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1 /* |
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2 ** 2001 September 15 |
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3 ** |
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4 ** The author disclaims copyright to this source code. In place of |
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5 ** a legal notice, here is a blessing: |
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6 ** |
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7 ** May you do good and not evil. |
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8 ** May you find forgiveness for yourself and forgive others. |
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9 ** May you share freely, never taking more than you give. |
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10 ** |
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11 ************************************************************************* |
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12 ** This header file defines the interface that the SQLite library |
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13 ** presents to client programs. If a C-function, structure, datatype, |
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14 ** or constant definition does not appear in this file, then it is |
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15 ** not a published API of SQLite, is subject to change without |
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16 ** notice, and should not be referenced by programs that use SQLite. |
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17 ** |
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18 ** Some of the definitions that are in this file are marked as |
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19 ** "experimental". Experimental interfaces are normally new |
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20 ** features recently added to SQLite. We do not anticipate changes |
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21 ** to experimental interfaces but reserve to make minor changes if |
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22 ** experience from use "in the wild" suggest such changes are prudent. |
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23 ** |
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24 ** The official C-language API documentation for SQLite is derived |
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25 ** from comments in this file. This file is the authoritative source |
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26 ** on how SQLite interfaces are suppose to operate. |
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27 ** |
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28 ** The name of this file under configuration management is "sqlite.h.in". |
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29 ** The makefile makes some minor changes to this file (such as inserting |
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30 ** the version number) and changes its name to "sqlite3.h" as |
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31 ** part of the build process. |
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32 ** |
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33 ** @(#) $Id: sqlite.h.in,v 1.436 2009/03/20 13:15:30 drh Exp $ |
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34 */ |
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35 #ifndef _SQLITE3_H_ |
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36 #define _SQLITE3_H_ |
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37 #include <stdarg.h> /* Needed for the definition of va_list */ |
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38 |
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39 /* |
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40 ** Make sure we can call this stuff from C++. |
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41 */ |
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42 #ifdef __cplusplus |
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43 extern "C" { |
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44 #endif |
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45 |
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46 |
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47 /* |
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48 ** Add the ability to override 'extern' |
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49 */ |
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50 #ifndef SQLITE_EXTERN |
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51 # define SQLITE_EXTERN extern |
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52 #endif |
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53 |
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54 /* |
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55 ** These no-op macros are used in front of interfaces to mark those |
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56 ** interfaces as either deprecated or experimental. New applications |
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57 ** should not use deprecated intrfaces - they are support for backwards |
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58 ** compatibility only. Application writers should be aware that |
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59 ** experimental interfaces are subject to change in point releases. |
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60 ** |
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61 ** These macros used to resolve to various kinds of compiler magic that |
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62 ** would generate warning messages when they were used. But that |
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63 ** compiler magic ended up generating such a flurry of bug reports |
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64 ** that we have taken it all out and gone back to using simple |
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65 ** noop macros. |
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66 */ |
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67 #define SQLITE_DEPRECATED |
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68 #define SQLITE_EXPERIMENTAL |
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69 |
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70 /* |
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71 ** Ensure these symbols were not defined by some previous header file. |
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72 */ |
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73 #ifdef SQLITE_VERSION |
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74 # undef SQLITE_VERSION |
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75 #endif |
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76 #ifdef SQLITE_VERSION_NUMBER |
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77 # undef SQLITE_VERSION_NUMBER |
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78 #endif |
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79 |
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80 /* |
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81 ** CAPI3REF: Compile-Time Library Version Numbers {H10010} <S60100> |
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82 ** |
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83 ** The SQLITE_VERSION and SQLITE_VERSION_NUMBER #defines in |
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84 ** the sqlite3.h file specify the version of SQLite with which |
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85 ** that header file is associated. |
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86 ** |
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87 ** The "version" of SQLite is a string of the form "X.Y.Z". |
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88 ** The phrase "alpha" or "beta" might be appended after the Z. |
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89 ** The X value is major version number always 3 in SQLite3. |
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90 ** The X value only changes when backwards compatibility is |
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91 ** broken and we intend to never break backwards compatibility. |
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92 ** The Y value is the minor version number and only changes when |
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93 ** there are major feature enhancements that are forwards compatible |
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94 ** but not backwards compatible. |
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95 ** The Z value is the release number and is incremented with |
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96 ** each release but resets back to 0 whenever Y is incremented. |
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97 ** |
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98 ** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()]. |
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99 ** |
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100 ** Requirements: [H10011] [H10014] |
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101 */ |
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102 #define SQLITE_VERSION "3.6.12" |
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103 #define SQLITE_VERSION_NUMBER 3006012 |
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104 |
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105 /* |
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106 ** CAPI3REF: Run-Time Library Version Numbers {H10020} <S60100> |
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107 ** KEYWORDS: sqlite3_version |
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108 ** |
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109 ** These features provide the same information as the [SQLITE_VERSION] |
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110 ** and [SQLITE_VERSION_NUMBER] #defines in the header, but are associated |
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111 ** with the library instead of the header file. Cautious programmers might |
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112 ** include a check in their application to verify that |
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113 ** sqlite3_libversion_number() always returns the value |
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114 ** [SQLITE_VERSION_NUMBER]. |
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115 ** |
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116 ** The sqlite3_libversion() function returns the same information as is |
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117 ** in the sqlite3_version[] string constant. The function is provided |
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118 ** for use in DLLs since DLL users usually do not have direct access to string |
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119 ** constants within the DLL. |
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120 ** |
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121 ** Requirements: [H10021] [H10022] [H10023] |
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122 */ |
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123 SQLITE_EXTERN const char sqlite3_version[]; |
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124 const char *sqlite3_libversion(void); |
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125 int sqlite3_libversion_number(void); |
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126 |
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127 /* |
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128 ** CAPI3REF: Test To See If The Library Is Threadsafe {H10100} <S60100> |
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129 ** |
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130 ** SQLite can be compiled with or without mutexes. When |
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131 ** the [SQLITE_THREADSAFE] C preprocessor macro 1 or 2, mutexes |
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132 ** are enabled and SQLite is threadsafe. When the |
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133 ** [SQLITE_THREADSAFE] macro is 0, |
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134 ** the mutexes are omitted. Without the mutexes, it is not safe |
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135 ** to use SQLite concurrently from more than one thread. |
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136 ** |
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137 ** Enabling mutexes incurs a measurable performance penalty. |
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138 ** So if speed is of utmost importance, it makes sense to disable |
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139 ** the mutexes. But for maximum safety, mutexes should be enabled. |
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140 ** The default behavior is for mutexes to be enabled. |
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141 ** |
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142 ** This interface can be used by a program to make sure that the |
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143 ** version of SQLite that it is linking against was compiled with |
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144 ** the desired setting of the [SQLITE_THREADSAFE] macro. |
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145 ** |
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146 ** This interface only reports on the compile-time mutex setting |
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147 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with |
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148 ** SQLITE_THREADSAFE=1 then mutexes are enabled by default but |
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149 ** can be fully or partially disabled using a call to [sqlite3_config()] |
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150 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], |
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151 ** or [SQLITE_CONFIG_MUTEX]. The return value of this function shows |
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152 ** only the default compile-time setting, not any run-time changes |
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153 ** to that setting. |
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154 ** |
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155 ** See the [threading mode] documentation for additional information. |
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156 ** |
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157 ** Requirements: [H10101] [H10102] |
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158 */ |
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159 int sqlite3_threadsafe(void); |
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160 |
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161 /* |
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162 ** CAPI3REF: Database Connection Handle {H12000} <S40200> |
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163 ** KEYWORDS: {database connection} {database connections} |
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164 ** |
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165 ** Each open SQLite database is represented by a pointer to an instance of |
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166 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 |
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167 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and |
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168 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] |
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169 ** is its destructor. There are many other interfaces (such as |
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170 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and |
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171 ** [sqlite3_busy_timeout()] to name but three) that are methods on an |
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172 ** sqlite3 object. |
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173 */ |
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174 typedef struct sqlite3 sqlite3; |
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175 |
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176 /* |
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177 ** CAPI3REF: 64-Bit Integer Types {H10200} <S10110> |
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178 ** KEYWORDS: sqlite_int64 sqlite_uint64 |
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179 ** |
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180 ** Because there is no cross-platform way to specify 64-bit integer types |
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181 ** SQLite includes typedefs for 64-bit signed and unsigned integers. |
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182 ** |
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183 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. |
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184 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards |
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185 ** compatibility only. |
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186 ** |
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187 ** Requirements: [H10201] [H10202] |
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188 */ |
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189 #ifdef SQLITE_INT64_TYPE |
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190 typedef SQLITE_INT64_TYPE sqlite_int64; |
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191 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; |
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192 #elif defined(_MSC_VER) || defined(__BORLANDC__) |
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193 typedef __int64 sqlite_int64; |
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194 typedef unsigned __int64 sqlite_uint64; |
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195 #else |
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196 typedef long long int sqlite_int64; |
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197 typedef unsigned long long int sqlite_uint64; |
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198 #endif |
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199 typedef sqlite_int64 sqlite3_int64; |
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200 typedef sqlite_uint64 sqlite3_uint64; |
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201 |
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202 /* |
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203 ** If compiling for a processor that lacks floating point support, |
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204 ** substitute integer for floating-point. |
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205 */ |
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206 #ifdef SQLITE_OMIT_FLOATING_POINT |
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207 # define double sqlite3_int64 |
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208 #endif |
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209 |
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210 /* |
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211 ** CAPI3REF: Closing A Database Connection {H12010} <S30100><S40200> |
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212 ** |
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213 ** This routine is the destructor for the [sqlite3] object. |
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214 ** |
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215 ** Applications should [sqlite3_finalize | finalize] all [prepared statements] |
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216 ** and [sqlite3_blob_close | close] all [BLOB handles] associated with |
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217 ** the [sqlite3] object prior to attempting to close the object. |
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218 ** The [sqlite3_next_stmt()] interface can be used to locate all |
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219 ** [prepared statements] associated with a [database connection] if desired. |
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220 ** Typical code might look like this: |
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221 ** |
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222 ** <blockquote><pre> |
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223 ** sqlite3_stmt *pStmt; |
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224 ** while( (pStmt = sqlite3_next_stmt(db, 0))!=0 ){ |
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225 ** sqlite3_finalize(pStmt); |
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226 ** } |
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227 ** </pre></blockquote> |
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228 ** |
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229 ** If [sqlite3_close()] is invoked while a transaction is open, |
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230 ** the transaction is automatically rolled back. |
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231 ** |
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232 ** The C parameter to [sqlite3_close(C)] must be either a NULL |
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233 ** pointer or an [sqlite3] object pointer obtained |
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234 ** from [sqlite3_open()], [sqlite3_open16()], or |
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235 ** [sqlite3_open_v2()], and not previously closed. |
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236 ** |
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237 ** Requirements: |
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238 ** [H12011] [H12012] [H12013] [H12014] [H12015] [H12019] |
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239 */ |
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240 int sqlite3_close(sqlite3 *); |
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241 |
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242 /* |
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243 ** The type for a callback function. |
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244 ** This is legacy and deprecated. It is included for historical |
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245 ** compatibility and is not documented. |
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246 */ |
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247 typedef int (*sqlite3_callback)(void*,int,char**, char**); |
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248 |
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249 /* |
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250 ** CAPI3REF: One-Step Query Execution Interface {H12100} <S10000> |
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251 ** |
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252 ** The sqlite3_exec() interface is a convenient way of running one or more |
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253 ** SQL statements without having to write a lot of C code. The UTF-8 encoded |
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254 ** SQL statements are passed in as the second parameter to sqlite3_exec(). |
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255 ** The statements are evaluated one by one until either an error or |
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256 ** an interrupt is encountered, or until they are all done. The 3rd parameter |
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257 ** is an optional callback that is invoked once for each row of any query |
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258 ** results produced by the SQL statements. The 5th parameter tells where |
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259 ** to write any error messages. |
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260 ** |
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261 ** The error message passed back through the 5th parameter is held |
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262 ** in memory obtained from [sqlite3_malloc()]. To avoid a memory leak, |
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263 ** the calling application should call [sqlite3_free()] on any error |
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264 ** message returned through the 5th parameter when it has finished using |
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265 ** the error message. |
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266 ** |
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267 ** If the SQL statement in the 2nd parameter is NULL or an empty string |
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268 ** or a string containing only whitespace and comments, then no SQL |
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269 ** statements are evaluated and the database is not changed. |
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270 ** |
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271 ** The sqlite3_exec() interface is implemented in terms of |
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272 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. |
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273 ** The sqlite3_exec() routine does nothing to the database that cannot be done |
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274 ** by [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()]. |
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275 ** |
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276 ** The first parameter to [sqlite3_exec()] must be an valid and open |
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277 ** [database connection]. |
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278 ** |
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279 ** The database connection must not be closed while |
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280 ** [sqlite3_exec()] is running. |
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281 ** |
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282 ** The calling function should use [sqlite3_free()] to free |
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283 ** the memory that *errmsg is left pointing at once the error |
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284 ** message is no longer needed. |
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285 ** |
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286 ** The SQL statement text in the 2nd parameter to [sqlite3_exec()] |
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287 ** must remain unchanged while [sqlite3_exec()] is running. |
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288 ** |
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289 ** Requirements: |
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290 ** [H12101] [H12102] [H12104] [H12105] [H12107] [H12110] [H12113] [H12116] |
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291 ** [H12119] [H12122] [H12125] [H12131] [H12134] [H12137] [H12138] |
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292 */ |
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293 int sqlite3_exec( |
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294 sqlite3*, /* An open database */ |
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295 const char *sql, /* SQL to be evaluated */ |
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296 int (*callback)(void*,int,char**,char**), /* Callback function */ |
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297 void *, /* 1st argument to callback */ |
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298 char **errmsg /* Error msg written here */ |
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299 ); |
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300 |
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301 /* |
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302 ** CAPI3REF: Result Codes {H10210} <S10700> |
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303 ** KEYWORDS: SQLITE_OK {error code} {error codes} |
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304 ** KEYWORDS: {result code} {result codes} |
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305 ** |
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306 ** Many SQLite functions return an integer result code from the set shown |
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307 ** here in order to indicates success or failure. |
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308 ** |
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309 ** New error codes may be added in future versions of SQLite. |
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310 ** |
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311 ** See also: [SQLITE_IOERR_READ | extended result codes] |
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312 */ |
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313 #define SQLITE_OK 0 /* Successful result */ |
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314 /* beginning-of-error-codes */ |
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315 #define SQLITE_ERROR 1 /* SQL error or missing database */ |
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316 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ |
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317 #define SQLITE_PERM 3 /* Access permission denied */ |
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318 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ |
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319 #define SQLITE_BUSY 5 /* The database file is locked */ |
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320 #define SQLITE_LOCKED 6 /* A table in the database is locked */ |
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321 #define SQLITE_NOMEM 7 /* A malloc() failed */ |
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322 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ |
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323 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ |
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324 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ |
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325 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ |
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326 #define SQLITE_NOTFOUND 12 /* NOT USED. Table or record not found */ |
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327 #define SQLITE_FULL 13 /* Insertion failed because database is full */ |
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328 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ |
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329 #define SQLITE_PROTOCOL 15 /* NOT USED. Database lock protocol error */ |
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330 #define SQLITE_EMPTY 16 /* Database is empty */ |
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331 #define SQLITE_SCHEMA 17 /* The database schema changed */ |
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332 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ |
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333 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ |
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334 #define SQLITE_MISMATCH 20 /* Data type mismatch */ |
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335 #define SQLITE_MISUSE 21 /* Library used incorrectly */ |
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336 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ |
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337 #define SQLITE_AUTH 23 /* Authorization denied */ |
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338 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ |
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339 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ |
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340 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ |
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341 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ |
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342 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ |
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343 /* end-of-error-codes */ |
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344 |
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345 /* |
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346 ** CAPI3REF: Extended Result Codes {H10220} <S10700> |
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347 ** KEYWORDS: {extended error code} {extended error codes} |
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348 ** KEYWORDS: {extended result code} {extended result codes} |
