not NULL (or a zero length string) and is not the name of any 7911** attached database, SQLITE_ERROR is returned to the caller. 7912** 7913** ^Unless it returns SQLITE_MISUSE, 7914** the sqlite3_wal_checkpoint_v2() interface 7915** sets the error information that is queried by 7916** [sqlite3_errcode()] and [sqlite3_errmsg()]. 7917** 7918** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 7919** from SQL. 7920*/ 7921int sqlite3_wal_checkpoint_v2( 7922 sqlite3 *db, /* Database handle */ 7923 const char *zDb, /* Name of attached database (or NULL) */ 7924 int eMode, /* SQLITE_CHECKPOINT_* value */ 7925 int *pnLog, /* OUT: Size of WAL log in frames */ 7926 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7927); 7928 7929/* 7930** CAPI3REF: Checkpoint Mode Values 7931** KEYWORDS: {checkpoint mode} 7932** 7933** These constants define all valid values for the "checkpoint mode" passed 7934** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 7935** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 7936** meaning of each of these checkpoint modes. 7937*/ 7938#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 7939#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 7940#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 7941#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 7942 7943/* 7944** CAPI3REF: Virtual Table Interface Configuration 7945** 7946** This function may be called by either the [xConnect] or [xCreate] method 7947** of a [virtual table] implementation to configure 7948** various facets of the virtual table interface. 7949** 7950** If this interface is invoked outside the context of an xConnect or 7951** xCreate virtual table method then the behavior is undefined. 7952** 7953** At present, there is only one option that may be configured using 7954** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7955** may be added in the future. 7956*/ 7957int sqlite3_vtab_config(sqlite3*, int op, ...); 7958 7959/* 7960** CAPI3REF: Virtual Table Configuration Options 7961** 7962** These macros define the various options to the 7963** [sqlite3_vtab_config()] interface that [virtual table] implementations 7964** can use to customize and optimize their behavior. 7965** 7966** <dl> 7967** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7968** <dd>Calls of the form 7969** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7970** where X is an integer. If X is zero, then the [virtual table] whose 7971** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7972** support constraints. In this configuration (which is the default) if 7973** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7974** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7975** specified as part of the users SQL statement, regardless of the actual 7976** ON CONFLICT mode specified. 7977** 7978** If X is non-zero, then the virtual table implementation guarantees 7979** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7980** any modifications to internal or persistent data structures have been made. 7981** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7982** is able to roll back a statement or database transaction, and abandon 7983** or continue processing the current SQL statement as appropriate. 7984** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7985** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7986** had been ABORT. 7987** 7988** Virtual table implementations that are required to handle OR REPLACE 7989** must do so within the [xUpdate] method. If a call to the 7990** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7991** CONFLICT policy is REPLACE, the virtual table implementation should 7992** silently replace the appropriate rows within the xUpdate callback and 7993** return SQLITE_OK. Or, if this is not possible, it may return 7994** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7995** constraint handling. 7996** </dl> 7997*/ 7998#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7999 8000/* 8001** CAPI3REF: Determine The Virtual Table Conflict Policy 8002** 8003** This function may only be called from within a call to the [xUpdate] method 8004** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8005** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8006** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8007** of the SQL statement that triggered the call to the [xUpdate] method of the 8008** [virtual table]. 8009*/ 8010int sqlite3_vtab_on_conflict(sqlite3 *); 8011 8012/* 8013** CAPI3REF: Conflict resolution modes 8014** KEYWORDS: {conflict resolution mode} 8015** 8016** These constants are returned by [sqlite3_vtab_on_conflict()] to 8017** inform a [virtual table] implementation what the [ON CONFLICT] mode 8018** is for the SQL statement being evaluated. 8019** 8020** Note that the [SQLITE_IGNORE] constant is also used as a potential 8021** return value from the [sqlite3_set_authorizer()] callback and that 8022** [SQLITE_ABORT] is also a [result code]. 