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349 ** |
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350 ** In its default configuration, SQLite API routines return one of 26 integer |
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351 ** [SQLITE_OK | result codes]. However, experience has shown that many of |
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352 ** these result codes are too coarse-grained. They do not provide as |
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353 ** much information about problems as programmers might like. In an effort to |
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354 ** address this, newer versions of SQLite (version 3.3.8 and later) include |
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355 ** support for additional result codes that provide more detailed information |
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356 ** about errors. The extended result codes are enabled or disabled |
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357 ** on a per database connection basis using the |
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358 ** [sqlite3_extended_result_codes()] API. |
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359 ** |
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360 ** Some of the available extended result codes are listed here. |
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361 ** One may expect the number of extended result codes will be expand |
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362 ** over time. Software that uses extended result codes should expect |
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363 ** to see new result codes in future releases of SQLite. |
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364 ** |
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365 ** The SQLITE_OK result code will never be extended. It will always |
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366 ** be exactly zero. |
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367 */ |
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368 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) |
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369 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) |
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370 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) |
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371 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) |
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372 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) |
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373 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) |
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374 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) |
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375 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) |
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376 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) |
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377 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) |
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378 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) |
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379 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) |
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380 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) |
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381 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) |
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382 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) |
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383 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) |
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384 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) |
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385 |
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386 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8) ) |
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387 |
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388 /* |
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389 ** CAPI3REF: Flags For File Open Operations {H10230} <H11120> <H12700> |
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390 ** |
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391 ** These bit values are intended for use in the |
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392 ** 3rd parameter to the [sqlite3_open_v2()] interface and |
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393 ** in the 4th parameter to the xOpen method of the |
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394 ** [sqlite3_vfs] object. |
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395 */ |
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396 #define SQLITE_OPEN_READONLY 0x00000001 |
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397 #define SQLITE_OPEN_READWRITE 0x00000002 |
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398 #define SQLITE_OPEN_CREATE 0x00000004 |
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399 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 |
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400 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 |
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401 #define SQLITE_OPEN_AUTOPROXY 0x00000020 |
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402 #define SQLITE_OPEN_MAIN_DB 0x00000100 |
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403 #define SQLITE_OPEN_TEMP_DB 0x00000200 |
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404 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 |
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405 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 |
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406 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 |
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407 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 |
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408 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 |
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409 #define SQLITE_OPEN_NOMUTEX 0x00008000 |
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410 #define SQLITE_OPEN_FULLMUTEX 0x00010000 |
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411 |
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412 /* |
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413 ** CAPI3REF: Device Characteristics {H10240} <H11120> |
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414 ** |
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415 ** The xDeviceCapabilities method of the [sqlite3_io_methods] |
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416 ** object returns an integer which is a vector of the these |
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417 ** bit values expressing I/O characteristics of the mass storage |
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418 ** device that holds the file that the [sqlite3_io_methods] |
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419 ** refers to. |
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420 ** |
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421 ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
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422 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
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423 ** mean that writes of blocks that are nnn bytes in size and |
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424 ** are aligned to an address which is an integer multiple of |
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425 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
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426 ** that when data is appended to a file, the data is appended |
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427 ** first then the size of the file is extended, never the other |
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428 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
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429 ** information is written to disk in the same order as calls |
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430 ** to xWrite(). |
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431 */ |
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432 #define SQLITE_IOCAP_ATOMIC 0x00000001 |
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433 #define SQLITE_IOCAP_ATOMIC512 0x00000002 |
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434 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 |
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435 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 |
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436 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 |
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437 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 |
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438 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 |
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439 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 |
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440 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 |
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441 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 |
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442 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 |
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443 |
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444 /* |
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445 ** CAPI3REF: File Locking Levels {H10250} <H11120> <H11310> |
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446 ** |
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447 ** SQLite uses one of these integer values as the second |
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448 ** argument to calls it makes to the xLock() and xUnlock() methods |
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449 ** of an [sqlite3_io_methods] object. |
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450 */ |
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451 #define SQLITE_LOCK_NONE 0 |
|
452 #define SQLITE_LOCK_SHARED 1 |
|
453 #define SQLITE_LOCK_RESERVED 2 |
|
454 #define SQLITE_LOCK_PENDING 3 |
|
455 #define SQLITE_LOCK_EXCLUSIVE 4 |
|
456 |
|
457 /* |
|
458 ** CAPI3REF: Synchronization Type Flags {H10260} <H11120> |
|
459 ** |
|
460 ** When SQLite invokes the xSync() method of an |
|
461 ** [sqlite3_io_methods] object it uses a combination of |
|
462 ** these integer values as the second argument. |
|
463 ** |
|
464 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the |
|
465 ** sync operation only needs to flush data to mass storage. Inode |
|
466 ** information need not be flushed. The SQLITE_SYNC_NORMAL flag means |
|
467 ** to use normal fsync() semantics. The SQLITE_SYNC_FULL flag means |
|
468 ** to use Mac OS X style fullsync instead of fsync(). |
|
469 */ |
|
470 #define SQLITE_SYNC_NORMAL 0x00002 |
|
471 #define SQLITE_SYNC_FULL 0x00003 |
|
472 #define SQLITE_SYNC_DATAONLY 0x00010 |
|
473 |
|
474 /* |
|
475 ** CAPI3REF: OS Interface Open File Handle {H11110} <S20110> |
|
476 ** |
|
477 ** An [sqlite3_file] object represents an open file in the OS |
|
478 ** interface layer. Individual OS interface implementations will |
|
479 ** want to subclass this object by appending additional fields |
|
480 ** for their own use. The pMethods entry is a pointer to an |
|
481 ** [sqlite3_io_methods] object that defines methods for performing |
|
482 ** I/O operations on the open file. |
|
483 */ |
|
484 typedef struct sqlite3_file sqlite3_file; |
|
485 struct sqlite3_file { |
|
486 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ |
|
487 }; |
|
488 |
|
489 /* |
|
490 ** CAPI3REF: OS Interface File Virtual Methods Object {H11120} <S20110> |
|
491 ** |
|
492 ** Every file opened by the [sqlite3_vfs] xOpen method populates an |
|
493 ** [sqlite3_file] object (or, more commonly, a subclass of the |
|
494 ** [sqlite3_file] object) with a pointer to an instance of this object. |
|
495 ** This object defines the methods used to perform various operations |
|
496 ** against the open file represented by the [sqlite3_file] object. |
|
497 ** |
|
498 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or |
|
499 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). |
|
500 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] |
|
501 ** flag may be ORed in to indicate that only the data of the file |
|
502 ** and not its inode needs to be synced. |
|
503 ** |
|
504 ** The integer values to xLock() and xUnlock() are one of |
|
505 ** <ul> |
|
506 ** <li> [SQLITE_LOCK_NONE], |
|
507 ** <li> [SQLITE_LOCK_SHARED], |
|
508 ** <li> [SQLITE_LOCK_RESERVED], |
|
509 ** <li> [SQLITE_LOCK_PENDING], or |
|
510 ** <li> [SQLITE_LOCK_EXCLUSIVE]. |
|
511 ** </ul> |
|
512 ** xLock() increases the lock. xUnlock() decreases the lock. |
|
513 ** The xCheckReservedLock() method checks whether any database connection, |
|
514 ** either in this process or in some other process, is holding a RESERVED, |
|
515 ** PENDING, or EXCLUSIVE lock on the file. It returns true |
|
516 ** if such a lock exists and false otherwise. |
|
517 ** |
|
518 ** The xFileControl() method is a generic interface that allows custom |
|
519 ** VFS implementations to directly control an open file using the |
|
520 ** [sqlite3_file_control()] interface. The second "op" argument is an |
|
521 ** integer opcode. The third argument is a generic pointer intended to |
|
522 ** point to a structure that may contain arguments or space in which to |
|
523 ** write return values. Potential uses for xFileControl() might be |
|
524 ** functions to enable blocking locks with timeouts, to change the |
|
525 ** locking strategy (for example to use dot-file locks), to inquire |
|
526 ** about the status of a lock, or to break stale locks. The SQLite |
|
527 ** core reserves all opcodes less than 100 for its own use. |
|
528 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. |
|
529 ** Applications that define a custom xFileControl method should use opcodes |
|
530 ** greater than 100 to avoid conflicts. |
|
531 ** |
|
532 ** The xSectorSize() method returns the sector size of the |
|
533 ** device that underlies the file. The sector size is the |
|
534 ** minimum write that can be performed without disturbing |
|
535 ** other bytes in the file. The xDeviceCharacteristics() |
|
536 ** method returns a bit vector describing behaviors of the |
|
537 ** underlying device: |
|
538 ** |
|
539 ** <ul> |
|
540 ** <li> [SQLITE_IOCAP_ATOMIC] |
|
541 ** <li> [SQLITE_IOCAP_ATOMIC512] |
|
542 ** <li> [SQLITE_IOCAP_ATOMIC1K] |
|
543 ** <li> [SQLITE_IOCAP_ATOMIC2K] |
|
544 ** <li> [SQLITE_IOCAP_ATOMIC4K] |
|
545 ** <li> [SQLITE_IOCAP_ATOMIC8K] |
|
546 ** <li> [SQLITE_IOCAP_ATOMIC16K] |
|
547 ** <li> [SQLITE_IOCAP_ATOMIC32K] |
|
548 ** <li> [SQLITE_IOCAP_ATOMIC64K] |
|
549 ** <li> [SQLITE_IOCAP_SAFE_APPEND] |
|
550 ** <li> [SQLITE_IOCAP_SEQUENTIAL] |
|
551 ** </ul> |
|
552 ** |
|
553 ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
|
554 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
|
555 ** mean that writes of blocks that are nnn bytes in size and |
|
556 ** are aligned to an address which is an integer multiple of |
|
557 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
|
558 ** that when data is appended to a file, the data is appended |
|
559 ** first then the size of the file is extended, never the other |
|
560 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
|
561 ** information is written to disk in the same order as calls |
|
562 ** to xWrite(). |
|
563 ** |
|
564 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill |
|
565 ** in the unread portions of the buffer with zeros. A VFS that |
|
566 ** fails to zero-fill short reads might seem to work. However, |
|
567 ** failure to zero-fill short reads will eventually lead to |
|
568 ** database corruption. |
|
569 */ |
|
570 typedef struct sqlite3_io_methods sqlite3_io_methods; |
|
571 struct sqlite3_io_methods { |
|
572 int iVersion; |
|
573 int (*xClose)(sqlite3_file*); |
|
574 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
|
575 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); |
|
576 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); |
|
577 int (*xSync)(sqlite3_file*, int flags); |
|
578 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); |
|
579 int (*xLock)(sqlite3_file*, int); |
|
580 int (*xUnlock)(sqlite3_file*, int); |
|
581 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
|
582 int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
|
583 int (*xSectorSize)(sqlite3_file*); |
|
584 int (*xDeviceCharacteristics)(sqlite3_file*); |
|
585 /* Additional methods may be added in future releases */ |
|
586 }; |
|
587 |
|
588 /* |
|
589 ** CAPI3REF: Standard File Control Opcodes {H11310} <S30800> |
|
590 ** |
|
591 ** These integer constants are opcodes for the xFileControl method |
|
592 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] |
|
593 ** interface. |
|
594 ** |
|
595 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This |
|
596 ** opcode causes the xFileControl method to write the current state of |
|
597 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], |
|
598 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) |
|
599 ** into an integer that the pArg argument points to. This capability |
|
600 ** is used during testing and only needs to be supported when SQLITE_TEST |
|
601 ** is defined. |
|
602 */ |
|
603 #define SQLITE_FCNTL_LOCKSTATE 1 |
|
604 #define SQLITE_GET_LOCKPROXYFILE 2 |
|
605 #define SQLITE_SET_LOCKPROXYFILE 3 |
|
606 #define SQLITE_LAST_ERRNO 4 |
|
607 |
|
608 /* |
|
609 ** CAPI3REF: Mutex Handle {H17110} <S20130> |
|
610 ** |
|
611 ** The mutex module within SQLite defines [sqlite3_mutex] to be an |
|
612 ** abstract type for a mutex object. The SQLite core never looks |
|
613 ** at the internal representation of an [sqlite3_mutex]. It only |
|
614 ** deals with pointers to the [sqlite3_mutex] object. |
|
615 ** |
|
616 ** Mutexes are created using [sqlite3_mutex_alloc()]. |
|
617 */ |
|
618 typedef struct sqlite3_mutex sqlite3_mutex; |
|
619 |
|
620 /* |
|
621 ** CAPI3REF: OS Interface Object {H11140} <S20100> |
|
622 ** |
|
623 ** An instance of the sqlite3_vfs object defines the interface between |
|
624 ** the SQLite core and the underlying operating system. The "vfs" |
|
625 ** in the name of the object stands for "virtual file system". |
|
626 ** |
|
627 ** The value of the iVersion field is initially 1 but may be larger in |
|
628 ** future versions of SQLite. Additional fields may be appended to this |
|
629 ** object when the iVersion value is increased. Note that the structure |
|
630 ** of the sqlite3_vfs object changes in the transaction between |
|
631 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not |
|
632 ** modified. |
|
633 ** |
|
634 ** The szOsFile field is the size of the subclassed [sqlite3_file] |
|
635 ** structure used by this VFS. mxPathname is the maximum length of |
|
636 ** a pathname in this VFS. |
|
637 ** |
|
638 ** Registered sqlite3_vfs objects are kept on a linked list formed by |
|
639 ** the pNext pointer. The [sqlite3_vfs_register()] |
|
640 ** and [sqlite3_vfs_unregister()] interfaces manage this list |
|
641 ** in a thread-safe way. The [sqlite3_vfs_find()] interface |
|
642 ** searches the list. Neither the application code nor the VFS |
|
643 ** implementation should use the pNext pointer. |
|
644 ** |
|
645 ** The pNext field is the only field in the sqlite3_vfs |
|
646 ** structure that SQLite will ever modify. SQLite will only access |
|
647 ** or modify this field while holding a particular static mutex. |
|
648 ** The application should never modify anything within the sqlite3_vfs |
|
649 ** object once the object has been registered. |
|
650 ** |
|
651 ** The zName field holds the name of the VFS module. The name must |
|
652 ** be unique across all VFS modules. |
|
653 ** |
|
654 ** SQLite will guarantee that the zFilename parameter to xOpen |
|
655 ** is either a NULL pointer or string obtained |
|
656 ** from xFullPathname(). SQLite further guarantees that |
|
657 ** the string will be valid and unchanged until xClose() is |
|
658 ** called. Because of the previous sentense, |
|
659 ** the [sqlite3_file] can safely store a pointer to the |
|
660 ** filename if it needs to remember the filename for some reason. |
|
661 ** If the zFilename parameter is xOpen is a NULL pointer then xOpen |
|
662 ** must invite its own temporary name for the file. Whenever the |
|
663 ** xFilename parameter is NULL it will also be the case that the |
|
664 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. |
|
665 ** |
|
666 ** The flags argument to xOpen() includes all bits set in |
|
667 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] |
|
668 ** or [sqlite3_open16()] is used, then flags includes at least |
|
669 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. |
|
670 ** If xOpen() opens a file read-only then it sets *pOutFlags to |
|
671 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. |
|
672 ** |
|
673 ** SQLite will also add one of the following flags to the xOpen() |
|
674 ** call, depending on the object being opened: |
|
675 ** |
|
676 ** <ul> |
|
677 ** <li> [SQLITE_OPEN_MAIN_DB] |
|
678 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] |
|
679 ** <li> [SQLITE_OPEN_TEMP_DB] |
|
680 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] |
|
681 ** <li> [SQLITE_OPEN_TRANSIENT_DB] |
|
682 ** <li> [SQLITE_OPEN_SUBJOURNAL] |
|
683 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] |
|
684 ** </ul> |
|
685 ** |
|
686 ** The file I/O implementation can use the object type flags to |
|
687 ** change the way it deals with files. For example, an application |
|
688 ** that does not care about crash recovery or rollback might make |
|
689 ** the open of a journal file a no-op. Writes to this journal would |
|
690 ** also be no-ops, and any attempt to read the journal would return |
|
691 ** SQLITE_IOERR. Or the implementation might recognize that a database |
|
692 ** file will be doing page-aligned sector reads and writes in a random |
|
693 ** order and set up its I/O subsystem accordingly. |
|
694 ** |
|
695 ** SQLite might also add one of the following flags to the xOpen method: |
|
696 ** |
|
697 ** <ul> |
|
698 ** <li> [SQLITE_OPEN_DELETEONCLOSE] |
|
699 ** <li> [SQLITE_OPEN_EXCLUSIVE] |
|
700 ** </ul> |
|
701 ** |
|
702 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be |
|
703 ** deleted when it is closed. The [SQLITE_OPEN_DELETEONCLOSE] |
|
704 ** will be set for TEMP databases, journals and for subjournals. |
|
705 ** |
|
706 ** The [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened |
|
707 ** for exclusive access. This flag is set for all files except |
|
708 ** for the main database file. |
|
709 ** |
|
710 ** At least szOsFile bytes of memory are allocated by SQLite |
|
711 ** to hold the [sqlite3_file] structure passed as the third |
|
712 ** argument to xOpen. The xOpen method does not have to |
|
713 ** allocate the structure; it should just fill it in. |
|
714 ** |
|
715 ** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] |
|
716 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to |
|
717 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] |
|
718 ** to test whether a file is at least readable. The file can be a |
|
719 ** directory. |
|
720 ** |
|
721 ** SQLite will always allocate at least mxPathname+1 bytes for the |
|
722 ** output buffer xFullPathname. The exact size of the output buffer |
|
723 ** is also passed as a parameter to both methods. If the output buffer |
|
724 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is |
|
725 ** handled as a fatal error by SQLite, vfs implementations should endeavor |
|
726 ** to prevent this by setting mxPathname to a sufficiently large value. |
|
727 ** |
|
728 ** The xRandomness(), xSleep(), and xCurrentTime() interfaces |
|
729 ** are not strictly a part of the filesystem, but they are |
|
730 ** included in the VFS structure for completeness. |
|
731 ** The xRandomness() function attempts to return nBytes bytes |
|
732 ** of good-quality randomness into zOut. The return value is |
|
733 ** the actual number of bytes of randomness obtained. |
|
734 ** The xSleep() method causes the calling thread to sleep for at |
|
735 ** least the number of microseconds given. The xCurrentTime() |
|
736 ** method returns a Julian Day Number for the current date and time. |
|
737 ** |
|
738 */ |
|
739 typedef struct sqlite3_vfs sqlite3_vfs; |
|
740 struct sqlite3_vfs { |
|
741 int iVersion; /* Structure version number */ |
|
742 int szOsFile; /* Size of subclassed sqlite3_file */ |
|
743 int mxPathname; /* Maximum file pathname length */ |
|
744 sqlite3_vfs *pNext; /* Next registered VFS */ |
|
745 const char *zName; /* Name of this virtual file system */ |
|
746 void *pAppData; /* Pointer to application-specific data */ |
|
747 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, |
|
748 int flags, int *pOutFlags); |
|
749 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); |
|
750 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
|
751 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
|
752 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); |
|
753 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); |
|
754 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
|
755 void (*xDlClose)(sqlite3_vfs*, void*); |
|
756 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); |
|
757 int (*xSleep)(sqlite3_vfs*, int microseconds); |
|
758 int (*xCurrentTime)(sqlite3_vfs*, double*); |
|
759 int (*xGetLastError)(sqlite3_vfs*, int, char *); |
|
760 /* New fields may be appended in figure versions. The iVersion |
|
761 ** value will increment whenever this happens. */ |
|
762 }; |
|
763 |
|
764 /* |
|
765 ** CAPI3REF: Flags for the xAccess VFS method {H11190} <H11140> |
|
766 ** |
|
767 ** These integer constants can be used as the third parameter to |
|
768 ** the xAccess method of an [sqlite3_vfs] object. {END} They determine |
|
769 ** what kind of permissions the xAccess method is looking for. |
|
770 ** With SQLITE_ACCESS_EXISTS, the xAccess method |
|
771 ** simply checks whether the file exists. |
|
772 ** With SQLITE_ACCESS_READWRITE, the xAccess method |
|
773 ** checks whether the file is both readable and writable. |
|
774 ** With SQLITE_ACCESS_READ, the xAccess method |
|
775 ** checks whether the file is readable. |
|
776 */ |
|
777 #define SQLITE_ACCESS_EXISTS 0 |
|
778 #define SQLITE_ACCESS_READWRITE 1 |
|
779 #define SQLITE_ACCESS_READ 2 |
|
780 |
|
781 /* |
|
782 ** CAPI3REF: Initialize The SQLite Library {H10130} <S20000><S30100> |
|
783 ** |
|
784 ** The sqlite3_initialize() routine initializes the |
|
785 ** SQLite library. The sqlite3_shutdown() routine |
|
786 ** deallocates any resources that were allocated by sqlite3_initialize(). |
|
787 ** |
|
788 ** A call to sqlite3_initialize() is an "effective" call if it is |
|
789 ** the first time sqlite3_initialize() is invoked during the lifetime of |
|
790 ** the process, or if it is the first time sqlite3_initialize() is invoked |
|
791 ** following a call to sqlite3_shutdown(). Only an effective call |
|
792 ** of sqlite3_initialize() does any initialization. All other calls |
|
793 ** are harmless no-ops. |
|
794 ** |
|
795 ** Among other things, sqlite3_initialize() shall invoke |
|
796 ** sqlite3_os_init(). Similarly, sqlite3_shutdown() |
|
797 ** shall invoke sqlite3_os_end(). |
|
798 ** |
|
799 ** The sqlite3_initialize() routine returns [SQLITE_OK] on success. |
|
800 ** If for some reason, sqlite3_initialize() is unable to initialize |
|
801 ** the library (perhaps it is unable to allocate a needed resource such |
|
802 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. |
|
803 ** |
|
804 ** The sqlite3_initialize() routine is called internally by many other |
|
805 ** SQLite interfaces so that an application usually does not need to |
|
806 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] |
|
807 ** calls sqlite3_initialize() so the SQLite library will be automatically |
|
808 ** initialized when [sqlite3_open()] is called if it has not be initialized |
|
809 ** already. However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] |
|
810 ** compile-time option, then the automatic calls to sqlite3_initialize() |
|
811 ** are omitted and the application must call sqlite3_initialize() directly |
|
812 ** prior to using any other SQLite interface. For maximum portability, |
|
813 ** it is recommended that applications always invoke sqlite3_initialize() |
|
814 ** directly prior to using any other SQLite interface. Future releases |
|
815 ** of SQLite may require this. In other words, the behavior exhibited |
|
816 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the |
|
817 ** default behavior in some future release of SQLite. |
|
818 ** |
|
819 ** The sqlite3_os_init() routine does operating-system specific |
|
820 ** initialization of the SQLite library. The sqlite3_os_end() |
|
821 ** routine undoes the effect of sqlite3_os_init(). Typical tasks |
|
822 ** performed by these routines include allocation or deallocation |
|
823 ** of static resources, initialization of global variables, |
|
824 ** setting up a default [sqlite3_vfs] module, or setting up |
|
825 ** a default configuration using [sqlite3_config()]. |
|
826 ** |
|
827 ** The application should never invoke either sqlite3_os_init() |
|
828 ** or sqlite3_os_end() directly. The application should only invoke |
|
829 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() |
|
830 ** interface is called automatically by sqlite3_initialize() and |
|
831 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate |
|
832 ** implementations for sqlite3_os_init() and sqlite3_os_end() |
|
833 ** are built into SQLite when it is compiled for unix, windows, or os/2. |
|
834 ** When built for other platforms (using the [SQLITE_OS_OTHER=1] compile-time |
|
835 ** option) the application must supply a suitable implementation for |
|
836 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied |
|
837 ** implementation of sqlite3_os_init() or sqlite3_os_end() |
|
838 ** must return [SQLITE_OK] on success and some other [error code] upon |
|
839 ** failure. |
|
840 */ |
|
841 int sqlite3_initialize(void); |
|
842 int sqlite3_shutdown(void); |
|
843 int sqlite3_os_init(void); |
|
844 int sqlite3_os_end(void); |
|
845 |
|
846 /* |
|
847 ** CAPI3REF: Configuring The SQLite Library {H14100} <S20000><S30200> |
|
848 ** EXPERIMENTAL |
|
849 ** |
|
850 ** The sqlite3_config() interface is used to make global configuration |
|
851 ** changes to SQLite in order to tune SQLite to the specific needs of |
|
852 ** the application. The default configuration is recommended for most |
|
853 ** applications and so this routine is usually not necessary. It is |
|
854 ** provided to support rare applications with unusual needs. |
|
855 ** |
|
856 ** The sqlite3_config() interface is not threadsafe. The application |
|
857 ** must insure that no other SQLite interfaces are invoked by other |
|
858 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() |
|
859 ** may only be invoked prior to library initialization using |
|
860 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. |
|
861 ** Note, however, that sqlite3_config() can be called as part of the |
|
862 ** implementation of an application-defined [sqlite3_os_init()]. |
|
863 ** |
|
864 ** The first argument to sqlite3_config() is an integer |
|
865 ** [SQLITE_CONFIG_SINGLETHREAD | configuration option] that determines |
|
866 ** what property of SQLite is to be configured. Subsequent arguments |
|
867 ** vary depending on the [SQLITE_CONFIG_SINGLETHREAD | configuration option] |
|
868 ** in the first argument. |
|
869 ** |
|
870 ** When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. |
|
871 ** If the option is unknown or SQLite is unable to set the option |
|
872 ** then this routine returns a non-zero [error code]. |
|
873 ** |
|
874 ** Requirements: |
|
875 ** [H14103] [H14106] [H14120] [H14123] [H14126] [H14129] [H14132] [H14135] |
|
876 ** [H14138] [H14141] [H14144] [H14147] [H14150] [H14153] [H14156] [H14159] |
|
877 ** [H14162] [H14165] [H14168] |
|
878 */ |
|
879 SQLITE_EXPERIMENTAL int sqlite3_config(int, ...); |
|
880 |
|
881 /* |
|
882 ** CAPI3REF: Configure database connections {H14200} <S20000> |
|
883 ** EXPERIMENTAL |
|
884 ** |
|
885 ** The sqlite3_db_config() interface is used to make configuration |
|
886 ** changes to a [database connection]. The interface is similar to |
|
887 ** [sqlite3_config()] except that the changes apply to a single |
|
888 ** [database connection] (specified in the first argument). The |
|
889 ** sqlite3_db_config() interface can only be used immediately after |
|
890 ** the database connection is created using [sqlite3_open()], |
|
891 ** [sqlite3_open16()], or [sqlite3_open_v2()]. |
|
892 ** |
|
893 ** The second argument to sqlite3_db_config(D,V,...) is the |
|
894 ** configuration verb - an integer code that indicates what |
|
895 ** aspect of the [database connection] is being configured. |
|
896 ** The only choice for this value is [SQLITE_DBCONFIG_LOOKASIDE]. |
|