8023*/ 8024#define SQLITE_ROLLBACK 1 8025/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8026#define SQLITE_FAIL 3 8027/* #define SQLITE_ABORT 4 // Also an error code */ 8028#define SQLITE_REPLACE 5 8029 8030/* 8031** CAPI3REF: Prepared Statement Scan Status Opcodes 8032** KEYWORDS: {scanstatus options} 8033** 8034** The following constants can be used for the T parameter to the 8035** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8036** different metric for sqlite3_stmt_scanstatus() to return. 8037** 8038** When the value returned to V is a string, space to hold that string is 8039** managed by the prepared statement S and will be automatically freed when 8040** S is finalized. 8041** 8042** <dl> 8043** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8044** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8045** set to the total number of times that the X-th loop has run.</dd> 8046** 8047** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8048** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8049** to the total number of rows examined by all iterations of the X-th loop.</dd> 8050** 8051** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8052** <dd>^The "double" variable pointed to by the T parameter will be set to the 8053** query planner's estimate for the average number of rows output from each 8054** iteration of the X-th loop. If the query planner's estimates was accurate, 8055** then this value will approximate the quotient NVISIT/NLOOP and the 8056** product of this value for all prior loops with the same SELECTID will 8057** be the NLOOP value for the current loop. 8058** 8059** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8060** <dd>^The "const char *" variable pointed to by the T parameter will be set 8061** to a zero-terminated UTF-8 string containing the name of the index or table 8062** used for the X-th loop. 8063** 8064** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8065** <dd>^The "const char *" variable pointed to by the T parameter will be set 8066** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8067** description for the X-th loop. 8068** 8069** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8070** <dd>^The "int" variable pointed to by the T parameter will be set to the 8071** "select-id" for the X-th loop. The select-id identifies which query or 8072** subquery the loop is part of. The main query has a select-id of zero. 8073** The select-id is the same value as is output in the first column 8074** of an [EXPLAIN QUERY PLAN] query. 8075** </dl> 8076*/ 8077#define SQLITE_SCANSTAT_NLOOP 0 8078#define SQLITE_SCANSTAT_NVISIT 1 8079#define SQLITE_SCANSTAT_EST 2 8080#define SQLITE_SCANSTAT_NAME 3 8081#define SQLITE_SCANSTAT_EXPLAIN 4 8082#define SQLITE_SCANSTAT_SELECTID 5 8083 8084/* 8085** CAPI3REF: Prepared Statement Scan Status 8086** METHOD: sqlite3_stmt 8087** 8088** This interface returns information about the predicted and measured 8089** performance for pStmt. Advanced applications can use this 8090** interface to compare the predicted and the measured performance and 8091** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8092** 8093** Since this interface is expected to be rarely used, it is only 8094** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8095** compile-time option. 8096** 8097** The "iScanStatusOp" parameter determines which status information to return. 8098** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8099** of this interface is undefined. 8100** ^The requested measurement is written into a variable pointed to by 8101** the "pOut" parameter. 8102** Parameter "idx" identifies the specific loop to retrieve statistics for. 8103** Loops are numbered starting from zero. ^If idx is out of range - less than 8104** zero or greater than or equal to the total number of loops used to implement 8105** the statement - a non-zero value is returned and the variable that pOut 8106** points to is unchanged. 8107** 8108** ^Statistics might not be available for all loops in all statements. ^In cases 8109** where there exist loops with no available statistics, this function behaves 8110** as if the loop did not exist - it returns non-zero and leave the variable 8111** that pOut points to unchanged. 8112** 8113** See also: [sqlite3_stmt_scanstatus_reset()] 8114*/ 8115int sqlite3_stmt_scanstatus( 8116 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8117 int idx, /* Index of loop to report on */ 8118 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8119 void *pOut /* Result written here */ 8120); 8121 8122/* 8123** CAPI3REF: Zero Scan-Status Counters 8124** METHOD: sqlite3_stmt 8125** 8126** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 8127** 8128** This API is only available if the library is built with pre-processor 8129** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 8130*/ 8131void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 8132 8133/* 8134** CAPI3REF: Flush caches to disk mid-transaction 8135** 8136** ^If a write-transaction is open on [database connection] D when the 8137** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 8138** pages in the pager-cache that are not currently in use are written out 8139** to disk. A dirty page may be in use if a database cursor created by an 8140** active SQL statement is reading from it, or if it is page 1 of a database 8141** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 8142** interface flushes caches for all schemas - "main", "temp", and 8143** any [attached] databases. 