897 ** New verbs are likely to be added in future releases of SQLite. |
|
898 ** Additional arguments depend on the verb. |
|
899 ** |
|
900 ** Requirements: |
|
901 ** [H14203] [H14206] [H14209] [H14212] [H14215] |
|
902 */ |
|
903 SQLITE_EXPERIMENTAL int sqlite3_db_config(sqlite3*, int op, ...); |
|
904 |
|
905 /* |
|
906 ** CAPI3REF: Memory Allocation Routines {H10155} <S20120> |
|
907 ** EXPERIMENTAL |
|
908 ** |
|
909 ** An instance of this object defines the interface between SQLite |
|
910 ** and low-level memory allocation routines. |
|
911 ** |
|
912 ** This object is used in only one place in the SQLite interface. |
|
913 ** A pointer to an instance of this object is the argument to |
|
914 ** [sqlite3_config()] when the configuration option is |
|
915 ** [SQLITE_CONFIG_MALLOC]. By creating an instance of this object |
|
916 ** and passing it to [sqlite3_config()] during configuration, an |
|
917 ** application can specify an alternative memory allocation subsystem |
|
918 ** for SQLite to use for all of its dynamic memory needs. |
|
919 ** |
|
920 ** Note that SQLite comes with a built-in memory allocator that is |
|
921 ** perfectly adequate for the overwhelming majority of applications |
|
922 ** and that this object is only useful to a tiny minority of applications |
|
923 ** with specialized memory allocation requirements. This object is |
|
924 ** also used during testing of SQLite in order to specify an alternative |
|
925 ** memory allocator that simulates memory out-of-memory conditions in |
|
926 ** order to verify that SQLite recovers gracefully from such |
|
927 ** conditions. |
|
928 ** |
|
929 ** The xMalloc, xFree, and xRealloc methods must work like the |
|
930 ** malloc(), free(), and realloc() functions from the standard library. |
|
931 ** |
|
932 ** xSize should return the allocated size of a memory allocation |
|
933 ** previously obtained from xMalloc or xRealloc. The allocated size |
|
934 ** is always at least as big as the requested size but may be larger. |
|
935 ** |
|
936 ** The xRoundup method returns what would be the allocated size of |
|
937 ** a memory allocation given a particular requested size. Most memory |
|
938 ** allocators round up memory allocations at least to the next multiple |
|
939 ** of 8. Some allocators round up to a larger multiple or to a power of 2. |
|
940 ** |
|
941 ** The xInit method initializes the memory allocator. (For example, |
|
942 ** it might allocate any require mutexes or initialize internal data |
|
943 ** structures. The xShutdown method is invoked (indirectly) by |
|
944 ** [sqlite3_shutdown()] and should deallocate any resources acquired |
|
945 ** by xInit. The pAppData pointer is used as the only parameter to |
|
946 ** xInit and xShutdown. |
|
947 */ |
|
948 typedef struct sqlite3_mem_methods sqlite3_mem_methods; |
|
949 struct sqlite3_mem_methods { |
|
950 void *(*xMalloc)(int); /* Memory allocation function */ |
|
951 void (*xFree)(void*); /* Free a prior allocation */ |
|
952 void *(*xRealloc)(void*,int); /* Resize an allocation */ |
|
953 int (*xSize)(void*); /* Return the size of an allocation */ |
|
954 int (*xRoundup)(int); /* Round up request size to allocation size */ |
|
955 int (*xInit)(void*); /* Initialize the memory allocator */ |
|
956 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ |
|
957 void *pAppData; /* Argument to xInit() and xShutdown() */ |
|
958 }; |
|
959 |
|
960 /* |
|
961 ** CAPI3REF: Configuration Options {H10160} <S20000> |
|
962 ** EXPERIMENTAL |
|
963 ** |
|
964 ** These constants are the available integer configuration options that |
|
965 ** can be passed as the first argument to the [sqlite3_config()] interface. |
|
966 ** |
|
967 ** New configuration options may be added in future releases of SQLite. |
|
968 ** Existing configuration options might be discontinued. Applications |
|
969 ** should check the return code from [sqlite3_config()] to make sure that |
|
970 ** the call worked. The [sqlite3_config()] interface will return a |
|
971 ** non-zero [error code] if a discontinued or unsupported configuration option |
|
972 ** is invoked. |
|
973 ** |
|
974 ** <dl> |
|
975 ** <dt>SQLITE_CONFIG_SINGLETHREAD</dt> |
|
976 ** <dd>There are no arguments to this option. This option disables |
|
977 ** all mutexing and puts SQLite into a mode where it can only be used |
|
978 ** by a single thread.</dd> |
|
979 ** |
|
980 ** <dt>SQLITE_CONFIG_MULTITHREAD</dt> |
|
981 ** <dd>There are no arguments to this option. This option disables |
|
982 ** mutexing on [database connection] and [prepared statement] objects. |
|
983 ** The application is responsible for serializing access to |
|
984 ** [database connections] and [prepared statements]. But other mutexes |
|
985 ** are enabled so that SQLite will be safe to use in a multi-threaded |
|
986 ** environment as long as no two threads attempt to use the same |
|
987 ** [database connection] at the same time. See the [threading mode] |
|
988 ** documentation for additional information.</dd> |
|
989 ** |
|
990 ** <dt>SQLITE_CONFIG_SERIALIZED</dt> |
|
991 ** <dd>There are no arguments to this option. This option enables |
|
992 ** all mutexes including the recursive |
|
993 ** mutexes on [database connection] and [prepared statement] objects. |
|
994 ** In this mode (which is the default when SQLite is compiled with |
|
995 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access |
|
996 ** to [database connections] and [prepared statements] so that the |
|
997 ** application is free to use the same [database connection] or the |
|
998 ** same [prepared statement] in different threads at the same time. |
|
999 ** See the [threading mode] documentation for additional information.</dd> |
|
1000 ** |
|
1001 ** <dt>SQLITE_CONFIG_MALLOC</dt> |
|
1002 ** <dd>This option takes a single argument which is a pointer to an |
|
1003 ** instance of the [sqlite3_mem_methods] structure. The argument specifies |
|
1004 ** alternative low-level memory allocation routines to be used in place of |
|
1005 ** the memory allocation routines built into SQLite.</dd> |
|
1006 ** |
|
1007 ** <dt>SQLITE_CONFIG_GETMALLOC</dt> |
|
1008 ** <dd>This option takes a single argument which is a pointer to an |
|
1009 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] |
|
1010 ** structure is filled with the currently defined memory allocation routines. |
|
1011 ** This option can be used to overload the default memory allocation |
|
1012 ** routines with a wrapper that simulations memory allocation failure or |
|
1013 ** tracks memory usage, for example.</dd> |
|
1014 ** |
|
1015 ** <dt>SQLITE_CONFIG_MEMSTATUS</dt> |
|
1016 ** <dd>This option takes single argument of type int, interpreted as a |
|
1017 ** boolean, which enables or disables the collection of memory allocation |
|
1018 ** statistics. When disabled, the following SQLite interfaces become |
|
1019 ** non-operational: |
|
1020 ** <ul> |
|
1021 ** <li> [sqlite3_memory_used()] |
|
1022 ** <li> [sqlite3_memory_highwater()] |
|
1023 ** <li> [sqlite3_soft_heap_limit()] |
|
1024 ** <li> [sqlite3_status()] |
|
1025 ** </ul> |
|
1026 ** </dd> |
|
1027 ** |
|
1028 ** <dt>SQLITE_CONFIG_SCRATCH</dt> |
|
1029 ** <dd>This option specifies a static memory buffer that SQLite can use for |
|
1030 ** scratch memory. There are three arguments: A pointer to the memory, the |
|
1031 ** size of each scratch buffer (sz), and the number of buffers (N). The sz |
|
1032 ** argument must be a multiple of 16. The sz parameter should be a few bytes |
|
1033 ** larger than the actual scratch space required due internal overhead. |
|
1034 ** The first |
|
1035 ** argument should point to an allocation of at least sz*N bytes of memory. |
|
1036 ** SQLite will use no more than one scratch buffer at once per thread, so |
|
1037 ** N should be set to the expected maximum number of threads. The sz |
|
1038 ** parameter should be 6 times the size of the largest database page size. |
|
1039 ** Scratch buffers are used as part of the btree balance operation. If |
|
1040 ** The btree balancer needs additional memory beyond what is provided by |
|
1041 ** scratch buffers or if no scratch buffer space is specified, then SQLite |
|
1042 ** goes to [sqlite3_malloc()] to obtain the memory it needs.</dd> |
|
1043 ** |
|
1044 ** <dt>SQLITE_CONFIG_PAGECACHE</dt> |
|
1045 ** <dd>This option specifies a static memory buffer that SQLite can use for |
|
1046 ** the database page cache with the default page cache implemenation. |
|
1047 ** This configuration should not be used if an application-define page |
|
1048 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. |
|
1049 ** There are three arguments to this option: A pointer to the |
|
1050 ** memory, the size of each page buffer (sz), and the number of pages (N). |
|
1051 ** The sz argument must be a power of two between 512 and 32768. The first |
|
1052 ** argument should point to an allocation of at least sz*N bytes of memory. |
|
1053 ** SQLite will use the memory provided by the first argument to satisfy its |
|
1054 ** memory needs for the first N pages that it adds to cache. If additional |
|
1055 ** page cache memory is needed beyond what is provided by this option, then |
|
1056 ** SQLite goes to [sqlite3_malloc()] for the additional storage space. |
|
1057 ** The implementation might use one or more of the N buffers to hold |
|
1058 ** memory accounting information. </dd> |
|
1059 ** |
|
1060 ** <dt>SQLITE_CONFIG_HEAP</dt> |
|
1061 ** <dd>This option specifies a static memory buffer that SQLite will use |
|
1062 ** for all of its dynamic memory allocation needs beyond those provided |
|
1063 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. |
|
1064 ** There are three arguments: A pointer to the memory, the number of |
|
1065 ** bytes in the memory buffer, and the minimum allocation size. If |
|
1066 ** the first pointer (the memory pointer) is NULL, then SQLite reverts |
|
1067 ** to using its default memory allocator (the system malloc() implementation), |
|
1068 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. If the |
|
1069 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or |
|
1070 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory |
|
1071 ** allocator is engaged to handle all of SQLites memory allocation needs.</dd> |
|
1072 ** |
|
1073 ** <dt>SQLITE_CONFIG_MUTEX</dt> |
|
1074 ** <dd>This option takes a single argument which is a pointer to an |
|
1075 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies |
|
1076 ** alternative low-level mutex routines to be used in place |
|
1077 ** the mutex routines built into SQLite.</dd> |
|
1078 ** |
|
1079 ** <dt>SQLITE_CONFIG_GETMUTEX</dt> |
|
1080 ** <dd>This option takes a single argument which is a pointer to an |
|
1081 ** instance of the [sqlite3_mutex_methods] structure. The |
|
1082 ** [sqlite3_mutex_methods] |
|
1083 ** structure is filled with the currently defined mutex routines. |
|
1084 ** This option can be used to overload the default mutex allocation |
|
1085 ** routines with a wrapper used to track mutex usage for performance |
|
1086 ** profiling or testing, for example.</dd> |
|
1087 ** |
|
1088 ** <dt>SQLITE_CONFIG_LOOKASIDE</dt> |
|
1089 ** <dd>This option takes two arguments that determine the default |
|
1090 ** memory allcation lookaside optimization. The first argument is the |
|
1091 ** size of each lookaside buffer slot and the second is the number of |
|
1092 ** slots allocated to each database connection.</dd> |
|
1093 ** |
|
1094 ** <dt>SQLITE_CONFIG_PCACHE</dt> |
|
1095 ** <dd>This option takes a single argument which is a pointer to |
|
1096 ** an [sqlite3_pcache_methods] object. This object specifies the interface |
|
1097 ** to a custom page cache implementation. SQLite makes a copy of the |
|
1098 ** object and uses it for page cache memory allocations.</dd> |
|
1099 ** |
|
1100 ** <dt>SQLITE_CONFIG_GETPCACHE</dt> |
|
1101 ** <dd>This option takes a single argument which is a pointer to an |
|
1102 ** [sqlite3_pcache_methods] object. SQLite copies of the current |
|
1103 ** page cache implementation into that object.</dd> |
|
1104 ** |
|
1105 ** </dl> |
|
1106 */ |
|
1107 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ |
|
1108 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ |
|
1109 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ |
|
1110 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ |
|
1111 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ |
|
1112 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ |
|
1113 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ |
|
1114 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ |
|
1115 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ |
|
1116 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ |
|
1117 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ |
|
1118 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ |
|
1119 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ |
|
1120 #define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ |
|
1121 #define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ |
|
1122 |
|
1123 /* |
|
1124 ** CAPI3REF: Configuration Options {H10170} <S20000> |
|
1125 ** EXPERIMENTAL |
|
1126 ** |
|
1127 ** These constants are the available integer configuration options that |
|
1128 ** can be passed as the second argument to the [sqlite3_db_config()] interface. |
|
1129 ** |
|
1130 ** New configuration options may be added in future releases of SQLite. |
|
1131 ** Existing configuration options might be discontinued. Applications |
|
1132 ** should check the return code from [sqlite3_db_config()] to make sure that |
|
1133 ** the call worked. The [sqlite3_db_config()] interface will return a |
|
1134 ** non-zero [error code] if a discontinued or unsupported configuration option |
|
1135 ** is invoked. |
|
1136 ** |
|
1137 ** <dl> |
|
1138 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> |
|
1139 ** <dd>This option takes three additional arguments that determine the |
|
1140 ** [lookaside memory allocator] configuration for the [database connection]. |
|
1141 ** The first argument (the third parameter to [sqlite3_db_config()] is a |
|
1142 ** pointer to a memory buffer to use for lookaside memory. The first |
|
1143 ** argument may be NULL in which case SQLite will allocate the lookaside |
|
1144 ** buffer itself using [sqlite3_malloc()]. The second argument is the |
|
1145 ** size of each lookaside buffer slot and the third argument is the number of |
|
1146 ** slots. The size of the buffer in the first argument must be greater than |
|
1147 ** or equal to the product of the second and third arguments.</dd> |
|
1148 ** |
|
1149 ** </dl> |
|
1150 */ |
|
1151 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ |
|
1152 |
|
1153 |
|
1154 /* |
|
1155 ** CAPI3REF: Enable Or Disable Extended Result Codes {H12200} <S10700> |
|
1156 ** |
|
1157 ** The sqlite3_extended_result_codes() routine enables or disables the |
|
1158 ** [extended result codes] feature of SQLite. The extended result |
|
1159 ** codes are disabled by default for historical compatibility considerations. |
|
1160 ** |
|
1161 ** Requirements: |
|
1162 ** [H12201] [H12202] |
|
1163 */ |
|
1164 int sqlite3_extended_result_codes(sqlite3*, int onoff); |
|
1165 |
|
1166 /* |
|
1167 ** CAPI3REF: Last Insert Rowid {H12220} <S10700> |
|
1168 ** |
|
1169 ** Each entry in an SQLite table has a unique 64-bit signed |
|
1170 ** integer key called the [ROWID | "rowid"]. The rowid is always available |
|
1171 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those |
|
1172 ** names are not also used by explicitly declared columns. If |
|
1173 ** the table has a column of type [INTEGER PRIMARY KEY] then that column |
|
1174 ** is another alias for the rowid. |
|
1175 ** |
|
1176 ** This routine returns the [rowid] of the most recent |
|
1177 ** successful [INSERT] into the database from the [database connection] |
|
1178 ** in the first argument. If no successful [INSERT]s |
|
1179 ** have ever occurred on that database connection, zero is returned. |
|
1180 ** |
|
1181 ** If an [INSERT] occurs within a trigger, then the [rowid] of the inserted |
|
1182 ** row is returned by this routine as long as the trigger is running. |
|
1183 ** But once the trigger terminates, the value returned by this routine |
|
1184 ** reverts to the last value inserted before the trigger fired. |
|
1185 ** |
|
1186 ** An [INSERT] that fails due to a constraint violation is not a |
|
1187 ** successful [INSERT] and does not change the value returned by this |
|
1188 ** routine. Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, |
|
1189 ** and INSERT OR ABORT make no changes to the return value of this |
|
1190 ** routine when their insertion fails. When INSERT OR REPLACE |
|
1191 ** encounters a constraint violation, it does not fail. The |
|
1192 ** INSERT continues to completion after deleting rows that caused |
|
1193 ** the constraint problem so INSERT OR REPLACE will always change |
|
1194 ** the return value of this interface. |
|
1195 ** |
|
1196 ** For the purposes of this routine, an [INSERT] is considered to |
|
1197 ** be successful even if it is subsequently rolled back. |
|
1198 ** |
|
1199 ** Requirements: |
|
1200 ** [H12221] [H12223] |
|
1201 ** |
|
1202 ** If a separate thread performs a new [INSERT] on the same |
|
1203 ** database connection while the [sqlite3_last_insert_rowid()] |
|
1204 ** function is running and thus changes the last insert [rowid], |
|
1205 ** then the value returned by [sqlite3_last_insert_rowid()] is |
|
1206 ** unpredictable and might not equal either the old or the new |
|
1207 ** last insert [rowid]. |
|
1208 */ |
|
1209 sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); |
|
1210 |
|
1211 /* |
|
1212 ** CAPI3REF: Count The Number Of Rows Modified {H12240} <S10600> |
|
1213 ** |
|
1214 ** This function returns the number of database rows that were changed |
|
1215 ** or inserted or deleted by the most recently completed SQL statement |
|
1216 ** on the [database connection] specified by the first parameter. |
|
1217 ** Only changes that are directly specified by the [INSERT], [UPDATE], |
|
1218 ** or [DELETE] statement are counted. Auxiliary changes caused by |
|
1219 ** triggers are not counted. Use the [sqlite3_total_changes()] function |
|
1220 ** to find the total number of changes including changes caused by triggers. |
|
1221 ** |
|
1222 ** A "row change" is a change to a single row of a single table |
|
1223 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that |
|
1224 ** are changed as side effects of REPLACE constraint resolution, |
|
1225 ** rollback, ABORT processing, DROP TABLE, or by any other |
|
1226 ** mechanisms do not count as direct row changes. |
|
1227 ** |
|
1228 ** A "trigger context" is a scope of execution that begins and |
|
1229 ** ends with the script of a trigger. Most SQL statements are |
|
1230 ** evaluated outside of any trigger. This is the "top level" |
|
1231 ** trigger context. If a trigger fires from the top level, a |
|
1232 ** new trigger context is entered for the duration of that one |
|
1233 ** trigger. Subtriggers create subcontexts for their duration. |
|
1234 ** |
|
1235 ** Calling [sqlite3_exec()] or [sqlite3_step()] recursively does |
|
1236 ** not create a new trigger context. |
|
1237 ** |
|
1238 ** This function returns the number of direct row changes in the |
|
1239 ** most recent INSERT, UPDATE, or DELETE statement within the same |
|
1240 ** trigger context. |
|
1241 ** |
|
1242 ** Thus, when called from the top level, this function returns the |
|
1243 ** number of changes in the most recent INSERT, UPDATE, or DELETE |
|
1244 ** that also occurred at the top level. Within the body of a trigger, |
|
1245 ** the sqlite3_changes() interface can be called to find the number of |
|
1246 ** changes in the most recently completed INSERT, UPDATE, or DELETE |
|
1247 ** statement within the body of the same trigger. |
|
1248 ** However, the number returned does not include changes |
|
1249 ** caused by subtriggers since those have their own context. |
|
1250 ** |
|
1251 ** SQLite implements the command "DELETE FROM table" without a WHERE clause |
|
1252 ** by dropping and recreating the table. Doing so is much faster than going |
|
1253 ** through and deleting individual elements from the table. Because of this |
|
1254 ** optimization, the deletions in "DELETE FROM table" are not row changes and |
|
1255 ** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] |
|
1256 ** functions, regardless of the number of elements that were originally |
|
1257 ** in the table. To get an accurate count of the number of rows deleted, use |
|
1258 ** "DELETE FROM table WHERE 1" instead. Or recompile using the |
|
1259 ** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the |
|
1260 ** optimization on all queries. |
|
1261 ** |
|
1262 ** Requirements: |
|
1263 ** [H12241] [H12243] |
|
1264 ** |
|
1265 ** If a separate thread makes changes on the same database connection |
|
1266 ** while [sqlite3_changes()] is running then the value returned |
|
1267 ** is unpredictable and not meaningful. |
|
1268 */ |
|
1269 int sqlite3_changes(sqlite3*); |
|
1270 |
|
1271 /* |
|
1272 ** CAPI3REF: Total Number Of Rows Modified {H12260} <S10600> |
|
1273 ** |
|
1274 ** This function returns the number of row changes caused by INSERT, |
|
1275 ** UPDATE or DELETE statements since the [database connection] was opened. |
|
1276 ** The count includes all changes from all trigger contexts. However, |
|
1277 ** the count does not include changes used to implement REPLACE constraints, |
|
1278 ** do rollbacks or ABORT processing, or DROP table processing. |
|
1279 ** The changes are counted as soon as the statement that makes them is |
|
1280 ** completed (when the statement handle is passed to [sqlite3_reset()] or |
|
1281 ** [sqlite3_finalize()]). |
|
1282 ** |
|
1283 ** SQLite implements the command "DELETE FROM table" without a WHERE clause |
|
1284 ** by dropping and recreating the table. (This is much faster than going |
|
1285 ** through and deleting individual elements from the table.) Because of this |
|
1286 ** optimization, the deletions in "DELETE FROM table" are not row changes and |
|
1287 ** will not be counted by the sqlite3_changes() or [sqlite3_total_changes()] |
|
1288 ** functions, regardless of the number of elements that were originally |
|
1289 ** in the table. To get an accurate count of the number of rows deleted, use |
|
1290 ** "DELETE FROM table WHERE 1" instead. Or recompile using the |
|
1291 ** [SQLITE_OMIT_TRUNCATE_OPTIMIZATION] compile-time option to disable the |
|
1292 ** optimization on all queries. |
|
1293 ** |
|
1294 ** See also the [sqlite3_changes()] interface. |
|
1295 ** |
|
1296 ** Requirements: |
|
1297 ** [H12261] [H12263] |
|
1298 ** |
|
1299 ** If a separate thread makes changes on the same database connection |
|
1300 ** while [sqlite3_total_changes()] is running then the value |
|
1301 ** returned is unpredictable and not meaningful. |
|
1302 */ |
|
1303 int sqlite3_total_changes(sqlite3*); |
|
1304 |
|
1305 /* |
|
1306 ** CAPI3REF: Interrupt A Long-Running Query {H12270} <S30500> |
|
1307 ** |
|
1308 ** This function causes any pending database operation to abort and |
|
1309 ** return at its earliest opportunity. This routine is typically |
|
1310 ** called in response to a user action such as pressing "Cancel" |
|
1311 ** or Ctrl-C where the user wants a long query operation to halt |
|
1312 ** immediately. |
|
1313 ** |
|
1314 ** It is safe to call this routine from a thread different from the |
|
1315 ** thread that is currently running the database operation. But it |
|
1316 ** is not safe to call this routine with a [database connection] that |
|
1317 ** is closed or might close before sqlite3_interrupt() returns. |
|
1318 ** |
|
1319 ** If an SQL operation is very nearly finished at the time when |
|
1320 ** sqlite3_interrupt() is called, then it might not have an opportunity |
|
1321 ** to be interrupted and might continue to completion. |
|
1322 ** |
|
1323 ** An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. |
|
1324 ** If the interrupted SQL operation is an INSERT, UPDATE, or DELETE |
|
1325 ** that is inside an explicit transaction, then the entire transaction |
|
1326 ** will be rolled back automatically. |
|
1327 ** |
|
1328 ** A call to sqlite3_interrupt() has no effect on SQL statements |
|
1329 ** that are started after sqlite3_interrupt() returns. |
|
1330 ** |
|
1331 ** Requirements: |
|
1332 ** [H12271] [H12272] |
|
1333 ** |
|
1334 ** If the database connection closes while [sqlite3_interrupt()] |
|
1335 ** is running then bad things will likely happen. |
|
1336 */ |
|
1337 void sqlite3_interrupt(sqlite3*); |
|
1338 |
|
1339 /* |
|
1340 ** CAPI3REF: Determine If An SQL Statement Is Complete {H10510} <S70200> |
|
1341 ** |
|
1342 ** These routines are useful for command-line input to determine if the |
|
1343 ** currently entered text seems to form complete a SQL statement or |
|
1344 ** if additional input is needed before sending the text into |
|
1345 ** SQLite for parsing. These routines return true if the input string |
|
1346 ** appears to be a complete SQL statement. A statement is judged to be |
|
1347 ** complete if it ends with a semicolon token and is not a fragment of a |
|
1348 ** CREATE TRIGGER statement. Semicolons that are embedded within |
|
1349 ** string literals or quoted identifier names or comments are not |
|
1350 ** independent tokens (they are part of the token in which they are |
|
1351 ** embedded) and thus do not count as a statement terminator. |
|
1352 ** |
|
1353 ** These routines do not parse the SQL statements thus |
|
1354 ** will not detect syntactically incorrect SQL. |
|
1355 ** |
|
1356 ** Requirements: [H10511] [H10512] |
|
1357 ** |
|
1358 ** The input to [sqlite3_complete()] must be a zero-terminated |
|
1359 ** UTF-8 string. |
|
1360 ** |
|
1361 ** The input to [sqlite3_complete16()] must be a zero-terminated |
|
1362 ** UTF-16 string in native byte order. |
|
1363 */ |
|
1364 int sqlite3_complete(const char *sql); |
|
1365 int sqlite3_complete16(const void *sql); |
|
1366 |
|
1367 /* |
|
1368 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors {H12310} <S40400> |
|
1369 ** |
|
1370 ** This routine sets a callback function that might be invoked whenever |
|
1371 ** an attempt is made to open a database table that another thread |
|
1372 ** or process has locked. |
|
1373 ** |
|
1374 ** If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] |
|
1375 ** is returned immediately upon encountering the lock. If the busy callback |
|
1376 ** is not NULL, then the callback will be invoked with two arguments. |
|
1377 ** |
|
1378 ** The first argument to the handler is a copy of the void* pointer which |
|
1379 ** is the third argument to sqlite3_busy_handler(). The second argument to |
|
1380 ** the handler callback is the number of times that the busy handler has |
|
1381 ** been invoked for this locking event. If the |
|
1382 ** busy callback returns 0, then no additional attempts are made to |
|
1383 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. |
|
1384 ** If the callback returns non-zero, then another attempt |
|
1385 ** is made to open the database for reading and the cycle repeats. |
|
1386 ** |
|
1387 ** The presence of a busy handler does not guarantee that it will be invoked |
|
1388 ** when there is lock contention. If SQLite determines that invoking the busy |
|
1389 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] |
|
1390 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. |
|
1391 ** Consider a scenario where one process is holding a read lock that |
|
1392 ** it is trying to promote to a reserved lock and |
|
1393 ** a second process is holding a reserved lock that it is trying |
|
1394 ** to promote to an exclusive lock. The first process cannot proceed |
|
1395 ** because it is blocked by the second and the second process cannot |
|
1396 ** proceed because it is blocked by the first. If both processes |
|
1397 ** invoke the busy handlers, neither will make any progress. Therefore, |
|
1398 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this |
|
1399 ** will induce the first process to release its read lock and allow |
|
1400 ** the second process to proceed. |
|
1401 ** |
|
1402 ** The default busy callback is NULL. |
|
1403 ** |
|
1404 ** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] |
|
1405 ** when SQLite is in the middle of a large transaction where all the |
|
1406 ** changes will not fit into the in-memory cache. SQLite will |
|
1407 ** already hold a RESERVED lock on the database file, but it needs |
|
1408 ** to promote this lock to EXCLUSIVE so that it can spill cache |
|
1409 ** pages into the database file without harm to concurrent |
|
1410 ** readers. If it is unable to promote the lock, then the in-memory |
|
1411 ** cache will be left in an inconsistent state and so the error |
|
1412 ** code is promoted from the relatively benign [SQLITE_BUSY] to |
|
1413 ** the more severe [SQLITE_IOERR_BLOCKED]. This error code promotion |
|
1414 ** forces an automatic rollback of the changes. See the |
|
1415 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> |
|
1416 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why |
|
1417 ** this is important. |
|
1418 ** |
|
1419 ** There can only be a single busy handler defined for each |
|
1420 ** [database connection]. Setting a new busy handler clears any |
|
1421 ** previously set handler. Note that calling [sqlite3_busy_timeout()] |
|
1422 ** will also set or clear the busy handler. |
|
1423 ** |
|
1424 ** The busy callback should not take any actions which modify the |
|
1425 ** database connection that invoked the busy handler. Any such actions |
|
1426 ** result in undefined behavior. |
|
1427 ** |
|
1428 ** Requirements: |
|
1429 ** [H12311] [H12312] [H12314] [H12316] [H12318] |
|
1430 ** |
|
1431 ** A busy handler must not close the database connection |
|
1432 ** or [prepared statement] that invoked the busy handler. |
|
1433 */ |
|
1434 int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); |
|
1435 |
|
1436 /* |
|
1437 ** CAPI3REF: Set A Busy Timeout {H12340} <S40410> |
|
1438 ** |
|
1439 ** This routine sets a [sqlite3_busy_handler | busy handler] that sleeps |
|
1440 ** for a specified amount of time when a table is locked. The handler |
|
1441 ** will sleep multiple times until at least "ms" milliseconds of sleeping |
|
1442 ** have accumulated. {H12343} After "ms" milliseconds of sleeping, |
|
1443 ** the handler returns 0 which causes [sqlite3_step()] to return |
|
1444 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. |
|
1445 ** |
|
1446 ** Calling this routine with an argument less than or equal to zero |
|
1447 ** turns off all busy handlers. |
|
1448 ** |
|
1449 ** There can only be a single busy handler for a particular |
|
1450 ** [database connection] any any given moment. If another busy handler |
|
1451 ** was defined (using [sqlite3_busy_handler()]) prior to calling |
|
1452 ** this routine, that other busy handler is cleared. |
|
1453 ** |
|
1454 ** Requirements: |
|
1455 ** [H12341] [H12343] [H12344] |
|
1456 */ |
|
1457 int sqlite3_busy_timeout(sqlite3*, int ms); |
|
1458 |
|
1459 /* |
|
1460 ** CAPI3REF: Convenience Routines For Running Queries {H12370} <S10000> |
|
1461 ** |
|
1462 ** Definition: A <b>result table</b> is memory data structure created by the |
|
1463 ** [sqlite3_get_table()] interface. A result table records the |
|
1464 ** complete query results from one or more queries. |
|
1465 ** |
|
1466 ** The table conceptually has a number of rows and columns. But |
|
1467 ** these numbers are not part of the result table itself. These |
|
1468 ** numbers are obtained separately. Let N be the number of rows |
|
1469 ** and M be the number of columns. |
|
1470 ** |
|
1471 ** A result table is an array of pointers to zero-terminated UTF-8 strings. |
|
1472 ** There are (N+1)*M elements in the array. The first M pointers point |
|
1473 ** to zero-terminated strings that contain the names of the columns. |
|
1474 ** The remaining entries all point to query results. NULL values result |
|
1475 ** in NULL pointers. All other values are in their UTF-8 zero-terminated |
|
1476 ** string representation as returned by [sqlite3_column_text()]. |
|
1477 ** |
|
1478 ** A result table might consist of one or more memory allocations. |
|
1479 ** It is not safe to pass a result table directly to [sqlite3_free()]. |
|
1480 ** A result table should be deallocated using [sqlite3_free_table()]. |
|
1481 ** |
|
1482 ** As an example of the result table format, suppose a query result |
|
1483 ** is as follows: |
|
1484 ** |
|
1485 ** <blockquote><pre> |
|
1486 ** Name | Age |
|
1487 ** ----------------------- |
|
1488 ** Alice | 43 |
|
1489 ** Bob | 28 |
|
1490 ** Cindy | 21 |
|
1491 ** </pre></blockquote> |
|
1492 ** |
|
1493 ** There are two column (M==2) and three rows (N==3). Thus the |
|
1494 ** result table has 8 entries. Suppose the result table is stored |
|
1495 ** in an array names azResult. Then azResult holds this content: |
|
1496 ** |
|
1497 ** <blockquote><pre> |
|
1498 ** azResult[0] = "Name"; |
|
1499 ** azResult[1] = "Age"; |
|
1500 ** azResult[2] = "Alice"; |
|
1501 ** azResult[3] = "43"; |
|
1502 ** azResult[4] = "Bob"; |
|
1503 ** azResult[5] = "28"; |
|
1504 ** azResult[6] = "Cindy"; |
|
1505 ** azResult[7] = "21"; |
|
1506 ** </pre></blockquote> |
|
1507 ** |
|
1508 ** The sqlite3_get_table() function evaluates one or more |
|
1509 ** semicolon-separated SQL statements in the zero-terminated UTF-8 |
|
1510 ** string of its 2nd parameter. It returns a result table to the |
|
1511 ** pointer given in its 3rd parameter. |
|
1512 ** |
|
1513 ** After the calling function has finished using the result, it should |
|
1514 ** pass the pointer to the result table to sqlite3_free_table() in order to |
|
1515 ** release the memory that was malloced. Because of the way the |
|
1516 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling |
|
1517 ** function must not try to call [sqlite3_free()] directly. Only |
|
1518 ** [sqlite3_free_table()] is able to release the memory properly and safely. |
|
1519 ** |
|
1520 ** The sqlite3_get_table() interface is implemented as a wrapper around |
|
1521 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access |
|
1522 ** to any internal data structures of SQLite. It uses only the public |
|
1523 ** interface defined here. As a consequence, errors that occur in the |
|
1524 ** wrapper layer outside of the internal [sqlite3_exec()] call are not |
|
1525 ** reflected in subsequent calls to [sqlite3_errcode()] or [sqlite3_errmsg()]. |
|
1526 ** |
|
1527 ** Requirements: |
|
1528 ** [H12371] [H12373] [H12374] [H12376] [H12379] [H12382] |
|
1529 */ |
|
1530 int sqlite3_get_table( |
|
1531 sqlite3 *db, /* An open database */ |
|
1532 const char *zSql, /* SQL to be evaluated */ |
|
1533 char ***pazResult, /* Results of the query */ |
|
1534 int *pnRow, /* Number of result rows written here */ |
|
1535 int *pnColumn, /* Number of result columns written here */ |
|
1536 char **pzErrmsg /* Error msg written here */ |
|
1537 ); |
|
1538 void sqlite3_free_table(char **result); |
|
1539 |
|
1540 /* |
|
1541 ** CAPI3REF: Formatted String Printing Functions {H17400} <S70000><S20000> |
|
1542 ** |
|
1543 ** These routines are workalikes of the "printf()" family of functions |
|
1544 ** from the standard C library. |
|
1545 ** |
|
1546 ** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their |
|
1547 ** results into memory obtained from [sqlite3_malloc()]. |
|
1548 ** The strings returned by these two routines should be |
|
1549 ** released by [sqlite3_free()]. Both routines return a |
|
1550 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough |
|
1551 ** memory to hold the resulting string. |
|
1552 ** |
|
1553 ** In sqlite3_snprintf() routine is similar to "snprintf()" from |
|
1554 ** the standard C library. The result is written into the |
|
1555 ** buffer supplied as the second parameter whose size is given by |
|
1556 ** the first parameter. Note that the order of the |
|
1557 ** first two parameters is reversed from snprintf(). This is an |
|
1558 ** historical accident that cannot be fixed without breaking |
|
1559 ** backwards compatibility. Note also that sqlite3_snprintf() |
|
1560 ** returns a pointer to its buffer instead of the number of |
|
1561 ** characters actually written into the buffer. We admit that |
|
1562 ** the number of characters written would be a more useful return |
|
1563 ** value but we cannot change the implementation of sqlite3_snprintf() |
|
1564 ** now without breaking compatibility. |
|
1565 ** |
|
1566 ** As long as the buffer size is greater than zero, sqlite3_snprintf() |
|
1567 ** guarantees that the buffer is always zero-terminated. The first |
|
1568 ** parameter "n" is the total size of the buffer, including space for |
|
1569 ** the zero terminator. So the longest string that can be completely |
|
1570 ** written will be n-1 characters. |
|
1571 ** |
|
1572 ** These routines all implement some additional formatting |
|
1573 ** options that are useful for constructing SQL statements. |
|
1574 ** All of the usual printf() formatting options apply. In addition, there |
|
1575 ** is are "%q", "%Q", and "%z" options. |
|
1576 ** |
|
1577 ** The %q option works like %s in that it substitutes a null-terminated |
|
1578 ** string from the argument list. But %q also doubles every '\'' character. |
|
1579 ** %q is designed for use inside a string literal. By doubling each '\'' |
|
1580 ** character it escapes that character and allows it to be inserted into |
|
1581 ** the string. |
|
1582 ** |
|
1583 ** For example, assume the string variable zText contains text as follows: |
|
1584 ** |
|
1585 ** <blockquote><pre> |
|
1586 ** char *zText = "It's a happy day!"; |
|
1587 ** </pre></blockquote> |
|
1588 ** |
|
1589 ** One can use this text in an SQL statement as follows: |
|
1590 ** |
|
1591 ** <blockquote><pre> |
|
1592 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); |
|
1593 ** sqlite3_exec(db, zSQL, 0, 0, 0); |
|
1594 ** sqlite3_free(zSQL); |
|
1595 ** </pre></blockquote> |
|
1596 ** |
|
1597 ** Because the %q format string is used, the '\'' character in zText |
|
1598 ** is escaped and the SQL generated is as follows: |
|
1599 ** |
|
1600 ** <blockquote><pre> |
|
1601 ** INSERT INTO table1 VALUES('It''s a happy day!') |
|
1602 ** </pre></blockquote> |
|
1603 ** |
|
1604 ** This is correct. Had we used %s instead of %q, the generated SQL |
|
1605 ** would have looked like this: |
|
1606 ** |
|
1607 ** <blockquote><pre> |
|
1608 ** INSERT INTO table1 VALUES('It's a happy day!'); |
|
1609 ** </pre></blockquote> |
|
1610 ** |
|
1611 ** This second example is an SQL syntax error. As a general rule you should |
|
1612 ** always use %q instead of %s when inserting text into a string literal. |
|
1613 ** |
|
1614 ** The %Q option works like %q except it also adds single quotes around |
|
1615 ** the outside of the total string. Additionally, if the parameter in the |
|
1616 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without |
|
1617 ** single quotes) in place of the %Q option. So, for example, one could say: |
|
1618 ** |
|
1619 ** <blockquote><pre> |
|
1620 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); |
|
1621 ** sqlite3_exec(db, zSQL, 0, 0, 0); |
|
1622 ** sqlite3_free(zSQL); |
|
1623 ** </pre></blockquote> |
|
1624 ** |
|
1625 ** The code above will render a correct SQL statement in the zSQL |
|
1626 ** variable even if the zText variable is a NULL pointer. |
|
1627 ** |
|
1628 ** The "%z" formatting option works exactly like "%s" with the |
|
1629 ** addition that after the string has been read and copied into |
|
1630 ** the result, [sqlite3_free()] is called on the input string. {END} |
|
1631 ** |
|
1632 ** Requirements: |
|
1633 ** [H17403] [H17406] [H17407] |
|
1634 */ |
|
1635 char *sqlite3_mprintf(const char*,...); |
|
1636 char *sqlite3_vmprintf(const char*, va_list); |
|
1637 char *sqlite3_snprintf(int,char*,const char*, ...); |
|
1638 |
|
1639 /* |
|
1640 ** CAPI3REF: Memory Allocation Subsystem {H17300} <S20000> |
|
1641 ** |
|
1642 ** The SQLite core uses these three routines for all of its own |
|
1643 ** internal memory allocation needs. "Core" in the previous sentence |
|
1644 ** does not include operating-system specific VFS implementation. The |
|
1645 ** Windows VFS uses native malloc() and free() for some operations. |
|
1646 ** |
|
1647 ** The sqlite3_malloc() routine returns a pointer to a block |
|
1648 ** of memory at least N bytes in length, where N is the parameter. |
|
1649 ** If sqlite3_malloc() is unable to obtain sufficient free |
|
1650 ** memory, it returns a NULL pointer. If the parameter N to |
|
1651 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns |
|
1652 ** a NULL pointer. |
|
1653 ** |
|
1654 ** Calling sqlite3_free() with a pointer previously returned |
|
1655 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so |
|
1656 ** that it might be reused. The sqlite3_free() routine is |
|
1657 ** a no-op if is called with a NULL pointer. Passing a NULL pointer |
|
1658 ** to sqlite3_free() is harmless. After being freed, memory |
|
1659 ** should neither be read nor written. Even reading previously freed |
|
1660 ** memory might result in a segmentation fault or other severe error. |
|
1661 ** Memory corruption, a segmentation fault, or other severe error |
|
1662 ** might result if sqlite3_free() is called with a non-NULL pointer that |
|
1663 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). |
|
1664 ** |
|
1665 ** The sqlite3_realloc() interface attempts to resize a |
|
1666 ** prior memory allocation to be at least N bytes, where N is the |
|
1667 ** second parameter. The memory allocation to be resized is the first |
|
1668 ** parameter. If the first parameter to sqlite3_realloc() |
|
1669 ** is a NULL pointer then its behavior is identical to calling |
|
1670 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). |
|
1671 ** If the second parameter to sqlite3_realloc() is zero or |
|
1672 ** negative then the behavior is exactly the same as calling |
|
1673 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). |
|
1674 ** sqlite3_realloc() returns a pointer to a memory allocation |
|
1675 ** of at least N bytes in size or NULL if sufficient memory is unavailable. |
|
1676 ** If M is the size of the prior allocation, then min(N,M) bytes |
|
1677 ** of the prior allocation are copied into the beginning of buffer returned |
|
1678 ** by sqlite3_realloc() and the prior allocation is freed. |
|
1679 ** If sqlite3_realloc() returns NULL, then the prior allocation |
|
1680 ** is not freed. |
|
1681 ** |
|
1682 ** The memory returned by sqlite3_malloc() and sqlite3_realloc() |
|
1683 ** is always aligned to at least an 8 byte boundary. {END} |
|
1684 ** |
|
1685 ** The default implementation of the memory allocation subsystem uses |
|
1686 ** the malloc(), realloc() and free() provided by the standard C library. |
|
1687 ** {H17382} However, if SQLite is compiled with the |
|
1688 ** SQLITE_MEMORY_SIZE=<i>NNN</i> C preprocessor macro (where <i>NNN</i> |
|
1689 ** is an integer), then SQLite create a static array of at least |
|
1690 ** <i>NNN</i> bytes in size and uses that array for all of its dynamic |
|
1691 ** memory allocation needs. {END} Additional memory allocator options |
|
1692 ** may be added in future releases. |
|
1693 ** |
|
1694 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define |
|
1695 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in |
|
1696 ** implementation of these routines to be omitted. That capability |
|
1697 ** is no longer provided. Only built-in memory allocators can be used. |
|
1698 ** |
|
1699 ** The Windows OS interface layer calls |
|
1700 ** the system malloc() and free() directly when converting |
|
1701 ** filenames between the UTF-8 encoding used by SQLite |
|
1702 ** and whatever filename encoding is used by the particular Windows |
|
1703 ** installation. Memory allocation errors are detected, but |
|
1704 ** they are reported back as [SQLITE_CANTOPEN] or |
|
1705 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. |
|
1706 ** |
|
1707 ** Requirements: |
|
1708 ** [H17303] [H17304] [H17305] [H17306] [H17310] [H17312] [H17315] [H17318] |
|
1709 ** [H17321] [H17322] [H17323] |
|
1710 ** |
|
1711 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] |
|
1712 ** must be either NULL or else pointers obtained from a prior |
|
1713 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have |
|
1714 ** not yet been released. |
|
1715 ** |
|
1716 ** The application must not read or write any part of |
|
1717 ** a block of memory after it has been released using |
|
1718 ** [sqlite3_free()] or [sqlite3_realloc()]. |
|
1719 */ |
|
1720 void *sqlite3_malloc(int); |
|
1721 void *sqlite3_realloc(void*, int); |
|
1722 void sqlite3_free(void*); |
|
1723 |
|
1724 /* |
|
1725 ** CAPI3REF: Memory Allocator Statistics {H17370} <S30210> |
|
1726 ** |
|
1727 ** SQLite provides these two interfaces for reporting on the status |
|
1728 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] |
|
1729 ** routines, which form the built-in memory allocation subsystem. |
|
1730 ** |
|
1731 ** Requirements: |
|
1732 ** [H17371] [H17373] [H17374] [H17375] |
|
1733 */ |
|
1734 sqlite3_int64 sqlite3_memory_used(void); |
|
1735 sqlite3_int64 sqlite3_memory_highwater(int resetFlag); |
|
1736 |
|
1737 /* |
|
1738 ** CAPI3REF: Pseudo-Random Number Generator {H17390} <S20000> |
|
1739 ** |
|
1740 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to |
|
1741 ** select random [ROWID | ROWIDs] when inserting new records into a table that |
|
1742 ** already uses the largest possible [ROWID]. The PRNG is also used for |
|
1743 ** the build-in random() and randomblob() SQL functions. This interface allows |
|
1744 ** applications to access the same PRNG for other purposes. |
|
1745 ** |
|
1746 ** A call to this routine stores N bytes of randomness into buffer P. |
|
1747 ** |
|
1748 ** The first time this routine is invoked (either internally or by |
|
1749 ** the application) the PRNG is seeded using randomness obtained |
|
1750 ** from the xRandomness method of the default [sqlite3_vfs] object. |
|
1751 ** On all subsequent invocations, the pseudo-randomness is generated |
|
1752 ** internally and without recourse to the [sqlite3_vfs] xRandomness |
|
1753 ** method. |
|
1754 ** |
|
1755 ** Requirements: |
|
1756 ** [H17392] |
|
1757 */ |
|
1758 void sqlite3_randomness(int N, void *P); |
|
1759 |
|
1760 /* |
|
1761 ** CAPI3REF: Compile-Time Authorization Callbacks {H12500} <S70100> |
|
1762 ** |
|
1763 ** This routine registers a authorizer callback with a particular |
|
1764 ** [database connection], supplied in the first argument. |
|
1765 ** The authorizer callback is invoked as SQL statements are being compiled |
|
1766 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], |
|
1767 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. At various |
|
1768 ** points during the compilation process, as logic is being created |
|
1769 ** to perform various actions, the authorizer callback is invoked to |
|
1770 ** see if those actions are allowed. The authorizer callback should |
|
1771 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the |
|
1772 ** specific action but allow the SQL statement to continue to be |
|
1773 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be |
|
1774 ** rejected with an error. If the authorizer callback returns |
|
1775 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] |
|
1776 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered |
|
1777 ** the authorizer will fail with an error message. |
|
1778 ** |
|
1779 ** When the callback returns [SQLITE_OK], that means the operation |
|
1780 ** requested is ok. When the callback returns [SQLITE_DENY], the |
|
1781 ** [sqlite3_prepare_v2()] or equivalent call that triggered the |
|
1782 ** authorizer will fail with an error message explaining that |
|
1783 ** access is denied. If the authorizer code is [SQLITE_READ] |
|
1784 ** and the callback returns [SQLITE_IGNORE] then the |
|
1785 ** [prepared statement] statement is constructed to substitute |
|
1786 ** a NULL value in place of the table column that would have |
|
1787 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] |
|
1788 ** return can be used to deny an untrusted user access to individual |
|
1789 ** columns of a table. |
|
1790 ** |
|
1791 ** The first parameter to the authorizer callback is a copy of the third |
|
1792 ** parameter to the sqlite3_set_authorizer() interface. The second parameter |
|
1793 ** to the callback is an integer [SQLITE_COPY | action code] that specifies |
|
1794 ** the particular action to be authorized. The third through sixth parameters |
|
1795 ** to the callback are zero-terminated strings that contain additional |
|
1796 ** details about the action to be authorized. |
|
1797 ** |
|
1798 ** An authorizer is used when [sqlite3_prepare | preparing] |
|
1799 ** SQL statements from an untrusted source, to ensure that the SQL statements |
|
1800 ** do not try to access data they are not allowed to see, or that they do not |
|
1801 ** try to execute malicious statements that damage the database. For |
|
1802 ** example, an application may allow a user to enter arbitrary |
|
1803 ** SQL queries for evaluation by a database. But the application does |
|
1804 ** not want the user to be able to make arbitrary changes to the |
|
1805 ** database. An authorizer could then be put in place while the |
|
1806 ** user-entered SQL is being [sqlite3_prepare | prepared] that |
|
1807 ** disallows everything except [SELECT] statements. |
|
1808 ** |
|
1809 ** Applications that need to process SQL from untrusted sources |
|
1810 ** might also consider lowering resource limits using [sqlite3_limit()] |
|
1811 ** and limiting database size using the [max_page_count] [PRAGMA] |
|
1812 ** in addition to using an authorizer. |
|
1813 ** |
|
1814 ** Only a single authorizer can be in place on a database connection |
|
1815 ** at a time. Each call to sqlite3_set_authorizer overrides the |
|
1816 ** previous call. Disable the authorizer by installing a NULL callback. |
|
1817 ** The authorizer is disabled by default. |
|
1818 ** |
|
1819 ** The authorizer callback must not do anything that will modify |
|
1820 ** the database connection that invoked the authorizer callback. |
|
1821 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
1822 ** database connections for the meaning of "modify" in this paragraph. |
|
1823 ** |
|
1824 ** When [sqlite3_prepare_v2()] is used to prepare a statement, the |
|
1825 ** statement might be reprepared during [sqlite3_step()] due to a |
|
1826 ** schema change. Hence, the application should ensure that the |
|
1827 ** correct authorizer callback remains in place during the [sqlite3_step()]. |
|
1828 ** |
|
1829 ** Note that the authorizer callback is invoked only during |
|
1830 ** [sqlite3_prepare()] or its variants. Authorization is not |
|
1831 ** performed during statement evaluation in [sqlite3_step()]. |
|
1832 ** |
|
1833 ** Requirements: |
|
1834 ** [H12501] [H12502] [H12503] [H12504] [H12505] [H12506] [H12507] [H12510] |
|
1835 ** [H12511] [H12512] [H12520] [H12521] [H12522] |
|
1836 */ |
|
1837 int sqlite3_set_authorizer( |
|
1838 sqlite3*, |
|
1839 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), |
|
1840 void *pUserData |
|
1841 ); |
|
1842 |
|
1843 /* |
|
1844 ** CAPI3REF: Authorizer Return Codes {H12590} <H12500> |
|
1845 ** |
|
1846 ** The [sqlite3_set_authorizer | authorizer callback function] must |
|
1847 ** return either [SQLITE_OK] or one of these two constants in order |
|
1848 ** to signal SQLite whether or not the action is permitted. See the |
|
1849 ** [sqlite3_set_authorizer | authorizer documentation] for additional |
|
1850 ** information. |
|
1851 */ |
|
1852 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ |
|
1853 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ |
|
1854 |
|
1855 /* |
|
1856 ** CAPI3REF: Authorizer Action Codes {H12550} <H12500> |
|
1857 ** |
|
1858 ** The [sqlite3_set_authorizer()] interface registers a callback function |
|
1859 ** that is invoked to authorize certain SQL statement actions. The |
|
1860 ** second parameter to the callback is an integer code that specifies |
|
1861 ** what action is being authorized. These are the integer action codes that |
|
1862 ** the authorizer callback may be passed. |
|
1863 ** |
|
1864 ** These action code values signify what kind of operation is to be |
|
1865 ** authorized. The 3rd and 4th parameters to the authorization |
|
1866 ** callback function will be parameters or NULL depending on which of these |
|
1867 ** codes is used as the second parameter. The 5th parameter to the |
|
1868 ** authorizer callback is the name of the database ("main", "temp", |
|
1869 ** etc.) if applicable. The 6th parameter to the authorizer callback |
|
1870 ** is the name of the inner-most trigger or view that is responsible for |
|
1871 ** the access attempt or NULL if this access attempt is directly from |
|
1872 ** top-level SQL code. |
|
1873 ** |
|
1874 ** Requirements: |
|
1875 ** [H12551] [H12552] [H12553] [H12554] |
|
1876 */ |
|
1877 /******************************************* 3rd ************ 4th ***********/ |
|
1878 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ |
|
1879 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ |
|
1880 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ |
|
1881 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ |
|
1882 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ |
|
1883 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ |
|
1884 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ |
|
1885 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ |
|
1886 #define SQLITE_DELETE 9 /* Table Name NULL */ |
|
1887 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ |
|
1888 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ |
|
1889 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ |
|
1890 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ |
|
1891 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ |
|
1892 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ |
|
1893 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ |
|
1894 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ |
|
1895 #define SQLITE_INSERT 18 /* Table Name NULL */ |
|
1896 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ |
|
1897 #define SQLITE_READ 20 /* Table Name Column Name */ |
|
1898 #define SQLITE_SELECT 21 /* NULL NULL */ |
|
1899 #define SQLITE_TRANSACTION 22 /* Operation NULL */ |
|
1900 #define SQLITE_UPDATE 23 /* Table Name Column Name */ |
|
1901 #define SQLITE_ATTACH 24 /* Filename NULL */ |
|
1902 #define SQLITE_DETACH 25 /* Database Name NULL */ |
|
1903 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ |
|
1904 #define SQLITE_REINDEX 27 /* Index Name NULL */ |
|
1905 #define SQLITE_ANALYZE 28 /* Table Name NULL */ |
|
1906 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ |
|
1907 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ |
|
1908 #define SQLITE_FUNCTION 31 /* NULL Function Name */ |
|
1909 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ |
|
1910 #define SQLITE_COPY 0 /* No longer used */ |
|
1911 |
|
1912 /* |
|
1913 ** CAPI3REF: Tracing And Profiling Functions {H12280} <S60400> |
|
1914 ** EXPERIMENTAL |
|
1915 ** |
|
1916 ** These routines register callback functions that can be used for |
|
1917 ** tracing and profiling the execution of SQL statements. |
|
1918 ** |
|
1919 ** The callback function registered by sqlite3_trace() is invoked at |
|
1920 ** various times when an SQL statement is being run by [sqlite3_step()]. |
|
1921 ** The callback returns a UTF-8 rendering of the SQL statement text |
|
1922 ** as the statement first begins executing. Additional callbacks occur |
|
1923 ** as each triggered subprogram is entered. The callbacks for triggers |
|
1924 ** contain a UTF-8 SQL comment that identifies the trigger. |
|
1925 ** |
|
1926 ** The callback function registered by sqlite3_profile() is invoked |
|
1927 ** as each SQL statement finishes. The profile callback contains |
|
1928 ** the original statement text and an estimate of wall-clock time |
|
1929 ** of how long that statement took to run. |
|
1930 ** |
|
1931 ** Requirements: |
|
1932 ** [H12281] [H12282] [H12283] [H12284] [H12285] [H12287] [H12288] [H12289] |
|
1933 ** [H12290] |
|
1934 */ |
|
1935 SQLITE_EXPERIMENTAL void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); |
|
1936 SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, |
|
1937 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
|
1938 |
|
1939 /* |
|
1940 ** CAPI3REF: Query Progress Callbacks {H12910} <S60400> |
|
1941 ** |
|
1942 ** This routine configures a callback function - the |
|
1943 ** progress callback - that is invoked periodically during long |
|
1944 ** running calls to [sqlite3_exec()], [sqlite3_step()] and |
|
1945 ** [sqlite3_get_table()]. An example use for this |
|
1946 ** interface is to keep a GUI updated during a large query. |
|
1947 ** |
|
1948 ** If the progress callback returns non-zero, the operation is |
|
1949 ** interrupted. This feature can be used to implement a |
|
1950 ** "Cancel" button on a GUI progress dialog box. |
|
1951 ** |
|
1952 ** The progress handler must not do anything that will modify |
|
1953 ** the database connection that invoked the progress handler. |
|
1954 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
1955 ** database connections for the meaning of "modify" in this paragraph. |
|
1956 ** |
|
1957 ** Requirements: |
|
1958 ** [H12911] [H12912] [H12913] [H12914] [H12915] [H12916] [H12917] [H12918] |
|
1959 ** |
|
1960 */ |
|
1961 void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
|
1962 |
|
1963 /* |
|
1964 ** CAPI3REF: Opening A New Database Connection {H12700} <S40200> |
|
1965 ** |
|
1966 ** These routines open an SQLite database file whose name is given by the |
|
1967 ** filename argument. The filename argument is interpreted as UTF-8 for |
|
1968 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte |
|
1969 ** order for sqlite3_open16(). A [database connection] handle is usually |
|
1970 ** returned in *ppDb, even if an error occurs. The only exception is that |
|
1971 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, |
|
1972 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] |
|
1973 ** object. If the database is opened (and/or created) successfully, then |
|
1974 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned. The |
|
1975 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain |
|
1976 ** an English language description of the error. |
|
1977 ** |
|
1978 ** The default encoding for the database will be UTF-8 if |
|
1979 ** sqlite3_open() or sqlite3_open_v2() is called and |
|
1980 ** UTF-16 in the native byte order if sqlite3_open16() is used. |
|
1981 ** |
|
1982 ** Whether or not an error occurs when it is opened, resources |
|
1983 ** associated with the [database connection] handle should be released by |
|
1984 ** passing it to [sqlite3_close()] when it is no longer required. |
|
1985 ** |
|
1986 ** The sqlite3_open_v2() interface works like sqlite3_open() |
|
1987 ** except that it accepts two additional parameters for additional control |
|
1988 ** over the new database connection. The flags parameter can take one of |
|
1989 ** the following three values, optionally combined with the |
|
1990 ** [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags: |
|
1991 ** |
|
1992 ** <dl> |
|
1993 ** <dt>[SQLITE_OPEN_READONLY]</dt> |
|
1994 ** <dd>The database is opened in read-only mode. If the database does not |
|
1995 ** already exist, an error is returned.</dd> |
|
1996 ** |
|
1997 ** <dt>[SQLITE_OPEN_READWRITE]</dt> |
|
1998 ** <dd>The database is opened for reading and writing if possible, or reading |
|
1999 ** only if the file is write protected by the operating system. In either |
|
2000 ** case the database must already exist, otherwise an error is returned.</dd> |
|
2001 ** |
|
2002 ** <dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> |
|
2003 ** <dd>The database is opened for reading and writing, and is creates it if |
|
2004 ** it does not already exist. This is the behavior that is always used for |
|
2005 ** sqlite3_open() and sqlite3_open16().</dd> |
|
2006 ** </dl> |
|
2007 ** |
|
2008 ** If the 3rd parameter to sqlite3_open_v2() is not one of the |
|
2009 ** combinations shown above or one of the combinations shown above combined |
|
2010 ** with the [SQLITE_OPEN_NOMUTEX] or [SQLITE_OPEN_FULLMUTEX] flags, |
|
2011 ** then the behavior is undefined. |
|
2012 ** |
|
2013 ** If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection |
|
2014 ** opens in the multi-thread [threading mode] as long as the single-thread |
|
2015 ** mode has not been set at compile-time or start-time. If the |
|
2016 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens |
|
2017 ** in the serialized [threading mode] unless single-thread was |
|
2018 ** previously selected at compile-time or start-time. |
|
2019 ** |
|
2020 ** If the filename is ":memory:", then a private, temporary in-memory database |
|
2021 ** is created for the connection. This in-memory database will vanish when |
|
2022 ** the database connection is closed. Future versions of SQLite might |
|
2023 ** make use of additional special filenames that begin with the ":" character. |
|
2024 ** It is recommended that when a database filename actually does begin with |
|
2025 ** a ":" character you should prefix the filename with a pathname such as |
|
2026 ** "./" to avoid ambiguity. |
|
2027 ** |
|
2028 ** If the filename is an empty string, then a private, temporary |
|
2029 ** on-disk database will be created. This private database will be |
|
2030 ** automatically deleted as soon as the database connection is closed. |
|
2031 ** |
|
2032 ** The fourth parameter to sqlite3_open_v2() is the name of the |
|
2033 ** [sqlite3_vfs] object that defines the operating system interface that |
|
2034 ** the new database connection should use. If the fourth parameter is |
|
2035 ** a NULL pointer then the default [sqlite3_vfs] object is used. |
|
2036 ** |
|
2037 ** <b>Note to Windows users:</b> The encoding used for the filename argument |
|
2038 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever |
|
2039 ** codepage is currently defined. Filenames containing international |
|
2040 ** characters must be converted to UTF-8 prior to passing them into |
|
2041 ** sqlite3_open() or sqlite3_open_v2(). |
|
2042 ** |
|
2043 ** Requirements: |
|
2044 ** [H12701] [H12702] [H12703] [H12704] [H12706] [H12707] [H12709] [H12711] |
|
2045 ** [H12712] [H12713] [H12714] [H12717] [H12719] [H12721] [H12723] |
|
2046 */ |
|
2047 int sqlite3_open( |
|
2048 const char *filename, /* Database filename (UTF-8) */ |
|
2049 sqlite3 **ppDb /* OUT: SQLite db handle */ |
|
2050 ); |
|
2051 int sqlite3_open16( |
|
2052 const void *filename, /* Database filename (UTF-16) */ |
|
2053 sqlite3 **ppDb /* OUT: SQLite db handle */ |
|
2054 ); |
|
2055 int sqlite3_open_v2( |
|
2056 const char *filename, /* Database filename (UTF-8) */ |
|
2057 sqlite3 **ppDb, /* OUT: SQLite db handle */ |
|
2058 int flags, /* Flags */ |
|
2059 const char *zVfs /* Name of VFS module to use */ |
|
2060 ); |
|
2061 |
|
2062 /* |
|
2063 ** CAPI3REF: Error Codes And Messages {H12800} <S60200> |
|
2064 ** |
|
2065 ** The sqlite3_errcode() interface returns the numeric [result code] or |
|
2066 ** [extended result code] for the most recent failed sqlite3_* API call |
|
2067 ** associated with a [database connection]. If a prior API call failed |
|
2068 ** but the most recent API call succeeded, the return value from |
|
2069 ** sqlite3_errcode() is undefined. The sqlite3_extended_errcode() |
|
2070 ** interface is the same except that it always returns the |
|
2071 ** [extended result code] even when extended result codes are |
|
2072 ** disabled. |
|
2073 ** |
|
2074 ** The sqlite3_errmsg() and sqlite3_errmsg16() return English-language |
|
2075 ** text that describes the error, as either UTF-8 or UTF-16 respectively. |
|
2076 ** Memory to hold the error message string is managed internally. |
|
2077 ** The application does not need to worry about freeing the result. |
|
2078 ** However, the error string might be overwritten or deallocated by |
|
2079 ** subsequent calls to other SQLite interface functions. |
|
2080 ** |
|
2081 ** When the serialized [threading mode] is in use, it might be the |
|
2082 ** case that a second error occurs on a separate thread in between |
|
2083 ** the time of the first error and the call to these interfaces. |
|
2084 ** When that happens, the second error will be reported since these |
|
2085 ** interfaces always report the most recent result. To avoid |
|
2086 ** this, each thread can obtain exclusive use of the [database connection] D |
|
2087 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning |
|
2088 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after |
|
2089 ** all calls to the interfaces listed here are completed. |
|
2090 ** |
|
2091 ** If an interface fails with SQLITE_MISUSE, that means the interface |
|
2092 ** was invoked incorrectly by the application. In that case, the |
|
2093 ** error code and message may or may not be set. |
|
2094 ** |
|
2095 ** Requirements: |
|
2096 ** [H12801] [H12802] [H12803] [H12807] [H12808] [H12809] |
|
2097 */ |
|
2098 int sqlite3_errcode(sqlite3 *db); |
|
2099 int sqlite3_extended_errcode(sqlite3 *db); |
|
2100 const char *sqlite3_errmsg(sqlite3*); |
|
2101 const void *sqlite3_errmsg16(sqlite3*); |
|
2102 |
|
2103 /* |
|
2104 ** CAPI3REF: SQL Statement Object {H13000} <H13010> |
|
2105 ** KEYWORDS: {prepared statement} {prepared statements} |
|
2106 ** |
|
2107 ** An instance of this object represents a single SQL statement. |
|
2108 ** This object is variously known as a "prepared statement" or a |
|
2109 ** "compiled SQL statement" or simply as a "statement". |
|
2110 ** |
|
2111 ** The life of a statement object goes something like this: |
|
2112 ** |
|
2113 ** <ol> |
|
2114 ** <li> Create the object using [sqlite3_prepare_v2()] or a related |
|
2115 ** function. |
|
2116 ** <li> Bind values to [host parameters] using the sqlite3_bind_*() |
|
2117 ** interfaces. |
|
2118 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. |
|
2119 ** <li> Reset the statement using [sqlite3_reset()] then go back |
|
2120 ** to step 2. Do this zero or more times. |
|
2121 ** <li> Destroy the object using [sqlite3_finalize()]. |
|
2122 ** </ol> |
|
2123 ** |
|
2124 ** Refer to documentation on individual methods above for additional |
|
2125 ** information. |
|
2126 */ |
|
2127 typedef struct sqlite3_stmt sqlite3_stmt; |
|
2128 |
|
2129 /* |
|
2130 ** CAPI3REF: Run-time Limits {H12760} <S20600> |
|
2131 ** |
|
2132 ** This interface allows the size of various constructs to be limited |
|
2133 ** on a connection by connection basis. The first parameter is the |
|
2134 ** [database connection] whose limit is to be set or queried. The |
|
2135 ** second parameter is one of the [limit categories] that define a |
|
2136 ** class of constructs to be size limited. The third parameter is the |
|
2137 ** new limit for that construct. The function returns the old limit. |
|