8144** 8145** ^If this function needs to obtain extra database locks before dirty pages 8146** can be flushed to disk, it does so. ^If those locks cannot be obtained 8147** immediately and there is a busy-handler callback configured, it is invoked 8148** in the usual manner. ^If the required lock still cannot be obtained, then 8149** the database is skipped and an attempt made to flush any dirty pages 8150** belonging to the next (if any) database. ^If any databases are skipped 8151** because locks cannot be obtained, but no other error occurs, this 8152** function returns SQLITE_BUSY. 8153** 8154** ^If any other error occurs while flushing dirty pages to disk (for 8155** example an IO error or out-of-memory condition), then processing is 8156** abandoned and an SQLite [error code] is returned to the caller immediately. 8157** 8158** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 8159** 8160** ^This function does not set the database handle error code or message 8161** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 8162*/ 8163int sqlite3_db_cacheflush(sqlite3*); 8164 8165/* 8166** CAPI3REF: The pre-update hook. 8167** 8168** ^These interfaces are only available if SQLite is compiled using the 8169** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 8170** 8171** ^The [sqlite3_preupdate_hook()] interface registers a callback function 8172** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 8173** on a [rowid table]. 8174** ^At most one preupdate hook may be registered at a time on a single 8175** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 8176** the previous setting. 8177** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 8178** with a NULL pointer as the second parameter. 8179** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 8180** the first parameter to callbacks. 8181** 8182** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate 8183** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID] 8184** tables. 8185** 8186** ^The second parameter to the preupdate callback is a pointer to 8187** the [database connection] that registered the preupdate hook. 8188** ^The third parameter to the preupdate callback is one of the constants 8189** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 8190** kind of update operation that is about to occur. 8191** ^(The fourth parameter to the preupdate callback is the name of the 8192** database within the database connection that is being modified. This 8193** will be "main" for the main database or "temp" for TEMP tables or 8194** the name given after the AS keyword in the [ATTACH] statement for attached 8195** databases.)^ 8196** ^The fifth parameter to the preupdate callback is the name of the 8197** table that is being modified. 8198** ^The sixth parameter to the preupdate callback is the initial [rowid] of the 8199** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is 8200** undefined for SQLITE_INSERT changes. 8201** ^The seventh parameter to the preupdate callback is the final [rowid] of 8202** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is 8203** undefined for SQLITE_DELETE changes. 8204** 8205** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 8206** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 8207** provide additional information about a preupdate event. These routines 8208** may only be called from within a preupdate callback. Invoking any of 8209** these routines from outside of a preupdate callback or with a 8210** [database connection] pointer that is different from the one supplied 8211** to the preupdate callback results in undefined and probably undesirable 8212** behavior. 8213** 8214** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 8215** in the row that is being inserted, updated, or deleted. 8216** 8217** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 8218** a [protected sqlite3_value] that contains the value of the Nth column of 8219** the table row before it is updated. The N parameter must be between 0 8220** and one less than the number of columns or the behavior will be 8221** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 8222** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 8223** behavior is undefined. The [sqlite3_value] that P points to 8224** will be destroyed when the preupdate callback returns. 8225** 8226** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 8227** a [protected sqlite3_value] that contains the value of the Nth column of 8228** the table row after it is updated. The N parameter must be between 0 8229** and one less than the number of columns or the behavior will be 8230** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 8231** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 8232** behavior is undefined. The [sqlite3_value] that P points to 8233** will be destroyed when the preupdate callback returns. 