2138 ** |
|
2139 ** If the new limit is a negative number, the limit is unchanged. |
|
2140 ** For the limit category of SQLITE_LIMIT_XYZ there is a |
|
2141 ** [limits | hard upper bound] |
|
2142 ** set by a compile-time C preprocessor macro named |
|
2143 ** [limits | SQLITE_MAX_XYZ]. |
|
2144 ** (The "_LIMIT_" in the name is changed to "_MAX_".) |
|
2145 ** Attempts to increase a limit above its hard upper bound are |
|
2146 ** silently truncated to the hard upper limit. |
|
2147 ** |
|
2148 ** Run time limits are intended for use in applications that manage |
|
2149 ** both their own internal database and also databases that are controlled |
|
2150 ** by untrusted external sources. An example application might be a |
|
2151 ** web browser that has its own databases for storing history and |
|
2152 ** separate databases controlled by JavaScript applications downloaded |
|
2153 ** off the Internet. The internal databases can be given the |
|
2154 ** large, default limits. Databases managed by external sources can |
|
2155 ** be given much smaller limits designed to prevent a denial of service |
|
2156 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] |
|
2157 ** interface to further control untrusted SQL. The size of the database |
|
2158 ** created by an untrusted script can be contained using the |
|
2159 ** [max_page_count] [PRAGMA]. |
|
2160 ** |
|
2161 ** New run-time limit categories may be added in future releases. |
|
2162 ** |
|
2163 ** Requirements: |
|
2164 ** [H12762] [H12766] [H12769] |
|
2165 */ |
|
2166 int sqlite3_limit(sqlite3*, int id, int newVal); |
|
2167 |
|
2168 /* |
|
2169 ** CAPI3REF: Run-Time Limit Categories {H12790} <H12760> |
|
2170 ** KEYWORDS: {limit category} {limit categories} |
|
2171 ** |
|
2172 ** These constants define various performance limits |
|
2173 ** that can be lowered at run-time using [sqlite3_limit()]. |
|
2174 ** The synopsis of the meanings of the various limits is shown below. |
|
2175 ** Additional information is available at [limits | Limits in SQLite]. |
|
2176 ** |
|
2177 ** <dl> |
|
2178 ** <dt>SQLITE_LIMIT_LENGTH</dt> |
|
2179 ** <dd>The maximum size of any string or BLOB or table row.<dd> |
|
2180 ** |
|
2181 ** <dt>SQLITE_LIMIT_SQL_LENGTH</dt> |
|
2182 ** <dd>The maximum length of an SQL statement.</dd> |
|
2183 ** |
|
2184 ** <dt>SQLITE_LIMIT_COLUMN</dt> |
|
2185 ** <dd>The maximum number of columns in a table definition or in the |
|
2186 ** result set of a [SELECT] or the maximum number of columns in an index |
|
2187 ** or in an ORDER BY or GROUP BY clause.</dd> |
|
2188 ** |
|
2189 ** <dt>SQLITE_LIMIT_EXPR_DEPTH</dt> |
|
2190 ** <dd>The maximum depth of the parse tree on any expression.</dd> |
|
2191 ** |
|
2192 ** <dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> |
|
2193 ** <dd>The maximum number of terms in a compound SELECT statement.</dd> |
|
2194 ** |
|
2195 ** <dt>SQLITE_LIMIT_VDBE_OP</dt> |
|
2196 ** <dd>The maximum number of instructions in a virtual machine program |
|
2197 ** used to implement an SQL statement.</dd> |
|
2198 ** |
|
2199 ** <dt>SQLITE_LIMIT_FUNCTION_ARG</dt> |
|
2200 ** <dd>The maximum number of arguments on a function.</dd> |
|
2201 ** |
|
2202 ** <dt>SQLITE_LIMIT_ATTACHED</dt> |
|
2203 ** <dd>The maximum number of [ATTACH | attached databases].</dd> |
|
2204 ** |
|
2205 ** <dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> |
|
2206 ** <dd>The maximum length of the pattern argument to the [LIKE] or |
|
2207 ** [GLOB] operators.</dd> |
|
2208 ** |
|
2209 ** <dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> |
|
2210 ** <dd>The maximum number of variables in an SQL statement that can |
|
2211 ** be bound.</dd> |
|
2212 ** </dl> |
|
2213 */ |
|
2214 #define SQLITE_LIMIT_LENGTH 0 |
|
2215 #define SQLITE_LIMIT_SQL_LENGTH 1 |
|
2216 #define SQLITE_LIMIT_COLUMN 2 |
|
2217 #define SQLITE_LIMIT_EXPR_DEPTH 3 |
|
2218 #define SQLITE_LIMIT_COMPOUND_SELECT 4 |
|
2219 #define SQLITE_LIMIT_VDBE_OP 5 |
|
2220 #define SQLITE_LIMIT_FUNCTION_ARG 6 |
|
2221 #define SQLITE_LIMIT_ATTACHED 7 |
|
2222 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 |
|
2223 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 |
|
2224 |
|
2225 /* |
|
2226 ** CAPI3REF: Compiling An SQL Statement {H13010} <S10000> |
|
2227 ** KEYWORDS: {SQL statement compiler} |
|
2228 ** |
|
2229 ** To execute an SQL query, it must first be compiled into a byte-code |
|
2230 ** program using one of these routines. |
|
2231 ** |
|
2232 ** The first argument, "db", is a [database connection] obtained from a |
|
2233 ** prior call to [sqlite3_open()], [sqlite3_open_v2()] or [sqlite3_open16()]. |
|
2234 ** |
|
2235 ** The second argument, "zSql", is the statement to be compiled, encoded |
|
2236 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() |
|
2237 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() |
|
2238 ** use UTF-16. |
|
2239 ** |
|
2240 ** If the nByte argument is less than zero, then zSql is read up to the |
|
2241 ** first zero terminator. If nByte is non-negative, then it is the maximum |
|
2242 ** number of bytes read from zSql. When nByte is non-negative, the |
|
2243 ** zSql string ends at either the first '\000' or '\u0000' character or |
|
2244 ** the nByte-th byte, whichever comes first. If the caller knows |
|
2245 ** that the supplied string is nul-terminated, then there is a small |
|
2246 ** performance advantage to be gained by passing an nByte parameter that |
|
2247 ** is equal to the number of bytes in the input string <i>including</i> |
|
2248 ** the nul-terminator bytes. |
|
2249 ** |
|
2250 ** *pzTail is made to point to the first byte past the end of the |
|
2251 ** first SQL statement in zSql. These routines only compile the first |
|
2252 ** statement in zSql, so *pzTail is left pointing to what remains |
|
2253 ** uncompiled. |
|
2254 ** |
|
2255 ** *ppStmt is left pointing to a compiled [prepared statement] that can be |
|
2256 ** executed using [sqlite3_step()]. If there is an error, *ppStmt is set |
|
2257 ** to NULL. If the input text contains no SQL (if the input is an empty |
|
2258 ** string or a comment) then *ppStmt is set to NULL. |
|
2259 ** {A13018} The calling procedure is responsible for deleting the compiled |
|
2260 ** SQL statement using [sqlite3_finalize()] after it has finished with it. |
|
2261 ** |
|
2262 ** On success, [SQLITE_OK] is returned, otherwise an [error code] is returned. |
|
2263 ** |
|
2264 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are |
|
2265 ** recommended for all new programs. The two older interfaces are retained |
|
2266 ** for backwards compatibility, but their use is discouraged. |
|
2267 ** In the "v2" interfaces, the prepared statement |
|
2268 ** that is returned (the [sqlite3_stmt] object) contains a copy of the |
|
2269 ** original SQL text. This causes the [sqlite3_step()] interface to |
|
2270 ** behave a differently in two ways: |
|
2271 ** |
|
2272 ** <ol> |
|
2273 ** <li> |
|
2274 ** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it |
|
2275 ** always used to do, [sqlite3_step()] will automatically recompile the SQL |
|
2276 ** statement and try to run it again. If the schema has changed in |
|
2277 ** a way that makes the statement no longer valid, [sqlite3_step()] will still |
|
2278 ** return [SQLITE_SCHEMA]. But unlike the legacy behavior, [SQLITE_SCHEMA] is |
|
2279 ** now a fatal error. Calling [sqlite3_prepare_v2()] again will not make the |
|
2280 ** error go away. Note: use [sqlite3_errmsg()] to find the text |
|
2281 ** of the parsing error that results in an [SQLITE_SCHEMA] return. |
|
2282 ** </li> |
|
2283 ** |
|
2284 ** <li> |
|
2285 ** When an error occurs, [sqlite3_step()] will return one of the detailed |
|
2286 ** [error codes] or [extended error codes]. The legacy behavior was that |
|
2287 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code |
|
2288 ** and you would have to make a second call to [sqlite3_reset()] in order |
|
2289 ** to find the underlying cause of the problem. With the "v2" prepare |
|
2290 ** interfaces, the underlying reason for the error is returned immediately. |
|
2291 ** </li> |
|
2292 ** </ol> |
|
2293 ** |
|
2294 ** Requirements: |
|
2295 ** [H13011] [H13012] [H13013] [H13014] [H13015] [H13016] [H13019] [H13021] |
|
2296 ** |
|
2297 */ |
|
2298 int sqlite3_prepare( |
|
2299 sqlite3 *db, /* Database handle */ |
|
2300 const char *zSql, /* SQL statement, UTF-8 encoded */ |
|
2301 int nByte, /* Maximum length of zSql in bytes. */ |
|
2302 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2303 const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2304 ); |
|
2305 int sqlite3_prepare_v2( |
|
2306 sqlite3 *db, /* Database handle */ |
|
2307 const char *zSql, /* SQL statement, UTF-8 encoded */ |
|
2308 int nByte, /* Maximum length of zSql in bytes. */ |
|
2309 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2310 const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2311 ); |
|
2312 int sqlite3_prepare16( |
|
2313 sqlite3 *db, /* Database handle */ |
|
2314 const void *zSql, /* SQL statement, UTF-16 encoded */ |
|
2315 int nByte, /* Maximum length of zSql in bytes. */ |
|
2316 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2317 const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2318 ); |
|
2319 int sqlite3_prepare16_v2( |
|
2320 sqlite3 *db, /* Database handle */ |
|
2321 const void *zSql, /* SQL statement, UTF-16 encoded */ |
|
2322 int nByte, /* Maximum length of zSql in bytes. */ |
|
2323 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2324 const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2325 ); |
|
2326 |
|
2327 /* |
|
2328 ** CAPI3REF: Retrieving Statement SQL {H13100} <H13000> |
|
2329 ** |
|
2330 ** This interface can be used to retrieve a saved copy of the original |
|
2331 ** SQL text used to create a [prepared statement] if that statement was |
|
2332 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. |
|
2333 ** |
|
2334 ** Requirements: |
|
2335 ** [H13101] [H13102] [H13103] |
|
2336 */ |
|
2337 const char *sqlite3_sql(sqlite3_stmt *pStmt); |
|
2338 |
|
2339 /* |
|
2340 ** CAPI3REF: Dynamically Typed Value Object {H15000} <S20200> |
|
2341 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} |
|
2342 ** |
|
2343 ** SQLite uses the sqlite3_value object to represent all values |
|
2344 ** that can be stored in a database table. SQLite uses dynamic typing |
|
2345 ** for the values it stores. Values stored in sqlite3_value objects |
|
2346 ** can be integers, floating point values, strings, BLOBs, or NULL. |
|
2347 ** |
|
2348 ** An sqlite3_value object may be either "protected" or "unprotected". |
|
2349 ** Some interfaces require a protected sqlite3_value. Other interfaces |
|
2350 ** will accept either a protected or an unprotected sqlite3_value. |
|
2351 ** Every interface that accepts sqlite3_value arguments specifies |
|
2352 ** whether or not it requires a protected sqlite3_value. |
|
2353 ** |
|
2354 ** The terms "protected" and "unprotected" refer to whether or not |
|
2355 ** a mutex is held. A internal mutex is held for a protected |
|
2356 ** sqlite3_value object but no mutex is held for an unprotected |
|
2357 ** sqlite3_value object. If SQLite is compiled to be single-threaded |
|
2358 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) |
|
2359 ** or if SQLite is run in one of reduced mutex modes |
|
2360 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] |
|
2361 ** then there is no distinction between protected and unprotected |
|
2362 ** sqlite3_value objects and they can be used interchangeably. However, |
|
2363 ** for maximum code portability it is recommended that applications |
|
2364 ** still make the distinction between between protected and unprotected |
|
2365 ** sqlite3_value objects even when not strictly required. |
|
2366 ** |
|
2367 ** The sqlite3_value objects that are passed as parameters into the |
|
2368 ** implementation of [application-defined SQL functions] are protected. |
|
2369 ** The sqlite3_value object returned by |
|
2370 ** [sqlite3_column_value()] is unprotected. |
|
2371 ** Unprotected sqlite3_value objects may only be used with |
|
2372 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. |
|
2373 ** The [sqlite3_value_blob | sqlite3_value_type()] family of |
|
2374 ** interfaces require protected sqlite3_value objects. |
|
2375 */ |
|
2376 typedef struct Mem sqlite3_value; |
|
2377 |
|
2378 /* |
|
2379 ** CAPI3REF: SQL Function Context Object {H16001} <S20200> |
|
2380 ** |
|
2381 ** The context in which an SQL function executes is stored in an |
|
2382 ** sqlite3_context object. A pointer to an sqlite3_context object |
|
2383 ** is always first parameter to [application-defined SQL functions]. |
|
2384 ** The application-defined SQL function implementation will pass this |
|
2385 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], |
|
2386 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], |
|
2387 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], |
|
2388 ** and/or [sqlite3_set_auxdata()]. |
|
2389 */ |
|
2390 typedef struct sqlite3_context sqlite3_context; |
|
2391 |
|
2392 /* |
|
2393 ** CAPI3REF: Binding Values To Prepared Statements {H13500} <S70300> |
|
2394 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} |
|
2395 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} |
|
2396 ** |
|
2397 ** In the SQL strings input to [sqlite3_prepare_v2()] and its variants, |
|
2398 ** literals may be replaced by a [parameter] in one of these forms: |
|
2399 ** |
|
2400 ** <ul> |
|
2401 ** <li> ? |
|
2402 ** <li> ?NNN |
|
2403 ** <li> :VVV |
|
2404 ** <li> @VVV |
|
2405 ** <li> $VVV |
|
2406 ** </ul> |
|
2407 ** |
|
2408 ** In the parameter forms shown above NNN is an integer literal, |
|
2409 ** and VVV is an alpha-numeric parameter name. The values of these |
|
2410 ** parameters (also called "host parameter names" or "SQL parameters") |
|
2411 ** can be set using the sqlite3_bind_*() routines defined here. |
|
2412 ** |
|
2413 ** The first argument to the sqlite3_bind_*() routines is always |
|
2414 ** a pointer to the [sqlite3_stmt] object returned from |
|
2415 ** [sqlite3_prepare_v2()] or its variants. |
|
2416 ** |
|
2417 ** The second argument is the index of the SQL parameter to be set. |
|
2418 ** The leftmost SQL parameter has an index of 1. When the same named |
|
2419 ** SQL parameter is used more than once, second and subsequent |
|
2420 ** occurrences have the same index as the first occurrence. |
|
2421 ** The index for named parameters can be looked up using the |
|
2422 ** [sqlite3_bind_parameter_index()] API if desired. The index |
|
2423 ** for "?NNN" parameters is the value of NNN. |
|
2424 ** The NNN value must be between 1 and the [sqlite3_limit()] |
|
2425 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). |
|
2426 ** |
|
2427 ** The third argument is the value to bind to the parameter. |
|
2428 ** |
|
2429 ** In those routines that have a fourth argument, its value is the |
|
2430 ** number of bytes in the parameter. To be clear: the value is the |
|
2431 ** number of <u>bytes</u> in the value, not the number of characters. |
|
2432 ** If the fourth parameter is negative, the length of the string is |
|
2433 ** the number of bytes up to the first zero terminator. |
|
2434 ** |
|
2435 ** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and |
|
2436 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or |
|
2437 ** string after SQLite has finished with it. If the fifth argument is |
|
2438 ** the special value [SQLITE_STATIC], then SQLite assumes that the |
|
2439 ** information is in static, unmanaged space and does not need to be freed. |
|
2440 ** If the fifth argument has the value [SQLITE_TRANSIENT], then |
|
2441 ** SQLite makes its own private copy of the data immediately, before |
|
2442 ** the sqlite3_bind_*() routine returns. |
|
2443 ** |
|
2444 ** The sqlite3_bind_zeroblob() routine binds a BLOB of length N that |
|
2445 ** is filled with zeroes. A zeroblob uses a fixed amount of memory |
|
2446 ** (just an integer to hold its size) while it is being processed. |
|
2447 ** Zeroblobs are intended to serve as placeholders for BLOBs whose |
|
2448 ** content is later written using |
|
2449 ** [sqlite3_blob_open | incremental BLOB I/O] routines. |
|
2450 ** A negative value for the zeroblob results in a zero-length BLOB. |
|
2451 ** |
|
2452 ** The sqlite3_bind_*() routines must be called after |
|
2453 ** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and |
|
2454 ** before [sqlite3_step()]. |
|
2455 ** Bindings are not cleared by the [sqlite3_reset()] routine. |
|
2456 ** Unbound parameters are interpreted as NULL. |
|
2457 ** |
|
2458 ** These routines return [SQLITE_OK] on success or an error code if |
|
2459 ** anything goes wrong. [SQLITE_RANGE] is returned if the parameter |
|
2460 ** index is out of range. [SQLITE_NOMEM] is returned if malloc() fails. |
|
2461 ** [SQLITE_MISUSE] might be returned if these routines are called on a |
|
2462 ** virtual machine that is the wrong state or which has already been finalized. |
|
2463 ** Detection of misuse is unreliable. Applications should not depend |
|
2464 ** on SQLITE_MISUSE returns. SQLITE_MISUSE is intended to indicate a |
|
2465 ** a logic error in the application. Future versions of SQLite might |
|
2466 ** panic rather than return SQLITE_MISUSE. |
|
2467 ** |
|
2468 ** See also: [sqlite3_bind_parameter_count()], |
|
2469 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. |
|
2470 ** |
|
2471 ** Requirements: |
|
2472 ** [H13506] [H13509] [H13512] [H13515] [H13518] [H13521] [H13524] [H13527] |
|
2473 ** [H13530] [H13533] [H13536] [H13539] [H13542] [H13545] [H13548] [H13551] |
|
2474 ** |
|
2475 */ |
|
2476 int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); |
|
2477 int sqlite3_bind_double(sqlite3_stmt*, int, double); |
|
2478 int sqlite3_bind_int(sqlite3_stmt*, int, int); |
|
2479 int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); |
|
2480 int sqlite3_bind_null(sqlite3_stmt*, int); |
|
2481 int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); |
|
2482 int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); |
|
2483 int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); |
|
2484 int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); |
|
2485 |
|
2486 /* |
|
2487 ** CAPI3REF: Number Of SQL Parameters {H13600} <S70300> |
|
2488 ** |
|
2489 ** This routine can be used to find the number of [SQL parameters] |
|
2490 ** in a [prepared statement]. SQL parameters are tokens of the |
|
2491 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as |
|
2492 ** placeholders for values that are [sqlite3_bind_blob | bound] |
|
2493 ** to the parameters at a later time. |
|
2494 ** |
|
2495 ** This routine actually returns the index of the largest (rightmost) |
|
2496 ** parameter. For all forms except ?NNN, this will correspond to the |
|
2497 ** number of unique parameters. If parameters of the ?NNN are used, |
|
2498 ** there may be gaps in the list. |
|
2499 ** |
|
2500 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
|
2501 ** [sqlite3_bind_parameter_name()], and |
|
2502 ** [sqlite3_bind_parameter_index()]. |
|
2503 ** |
|
2504 ** Requirements: |
|
2505 ** [H13601] |
|
2506 */ |
|
2507 int sqlite3_bind_parameter_count(sqlite3_stmt*); |
|
2508 |
|
2509 /* |
|
2510 ** CAPI3REF: Name Of A Host Parameter {H13620} <S70300> |
|
2511 ** |
|
2512 ** This routine returns a pointer to the name of the n-th |
|
2513 ** [SQL parameter] in a [prepared statement]. |
|
2514 ** SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" |
|
2515 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" |
|
2516 ** respectively. |
|
2517 ** In other words, the initial ":" or "$" or "@" or "?" |
|
2518 ** is included as part of the name. |
|
2519 ** Parameters of the form "?" without a following integer have no name |
|
2520 ** and are also referred to as "anonymous parameters". |
|
2521 ** |
|
2522 ** The first host parameter has an index of 1, not 0. |
|
2523 ** |
|
2524 ** If the value n is out of range or if the n-th parameter is |
|
2525 ** nameless, then NULL is returned. The returned string is |
|
2526 ** always in UTF-8 encoding even if the named parameter was |
|
2527 ** originally specified as UTF-16 in [sqlite3_prepare16()] or |
|
2528 ** [sqlite3_prepare16_v2()]. |
|
2529 ** |
|
2530 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
|
2531 ** [sqlite3_bind_parameter_count()], and |
|
2532 ** [sqlite3_bind_parameter_index()]. |
|
2533 ** |
|
2534 ** Requirements: |
|
2535 ** [H13621] |
|
2536 */ |
|
2537 const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
|
2538 |
|
2539 /* |
|
2540 ** CAPI3REF: Index Of A Parameter With A Given Name {H13640} <S70300> |
|
2541 ** |
|
2542 ** Return the index of an SQL parameter given its name. The |
|
2543 ** index value returned is suitable for use as the second |
|
2544 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. A zero |
|
2545 ** is returned if no matching parameter is found. The parameter |
|
2546 ** name must be given in UTF-8 even if the original statement |
|
2547 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. |
|
2548 ** |
|
2549 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
|
2550 ** [sqlite3_bind_parameter_count()], and |
|
2551 ** [sqlite3_bind_parameter_index()]. |
|
2552 ** |
|
2553 ** Requirements: |
|
2554 ** [H13641] |
|
2555 */ |
|
2556 int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
|
2557 |
|
2558 /* |
|
2559 ** CAPI3REF: Reset All Bindings On A Prepared Statement {H13660} <S70300> |
|
2560 ** |
|
2561 ** Contrary to the intuition of many, [sqlite3_reset()] does not reset |
|
2562 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. |
|
2563 ** Use this routine to reset all host parameters to NULL. |
|
2564 ** |
|
2565 ** Requirements: |
|
2566 ** [H13661] |
|
2567 */ |
|
2568 int sqlite3_clear_bindings(sqlite3_stmt*); |
|
2569 |
|
2570 /* |
|
2571 ** CAPI3REF: Number Of Columns In A Result Set {H13710} <S10700> |
|
2572 ** |
|
2573 ** Return the number of columns in the result set returned by the |
|
2574 ** [prepared statement]. This routine returns 0 if pStmt is an SQL |
|
2575 ** statement that does not return data (for example an [UPDATE]). |
|
2576 ** |
|
2577 ** Requirements: |
|
2578 ** [H13711] |
|
2579 */ |
|
2580 int sqlite3_column_count(sqlite3_stmt *pStmt); |
|
2581 |
|
2582 /* |
|
2583 ** CAPI3REF: Column Names In A Result Set {H13720} <S10700> |
|
2584 ** |
|
2585 ** These routines return the name assigned to a particular column |
|
2586 ** in the result set of a [SELECT] statement. The sqlite3_column_name() |
|
2587 ** interface returns a pointer to a zero-terminated UTF-8 string |
|
2588 ** and sqlite3_column_name16() returns a pointer to a zero-terminated |
|
2589 ** UTF-16 string. The first parameter is the [prepared statement] |
|
2590 ** that implements the [SELECT] statement. The second parameter is the |
|
2591 ** column number. The leftmost column is number 0. |
|
2592 ** |
|
2593 ** The returned string pointer is valid until either the [prepared statement] |
|
2594 ** is destroyed by [sqlite3_finalize()] or until the next call to |
|
2595 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. |
|
2596 ** |
|
2597 ** If sqlite3_malloc() fails during the processing of either routine |
|
2598 ** (for example during a conversion from UTF-8 to UTF-16) then a |
|
2599 ** NULL pointer is returned. |
|
2600 ** |
|
2601 ** The name of a result column is the value of the "AS" clause for |
|
2602 ** that column, if there is an AS clause. If there is no AS clause |
|
2603 ** then the name of the column is unspecified and may change from |
|
2604 ** one release of SQLite to the next. |
|
2605 ** |
|
2606 ** Requirements: |
|
2607 ** [H13721] [H13723] [H13724] [H13725] [H13726] [H13727] |
|
2608 */ |
|
2609 const char *sqlite3_column_name(sqlite3_stmt*, int N); |
|
2610 const void *sqlite3_column_name16(sqlite3_stmt*, int N); |
|
2611 |
|
2612 /* |
|
2613 ** CAPI3REF: Source Of Data In A Query Result {H13740} <S10700> |
|
2614 ** |
|
2615 ** These routines provide a means to determine what column of what |
|
2616 ** table in which database a result of a [SELECT] statement comes from. |
|
2617 ** The name of the database or table or column can be returned as |
|
2618 ** either a UTF-8 or UTF-16 string. The _database_ routines return |
|
2619 ** the database name, the _table_ routines return the table name, and |
|
2620 ** the origin_ routines return the column name. |
|
2621 ** The returned string is valid until the [prepared statement] is destroyed |
|
2622 ** using [sqlite3_finalize()] or until the same information is requested |
|
2623 ** again in a different encoding. |
|
2624 ** |
|
2625 ** The names returned are the original un-aliased names of the |
|
2626 ** database, table, and column. |
|
2627 ** |
|
2628 ** The first argument to the following calls is a [prepared statement]. |
|
2629 ** These functions return information about the Nth column returned by |
|
2630 ** the statement, where N is the second function argument. |
|
2631 ** |
|
2632 ** If the Nth column returned by the statement is an expression or |
|
2633 ** subquery and is not a column value, then all of these functions return |
|
2634 ** NULL. These routine might also return NULL if a memory allocation error |
|
2635 ** occurs. Otherwise, they return the name of the attached database, table |
|
2636 ** and column that query result column was extracted from. |
|
2637 ** |
|
2638 ** As with all other SQLite APIs, those postfixed with "16" return |
|
2639 ** UTF-16 encoded strings, the other functions return UTF-8. {END} |
|
2640 ** |
|
2641 ** These APIs are only available if the library was compiled with the |
|
2642 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. |
|
2643 ** |
|
2644 ** {A13751} |
|
2645 ** If two or more threads call one or more of these routines against the same |
|
2646 ** prepared statement and column at the same time then the results are |
|
2647 ** undefined. |
|
2648 ** |
|
2649 ** Requirements: |
|
2650 ** [H13741] [H13742] [H13743] [H13744] [H13745] [H13746] [H13748] |
|
2651 ** |
|
2652 ** If two or more threads call one or more |
|
2653 ** [sqlite3_column_database_name | column metadata interfaces] |
|
2654 ** for the same [prepared statement] and result column |
|
2655 ** at the same time then the results are undefined. |
|
2656 */ |
|
2657 const char *sqlite3_column_database_name(sqlite3_stmt*,int); |
|
2658 const void *sqlite3_column_database_name16(sqlite3_stmt*,int); |
|
2659 const char *sqlite3_column_table_name(sqlite3_stmt*,int); |
|
2660 const void *sqlite3_column_table_name16(sqlite3_stmt*,int); |
|
2661 const char *sqlite3_column_origin_name(sqlite3_stmt*,int); |
|
2662 const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); |
|
2663 |
|
2664 /* |
|
2665 ** CAPI3REF: Declared Datatype Of A Query Result {H13760} <S10700> |
|
2666 ** |
|
2667 ** The first parameter is a [prepared statement]. |
|
2668 ** If this statement is a [SELECT] statement and the Nth column of the |
|
2669 ** returned result set of that [SELECT] is a table column (not an |
|
2670 ** expression or subquery) then the declared type of the table |
|
2671 ** column is returned. If the Nth column of the result set is an |
|
2672 ** expression or subquery, then a NULL pointer is returned. |
|
2673 ** The returned string is always UTF-8 encoded. {END} |
|
2674 ** |
|
2675 ** For example, given the database schema: |
|
2676 ** |
|
2677 ** CREATE TABLE t1(c1 VARIANT); |
|
2678 ** |
|
2679 ** and the following statement to be compiled: |
|
2680 ** |
|
2681 ** SELECT c1 + 1, c1 FROM t1; |
|
2682 ** |
|
2683 ** this routine would return the string "VARIANT" for the second result |
|
2684 ** column (i==1), and a NULL pointer for the first result column (i==0). |
|
2685 ** |
|
2686 ** SQLite uses dynamic run-time typing. So just because a column |
|
2687 ** is declared to contain a particular type does not mean that the |
|
2688 ** data stored in that column is of the declared type. SQLite is |
|
2689 ** strongly typed, but the typing is dynamic not static. Type |
|
2690 ** is associated with individual values, not with the containers |
|
2691 ** used to hold those values. |
|
2692 ** |
|
2693 ** Requirements: |
|
2694 ** [H13761] [H13762] [H13763] |
|
2695 */ |
|
2696 const char *sqlite3_column_decltype(sqlite3_stmt*,int); |
|
2697 const void *sqlite3_column_decltype16(sqlite3_stmt*,int); |
|
2698 |
|
2699 /* |
|
2700 ** CAPI3REF: Evaluate An SQL Statement {H13200} <S10000> |
|
2701 ** |
|
2702 ** After a [prepared statement] has been prepared using either |
|
2703 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy |
|
2704 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function |
|
2705 ** must be called one or more times to evaluate the statement. |
|
2706 ** |
|
2707 ** The details of the behavior of the sqlite3_step() interface depend |
|
2708 ** on whether the statement was prepared using the newer "v2" interface |
|
2709 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy |
|
2710 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the |
|
2711 ** new "v2" interface is recommended for new applications but the legacy |
|
2712 ** interface will continue to be supported. |
|
2713 ** |
|
2714 ** In the legacy interface, the return value will be either [SQLITE_BUSY], |
|
2715 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. |
|
2716 ** With the "v2" interface, any of the other [result codes] or |
|
2717 ** [extended result codes] might be returned as well. |
|
2718 ** |
|
2719 ** [SQLITE_BUSY] means that the database engine was unable to acquire the |
|
2720 ** database locks it needs to do its job. If the statement is a [COMMIT] |
|
2721 ** or occurs outside of an explicit transaction, then you can retry the |
|
2722 ** statement. If the statement is not a [COMMIT] and occurs within a |
|
2723 ** explicit transaction then you should rollback the transaction before |
|
2724 ** continuing. |
|
2725 ** |
|
2726 ** [SQLITE_DONE] means that the statement has finished executing |
|
2727 ** successfully. sqlite3_step() should not be called again on this virtual |
|
2728 ** machine without first calling [sqlite3_reset()] to reset the virtual |
|
2729 ** machine back to its initial state. |
|
2730 ** |
|
2731 ** If the SQL statement being executed returns any data, then [SQLITE_ROW] |
|
2732 ** is returned each time a new row of data is ready for processing by the |
|
2733 ** caller. The values may be accessed using the [column access functions]. |
|
2734 ** sqlite3_step() is called again to retrieve the next row of data. |
|
2735 ** |
|
2736 ** [SQLITE_ERROR] means that a run-time error (such as a constraint |
|
2737 ** violation) has occurred. sqlite3_step() should not be called again on |
|
2738 ** the VM. More information may be found by calling [sqlite3_errmsg()]. |
|
2739 ** With the legacy interface, a more specific error code (for example, |
|
2740 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) |
|
2741 ** can be obtained by calling [sqlite3_reset()] on the |
|
2742 ** [prepared statement]. In the "v2" interface, |
|
2743 ** the more specific error code is returned directly by sqlite3_step(). |
|
2744 ** |
|
2745 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. |
|
2746 ** Perhaps it was called on a [prepared statement] that has |
|
2747 ** already been [sqlite3_finalize | finalized] or on one that had |
|
2748 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could |
|
2749 ** be the case that the same database connection is being used by two or |
|
2750 ** more threads at the same moment in time. |
|
2751 ** |
|
2752 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() |
|
2753 ** API always returns a generic error code, [SQLITE_ERROR], following any |
|
2754 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call |
|
2755 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the |
|
2756 ** specific [error codes] that better describes the error. |
|
2757 ** We admit that this is a goofy design. The problem has been fixed |
|
2758 ** with the "v2" interface. If you prepare all of your SQL statements |
|
2759 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead |
|
2760 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, |
|
2761 ** then the more specific [error codes] are returned directly |
|
2762 ** by sqlite3_step(). The use of the "v2" interface is recommended. |
|
2763 ** |
|
2764 ** Requirements: |
|
2765 ** [H13202] [H15304] [H15306] [H15308] [H15310] |
|
2766 */ |
|
2767 int sqlite3_step(sqlite3_stmt*); |
|
2768 |
|
2769 /* |
|
2770 ** CAPI3REF: Number of columns in a result set {H13770} <S10700> |
|
2771 ** |
|
2772 ** Returns the number of values in the current row of the result set. |
|
2773 ** |
|
2774 ** Requirements: |
|
2775 ** [H13771] [H13772] |
|
2776 */ |
|
2777 int sqlite3_data_count(sqlite3_stmt *pStmt); |
|
2778 |
|
2779 /* |
|
2780 ** CAPI3REF: Fundamental Datatypes {H10265} <S10110><S10120> |
|
2781 ** KEYWORDS: SQLITE_TEXT |
|
2782 ** |
|
2783 ** {H10266} Every value in SQLite has one of five fundamental datatypes: |
|
2784 ** |
|
2785 ** <ul> |
|
2786 ** <li> 64-bit signed integer |
|
2787 ** <li> 64-bit IEEE floating point number |
|
2788 ** <li> string |
|
2789 ** <li> BLOB |
|
2790 ** <li> NULL |
|
2791 ** </ul> {END} |
|
2792 ** |
|
2793 ** These constants are codes for each of those types. |
|
2794 ** |
|
2795 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 |
|
2796 ** for a completely different meaning. Software that links against both |
|
2797 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not |
|
2798 ** SQLITE_TEXT. |
|
2799 */ |
|
2800 #define SQLITE_INTEGER 1 |
|
2801 #define SQLITE_FLOAT 2 |
|
2802 #define SQLITE_BLOB 4 |
|
2803 #define SQLITE_NULL 5 |
|
2804 #ifdef SQLITE_TEXT |
|
2805 # undef SQLITE_TEXT |
|
2806 #else |
|
2807 # define SQLITE_TEXT 3 |
|
2808 #endif |
|
2809 #define SQLITE3_TEXT 3 |
|
2810 |
|
2811 /* |
|
2812 ** CAPI3REF: Result Values From A Query {H13800} <S10700> |
|
2813 ** KEYWORDS: {column access functions} |
|
2814 ** |
|
2815 ** These routines form the "result set query" interface. |
|
2816 ** |
|
2817 ** These routines return information about a single column of the current |
|
2818 ** result row of a query. In every case the first argument is a pointer |
|
2819 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] |
|
2820 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) |
|
2821 ** and the second argument is the index of the column for which information |
|
2822 ** should be returned. The leftmost column of the result set has the index 0. |
|
2823 ** |
|
2824 ** If the SQL statement does not currently point to a valid row, or if the |
|
2825 ** column index is out of range, the result is undefined. |
|
2826 ** These routines may only be called when the most recent call to |
|
2827 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither |
|
2828 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. |
|
2829 ** If any of these routines are called after [sqlite3_reset()] or |
|
2830 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned |
|
2831 ** something other than [SQLITE_ROW], the results are undefined. |
|
2832 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] |
|
2833 ** are called from a different thread while any of these routines |
|
2834 ** are pending, then the results are undefined. |
|
2835 ** |
|
2836 ** The sqlite3_column_type() routine returns the |
|
2837 ** [SQLITE_INTEGER | datatype code] for the initial data type |
|
2838 ** of the result column. The returned value is one of [SQLITE_INTEGER], |
|
2839 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value |
|
2840 ** returned by sqlite3_column_type() is only meaningful if no type |
|
2841 ** conversions have occurred as described below. After a type conversion, |
|
2842 ** the value returned by sqlite3_column_type() is undefined. Future |
|
2843 ** versions of SQLite may change the behavior of sqlite3_column_type() |
|
2844 ** following a type conversion. |
|
2845 ** |
|
2846 ** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() |
|
2847 ** routine returns the number of bytes in that BLOB or string. |
|
2848 ** If the result is a UTF-16 string, then sqlite3_column_bytes() converts |
|
2849 ** the string to UTF-8 and then returns the number of bytes. |
|
2850 ** If the result is a numeric value then sqlite3_column_bytes() uses |
|
2851 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns |
|
2852 ** the number of bytes in that string. |
|
2853 ** The value returned does not include the zero terminator at the end |
|
2854 ** of the string. For clarity: the value returned is the number of |
|
2855 ** bytes in the string, not the number of characters. |
|
2856 ** |
|
2857 ** Strings returned by sqlite3_column_text() and sqlite3_column_text16(), |
|
2858 ** even empty strings, are always zero terminated. The return |
|
2859 ** value from sqlite3_column_blob() for a zero-length BLOB is an arbitrary |
|
2860 ** pointer, possibly even a NULL pointer. |
|
2861 ** |
|
2862 ** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes() |
|
2863 ** but leaves the result in UTF-16 in native byte order instead of UTF-8. |
|
2864 ** The zero terminator is not included in this count. |
|
2865 ** |
|
2866 ** The object returned by [sqlite3_column_value()] is an |
|
2867 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object |
|
2868 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. |
|
2869 ** If the [unprotected sqlite3_value] object returned by |
|
2870 ** [sqlite3_column_value()] is used in any other way, including calls |
|
2871 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], |
|
2872 ** or [sqlite3_value_bytes()], then the behavior is undefined. |
|
2873 ** |
|
2874 ** These routines attempt to convert the value where appropriate. For |
|
2875 ** example, if the internal representation is FLOAT and a text result |
|
2876 ** is requested, [sqlite3_snprintf()] is used internally to perform the |
|
2877 ** conversion automatically. The following table details the conversions |
|
2878 ** that are applied: |
|
2879 ** |
|
2880 ** <blockquote> |
|
2881 ** <table border="1"> |
|
2882 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion |
|
2883 ** |
|
2884 ** <tr><td> NULL <td> INTEGER <td> Result is 0 |
|
2885 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 |
|
2886 ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer |
|
2887 ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer |
|
2888 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float |
|
2889 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer |
|
2890 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT |
|
2891 ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer |
|
2892 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float |
|
2893 ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT |
|
2894 ** <tr><td> TEXT <td> INTEGER <td> Use atoi() |
|
2895 ** <tr><td> TEXT <td> FLOAT <td> Use atof() |
|
2896 ** <tr><td> TEXT <td> BLOB <td> No change |
|
2897 ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() |
|
2898 ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() |
|
2899 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed |
|
2900 ** </table> |
|
2901 ** </blockquote> |
|
2902 ** |
|
2903 ** The table above makes reference to standard C library functions atoi() |
|
2904 ** and atof(). SQLite does not really use these functions. It has its |
|
2905 ** own equivalent internal routines. The atoi() and atof() names are |
|
2906 ** used in the table for brevity and because they are familiar to most |
|
2907 ** C programmers. |
|
2908 ** |
|
2909 ** Note that when type conversions occur, pointers returned by prior |
|
2910 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or |
|
2911 ** sqlite3_column_text16() may be invalidated. |
|
2912 ** Type conversions and pointer invalidations might occur |
|
2913 ** in the following cases: |
|
2914 ** |
|
2915 ** <ul> |
|
2916 ** <li> The initial content is a BLOB and sqlite3_column_text() or |
|
2917 ** sqlite3_column_text16() is called. A zero-terminator might |
|
2918 ** need to be added to the string.</li> |
|
2919 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or |
|
2920 ** sqlite3_column_text16() is called. The content must be converted |
|
2921 ** to UTF-16.</li> |
|
2922 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or |
|
2923 ** sqlite3_column_text() is called. The content must be converted |
|
2924 ** to UTF-8.</li> |
|
2925 ** </ul> |
|
2926 ** |
|
2927 ** Conversions between UTF-16be and UTF-16le are always done in place and do |
|
2928 ** not invalidate a prior pointer, though of course the content of the buffer |
|
2929 ** that the prior pointer points to will have been modified. Other kinds |
|
2930 ** of conversion are done in place when it is possible, but sometimes they |
|
2931 ** are not possible and in those cases prior pointers are invalidated. |
|
2932 ** |
|
2933 ** The safest and easiest to remember policy is to invoke these routines |
|
2934 ** in one of the following ways: |
|
2935 ** |
|
2936 ** <ul> |
|
2937 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> |
|
2938 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> |
|
2939 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> |
|
2940 ** </ul> |
|
2941 ** |
|
2942 ** In other words, you should call sqlite3_column_text(), |
|
2943 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result |
|
2944 ** into the desired format, then invoke sqlite3_column_bytes() or |
|
2945 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls |
|
2946 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to |
|
2947 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() |
|
2948 ** with calls to sqlite3_column_bytes(). |
|
2949 ** |
|
2950 ** The pointers returned are valid until a type conversion occurs as |
|
2951 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or |
|
2952 ** [sqlite3_finalize()] is called. The memory space used to hold strings |
|
2953 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned |
|
2954 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into |
|
2955 ** [sqlite3_free()]. |
|
2956 ** |
|
2957 ** If a memory allocation error occurs during the evaluation of any |
|
2958 ** of these routines, a default value is returned. The default value |
|
2959 ** is either the integer 0, the floating point number 0.0, or a NULL |
|
2960 ** pointer. Subsequent calls to [sqlite3_errcode()] will return |
|
2961 ** [SQLITE_NOMEM]. |
|
2962 ** |
|
2963 ** Requirements: |
|
2964 ** [H13803] [H13806] [H13809] [H13812] [H13815] [H13818] [H13821] [H13824] |
|
2965 ** [H13827] [H13830] |
|
2966 */ |
|
2967 const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); |
|
2968 int sqlite3_column_bytes(sqlite3_stmt*, int iCol); |
|
2969 int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); |
|
2970 double sqlite3_column_double(sqlite3_stmt*, int iCol); |
|
2971 int sqlite3_column_int(sqlite3_stmt*, int iCol); |
|
2972 sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); |
|
2973 const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); |
|
2974 const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); |
|
2975 int sqlite3_column_type(sqlite3_stmt*, int iCol); |
|
2976 sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); |
|
2977 |
|
2978 /* |
|
2979 ** CAPI3REF: Destroy A Prepared Statement Object {H13300} <S70300><S30100> |
|
2980 ** |
|
2981 ** The sqlite3_finalize() function is called to delete a [prepared statement]. |
|
2982 ** If the statement was executed successfully or not executed at all, then |
|
2983 ** SQLITE_OK is returned. If execution of the statement failed then an |
|
2984 ** [error code] or [extended error code] is returned. |
|
2985 ** |
|
2986 ** This routine can be called at any point during the execution of the |
|
2987 ** [prepared statement]. If the virtual machine has not |
|
2988 ** completed execution when this routine is called, that is like |
|
2989 ** encountering an error or an [sqlite3_interrupt | interrupt]. |
|
2990 ** Incomplete updates may be rolled back and transactions canceled, |
|
2991 ** depending on the circumstances, and the |
|
2992 ** [error code] returned will be [SQLITE_ABORT]. |
|
2993 ** |
|
2994 ** Requirements: |
|
2995 ** [H11302] [H11304] |
|
2996 */ |
|
2997 int sqlite3_finalize(sqlite3_stmt *pStmt); |
|
2998 |
|
2999 /* |
|
3000 ** CAPI3REF: Reset A Prepared Statement Object {H13330} <S70300> |
|
3001 ** |
|
3002 ** The sqlite3_reset() function is called to reset a [prepared statement] |
|
3003 ** object back to its initial state, ready to be re-executed. |
|
3004 ** Any SQL statement variables that had values bound to them using |
|
3005 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. |
|
3006 ** Use [sqlite3_clear_bindings()] to reset the bindings. |
|
3007 ** |
|
3008 ** {H11332} The [sqlite3_reset(S)] interface resets the [prepared statement] S |
|
3009 ** back to the beginning of its program. |
|
3010 ** |
|
3011 ** {H11334} If the most recent call to [sqlite3_step(S)] for the |
|
3012 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], |
|
3013 ** or if [sqlite3_step(S)] has never before been called on S, |
|
3014 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. |
|
3015 ** |
|
3016 ** {H11336} If the most recent call to [sqlite3_step(S)] for the |
|
3017 ** [prepared statement] S indicated an error, then |
|
3018 ** [sqlite3_reset(S)] returns an appropriate [error code]. |
|
3019 ** |
|
3020 ** {H11338} The [sqlite3_reset(S)] interface does not change the values |
|
3021 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. |
|
3022 */ |
|
3023 int sqlite3_reset(sqlite3_stmt *pStmt); |
|
3024 |
|
3025 /* |
|
3026 ** CAPI3REF: Create Or Redefine SQL Functions {H16100} <S20200> |
|
3027 ** KEYWORDS: {function creation routines} |
|
3028 ** KEYWORDS: {application-defined SQL function} |
|
3029 ** KEYWORDS: {application-defined SQL functions} |
|
3030 ** |
|
3031 ** These two functions (collectively known as "function creation routines") |
|
3032 ** are used to add SQL functions or aggregates or to redefine the behavior |
|
3033 ** of existing SQL functions or aggregates. The only difference between the |
|
3034 ** two is that the second parameter, the name of the (scalar) function or |
|
3035 ** aggregate, is encoded in UTF-8 for sqlite3_create_function() and UTF-16 |
|
3036 ** for sqlite3_create_function16(). |
|
3037 ** |
|
3038 ** The first parameter is the [database connection] to which the SQL |
|
3039 ** function is to be added. If a single program uses more than one database |
|
3040 ** connection internally, then SQL functions must be added individually to |
|
3041 ** each database connection. |
|
3042 ** |
|
3043 ** The second parameter is the name of the SQL function to be created or |
|
3044 ** redefined. The length of the name is limited to 255 bytes, exclusive of |
|
3045 ** the zero-terminator. Note that the name length limit is in bytes, not |
|
3046 ** characters. Any attempt to create a function with a longer name |
|
3047 ** will result in [SQLITE_ERROR] being returned. |
|
3048 ** |
|
3049 ** The third parameter (nArg) |
|
3050 ** is the number of arguments that the SQL function or |
|
3051 ** aggregate takes. If this parameter is negative, then the SQL function or |
|
3052 ** aggregate may take any number of arguments. |
|
3053 ** |
|
3054 ** The fourth parameter, eTextRep, specifies what |
|
3055 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for |
|
3056 ** its parameters. Any SQL function implementation should be able to work |
|
3057 ** work with UTF-8, UTF-16le, or UTF-16be. But some implementations may be |
|
3058 ** more efficient with one encoding than another. It is allowed to |
|
3059 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple |
|
3060 ** times with the same function but with different values of eTextRep. |
|
3061 ** When multiple implementations of the same function are available, SQLite |
|
3062 ** will pick the one that involves the least amount of data conversion. |
|
3063 ** If there is only a single implementation which does not care what text |
|
3064 ** encoding is used, then the fourth argument should be [SQLITE_ANY]. |
|
3065 ** |
|
3066 ** The fifth parameter is an arbitrary pointer. The implementation of the |
|
3067 ** function can gain access to this pointer using [sqlite3_user_data()]. |
|
3068 ** |
|
3069 ** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are |
|
3070 ** pointers to C-language functions that implement the SQL function or |
|
3071 ** aggregate. A scalar SQL function requires an implementation of the xFunc |
|
3072 ** callback only, NULL pointers should be passed as the xStep and xFinal |
|
3073 ** parameters. An aggregate SQL function requires an implementation of xStep |
|
3074 ** and xFinal and NULL should be passed for xFunc. To delete an existing |
|
3075 ** SQL function or aggregate, pass NULL for all three function callbacks. |
|
3076 ** |
|
3077 ** It is permitted to register multiple implementations of the same |
|
3078 ** functions with the same name but with either differing numbers of |
|
3079 ** arguments or differing preferred text encodings. SQLite will use |
|
3080 ** the implementation most closely matches the way in which the |
|
3081 ** SQL function is used. A function implementation with a non-negative |
|
3082 ** nArg parameter is a better match than a function implementation with |
|
3083 ** a negative nArg. A function where the preferred text encoding |
|
3084 ** matches the database encoding is a better |
|
3085 ** match than a function where the encoding is different. |
|
3086 ** A function where the encoding difference is between UTF16le and UTF16be |
|
3087 ** is a closer match than a function where the encoding difference is |
|
3088 ** between UTF8 and UTF16. |
|
3089 ** |
|
3090 ** Built-in functions may be overloaded by new application-defined functions. |
|
3091 ** The first application-defined function with a given name overrides all |
|
3092 ** built-in functions in the same [database connection] with the same name. |
|
3093 ** Subsequent application-defined functions of the same name only override |
|
3094 ** prior application-defined functions that are an exact match for the |
|
3095 ** number of parameters and preferred encoding. |
|
3096 ** |
|
3097 ** An application-defined function is permitted to call other |
|
3098 ** SQLite interfaces. However, such calls must not |
|
3099 ** close the database connection nor finalize or reset the prepared |
|
3100 ** statement in which the function is running. |
|
3101 ** |
|
3102 ** Requirements: |
|
3103 ** [H16103] [H16106] [H16109] [H16112] [H16118] [H16121] [H16124] [H16127] |
|
3104 ** [H16130] [H16133] [H16136] [H16139] [H16142] |
|
3105 */ |
|
3106 int sqlite3_create_function( |
|
3107 sqlite3 *db, |
|
3108 const char *zFunctionName, |
|
3109 int nArg, |
|
3110 int eTextRep, |
|
3111 void *pApp, |
|
3112 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
|
3113 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
|
3114 void (*xFinal)(sqlite3_context*) |
|
3115 ); |
|
3116 int sqlite3_create_function16( |
|
3117 sqlite3 *db, |
|
3118 const void *zFunctionName, |
|
3119 int nArg, |
|
3120 int eTextRep, |
|
3121 void *pApp, |
|
3122 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
|
3123 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
|
3124 void (*xFinal)(sqlite3_context*) |
|
3125 ); |
|
3126 |
|
3127 /* |
|
3128 ** CAPI3REF: Text Encodings {H10267} <S50200> <H16100> |
|
3129 ** |
|
3130 ** These constant define integer codes that represent the various |
|
3131 ** text encodings supported by SQLite. |
|
3132 */ |
|
3133 #define SQLITE_UTF8 1 |
|
3134 #define SQLITE_UTF16LE 2 |
|
3135 #define SQLITE_UTF16BE 3 |
|
3136 #define SQLITE_UTF16 4 /* Use native byte order */ |
|
3137 #define SQLITE_ANY 5 /* sqlite3_create_function only */ |
|
3138 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
|
3139 |
|
3140 /* |
|
3141 ** CAPI3REF: Deprecated Functions |
|
3142 ** DEPRECATED |
|
3143 ** |
|
3144 ** These functions are [deprecated]. In order to maintain |
|
3145 ** backwards compatibility with older code, these functions continue |
|
3146 ** to be supported. However, new applications should avoid |
|
3147 ** the use of these functions. To help encourage people to avoid |
|
3148 ** using these functions, we are not going to tell you what they do. |
|
3149 */ |
|
3150 #ifndef SQLITE_OMIT_DEPRECATED |
|
3151 SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); |
|
3152 SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); |
|
3153 SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); |
|
3154 SQLITE_DEPRECATED int sqlite3_global_recover(void); |
|
3155 SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); |
|
3156 SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); |
|
3157 #endif |
|
3158 |
|
3159 /* |
|
3160 ** CAPI3REF: Obtaining SQL Function Parameter Values {H15100} <S20200> |
|
3161 ** |
|
3162 ** The C-language implementation of SQL functions and aggregates uses |
|
3163 ** this set of interface routines to access the parameter values on |
|
3164 ** the function or aggregate. |
|
3165 ** |
|
3166 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters |
|
3167 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] |
|
3168 ** define callbacks that implement the SQL functions and aggregates. |
|
3169 ** The 4th parameter to these callbacks is an array of pointers to |
|
3170 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for |
|
3171 ** each parameter to the SQL function. These routines are used to |
|
3172 ** extract values from the [sqlite3_value] objects. |
|
3173 ** |
|
3174 ** These routines work only with [protected sqlite3_value] objects. |
|
3175 ** Any attempt to use these routines on an [unprotected sqlite3_value] |
|
3176 ** object results in undefined behavior. |
|
3177 ** |
|
3178 ** These routines work just like the corresponding [column access functions] |
|
3179 ** except that these routines take a single [protected sqlite3_value] object |
|
3180 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. |
|
3181 ** |
|
3182 ** The sqlite3_value_text16() interface extracts a UTF-16 string |
|
3183 ** in the native byte-order of the host machine. The |
|
3184 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces |
|
3185 ** extract UTF-16 strings as big-endian and little-endian respectively. |
|
3186 ** |
|
3187 ** The sqlite3_value_numeric_type() interface attempts to apply |
|
3188 ** numeric affinity to the value. This means that an attempt is |
|
3189 ** made to convert the value to an integer or floating point. If |
|
3190 ** such a conversion is possible without loss of information (in other |
|
3191 ** words, if the value is a string that looks like a number) |
|
3192 ** then the conversion is performed. Otherwise no conversion occurs. |
|
3193 ** The [SQLITE_INTEGER | datatype] after conversion is returned. |
|
3194 ** |
|
3195 ** Please pay particular attention to the fact that the pointer returned |
|
3196 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or |
|
3197 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to |
|
3198 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], |
|
3199 ** or [sqlite3_value_text16()]. |
|
3200 ** |
|
3201 ** These routines must be called from the same thread as |
|
3202 ** the SQL function that supplied the [sqlite3_value*] parameters. |
|
3203 ** |
|
3204 ** Requirements: |
|
3205 ** [H15103] [H15106] [H15109] [H15112] [H15115] [H15118] [H15121] [H15124] |
|
3206 ** [H15127] [H15130] [H15133] [H15136] |
|
3207 */ |
|
3208 const void *sqlite3_value_blob(sqlite3_value*); |
|
3209 int sqlite3_value_bytes(sqlite3_value*); |
|
3210 int sqlite3_value_bytes16(sqlite3_value*); |
|
3211 double sqlite3_value_double(sqlite3_value*); |
|
3212 int sqlite3_value_int(sqlite3_value*); |
|
3213 sqlite3_int64 sqlite3_value_int64(sqlite3_value*); |
|
3214 const unsigned char *sqlite3_value_text(sqlite3_value*); |
|
3215 const void *sqlite3_value_text16(sqlite3_value*); |
|
3216 const void *sqlite3_value_text16le(sqlite3_value*); |
|
3217 const void *sqlite3_value_text16be(sqlite3_value*); |
|
3218 int sqlite3_value_type(sqlite3_value*); |
|
3219 int sqlite3_value_numeric_type(sqlite3_value*); |
|
3220 |
|
3221 /* |
|
3222 ** CAPI3REF: Obtain Aggregate Function Context {H16210} <S20200> |
|
3223 ** |
|
3224 ** The implementation of aggregate SQL functions use this routine to allocate |
|
3225 ** a structure for storing their state. |
|
3226 ** |
|
3227 ** The first time the sqlite3_aggregate_context() routine is called for a |
|
3228 ** particular aggregate, SQLite allocates nBytes of memory, zeroes out that |
|
3229 ** memory, and returns a pointer to it. On second and subsequent calls to |
|
3230 ** sqlite3_aggregate_context() for the same aggregate function index, |
|
3231 ** the same buffer is returned. The implementation of the aggregate can use |
|
3232 ** the returned buffer to accumulate data. |
|
3233 ** |
|
3234 ** SQLite automatically frees the allocated buffer when the aggregate |
|
3235 ** query concludes. |
|
3236 ** |
|
3237 ** The first parameter should be a copy of the |
|
3238 ** [sqlite3_context | SQL function context] that is the first parameter |
|
3239 ** to the callback routine that implements the aggregate function. |
|
3240 ** |
|
3241 ** This routine must be called from the same thread in which |
|
3242 ** the aggregate SQL function is running. |
|
3243 ** |
|
3244 ** Requirements: |
|
3245 ** [H16211] [H16213] [H16215] [H16217] |
|
3246 */ |
|
3247 void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
|
3248 |
|
3249 /* |
|
3250 ** CAPI3REF: User Data For Functions {H16240} <S20200> |
|
3251 ** |
|
3252 ** The sqlite3_user_data() interface returns a copy of |
|
3253 ** the pointer that was the pUserData parameter (the 5th parameter) |
|
3254 ** of the [sqlite3_create_function()] |
|
3255 ** and [sqlite3_create_function16()] routines that originally |
|
3256 ** registered the application defined function. {END} |
|
3257 ** |
|
3258 ** This routine must be called from the same thread in which |
|
3259 ** the application-defined function is running. |
|
3260 ** |
|
3261 ** Requirements: |
|
3262 ** [H16243] |
|
3263 */ |
|
3264 void *sqlite3_user_data(sqlite3_context*); |
|
3265 |
|
3266 /* |
|
3267 ** CAPI3REF: Database Connection For Functions {H16250} <S60600><S20200> |
|
3268 ** |
|
3269 ** The sqlite3_context_db_handle() interface returns a copy of |
|
3270 ** the pointer to the [database connection] (the 1st parameter) |
|
3271 ** of the [sqlite3_create_function()] |
|
3272 ** and [sqlite3_create_function16()] routines that originally |
|
3273 ** registered the application defined function. |
|
3274 ** |
|
3275 ** Requirements: |
|
3276 ** [H16253] |
|
3277 */ |
|
3278 sqlite3 *sqlite3_context_db_handle(sqlite3_context*); |
|
3279 |
|
3280 /* |
|
3281 ** CAPI3REF: Function Auxiliary Data {H16270} <S20200> |
|
3282 ** |
|
3283 ** The following two functions may be used by scalar SQL functions to |
|
3284 ** associate metadata with argument values. If the same value is passed to |
|
3285 ** multiple invocations of the same SQL function during query execution, under |
|
3286 ** some circumstances the associated metadata may be preserved. This may |
|
3287 ** be used, for example, to add a regular-expression matching scalar |
|
3288 ** function. The compiled version of the regular expression is stored as |
|
3289 ** metadata associated with the SQL value passed as the regular expression |
|
3290 ** pattern. The compiled regular expression can be reused on multiple |
|
3291 ** invocations of the same function so that the original pattern string |
|
3292 ** does not need to be recompiled on each invocation. |
|
3293 ** |
|
3294 ** The sqlite3_get_auxdata() interface returns a pointer to the metadata |
|
3295 ** associated by the sqlite3_set_auxdata() function with the Nth argument |
|
3296 ** value to the application-defined function. If no metadata has been ever |
|
3297 ** been set for the Nth argument of the function, or if the corresponding |
|
3298 ** function parameter has changed since the meta-data was set, |
|
3299 ** then sqlite3_get_auxdata() returns a NULL pointer. |
|
3300 ** |
|
3301 ** The sqlite3_set_auxdata() interface saves the metadata |
|
3302 ** pointed to by its 3rd parameter as the metadata for the N-th |
|
3303 ** argument of the application-defined function. Subsequent |
|
3304 ** calls to sqlite3_get_auxdata() might return this data, if it has |
|
3305 ** not been destroyed. |
|
3306 ** If it is not NULL, SQLite will invoke the destructor |
|
3307 ** function given by the 4th parameter to sqlite3_set_auxdata() on |
|
3308 ** the metadata when the corresponding function parameter changes |
|
3309 ** or when the SQL statement completes, whichever comes first. |
|
3310 ** |
|
3311 ** SQLite is free to call the destructor and drop metadata on any |
|
3312 ** parameter of any function at any time. The only guarantee is that |
|
3313 ** the destructor will be called before the metadata is dropped. |
|
3314 ** |
|
3315 ** In practice, metadata is preserved between function calls for |
|
3316 ** expressions that are constant at compile time. This includes literal |
|
3317 ** values and SQL variables. |
|
3318 ** |
|
3319 ** These routines must be called from the same thread in which |
|
3320 ** the SQL function is running. |
|
3321 ** |
|
3322 ** Requirements: |
|
3323 ** [H16272] [H16274] [H16276] [H16277] [H16278] [H16279] |
|
3324 */ |
|
3325 void *sqlite3_get_auxdata(sqlite3_context*, int N); |
|
3326 void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); |
|
3327 |
|
3328 |
|
3329 /* |
|
3330 ** CAPI3REF: Constants Defining Special Destructor Behavior {H10280} <S30100> |
|
3331 ** |
|
3332 ** These are special values for the destructor that is passed in as the |
|
3333 ** final argument to routines like [sqlite3_result_blob()]. If the destructor |
|
3334 ** argument is SQLITE_STATIC, it means that the content pointer is constant |
|
3335 ** and will never change. It does not need to be destroyed. The |
|
3336 ** SQLITE_TRANSIENT value means that the content will likely change in |
|
3337 ** the near future and that SQLite should make its own private copy of |
|
3338 ** the content before returning. |
|
3339 ** |
|
3340 ** The typedef is necessary to work around problems in certain |
|
3341 ** C++ compilers. See ticket #2191. |
|
3342 */ |
|
3343 typedef void (*sqlite3_destructor_type)(void*); |
|
3344 #define SQLITE_STATIC ((sqlite3_destructor_type)0) |
|
3345 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) |
|
3346 |
|
3347 /* |
|
3348 ** CAPI3REF: Setting The Result Of An SQL Function {H16400} <S20200> |
|
3349 ** |
|
3350 ** These routines are used by the xFunc or xFinal callbacks that |
|
3351 ** implement SQL functions and aggregates. See |
|
3352 ** [sqlite3_create_function()] and [sqlite3_create_function16()] |
|
3353 ** for additional information. |
|
3354 ** |
|
3355 ** These functions work very much like the [parameter binding] family of |
|
3356 ** functions used to bind values to host parameters in prepared statements. |
|
3357 ** Refer to the [SQL parameter] documentation for additional information. |
|
3358 ** |
|
3359 ** The sqlite3_result_blob() interface sets the result from |
|
3360 ** an application-defined function to be the BLOB whose content is pointed |
|
3361 ** to by the second parameter and which is N bytes long where N is the |
|
3362 ** third parameter. |
|
3363 ** |
|
3364 ** The sqlite3_result_zeroblob() interfaces set the result of |
|
3365 ** the application-defined function to be a BLOB containing all zero |
|
3366 ** bytes and N bytes in size, where N is the value of the 2nd parameter. |
|
3367 ** |
|
3368 ** The sqlite3_result_double() interface sets the result from |
|
3369 ** an application-defined function to be a floating point value specified |
|
3370 ** by its 2nd argument. |
|
3371 ** |
|
3372 ** The sqlite3_result_error() and sqlite3_result_error16() functions |
|
3373 ** cause the implemented SQL function to throw an exception. |
|
3374 ** SQLite uses the string pointed to by the |
|
3375 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() |
|
3376 ** as the text of an error message. SQLite interprets the error |
|
3377 ** message string from sqlite3_result_error() as UTF-8. SQLite |
|
3378 ** interprets the string from sqlite3_result_error16() as UTF-16 in native |
|
3379 ** byte order. If the third parameter to sqlite3_result_error() |
|
3380 ** or sqlite3_result_error16() is negative then SQLite takes as the error |
|
3381 ** message all text up through the first zero character. |
|
3382 ** If the third parameter to sqlite3_result_error() or |
|
3383 ** sqlite3_result_error16() is non-negative then SQLite takes that many |
|
3384 ** bytes (not characters) from the 2nd parameter as the error message. |
|
3385 ** The sqlite3_result_error() and sqlite3_result_error16() |
|
3386 ** routines make a private copy of the error message text before |
|
3387 ** they return. Hence, the calling function can deallocate or |
|
3388 ** modify the text after they return without harm. |
|
3389 ** The sqlite3_result_error_code() function changes the error code |
|
3390 ** returned by SQLite as a result of an error in a function. By default, |
|
3391 ** the error code is SQLITE_ERROR. A subsequent call to sqlite3_result_error() |
|
3392 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. |
|
3393 ** |
|
3394 ** The sqlite3_result_toobig() interface causes SQLite to throw an error |
|
3395 ** indicating that a string or BLOB is to long to represent. |
|
3396 ** |
|
3397 ** The sqlite3_result_nomem() interface causes SQLite to throw an error |
|
3398 ** indicating that a memory allocation failed. |
|
3399 ** |
|
3400 ** The sqlite3_result_int() interface sets the return value |
|
3401 ** of the application-defined function to be the 32-bit signed integer |
|
3402 ** value given in the 2nd argument. |
|
3403 ** The sqlite3_result_int64() interface sets the return value |
|
3404 ** of the application-defined function to be the 64-bit signed integer |
|
3405 ** value given in the 2nd argument. |
|
3406 ** |
|
3407 ** The sqlite3_result_null() interface sets the return value |
|
3408 ** of the application-defined function to be NULL. |
|
3409 ** |
|
3410 ** The sqlite3_result_text(), sqlite3_result_text16(), |
|
3411 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces |
|
3412 ** set the return value of the application-defined function to be |
|
3413 ** a text string which is represented as UTF-8, UTF-16 native byte order, |
|
3414 ** UTF-16 little endian, or UTF-16 big endian, respectively. |
|
3415 ** SQLite takes the text result from the application from |
|
3416 ** the 2nd parameter of the sqlite3_result_text* interfaces. |
|
3417 ** If the 3rd parameter to the sqlite3_result_text* interfaces |
|
3418 ** is negative, then SQLite takes result text from the 2nd parameter |
|
3419 ** through the first zero character. |
|
3420 ** If the 3rd parameter to the sqlite3_result_text* interfaces |
|
3421 ** is non-negative, then as many bytes (not characters) of the text |
|
3422 ** pointed to by the 2nd parameter are taken as the application-defined |
|
3423 ** function result. |
|
3424 ** If the 4th parameter to the sqlite3_result_text* interfaces |
|
3425 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that |
|
3426 ** function as the destructor on the text or BLOB result when it has |