8234** 8235** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 8236** callback was invoked as a result of a direct insert, update, or delete 8237** operation; or 1 for inserts, updates, or deletes invoked by top-level 8238** triggers; or 2 for changes resulting from triggers called by top-level 8239** triggers; and so forth. 8240** 8241** See also: [sqlite3_update_hook()] 8242*/ 8243#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 8244void *sqlite3_preupdate_hook( 8245 sqlite3 *db, 8246 void(*xPreUpdate)( 8247 void *pCtx, /* Copy of third arg to preupdate_hook() */ 8248 sqlite3 *db, /* Database handle */ 8249 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 8250 char const *zDb, /* Database name */ 8251 char const *zName, /* Table name */ 8252 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 8253 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 8254 ), 8255 void* 8256); 8257int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 8258int sqlite3_preupdate_count(sqlite3 *); 8259int sqlite3_preupdate_depth(sqlite3 *); 8260int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 8261#endif 8262 8263/* 8264** CAPI3REF: Low-level system error code 8265** 8266** ^Attempt to return the underlying operating system error code or error 8267** number that caused the most recent I/O error or failure to open a file. 8268** The return value is OS-dependent. For example, on unix systems, after 8269** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 8270** called to get back the underlying "errno" that caused the problem, such 8271** as ENOSPC, EAUTH, EISDIR, and so forth. 8272*/ 8273int sqlite3_system_errno(sqlite3*); 8274 8275/* 8276** CAPI3REF: Database Snapshot 8277** KEYWORDS: {snapshot} {sqlite3_snapshot} 8278** EXPERIMENTAL 8279** 8280** An instance of the snapshot object records the state of a [WAL mode] 8281** database for some specific point in history. 8282** 8283** In [WAL mode], multiple [database connections] that are open on the 8284** same database file can each be reading a different historical version 8285** of the database file. When a [database connection] begins a read 8286** transaction, that connection sees an unchanging copy of the database 8287** as it existed for the point in time when the transaction first started. 8288** Subsequent changes to the database from other connections are not seen 8289** by the reader until a new read transaction is started. 8290** 8291** The sqlite3_snapshot object records state information about an historical 8292** version of the database file so that it is possible to later open a new read 8293** transaction that sees that historical version of the database rather than 8294** the most recent version. 8295** 8296** The constructor for this object is [sqlite3_snapshot_get()]. The 8297** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer 8298** to an historical snapshot (if possible). The destructor for 8299** sqlite3_snapshot objects is [sqlite3_snapshot_free()]. 8300*/ 8301typedef struct sqlite3_snapshot { 8302 unsigned char hidden[48]; 8303} sqlite3_snapshot; 8304 8305/* 8306** CAPI3REF: Record A Database Snapshot 8307** EXPERIMENTAL 8308** 8309** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 8310** new [sqlite3_snapshot] object that records the current state of 8311** schema S in database connection D. ^On success, the 8312** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 8313** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 8314** If there is not already a read-transaction open on schema S when 8315** this function is called, one is opened automatically. 8316** 8317** The following must be true for this function to succeed. If any of 8318** the following statements are false when sqlite3_snapshot_get() is 8319** called, SQLITE_ERROR is returned. The final value of *P is undefined 8320** in this case. 8321** 8322** <ul> 8323** <li> The database handle must be in [autocommit mode]. 8324** 8325** <li> Schema S of [database connection] D must be a [WAL mode] database. 8326** 8327** <li> There must not be a write transaction open on schema S of database 8328** connection D. 8329** 8330** <li> One or more transactions must have been written to the current wal 8331** file since it was created on disk (by any connection). This means 8332** that a snapshot cannot be taken on a wal mode database with no wal 8333** file immediately after it is first opened. At least one transaction 8334** must be written to it first. 8335** </ul> 8336** 8337** This function may also return SQLITE_NOMEM. If it is called with the 8338** database handle in autocommit mode but fails for some other reason, 8339** whether or not a read transaction is opened on schema S is undefined. 