|
3427 ** finished using that result. |
|
3428 ** If the 4th parameter to the sqlite3_result_text* interfaces or |
|
3429 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite |
|
3430 ** assumes that the text or BLOB result is in constant space and does not |
|
3431 ** copy the it or call a destructor when it has finished using that result. |
|
3432 ** If the 4th parameter to the sqlite3_result_text* interfaces |
|
3433 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT |
|
3434 ** then SQLite makes a copy of the result into space obtained from |
|
3435 ** from [sqlite3_malloc()] before it returns. |
|
3436 ** |
|
3437 ** The sqlite3_result_value() interface sets the result of |
|
3438 ** the application-defined function to be a copy the |
|
3439 ** [unprotected sqlite3_value] object specified by the 2nd parameter. The |
|
3440 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] |
|
3441 ** so that the [sqlite3_value] specified in the parameter may change or |
|
3442 ** be deallocated after sqlite3_result_value() returns without harm. |
|
3443 ** A [protected sqlite3_value] object may always be used where an |
|
3444 ** [unprotected sqlite3_value] object is required, so either |
|
3445 ** kind of [sqlite3_value] object can be used with this interface. |
|
3446 ** |
|
3447 ** If these routines are called from within the different thread |
|
3448 ** than the one containing the application-defined function that received |
|
3449 ** the [sqlite3_context] pointer, the results are undefined. |
|
3450 ** |
|
3451 ** Requirements: |
|
3452 ** [H16403] [H16406] [H16409] [H16412] [H16415] [H16418] [H16421] [H16424] |
|
3453 ** [H16427] [H16430] [H16433] [H16436] [H16439] [H16442] [H16445] [H16448] |
|
3454 ** [H16451] [H16454] [H16457] [H16460] [H16463] |
|
3455 */ |
|
3456 void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); |
|
3457 void sqlite3_result_double(sqlite3_context*, double); |
|
3458 void sqlite3_result_error(sqlite3_context*, const char*, int); |
|
3459 void sqlite3_result_error16(sqlite3_context*, const void*, int); |
|
3460 void sqlite3_result_error_toobig(sqlite3_context*); |
|
3461 void sqlite3_result_error_nomem(sqlite3_context*); |
|
3462 void sqlite3_result_error_code(sqlite3_context*, int); |
|
3463 void sqlite3_result_int(sqlite3_context*, int); |
|
3464 void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); |
|
3465 void sqlite3_result_null(sqlite3_context*); |
|
3466 void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); |
|
3467 void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); |
|
3468 void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); |
|
3469 void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); |
|
3470 void sqlite3_result_value(sqlite3_context*, sqlite3_value*); |
|
3471 void sqlite3_result_zeroblob(sqlite3_context*, int n); |
|
3472 |
|
3473 /* |
|
3474 ** CAPI3REF: Define New Collating Sequences {H16600} <S20300> |
|
3475 ** |
|
3476 ** These functions are used to add new collation sequences to the |
|
3477 ** [database connection] specified as the first argument. |
|
3478 ** |
|
3479 ** The name of the new collation sequence is specified as a UTF-8 string |
|
3480 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() |
|
3481 ** and a UTF-16 string for sqlite3_create_collation16(). In all cases |
|
3482 ** the name is passed as the second function argument. |
|
3483 ** |
|
3484 ** The third argument may be one of the constants [SQLITE_UTF8], |
|
3485 ** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied |
|
3486 ** routine expects to be passed pointers to strings encoded using UTF-8, |
|
3487 ** UTF-16 little-endian, or UTF-16 big-endian, respectively. The |
|
3488 ** third argument might also be [SQLITE_UTF16_ALIGNED] to indicate that |
|
3489 ** the routine expects pointers to 16-bit word aligned strings |
|
3490 ** of UTF-16 in the native byte order of the host computer. |
|
3491 ** |
|
3492 ** A pointer to the user supplied routine must be passed as the fifth |
|
3493 ** argument. If it is NULL, this is the same as deleting the collation |
|
3494 ** sequence (so that SQLite cannot call it anymore). |
|
3495 ** Each time the application supplied function is invoked, it is passed |
|
3496 ** as its first parameter a copy of the void* passed as the fourth argument |
|
3497 ** to sqlite3_create_collation() or sqlite3_create_collation16(). |
|
3498 ** |
|
3499 ** The remaining arguments to the application-supplied routine are two strings, |
|
3500 ** each represented by a (length, data) pair and encoded in the encoding |
|
3501 ** that was passed as the third argument when the collation sequence was |
|
3502 ** registered. {END} The application defined collation routine should |
|
3503 ** return negative, zero or positive if the first string is less than, |
|
3504 ** equal to, or greater than the second string. i.e. (STRING1 - STRING2). |
|
3505 ** |
|
3506 ** The sqlite3_create_collation_v2() works like sqlite3_create_collation() |
|
3507 ** except that it takes an extra argument which is a destructor for |
|
3508 ** the collation. The destructor is called when the collation is |
|
3509 ** destroyed and is passed a copy of the fourth parameter void* pointer |
|
3510 ** of the sqlite3_create_collation_v2(). |
|
3511 ** Collations are destroyed when they are overridden by later calls to the |
|
3512 ** collation creation functions or when the [database connection] is closed |
|
3513 ** using [sqlite3_close()]. |
|
3514 ** |
|
3515 ** Requirements: |
|
3516 ** [H16603] [H16604] [H16606] [H16609] [H16612] [H16615] [H16618] [H16621] |
|
3517 ** [H16624] [H16627] [H16630] |
|
3518 */ |
|
3519 int sqlite3_create_collation( |
|
3520 sqlite3*, |
|
3521 const char *zName, |
|
3522 int eTextRep, |
|
3523 void*, |
|
3524 int(*xCompare)(void*,int,const void*,int,const void*) |
|
3525 ); |
|
3526 int sqlite3_create_collation_v2( |
|
3527 sqlite3*, |
|
3528 const char *zName, |
|
3529 int eTextRep, |
|
3530 void*, |
|
3531 int(*xCompare)(void*,int,const void*,int,const void*), |
|
3532 void(*xDestroy)(void*) |
|
3533 ); |
|
3534 int sqlite3_create_collation16( |
|
3535 sqlite3*, |
|
3536 const void *zName, |
|
3537 int eTextRep, |
|
3538 void*, |
|
3539 int(*xCompare)(void*,int,const void*,int,const void*) |
|
3540 ); |
|
3541 |
|
3542 /* |
|
3543 ** CAPI3REF: Collation Needed Callbacks {H16700} <S20300> |
|
3544 ** |
|
3545 ** To avoid having to register all collation sequences before a database |
|
3546 ** can be used, a single callback function may be registered with the |
|
3547 ** [database connection] to be called whenever an undefined collation |
|
3548 ** sequence is required. |
|
3549 ** |
|
3550 ** If the function is registered using the sqlite3_collation_needed() API, |
|
3551 ** then it is passed the names of undefined collation sequences as strings |
|
3552 ** encoded in UTF-8. {H16703} If sqlite3_collation_needed16() is used, |
|
3553 ** the names are passed as UTF-16 in machine native byte order. |
|
3554 ** A call to either function replaces any existing callback. |
|
3555 ** |
|
3556 ** When the callback is invoked, the first argument passed is a copy |
|
3557 ** of the second argument to sqlite3_collation_needed() or |
|
3558 ** sqlite3_collation_needed16(). The second argument is the database |
|
3559 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], |
|
3560 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation |
|
3561 ** sequence function required. The fourth parameter is the name of the |
|
3562 ** required collation sequence. |
|
3563 ** |
|
3564 ** The callback function should register the desired collation using |
|
3565 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or |
|
3566 ** [sqlite3_create_collation_v2()]. |
|
3567 ** |
|
3568 ** Requirements: |
|
3569 ** [H16702] [H16704] [H16706] |
|
3570 */ |
|
3571 int sqlite3_collation_needed( |
|
3572 sqlite3*, |
|
3573 void*, |
|
3574 void(*)(void*,sqlite3*,int eTextRep,const char*) |
|
3575 ); |
|
3576 int sqlite3_collation_needed16( |
|
3577 sqlite3*, |
|
3578 void*, |
|
3579 void(*)(void*,sqlite3*,int eTextRep,const void*) |
|
3580 ); |
|
3581 |
|
3582 /* |
|
3583 ** Specify the key for an encrypted database. This routine should be |
|
3584 ** called right after sqlite3_open(). |
|
3585 ** |
|
3586 ** The code to implement this API is not available in the public release |
|
3587 ** of SQLite. |
|
3588 */ |
|
3589 int sqlite3_key( |
|
3590 sqlite3 *db, /* Database to be rekeyed */ |
|
3591 const void *pKey, int nKey /* The key */ |
|
3592 ); |
|
3593 |
|
3594 /* |
|
3595 ** Change the key on an open database. If the current database is not |
|
3596 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the |
|
3597 ** database is decrypted. |
|
3598 ** |
|
3599 ** The code to implement this API is not available in the public release |
|
3600 ** of SQLite. |
|
3601 */ |
|
3602 int sqlite3_rekey( |
|
3603 sqlite3 *db, /* Database to be rekeyed */ |
|
3604 const void *pKey, int nKey /* The new key */ |
|
3605 ); |
|
3606 |
|
3607 /* |
|
3608 ** CAPI3REF: Suspend Execution For A Short Time {H10530} <S40410> |
|
3609 ** |
|
3610 ** The sqlite3_sleep() function causes the current thread to suspend execution |
|
3611 ** for at least a number of milliseconds specified in its parameter. |
|
3612 ** |
|
3613 ** If the operating system does not support sleep requests with |
|
3614 ** millisecond time resolution, then the time will be rounded up to |
|
3615 ** the nearest second. The number of milliseconds of sleep actually |
|
3616 ** requested from the operating system is returned. |
|
3617 ** |
|
3618 ** SQLite implements this interface by calling the xSleep() |
|
3619 ** method of the default [sqlite3_vfs] object. |
|
3620 ** |
|
3621 ** Requirements: [H10533] [H10536] |
|
3622 */ |
|
3623 int sqlite3_sleep(int); |
|
3624 |
|
3625 /* |
|
3626 ** CAPI3REF: Name Of The Folder Holding Temporary Files {H10310} <S20000> |
|
3627 ** |
|
3628 ** If this global variable is made to point to a string which is |
|
3629 ** the name of a folder (a.k.a. directory), then all temporary files |
|
3630 ** created by SQLite will be placed in that directory. If this variable |
|
3631 ** is a NULL pointer, then SQLite performs a search for an appropriate |
|
3632 ** temporary file directory. |
|
3633 ** |
|
3634 ** It is not safe to modify this variable once a [database connection] |
|
3635 ** has been opened. It is intended that this variable be set once |
|
3636 ** as part of process initialization and before any SQLite interface |
|
3637 ** routines have been call and remain unchanged thereafter. |
|
3638 */ |
|
3639 SQLITE_EXTERN char *sqlite3_temp_directory; |
|
3640 |
|
3641 /* |
|
3642 ** CAPI3REF: Test For Auto-Commit Mode {H12930} <S60200> |
|
3643 ** KEYWORDS: {autocommit mode} |
|
3644 ** |
|
3645 ** The sqlite3_get_autocommit() interface returns non-zero or |
|
3646 ** zero if the given database connection is or is not in autocommit mode, |
|
3647 ** respectively. Autocommit mode is on by default. |
|
3648 ** Autocommit mode is disabled by a [BEGIN] statement. |
|
3649 ** Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. |
|
3650 ** |
|
3651 ** If certain kinds of errors occur on a statement within a multi-statement |
|
3652 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], |
|
3653 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the |
|
3654 ** transaction might be rolled back automatically. The only way to |
|
3655 ** find out whether SQLite automatically rolled back the transaction after |
|
3656 ** an error is to use this function. |
|
3657 ** |
|
3658 ** If another thread changes the autocommit status of the database |
|
3659 ** connection while this routine is running, then the return value |
|
3660 ** is undefined. |
|
3661 ** |
|
3662 ** Requirements: [H12931] [H12932] [H12933] [H12934] |
|
3663 */ |
|
3664 int sqlite3_get_autocommit(sqlite3*); |
|
3665 |
|
3666 /* |
|
3667 ** CAPI3REF: Find The Database Handle Of A Prepared Statement {H13120} <S60600> |
|
3668 ** |
|
3669 ** The sqlite3_db_handle interface returns the [database connection] handle |
|
3670 ** to which a [prepared statement] belongs. The [database connection] |
|
3671 ** returned by sqlite3_db_handle is the same [database connection] that was the first argument |
|
3672 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to |
|
3673 ** create the statement in the first place. |
|
3674 ** |
|
3675 ** Requirements: [H13123] |
|
3676 */ |
|
3677 sqlite3 *sqlite3_db_handle(sqlite3_stmt*); |
|
3678 |
|
3679 /* |
|
3680 ** CAPI3REF: Find the next prepared statement {H13140} <S60600> |
|
3681 ** |
|
3682 ** This interface returns a pointer to the next [prepared statement] after |
|
3683 ** pStmt associated with the [database connection] pDb. If pStmt is NULL |
|
3684 ** then this interface returns a pointer to the first prepared statement |
|
3685 ** associated with the database connection pDb. If no prepared statement |
|
3686 ** satisfies the conditions of this routine, it returns NULL. |
|
3687 ** |
|
3688 ** The [database connection] pointer D in a call to |
|
3689 ** [sqlite3_next_stmt(D,S)] must refer to an open database |
|
3690 ** connection and in particular must not be a NULL pointer. |
|
3691 ** |
|
3692 ** Requirements: [H13143] [H13146] [H13149] [H13152] |
|
3693 */ |
|
3694 sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); |
|
3695 |
|
3696 /* |
|
3697 ** CAPI3REF: Commit And Rollback Notification Callbacks {H12950} <S60400> |
|
3698 ** |
|
3699 ** The sqlite3_commit_hook() interface registers a callback |
|
3700 ** function to be invoked whenever a transaction is committed. |
|
3701 ** Any callback set by a previous call to sqlite3_commit_hook() |
|
3702 ** for the same database connection is overridden. |
|
3703 ** The sqlite3_rollback_hook() interface registers a callback |
|
3704 ** function to be invoked whenever a transaction is committed. |
|
3705 ** Any callback set by a previous call to sqlite3_commit_hook() |
|
3706 ** for the same database connection is overridden. |
|
3707 ** The pArg argument is passed through to the callback. |
|
3708 ** If the callback on a commit hook function returns non-zero, |
|
3709 ** then the commit is converted into a rollback. |
|
3710 ** |
|
3711 ** If another function was previously registered, its |
|
3712 ** pArg value is returned. Otherwise NULL is returned. |
|
3713 ** |
|
3714 ** The callback implementation must not do anything that will modify |
|
3715 ** the database connection that invoked the callback. Any actions |
|
3716 ** to modify the database connection must be deferred until after the |
|
3717 ** completion of the [sqlite3_step()] call that triggered the commit |
|
3718 ** or rollback hook in the first place. |
|
3719 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
3720 ** database connections for the meaning of "modify" in this paragraph. |
|
3721 ** |
|
3722 ** Registering a NULL function disables the callback. |
|
3723 ** |
|
3724 ** For the purposes of this API, a transaction is said to have been |
|
3725 ** rolled back if an explicit "ROLLBACK" statement is executed, or |
|
3726 ** an error or constraint causes an implicit rollback to occur. |
|
3727 ** The rollback callback is not invoked if a transaction is |
|
3728 ** automatically rolled back because the database connection is closed. |
|
3729 ** The rollback callback is not invoked if a transaction is |
|
3730 ** rolled back because a commit callback returned non-zero. |
|
3731 ** <todo> Check on this </todo> |
|
3732 ** |
|
3733 ** Requirements: |
|
3734 ** [H12951] [H12952] [H12953] [H12954] [H12955] |
|
3735 ** [H12961] [H12962] [H12963] [H12964] |
|
3736 */ |
|
3737 void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
|
3738 void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); |
|
3739 |
|
3740 /* |
|
3741 ** CAPI3REF: Data Change Notification Callbacks {H12970} <S60400> |
|
3742 ** |
|
3743 ** The sqlite3_update_hook() interface registers a callback function |
|
3744 ** with the [database connection] identified by the first argument |
|
3745 ** to be invoked whenever a row is updated, inserted or deleted. |
|
3746 ** Any callback set by a previous call to this function |
|
3747 ** for the same database connection is overridden. |
|
3748 ** |
|
3749 ** The second argument is a pointer to the function to invoke when a |
|
3750 ** row is updated, inserted or deleted. |
|
3751 ** The first argument to the callback is a copy of the third argument |
|
3752 ** to sqlite3_update_hook(). |
|
3753 ** The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], |
|
3754 ** or [SQLITE_UPDATE], depending on the operation that caused the callback |
|
3755 ** to be invoked. |
|
3756 ** The third and fourth arguments to the callback contain pointers to the |
|
3757 ** database and table name containing the affected row. |
|
3758 ** The final callback parameter is the [rowid] of the row. |
|
3759 ** In the case of an update, this is the [rowid] after the update takes place. |
|
3760 ** |
|
3761 ** The update hook is not invoked when internal system tables are |
|
3762 ** modified (i.e. sqlite_master and sqlite_sequence). |
|
3763 ** |
|
3764 ** The update hook implementation must not do anything that will modify |
|
3765 ** the database connection that invoked the update hook. Any actions |
|
3766 ** to modify the database connection must be deferred until after the |
|
3767 ** completion of the [sqlite3_step()] call that triggered the update hook. |
|
3768 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
3769 ** database connections for the meaning of "modify" in this paragraph. |
|
3770 ** |
|
3771 ** If another function was previously registered, its pArg value |
|
3772 ** is returned. Otherwise NULL is returned. |
|
3773 ** |
|
3774 ** Requirements: |
|
3775 ** [H12971] [H12973] [H12975] [H12977] [H12979] [H12981] [H12983] [H12986] |
|
3776 */ |
|
3777 void *sqlite3_update_hook( |
|
3778 sqlite3*, |
|
3779 void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
|
3780 void* |
|
3781 ); |
|
3782 |
|
3783 /* |
|
3784 ** CAPI3REF: Enable Or Disable Shared Pager Cache {H10330} <S30900> |
|
3785 ** KEYWORDS: {shared cache} {shared cache mode} |
|
3786 ** |
|
3787 ** This routine enables or disables the sharing of the database cache |
|
3788 ** and schema data structures between [database connection | connections] |
|
3789 ** to the same database. Sharing is enabled if the argument is true |
|
3790 ** and disabled if the argument is false. |
|
3791 ** |
|
3792 ** Cache sharing is enabled and disabled for an entire process. |
|
3793 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, |
|
3794 ** sharing was enabled or disabled for each thread separately. |
|
3795 ** |
|
3796 ** The cache sharing mode set by this interface effects all subsequent |
|
3797 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. |
|
3798 ** Existing database connections continue use the sharing mode |
|
3799 ** that was in effect at the time they were opened. |
|
3800 ** |
|
3801 ** Virtual tables cannot be used with a shared cache. When shared |
|
3802 ** cache is enabled, the [sqlite3_create_module()] API used to register |
|
3803 ** virtual tables will always return an error. |
|
3804 ** |
|
3805 ** This routine returns [SQLITE_OK] if shared cache was enabled or disabled |
|
3806 ** successfully. An [error code] is returned otherwise. |
|
3807 ** |
|
3808 ** Shared cache is disabled by default. But this might change in |
|
3809 ** future releases of SQLite. Applications that care about shared |
|
3810 ** cache setting should set it explicitly. |
|
3811 ** |
|
3812 ** See Also: [SQLite Shared-Cache Mode] |
|
3813 ** |
|
3814 ** Requirements: [H10331] [H10336] [H10337] [H10339] |
|
3815 */ |
|
3816 int sqlite3_enable_shared_cache(int); |
|
3817 |
|
3818 /* |
|
3819 ** CAPI3REF: Attempt To Free Heap Memory {H17340} <S30220> |
|
3820 ** |
|
3821 ** The sqlite3_release_memory() interface attempts to free N bytes |
|
3822 ** of heap memory by deallocating non-essential memory allocations |
|
3823 ** held by the database library. {END} Memory used to cache database |
|
3824 ** pages to improve performance is an example of non-essential memory. |
|
3825 ** sqlite3_release_memory() returns the number of bytes actually freed, |
|
3826 ** which might be more or less than the amount requested. |
|
3827 ** |
|
3828 ** Requirements: [H17341] [H17342] |
|
3829 */ |
|
3830 int sqlite3_release_memory(int); |
|
3831 |
|
3832 /* |
|
3833 ** CAPI3REF: Impose A Limit On Heap Size {H17350} <S30220> |
|
3834 ** |
|
3835 ** The sqlite3_soft_heap_limit() interface places a "soft" limit |
|
3836 ** on the amount of heap memory that may be allocated by SQLite. |
|
3837 ** If an internal allocation is requested that would exceed the |
|
3838 ** soft heap limit, [sqlite3_release_memory()] is invoked one or |
|
3839 ** more times to free up some space before the allocation is performed. |
|
3840 ** |
|
3841 ** The limit is called "soft", because if [sqlite3_release_memory()] |
|
3842 ** cannot free sufficient memory to prevent the limit from being exceeded, |
|
3843 ** the memory is allocated anyway and the current operation proceeds. |
|
3844 ** |
|
3845 ** A negative or zero value for N means that there is no soft heap limit and |
|
3846 ** [sqlite3_release_memory()] will only be called when memory is exhausted. |
|
3847 ** The default value for the soft heap limit is zero. |
|
3848 ** |
|
3849 ** SQLite makes a best effort to honor the soft heap limit. |
|
3850 ** But if the soft heap limit cannot be honored, execution will |
|
3851 ** continue without error or notification. This is why the limit is |
|
3852 ** called a "soft" limit. It is advisory only. |
|
3853 ** |
|
3854 ** Prior to SQLite version 3.5.0, this routine only constrained the memory |
|
3855 ** allocated by a single thread - the same thread in which this routine |
|
3856 ** runs. Beginning with SQLite version 3.5.0, the soft heap limit is |
|
3857 ** applied to all threads. The value specified for the soft heap limit |
|
3858 ** is an upper bound on the total memory allocation for all threads. In |
|
3859 ** version 3.5.0 there is no mechanism for limiting the heap usage for |
|
3860 ** individual threads. |
|
3861 ** |
|
3862 ** Requirements: |
|
3863 ** [H16351] [H16352] [H16353] [H16354] [H16355] [H16358] |
|
3864 */ |
|
3865 void sqlite3_soft_heap_limit(int); |
|
3866 |
|
3867 /* |
|
3868 ** CAPI3REF: Extract Metadata About A Column Of A Table {H12850} <S60300> |
|
3869 ** |
|
3870 ** This routine returns metadata about a specific column of a specific |
|
3871 ** database table accessible using the [database connection] handle |
|
3872 ** passed as the first function argument. |
|
3873 ** |
|
3874 ** The column is identified by the second, third and fourth parameters to |
|
3875 ** this function. The second parameter is either the name of the database |
|
3876 ** (i.e. "main", "temp" or an attached database) containing the specified |
|
3877 ** table or NULL. If it is NULL, then all attached databases are searched |
|
3878 ** for the table using the same algorithm used by the database engine to |
|
3879 ** resolve unqualified table references. |
|
3880 ** |
|
3881 ** The third and fourth parameters to this function are the table and column |
|
3882 ** name of the desired column, respectively. Neither of these parameters |
|
3883 ** may be NULL. |
|
3884 ** |
|
3885 ** Metadata is returned by writing to the memory locations passed as the 5th |
|
3886 ** and subsequent parameters to this function. Any of these arguments may be |
|
3887 ** NULL, in which case the corresponding element of metadata is omitted. |
|
3888 ** |
|
3889 ** <blockquote> |
|
3890 ** <table border="1"> |
|
3891 ** <tr><th> Parameter <th> Output<br>Type <th> Description |
|
3892 ** |
|
3893 ** <tr><td> 5th <td> const char* <td> Data type |
|
3894 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence |
|
3895 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint |
|
3896 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY |
|
3897 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] |
|
3898 ** </table> |
|
3899 ** </blockquote> |
|
3900 ** |
|
3901 ** The memory pointed to by the character pointers returned for the |
|
3902 ** declaration type and collation sequence is valid only until the next |
|
3903 ** call to any SQLite API function. |
|
3904 ** |
|
3905 ** If the specified table is actually a view, an [error code] is returned. |
|
3906 ** |
|
3907 ** If the specified column is "rowid", "oid" or "_rowid_" and an |
|
3908 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output |
|
3909 ** parameters are set for the explicitly declared column. If there is no |
|
3910 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output |
|
3911 ** parameters are set as follows: |
|
3912 ** |
|
3913 ** <pre> |
|
3914 ** data type: "INTEGER" |
|
3915 ** collation sequence: "BINARY" |
|
3916 ** not null: 0 |
|
3917 ** primary key: 1 |
|
3918 ** auto increment: 0 |
|
3919 ** </pre> |
|
3920 ** |
|
3921 ** This function may load one or more schemas from database files. If an |
|
3922 ** error occurs during this process, or if the requested table or column |
|
3923 ** cannot be found, an [error code] is returned and an error message left |
|
3924 ** in the [database connection] (to be retrieved using sqlite3_errmsg()). |
|
3925 ** |
|
3926 ** This API is only available if the library was compiled with the |
|
3927 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. |
|
3928 */ |
|
3929 int sqlite3_table_column_metadata( |
|
3930 sqlite3 *db, /* Connection handle */ |
|
3931 const char *zDbName, /* Database name or NULL */ |
|
3932 const char *zTableName, /* Table name */ |
|
3933 const char *zColumnName, /* Column name */ |
|
3934 char const **pzDataType, /* OUTPUT: Declared data type */ |
|
3935 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ |
|
3936 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ |
|
3937 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ |
|
3938 int *pAutoinc /* OUTPUT: True if column is auto-increment */ |
|
3939 ); |
|
3940 |
|
3941 /* |
|
3942 ** CAPI3REF: Load An Extension {H12600} <S20500> |
|
3943 ** |
|
3944 ** This interface loads an SQLite extension library from the named file. |
|
3945 ** |
|
3946 ** {H12601} The sqlite3_load_extension() interface attempts to load an |
|
3947 ** SQLite extension library contained in the file zFile. |
|
3948 ** |
|
3949 ** {H12602} The entry point is zProc. |
|
3950 ** |
|
3951 ** {H12603} zProc may be 0, in which case the name of the entry point |
|
3952 ** defaults to "sqlite3_extension_init". |
|
3953 ** |
|
3954 ** {H12604} The sqlite3_load_extension() interface shall return |
|
3955 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. |
|
3956 ** |
|
3957 ** {H12605} If an error occurs and pzErrMsg is not 0, then the |
|
3958 ** [sqlite3_load_extension()] interface shall attempt to |
|
3959 ** fill *pzErrMsg with error message text stored in memory |
|
3960 ** obtained from [sqlite3_malloc()]. {END} The calling function |
|
3961 ** should free this memory by calling [sqlite3_free()]. |
|
3962 ** |
|
3963 ** {H12606} Extension loading must be enabled using |
|
3964 ** [sqlite3_enable_load_extension()] prior to calling this API, |
|
3965 ** otherwise an error will be returned. |
|
3966 */ |
|
3967 int sqlite3_load_extension( |
|
3968 sqlite3 *db, /* Load the extension into this database connection */ |
|
3969 const char *zFile, /* Name of the shared library containing extension */ |
|
3970 const char *zProc, /* Entry point. Derived from zFile if 0 */ |
|
3971 char **pzErrMsg /* Put error message here if not 0 */ |
|
3972 ); |
|
3973 |
|
3974 /* |
|
3975 ** CAPI3REF: Enable Or Disable Extension Loading {H12620} <S20500> |
|
3976 ** |
|
3977 ** So as not to open security holes in older applications that are |
|
3978 ** unprepared to deal with extension loading, and as a means of disabling |
|
3979 ** extension loading while evaluating user-entered SQL, the following API |
|
3980 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. |
|
3981 ** |
|
3982 ** Extension loading is off by default. See ticket #1863. |
|
3983 ** |
|
3984 ** {H12621} Call the sqlite3_enable_load_extension() routine with onoff==1 |
|
3985 ** to turn extension loading on and call it with onoff==0 to turn |
|
3986 ** it back off again. |
|
3987 ** |
|
3988 ** {H12622} Extension loading is off by default. |
|
3989 */ |
|
3990 int sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
|
3991 |
|
3992 /* |
|
3993 ** CAPI3REF: Automatically Load An Extensions {H12640} <S20500> |
|
3994 ** |
|
3995 ** This API can be invoked at program startup in order to register |
|
3996 ** one or more statically linked extensions that will be available |
|
3997 ** to all new [database connections]. {END} |
|
3998 ** |
|
3999 ** This routine stores a pointer to the extension in an array that is |
|
4000 ** obtained from [sqlite3_malloc()]. If you run a memory leak checker |
|
4001 ** on your program and it reports a leak because of this array, invoke |
|
4002 ** [sqlite3_reset_auto_extension()] prior to shutdown to free the memory. |
|
4003 ** |
|
4004 ** {H12641} This function registers an extension entry point that is |
|
4005 ** automatically invoked whenever a new [database connection] |
|
4006 ** is opened using [sqlite3_open()], [sqlite3_open16()], |
|
4007 ** or [sqlite3_open_v2()]. |
|
4008 ** |
|
4009 ** {H12642} Duplicate extensions are detected so calling this routine |
|
4010 ** multiple times with the same extension is harmless. |
|
4011 ** |
|
4012 ** {H12643} This routine stores a pointer to the extension in an array |
|
4013 ** that is obtained from [sqlite3_malloc()]. |
|
4014 ** |
|
4015 ** {H12644} Automatic extensions apply across all threads. |
|
4016 */ |
|
4017 int sqlite3_auto_extension(void (*xEntryPoint)(void)); |
|
4018 |
|
4019 /* |
|
4020 ** CAPI3REF: Reset Automatic Extension Loading {H12660} <S20500> |
|
4021 ** |
|
4022 ** This function disables all previously registered automatic |
|
4023 ** extensions. {END} It undoes the effect of all prior |
|
4024 ** [sqlite3_auto_extension()] calls. |
|
4025 ** |
|
4026 ** {H12661} This function disables all previously registered |
|
4027 ** automatic extensions. |
|
4028 ** |
|
4029 ** {H12662} This function disables automatic extensions in all threads. |
|
4030 */ |
|
4031 void sqlite3_reset_auto_extension(void); |
|
4032 |
|
4033 /* |
|
4034 ****** EXPERIMENTAL - subject to change without notice ************** |
|
4035 ** |
|
4036 ** The interface to the virtual-table mechanism is currently considered |
|
4037 ** to be experimental. The interface might change in incompatible ways. |
|
4038 ** If this is a problem for you, do not use the interface at this time. |
|
4039 ** |
|
4040 ** When the virtual-table mechanism stabilizes, we will declare the |
|
4041 ** interface fixed, support it indefinitely, and remove this comment. |
|
4042 */ |
|
4043 |
|
4044 /* |
|
4045 ** Structures used by the virtual table interface |
|
4046 */ |
|
4047 typedef struct sqlite3_vtab sqlite3_vtab; |
|
4048 typedef struct sqlite3_index_info sqlite3_index_info; |
|
4049 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; |
|
4050 typedef struct sqlite3_module sqlite3_module; |
|
4051 |
|
4052 /* |
|
4053 ** CAPI3REF: Virtual Table Object {H18000} <S20400> |
|
4054 ** KEYWORDS: sqlite3_module |
|
4055 ** EXPERIMENTAL |
|
4056 ** |
|
4057 ** A module is a class of virtual tables. Each module is defined |
|
4058 ** by an instance of the following structure. This structure consists |
|
4059 ** mostly of methods for the module. |
|
4060 ** |
|
4061 ** This interface is experimental and is subject to change or |
|
4062 ** removal in future releases of SQLite. |
|
4063 */ |
|
4064 struct sqlite3_module { |
|
4065 int iVersion; |
|
4066 int (*xCreate)(sqlite3*, void *pAux, |
|
4067 int argc, const char *const*argv, |
|
4068 sqlite3_vtab **ppVTab, char**); |
|
4069 int (*xConnect)(sqlite3*, void *pAux, |
|
4070 int argc, const char *const*argv, |
|
4071 sqlite3_vtab **ppVTab, char**); |
|
4072 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); |
|
4073 int (*xDisconnect)(sqlite3_vtab *pVTab); |
|
4074 int (*xDestroy)(sqlite3_vtab *pVTab); |
|
4075 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); |
|
4076 int (*xClose)(sqlite3_vtab_cursor*); |
|
4077 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
|
4078 int argc, sqlite3_value **argv); |
|
4079 int (*xNext)(sqlite3_vtab_cursor*); |
|
4080 int (*xEof)(sqlite3_vtab_cursor*); |
|
4081 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); |
|
4082 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); |
|
4083 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); |
|
4084 int (*xBegin)(sqlite3_vtab *pVTab); |
|
4085 int (*xSync)(sqlite3_vtab *pVTab); |
|
4086 int (*xCommit)(sqlite3_vtab *pVTab); |
|
4087 int (*xRollback)(sqlite3_vtab *pVTab); |
|
4088 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, |
|
4089 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), |
|
4090 void **ppArg); |
|
4091 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
|
4092 }; |
|
4093 |
|
4094 /* |
|
4095 ** CAPI3REF: Virtual Table Indexing Information {H18100} <S20400> |
|
4096 ** KEYWORDS: sqlite3_index_info |
|
4097 ** EXPERIMENTAL |
|
4098 ** |
|
4099 ** The sqlite3_index_info structure and its substructures is used to |
|
4100 ** pass information into and receive the reply from the xBestIndex |
|
4101 ** method of an sqlite3_module. The fields under **Inputs** are the |
|
4102 ** inputs to xBestIndex and are read-only. xBestIndex inserts its |
|
4103 ** results into the **Outputs** fields. |
|
4104 ** |
|
4105 ** The aConstraint[] array records WHERE clause constraints of the form: |