8340** 8341** The [sqlite3_snapshot] object returned from a successful call to 8342** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 8343** to avoid a memory leak. 8344** 8345** The [sqlite3_snapshot_get()] interface is only available when the 8346** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8347*/ 8348SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 8349 sqlite3 *db, 8350 const char *zSchema, 8351 sqlite3_snapshot **ppSnapshot 8352); 8353 8354/* 8355** CAPI3REF: Start a read transaction on an historical snapshot 8356** EXPERIMENTAL 8357** 8358** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a 8359** read transaction for schema S of 8360** [database connection] D such that the read transaction 8361** refers to historical [snapshot] P, rather than the most 8362** recent change to the database. 8363** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success 8364** or an appropriate [error code] if it fails. 8365** 8366** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be 8367** the first operation following the [BEGIN] that takes the schema S 8368** out of [autocommit mode]. 8369** ^In other words, schema S must not currently be in 8370** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the 8371** database connection D must be out of [autocommit mode]. 8372** ^A [snapshot] will fail to open if it has been overwritten by a 8373** [checkpoint]. 8374** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 8375** database connection D does not know that the database file for 8376** schema S is in [WAL mode]. A database connection might not know 8377** that the database file is in [WAL mode] if there has been no prior 8378** I/O on that database connection, or if the database entered [WAL mode] 8379** after the most recent I/O on the database connection.)^ 8380** (Hint: Run "[PRAGMA application_id]" against a newly opened 8381** database connection in order to make it ready to use snapshots.) 8382** 8383** The [sqlite3_snapshot_open()] interface is only available when the 8384** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8385*/ 8386SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 8387 sqlite3 *db, 8388 const char *zSchema, 8389 sqlite3_snapshot *pSnapshot 8390); 8391 8392/* 8393** CAPI3REF: Destroy a snapshot 8394** EXPERIMENTAL 8395** 8396** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 8397** The application must eventually free every [sqlite3_snapshot] object 8398** using this routine to avoid a memory leak. 8399** 8400** The [sqlite3_snapshot_free()] interface is only available when the 8401** SQLITE_ENABLE_SNAPSHOT compile-time option is used. 8402*/ 8403SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 8404 8405/* 8406** CAPI3REF: Compare the ages of two snapshot handles. 8407** EXPERIMENTAL 8408** 8409** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 8410** of two valid snapshot handles. 8411** 8412** If the two snapshot handles are not associated with the same database 8413** file, the result of the comparison is undefined. 8414** 8415** Additionally, the result of the comparison is only valid if both of the 8416** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 8417** last time the wal file was deleted. The wal file is deleted when the 8418** database is changed back to rollback mode or when the number of database 8419** clients drops to zero. If either snapshot handle was obtained before the 8420** wal file was last deleted, the value returned by this function 8421** is undefined. 8422** 8423** Otherwise, this API returns a negative value if P1 refers to an older 8424** snapshot than P2, zero if the two handles refer to the same database 8425** snapshot, and a positive value if P1 is a newer snapshot than P2. 8426*/ 8427SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 8428 sqlite3_snapshot *p1, 8429 sqlite3_snapshot *p2 8430); 8431 8432/* 8433** CAPI3REF: Recover snapshots from a wal file 8434** EXPERIMENTAL 8435** 8436** If all connections disconnect from a database file but do not perform 8437** a checkpoint, the existing wal file is opened along with the database 8438** file the next time the database is opened. At this point it is only 8439** possible to successfully call sqlite3_snapshot_open() to open the most 8440** recent snapshot of the database (the one at the head of the wal file), 8441** even though the wal file may contain other valid snapshots for which 8442** clients have sqlite3_snapshot handles. 8443** 8444** This function attempts to scan the wal file associated with database zDb 8445** of database handle db and make all valid snapshots available to 8446** sqlite3_snapshot_open(). It is an error if there is already a read 8447** transaction open on the database, or if the database is not a wal mode 8448** database. 8449** 8450** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 8451*/ 8452SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 8453 8454/* 8455** Undo the hack that converts floating point types to integer for 8456** builds on processors without floating point support. 8457*/ 8458#ifdef SQLITE_OMIT_FLOATING_POINT 8459# undef double 8460#endif 8461 8462#ifdef __cplusplus 8463} /* End of the 'extern "C"' block */ 8464#endif 8465#endif /* SQLITE3_H */ 8466