|
4106 ** |
|
4107 ** <pre>column OP expr</pre> |
|
4108 ** |
|
4109 ** where OP is =, <, <=, >, or >=. The particular operator is |
|
4110 ** stored in aConstraint[].op. The index of the column is stored in |
|
4111 ** aConstraint[].iColumn. aConstraint[].usable is TRUE if the |
|
4112 ** expr on the right-hand side can be evaluated (and thus the constraint |
|
4113 ** is usable) and false if it cannot. |
|
4114 ** |
|
4115 ** The optimizer automatically inverts terms of the form "expr OP column" |
|
4116 ** and makes other simplifications to the WHERE clause in an attempt to |
|
4117 ** get as many WHERE clause terms into the form shown above as possible. |
|
4118 ** The aConstraint[] array only reports WHERE clause terms in the correct |
|
4119 ** form that refer to the particular virtual table being queried. |
|
4120 ** |
|
4121 ** Information about the ORDER BY clause is stored in aOrderBy[]. |
|
4122 ** Each term of aOrderBy records a column of the ORDER BY clause. |
|
4123 ** |
|
4124 ** The xBestIndex method must fill aConstraintUsage[] with information |
|
4125 ** about what parameters to pass to xFilter. If argvIndex>0 then |
|
4126 ** the right-hand side of the corresponding aConstraint[] is evaluated |
|
4127 ** and becomes the argvIndex-th entry in argv. If aConstraintUsage[].omit |
|
4128 ** is true, then the constraint is assumed to be fully handled by the |
|
4129 ** virtual table and is not checked again by SQLite. |
|
4130 ** |
|
4131 ** The idxNum and idxPtr values are recorded and passed into xFilter. |
|
4132 ** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true. |
|
4133 ** |
|
4134 ** The orderByConsumed means that output from xFilter will occur in |
|
4135 ** the correct order to satisfy the ORDER BY clause so that no separate |
|
4136 ** sorting step is required. |
|
4137 ** |
|
4138 ** The estimatedCost value is an estimate of the cost of doing the |
|
4139 ** particular lookup. A full scan of a table with N entries should have |
|
4140 ** a cost of N. A binary search of a table of N entries should have a |
|
4141 ** cost of approximately log(N). |
|
4142 ** |
|
4143 ** This interface is experimental and is subject to change or |
|
4144 ** removal in future releases of SQLite. |
|
4145 */ |
|
4146 struct sqlite3_index_info { |
|
4147 /* Inputs */ |
|
4148 int nConstraint; /* Number of entries in aConstraint */ |
|
4149 struct sqlite3_index_constraint { |
|
4150 int iColumn; /* Column on left-hand side of constraint */ |
|
4151 unsigned char op; /* Constraint operator */ |
|
4152 unsigned char usable; /* True if this constraint is usable */ |
|
4153 int iTermOffset; /* Used internally - xBestIndex should ignore */ |
|
4154 } *aConstraint; /* Table of WHERE clause constraints */ |
|
4155 int nOrderBy; /* Number of terms in the ORDER BY clause */ |
|
4156 struct sqlite3_index_orderby { |
|
4157 int iColumn; /* Column number */ |
|
4158 unsigned char desc; /* True for DESC. False for ASC. */ |
|
4159 } *aOrderBy; /* The ORDER BY clause */ |
|
4160 /* Outputs */ |
|
4161 struct sqlite3_index_constraint_usage { |
|
4162 int argvIndex; /* if >0, constraint is part of argv to xFilter */ |
|
4163 unsigned char omit; /* Do not code a test for this constraint */ |
|
4164 } *aConstraintUsage; |
|
4165 int idxNum; /* Number used to identify the index */ |
|
4166 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ |
|
4167 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ |
|
4168 int orderByConsumed; /* True if output is already ordered */ |
|
4169 double estimatedCost; /* Estimated cost of using this index */ |
|
4170 }; |
|
4171 #define SQLITE_INDEX_CONSTRAINT_EQ 2 |
|
4172 #define SQLITE_INDEX_CONSTRAINT_GT 4 |
|
4173 #define SQLITE_INDEX_CONSTRAINT_LE 8 |
|
4174 #define SQLITE_INDEX_CONSTRAINT_LT 16 |
|
4175 #define SQLITE_INDEX_CONSTRAINT_GE 32 |
|
4176 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 |
|
4177 |
|
4178 /* |
|
4179 ** CAPI3REF: Register A Virtual Table Implementation {H18200} <S20400> |
|
4180 ** EXPERIMENTAL |
|
4181 ** |
|
4182 ** This routine is used to register a new module name with a |
|
4183 ** [database connection]. Module names must be registered before |
|
4184 ** creating new virtual tables on the module, or before using |
|
4185 ** preexisting virtual tables of the module. |
|
4186 ** |
|
4187 ** This interface is experimental and is subject to change or |
|
4188 ** removal in future releases of SQLite. |
|
4189 */ |
|
4190 SQLITE_EXPERIMENTAL int sqlite3_create_module( |
|
4191 sqlite3 *db, /* SQLite connection to register module with */ |
|
4192 const char *zName, /* Name of the module */ |
|
4193 const sqlite3_module *, /* Methods for the module */ |
|
4194 void * /* Client data for xCreate/xConnect */ |
|
4195 ); |
|
4196 |
|
4197 /* |
|
4198 ** CAPI3REF: Register A Virtual Table Implementation {H18210} <S20400> |
|
4199 ** EXPERIMENTAL |
|
4200 ** |
|
4201 ** This routine is identical to the [sqlite3_create_module()] method above, |
|
4202 ** except that it allows a destructor function to be specified. It is |
|
4203 ** even more experimental than the rest of the virtual tables API. |
|
4204 */ |
|
4205 SQLITE_EXPERIMENTAL int sqlite3_create_module_v2( |
|
4206 sqlite3 *db, /* SQLite connection to register module with */ |
|
4207 const char *zName, /* Name of the module */ |
|
4208 const sqlite3_module *, /* Methods for the module */ |
|
4209 void *, /* Client data for xCreate/xConnect */ |
|
4210 void(*xDestroy)(void*) /* Module destructor function */ |
|
4211 ); |
|
4212 |
|
4213 /* |
|
4214 ** CAPI3REF: Virtual Table Instance Object {H18010} <S20400> |
|
4215 ** KEYWORDS: sqlite3_vtab |
|
4216 ** EXPERIMENTAL |
|
4217 ** |
|
4218 ** Every module implementation uses a subclass of the following structure |
|
4219 ** to describe a particular instance of the module. Each subclass will |
|
4220 ** be tailored to the specific needs of the module implementation. |
|
4221 ** The purpose of this superclass is to define certain fields that are |
|
4222 ** common to all module implementations. |
|
4223 ** |
|
4224 ** Virtual tables methods can set an error message by assigning a |
|
4225 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should |
|
4226 ** take care that any prior string is freed by a call to [sqlite3_free()] |
|
4227 ** prior to assigning a new string to zErrMsg. After the error message |
|
4228 ** is delivered up to the client application, the string will be automatically |
|
4229 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. Note |
|
4230 ** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field |
|
4231 ** since virtual tables are commonly implemented in loadable extensions which |
|
4232 ** do not have access to sqlite3MPrintf() or sqlite3Free(). |
|
4233 ** |
|
4234 ** This interface is experimental and is subject to change or |
|
4235 ** removal in future releases of SQLite. |
|
4236 */ |
|
4237 struct sqlite3_vtab { |
|
4238 const sqlite3_module *pModule; /* The module for this virtual table */ |
|
4239 int nRef; /* Used internally */ |
|
4240 char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
|
4241 /* Virtual table implementations will typically add additional fields */ |
|
4242 }; |
|
4243 |
|
4244 /* |
|
4245 ** CAPI3REF: Virtual Table Cursor Object {H18020} <S20400> |
|
4246 ** KEYWORDS: sqlite3_vtab_cursor |
|
4247 ** EXPERIMENTAL |
|
4248 ** |
|
4249 ** Every module implementation uses a subclass of the following structure |
|
4250 ** to describe cursors that point into the virtual table and are used |
|
4251 ** to loop through the virtual table. Cursors are created using the |
|
4252 ** xOpen method of the module. Each module implementation will define |
|
4253 ** the content of a cursor structure to suit its own needs. |
|
4254 ** |
|
4255 ** This superclass exists in order to define fields of the cursor that |
|
4256 ** are common to all implementations. |
|
4257 ** |
|
4258 ** This interface is experimental and is subject to change or |
|
4259 ** removal in future releases of SQLite. |
|
4260 */ |
|
4261 struct sqlite3_vtab_cursor { |
|
4262 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ |
|
4263 /* Virtual table implementations will typically add additional fields */ |
|
4264 }; |
|
4265 |
|
4266 /* |
|
4267 ** CAPI3REF: Declare The Schema Of A Virtual Table {H18280} <S20400> |
|
4268 ** EXPERIMENTAL |
|
4269 ** |
|
4270 ** The xCreate and xConnect methods of a module use the following API |
|
4271 ** to declare the format (the names and datatypes of the columns) of |
|
4272 ** the virtual tables they implement. |
|
4273 ** |
|
4274 ** This interface is experimental and is subject to change or |
|
4275 ** removal in future releases of SQLite. |
|
4276 */ |
|
4277 SQLITE_EXPERIMENTAL int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable); |
|
4278 |
|
4279 /* |
|
4280 ** CAPI3REF: Overload A Function For A Virtual Table {H18300} <S20400> |
|
4281 ** EXPERIMENTAL |
|
4282 ** |
|
4283 ** Virtual tables can provide alternative implementations of functions |
|
4284 ** using the xFindFunction method. But global versions of those functions |
|
4285 ** must exist in order to be overloaded. |
|
4286 ** |
|
4287 ** This API makes sure a global version of a function with a particular |
|
4288 ** name and number of parameters exists. If no such function exists |
|
4289 ** before this API is called, a new function is created. The implementation |
|
4290 ** of the new function always causes an exception to be thrown. So |
|
4291 ** the new function is not good for anything by itself. Its only |
|
4292 ** purpose is to be a placeholder function that can be overloaded |
|
4293 ** by virtual tables. |
|
4294 ** |
|
4295 ** This API should be considered part of the virtual table interface, |
|
4296 ** which is experimental and subject to change. |
|
4297 */ |
|
4298 SQLITE_EXPERIMENTAL int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
|
4299 |
|
4300 /* |
|
4301 ** The interface to the virtual-table mechanism defined above (back up |
|
4302 ** to a comment remarkably similar to this one) is currently considered |
|
4303 ** to be experimental. The interface might change in incompatible ways. |
|
4304 ** If this is a problem for you, do not use the interface at this time. |
|
4305 ** |
|
4306 ** When the virtual-table mechanism stabilizes, we will declare the |
|
4307 ** interface fixed, support it indefinitely, and remove this comment. |
|
4308 ** |
|
4309 ****** EXPERIMENTAL - subject to change without notice ************** |
|
4310 */ |
|
4311 |
|
4312 /* |
|
4313 ** CAPI3REF: A Handle To An Open BLOB {H17800} <S30230> |
|
4314 ** KEYWORDS: {BLOB handle} {BLOB handles} |
|
4315 ** |
|
4316 ** An instance of this object represents an open BLOB on which |
|
4317 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. |
|
4318 ** Objects of this type are created by [sqlite3_blob_open()] |
|
4319 ** and destroyed by [sqlite3_blob_close()]. |
|
4320 ** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces |
|
4321 ** can be used to read or write small subsections of the BLOB. |
|
4322 ** The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. |
|
4323 */ |
|
4324 typedef struct sqlite3_blob sqlite3_blob; |
|
4325 |
|
4326 /* |
|
4327 ** CAPI3REF: Open A BLOB For Incremental I/O {H17810} <S30230> |
|
4328 ** |
|
4329 ** This interfaces opens a [BLOB handle | handle] to the BLOB located |
|
4330 ** in row iRow, column zColumn, table zTable in database zDb; |
|
4331 ** in other words, the same BLOB that would be selected by: |
|
4332 ** |
|
4333 ** <pre> |
|
4334 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; |
|
4335 ** </pre> {END} |
|
4336 ** |
|
4337 ** If the flags parameter is non-zero, the the BLOB is opened for read |
|
4338 ** and write access. If it is zero, the BLOB is opened for read access. |
|
4339 ** |
|
4340 ** Note that the database name is not the filename that contains |
|
4341 ** the database but rather the symbolic name of the database that |
|
4342 ** is assigned when the database is connected using [ATTACH]. |
|
4343 ** For the main database file, the database name is "main". |
|
4344 ** For TEMP tables, the database name is "temp". |
|
4345 ** |
|
4346 ** On success, [SQLITE_OK] is returned and the new [BLOB handle] is written |
|
4347 ** to *ppBlob. Otherwise an [error code] is returned and any value written |
|
4348 ** to *ppBlob should not be used by the caller. |
|
4349 ** This function sets the [database connection] error code and message |
|
4350 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()]. |
|
4351 ** |
|
4352 ** If the row that a BLOB handle points to is modified by an |
|
4353 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects |
|
4354 ** then the BLOB handle is marked as "expired". |
|
4355 ** This is true if any column of the row is changed, even a column |
|
4356 ** other than the one the BLOB handle is open on. |
|
4357 ** Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for |
|
4358 ** a expired BLOB handle fail with an return code of [SQLITE_ABORT]. |
|
4359 ** Changes written into a BLOB prior to the BLOB expiring are not |
|
4360 ** rollback by the expiration of the BLOB. Such changes will eventually |
|
4361 ** commit if the transaction continues to completion. |
|
4362 ** |
|
4363 ** Requirements: |
|
4364 ** [H17813] [H17814] [H17816] [H17819] [H17821] [H17824] |
|
4365 */ |
|
4366 int sqlite3_blob_open( |
|
4367 sqlite3*, |
|
4368 const char *zDb, |
|
4369 const char *zTable, |
|
4370 const char *zColumn, |
|
4371 sqlite3_int64 iRow, |
|
4372 int flags, |
|
4373 sqlite3_blob **ppBlob |
|
4374 ); |
|
4375 |
|
4376 /* |
|
4377 ** CAPI3REF: Close A BLOB Handle {H17830} <S30230> |
|
4378 ** |
|
4379 ** Closes an open [BLOB handle]. |
|
4380 ** |
|
4381 ** Closing a BLOB shall cause the current transaction to commit |
|
4382 ** if there are no other BLOBs, no pending prepared statements, and the |
|
4383 ** database connection is in [autocommit mode]. |
|
4384 ** If any writes were made to the BLOB, they might be held in cache |
|
4385 ** until the close operation if they will fit. {END} |
|
4386 ** |
|
4387 ** Closing the BLOB often forces the changes |
|
4388 ** out to disk and so if any I/O errors occur, they will likely occur |
|
4389 ** at the time when the BLOB is closed. {H17833} Any errors that occur during |
|
4390 ** closing are reported as a non-zero return value. |
|
4391 ** |
|
4392 ** The BLOB is closed unconditionally. Even if this routine returns |
|
4393 ** an error code, the BLOB is still closed. |
|
4394 ** |
|
4395 ** Requirements: |
|
4396 ** [H17833] [H17836] [H17839] |
|
4397 */ |
|
4398 int sqlite3_blob_close(sqlite3_blob *); |
|
4399 |
|
4400 /* |
|
4401 ** CAPI3REF: Return The Size Of An Open BLOB {H17840} <S30230> |
|
4402 ** |
|
4403 ** Returns the size in bytes of the BLOB accessible via the open |
|
4404 ** []BLOB handle] in its only argument. |
|
4405 ** |
|
4406 ** Requirements: |
|
4407 ** [H17843] |
|
4408 */ |
|
4409 int sqlite3_blob_bytes(sqlite3_blob *); |
|
4410 |
|
4411 /* |
|
4412 ** CAPI3REF: Read Data From A BLOB Incrementally {H17850} <S30230> |
|
4413 ** |
|
4414 ** This function is used to read data from an open [BLOB handle] into a |
|
4415 ** caller-supplied buffer. N bytes of data are copied into buffer Z |
|
4416 ** from the open BLOB, starting at offset iOffset. |
|
4417 ** |
|
4418 ** If offset iOffset is less than N bytes from the end of the BLOB, |
|
4419 ** [SQLITE_ERROR] is returned and no data is read. If N or iOffset is |
|
4420 ** less than zero, [SQLITE_ERROR] is returned and no data is read. |
|
4421 ** |
|
4422 ** An attempt to read from an expired [BLOB handle] fails with an |
|
4423 ** error code of [SQLITE_ABORT]. |
|
4424 ** |
|
4425 ** On success, SQLITE_OK is returned. |
|
4426 ** Otherwise, an [error code] or an [extended error code] is returned. |
|
4427 ** |
|
4428 ** Requirements: |
|
4429 ** [H17853] [H17856] [H17859] [H17862] [H17863] [H17865] [H17868] |
|
4430 */ |
|
4431 int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); |
|
4432 |
|
4433 /* |
|
4434 ** CAPI3REF: Write Data Into A BLOB Incrementally {H17870} <S30230> |
|
4435 ** |
|
4436 ** This function is used to write data into an open [BLOB handle] from a |
|
4437 ** caller-supplied buffer. N bytes of data are copied from the buffer Z |
|
4438 ** into the open BLOB, starting at offset iOffset. |
|
4439 ** |
|
4440 ** If the [BLOB handle] passed as the first argument was not opened for |
|
4441 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), |
|
4442 ** this function returns [SQLITE_READONLY]. |
|
4443 ** |
|
4444 ** This function may only modify the contents of the BLOB; it is |
|
4445 ** not possible to increase the size of a BLOB using this API. |
|
4446 ** If offset iOffset is less than N bytes from the end of the BLOB, |
|
4447 ** [SQLITE_ERROR] is returned and no data is written. If N is |
|
4448 ** less than zero [SQLITE_ERROR] is returned and no data is written. |
|
4449 ** |
|
4450 ** An attempt to write to an expired [BLOB handle] fails with an |
|
4451 ** error code of [SQLITE_ABORT]. Writes to the BLOB that occurred |
|
4452 ** before the [BLOB handle] expired are not rolled back by the |
|
4453 ** expiration of the handle, though of course those changes might |
|
4454 ** have been overwritten by the statement that expired the BLOB handle |
|
4455 ** or by other independent statements. |
|
4456 ** |
|
4457 ** On success, SQLITE_OK is returned. |
|
4458 ** Otherwise, an [error code] or an [extended error code] is returned. |
|
4459 ** |
|
4460 ** Requirements: |
|
4461 ** [H17873] [H17874] [H17875] [H17876] [H17877] [H17879] [H17882] [H17885] |
|
4462 ** [H17888] |
|
4463 */ |
|
4464 int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
|
4465 |
|
4466 /* |
|
4467 ** CAPI3REF: Virtual File System Objects {H11200} <S20100> |
|
4468 ** |
|
4469 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object |
|
4470 ** that SQLite uses to interact |
|
4471 ** with the underlying operating system. Most SQLite builds come with a |
|
4472 ** single default VFS that is appropriate for the host computer. |
|
4473 ** New VFSes can be registered and existing VFSes can be unregistered. |
|
4474 ** The following interfaces are provided. |
|
4475 ** |
|
4476 ** The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. |
|
4477 ** Names are case sensitive. |
|
4478 ** Names are zero-terminated UTF-8 strings. |
|
4479 ** If there is no match, a NULL pointer is returned. |
|
4480 ** If zVfsName is NULL then the default VFS is returned. |
|
4481 ** |
|
4482 ** New VFSes are registered with sqlite3_vfs_register(). |
|
4483 ** Each new VFS becomes the default VFS if the makeDflt flag is set. |
|
4484 ** The same VFS can be registered multiple times without injury. |
|
4485 ** To make an existing VFS into the default VFS, register it again |
|
4486 ** with the makeDflt flag set. If two different VFSes with the |
|
4487 ** same name are registered, the behavior is undefined. If a |
|
4488 ** VFS is registered with a name that is NULL or an empty string, |
|
4489 ** then the behavior is undefined. |
|
4490 ** |
|
4491 ** Unregister a VFS with the sqlite3_vfs_unregister() interface. |
|
4492 ** If the default VFS is unregistered, another VFS is chosen as |
|
4493 ** the default. The choice for the new VFS is arbitrary. |
|
4494 ** |
|
4495 ** Requirements: |
|
4496 ** [H11203] [H11206] [H11209] [H11212] [H11215] [H11218] |
|
4497 */ |
|
4498 sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); |
|
4499 int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); |
|
4500 int sqlite3_vfs_unregister(sqlite3_vfs*); |
|
4501 |
|
4502 /* |
|
4503 ** CAPI3REF: Mutexes {H17000} <S20000> |
|
4504 ** |
|
4505 ** The SQLite core uses these routines for thread |
|
4506 ** synchronization. Though they are intended for internal |
|
4507 ** use by SQLite, code that links against SQLite is |
|
4508 ** permitted to use any of these routines. |
|
4509 ** |
|
4510 ** The SQLite source code contains multiple implementations |
|
4511 ** of these mutex routines. An appropriate implementation |
|
4512 ** is selected automatically at compile-time. The following |
|
4513 ** implementations are available in the SQLite core: |
|
4514 ** |
|
4515 ** <ul> |
|
4516 ** <li> SQLITE_MUTEX_OS2 |
|
4517 ** <li> SQLITE_MUTEX_PTHREAD |
|
4518 ** <li> SQLITE_MUTEX_W32 |
|
4519 ** <li> SQLITE_MUTEX_NOOP |
|
4520 ** </ul> |
|
4521 ** |
|
4522 ** The SQLITE_MUTEX_NOOP implementation is a set of routines |
|
4523 ** that does no real locking and is appropriate for use in |
|
4524 ** a single-threaded application. The SQLITE_MUTEX_OS2, |
|
4525 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations |
|
4526 ** are appropriate for use on OS/2, Unix, and Windows. |
|
4527 ** |
|
4528 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor |
|
4529 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex |
|
4530 ** implementation is included with the library. In this case the |
|
4531 ** application must supply a custom mutex implementation using the |
|
4532 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function |
|
4533 ** before calling sqlite3_initialize() or any other public sqlite3_ |
|
4534 ** function that calls sqlite3_initialize(). |
|
4535 ** |
|
4536 ** {H17011} The sqlite3_mutex_alloc() routine allocates a new |
|
4537 ** mutex and returns a pointer to it. {H17012} If it returns NULL |
|
4538 ** that means that a mutex could not be allocated. {H17013} SQLite |
|
4539 ** will unwind its stack and return an error. {H17014} The argument |
|
4540 ** to sqlite3_mutex_alloc() is one of these integer constants: |
|
4541 ** |
|
4542 ** <ul> |
|
4543 ** <li> SQLITE_MUTEX_FAST |
|
4544 ** <li> SQLITE_MUTEX_RECURSIVE |
|
4545 ** <li> SQLITE_MUTEX_STATIC_MASTER |
|
4546 ** <li> SQLITE_MUTEX_STATIC_MEM |
|
4547 ** <li> SQLITE_MUTEX_STATIC_MEM2 |
|
4548 ** <li> SQLITE_MUTEX_STATIC_PRNG |
|
4549 ** <li> SQLITE_MUTEX_STATIC_LRU |
|
4550 ** <li> SQLITE_MUTEX_STATIC_LRU2 |
|
4551 ** </ul> |
|
4552 ** |
|
4553 ** {H17015} The first two constants cause sqlite3_mutex_alloc() to create |
|
4554 ** a new mutex. The new mutex is recursive when SQLITE_MUTEX_RECURSIVE |
|
4555 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. {END} |
|
4556 ** The mutex implementation does not need to make a distinction |
|
4557 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does |
|
4558 ** not want to. {H17016} But SQLite will only request a recursive mutex in |
|
4559 ** cases where it really needs one. {END} If a faster non-recursive mutex |
|
4560 ** implementation is available on the host platform, the mutex subsystem |
|
4561 ** might return such a mutex in response to SQLITE_MUTEX_FAST. |
|
4562 ** |
|
4563 ** {H17017} The other allowed parameters to sqlite3_mutex_alloc() each return |
|
4564 ** a pointer to a static preexisting mutex. {END} Four static mutexes are |
|
4565 ** used by the current version of SQLite. Future versions of SQLite |
|
4566 ** may add additional static mutexes. Static mutexes are for internal |
|
4567 ** use by SQLite only. Applications that use SQLite mutexes should |
|
4568 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or |
|
4569 ** SQLITE_MUTEX_RECURSIVE. |
|
4570 ** |
|
4571 ** {H17018} Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST |
|
4572 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() |
|
4573 ** returns a different mutex on every call. {H17034} But for the static |
|
4574 ** mutex types, the same mutex is returned on every call that has |
|
4575 ** the same type number. |
|
4576 ** |
|
4577 ** {H17019} The sqlite3_mutex_free() routine deallocates a previously |
|
4578 ** allocated dynamic mutex. {H17020} SQLite is careful to deallocate every |
|
4579 ** dynamic mutex that it allocates. {A17021} The dynamic mutexes must not be in |
|
4580 ** use when they are deallocated. {A17022} Attempting to deallocate a static |
|
4581 ** mutex results in undefined behavior. {H17023} SQLite never deallocates |
|
4582 ** a static mutex. {END} |
|
4583 ** |
|
4584 ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt |
|
4585 ** to enter a mutex. {H17024} If another thread is already within the mutex, |
|
4586 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return |
|
4587 ** SQLITE_BUSY. {H17025} The sqlite3_mutex_try() interface returns [SQLITE_OK] |
|
4588 ** upon successful entry. {H17026} Mutexes created using |
|
4589 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. |
|
4590 ** {H17027} In such cases the, |
|
4591 ** mutex must be exited an equal number of times before another thread |
|
4592 ** can enter. {A17028} If the same thread tries to enter any other |
|
4593 ** kind of mutex more than once, the behavior is undefined. |
|
4594 ** {H17029} SQLite will never exhibit |
|
4595 ** such behavior in its own use of mutexes. |
|
4596 ** |
|
4597 ** Some systems (for example, Windows 95) do not support the operation |
|
4598 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() |
|
4599 ** will always return SQLITE_BUSY. {H17030} The SQLite core only ever uses |
|
4600 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior. |
|
4601 ** |
|
4602 ** {H17031} The sqlite3_mutex_leave() routine exits a mutex that was |
|
4603 ** previously entered by the same thread. {A17032} The behavior |
|
4604 ** is undefined if the mutex is not currently entered by the |
|
4605 ** calling thread or is not currently allocated. {H17033} SQLite will |
|
4606 ** never do either. {END} |
|
4607 ** |
|
4608 ** If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or |
|
4609 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines |
|
4610 ** behave as no-ops. |
|
4611 ** |
|
4612 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. |
|
4613 */ |
|
4614 sqlite3_mutex *sqlite3_mutex_alloc(int); |
|
4615 void sqlite3_mutex_free(sqlite3_mutex*); |
|
4616 void sqlite3_mutex_enter(sqlite3_mutex*); |
|
4617 int sqlite3_mutex_try(sqlite3_mutex*); |
|
4618 void sqlite3_mutex_leave(sqlite3_mutex*); |
|
4619 |
|
4620 /* |
|
4621 ** CAPI3REF: Mutex Methods Object {H17120} <S20130> |
|
4622 ** EXPERIMENTAL |
|
4623 ** |
|
4624 ** An instance of this structure defines the low-level routines |
|
4625 ** used to allocate and use mutexes. |
|
4626 ** |
|
4627 ** Usually, the default mutex implementations provided by SQLite are |
|
4628 ** sufficient, however the user has the option of substituting a custom |
|
4629 ** implementation for specialized deployments or systems for which SQLite |
|
4630 ** does not provide a suitable implementation. In this case, the user |
|
4631 ** creates and populates an instance of this structure to pass |
|
4632 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. |
|
4633 ** Additionally, an instance of this structure can be used as an |
|
4634 ** output variable when querying the system for the current mutex |
|
4635 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. |
|
4636 ** |
|
4637 ** The xMutexInit method defined by this structure is invoked as |
|
4638 ** part of system initialization by the sqlite3_initialize() function. |
|
4639 ** {H17001} The xMutexInit routine shall be called by SQLite once for each |
|
4640 ** effective call to [sqlite3_initialize()]. |
|
4641 ** |
|
4642 ** The xMutexEnd method defined by this structure is invoked as |
|
4643 ** part of system shutdown by the sqlite3_shutdown() function. The |
|
4644 ** implementation of this method is expected to release all outstanding |
|
4645 ** resources obtained by the mutex methods implementation, especially |
|
4646 ** those obtained by the xMutexInit method. {H17003} The xMutexEnd() |
|
4647 ** interface shall be invoked once for each call to [sqlite3_shutdown()]. |
|
4648 ** |
|
4649 ** The remaining seven methods defined by this structure (xMutexAlloc, |
|
4650 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and |
|
4651 ** xMutexNotheld) implement the following interfaces (respectively): |
|
4652 ** |
|
4653 ** <ul> |
|
4654 ** <li> [sqlite3_mutex_alloc()] </li> |
|
4655 ** <li> [sqlite3_mutex_free()] </li> |
|
4656 ** <li> [sqlite3_mutex_enter()] </li> |
|
4657 ** <li> [sqlite3_mutex_try()] </li> |
|
4658 ** <li> [sqlite3_mutex_leave()] </li> |
|
4659 ** <li> [sqlite3_mutex_held()] </li> |
|
4660 ** <li> [sqlite3_mutex_notheld()] </li> |
|
4661 ** </ul> |
|
4662 ** |
|
4663 ** The only difference is that the public sqlite3_XXX functions enumerated |
|
4664 ** above silently ignore any invocations that pass a NULL pointer instead |
|
4665 ** of a valid mutex handle. The implementations of the methods defined |
|
4666 ** by this structure are not required to handle this case, the results |
|
4667 ** of passing a NULL pointer instead of a valid mutex handle are undefined |
|
4668 ** (i.e. it is acceptable to provide an implementation that segfaults if |
|
4669 ** it is passed a NULL pointer). |
|
4670 */ |
|
4671 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; |
|
4672 struct sqlite3_mutex_methods { |
|
4673 int (*xMutexInit)(void); |
|
4674 int (*xMutexEnd)(void); |
|
4675 sqlite3_mutex *(*xMutexAlloc)(int); |
|
4676 void (*xMutexFree)(sqlite3_mutex *); |
|
4677 void (*xMutexEnter)(sqlite3_mutex *); |
|
4678 int (*xMutexTry)(sqlite3_mutex *); |
|
4679 void (*xMutexLeave)(sqlite3_mutex *); |
|
4680 int (*xMutexHeld)(sqlite3_mutex *); |
|
4681 int (*xMutexNotheld)(sqlite3_mutex *); |
|
4682 }; |
|
4683 |
|
4684 /* |
|
4685 ** CAPI3REF: Mutex Verification Routines {H17080} <S20130> <S30800> |
|
4686 ** |
|
4687 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines |
|
4688 ** are intended for use inside assert() statements. {H17081} The SQLite core |
|
4689 ** never uses these routines except inside an assert() and applications |
|
4690 ** are advised to follow the lead of the core. {H17082} The core only |
|
4691 ** provides implementations for these routines when it is compiled |
|
4692 ** with the SQLITE_DEBUG flag. {A17087} External mutex implementations |
|
4693 ** are only required to provide these routines if SQLITE_DEBUG is |
|
4694 ** defined and if NDEBUG is not defined. |
|
4695 ** |
|
4696 ** {H17083} These routines should return true if the mutex in their argument |
|
4697 ** is held or not held, respectively, by the calling thread. |
|
4698 ** |
|
4699 ** {X17084} The implementation is not required to provided versions of these |
|
4700 ** routines that actually work. If the implementation does not provide working |
|
4701 ** versions of these routines, it should at least provide stubs that always |
|
4702 ** return true so that one does not get spurious assertion failures. |
|
4703 ** |
|
4704 ** {H17085} If the argument to sqlite3_mutex_held() is a NULL pointer then |
|
4705 ** the routine should return 1. {END} This seems counter-intuitive since |
|
4706 ** clearly the mutex cannot be held if it does not exist. But the |
|
4707 ** the reason the mutex does not exist is because the build is not |
|
4708 ** using mutexes. And we do not want the assert() containing the |
|
4709 ** call to sqlite3_mutex_held() to fail, so a non-zero return is |
|
4710 ** the appropriate thing to do. {H17086} The sqlite3_mutex_notheld() |
|
4711 ** interface should also return 1 when given a NULL pointer. |
|
4712 */ |
|
4713 int sqlite3_mutex_held(sqlite3_mutex*); |
|
4714 int sqlite3_mutex_notheld(sqlite3_mutex*); |
|
4715 |
|
4716 /* |
|
4717 ** CAPI3REF: Mutex Types {H17001} <H17000> |
|
4718 ** |
|
4719 ** The [sqlite3_mutex_alloc()] interface takes a single argument |
|
4720 ** which is one of these integer constants. |
|
4721 ** |
|
4722 ** The set of static mutexes may change from one SQLite release to the |
|
4723 ** next. Applications that override the built-in mutex logic must be |
|
4724 ** prepared to accommodate additional static mutexes. |
|
4725 */ |
|
4726 #define SQLITE_MUTEX_FAST 0 |
|
4727 #define SQLITE_MUTEX_RECURSIVE 1 |
|
4728 #define SQLITE_MUTEX_STATIC_MASTER 2 |
|
4729 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ |
|
4730 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
|
4731 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ |
|
4732 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ |
|
4733 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ |
|
4734 #define SQLITE_MUTEX_STATIC_LRU2 7 /* lru page list */ |
|
4735 |
|
4736 /* |
|
4737 ** CAPI3REF: Retrieve the mutex for a database connection {H17002} <H17000> |
|
4738 ** |
|
4739 ** This interface returns a pointer the [sqlite3_mutex] object that |
|
4740 ** serializes access to the [database connection] given in the argument |
|
4741 ** when the [threading mode] is Serialized. |
|
4742 ** If the [threading mode] is Single-thread or Multi-thread then this |
|
4743 ** routine returns a NULL pointer. |
|
4744 */ |
|
4745 sqlite3_mutex *sqlite3_db_mutex(sqlite3*); |
|
4746 |
|
4747 /* |
|
4748 ** CAPI3REF: Low-Level Control Of Database Files {H11300} <S30800> |
|
4749 ** |
|
4750 ** {H11301} The [sqlite3_file_control()] interface makes a direct call to the |
|
4751 ** xFileControl method for the [sqlite3_io_methods] object associated |
|
4752 ** with a particular database identified by the second argument. {H11302} The |
|
4753 ** name of the database is the name assigned to the database by the |
|
4754 ** <a href="lang_attach.html">ATTACH</a> SQL command that opened the |
|
4755 ** database. {H11303} To control the main database file, use the name "main" |
|
4756 ** or a NULL pointer. {H11304} The third and fourth parameters to this routine |
|
4757 ** are passed directly through to the second and third parameters of |
|
4758 ** the xFileControl method. {H11305} The return value of the xFileControl |
|
4759 ** method becomes the return value of this routine. |
|
4760 ** |
|
4761 ** {H11306} If the second parameter (zDbName) does not match the name of any |
|
4762 ** open database file, then SQLITE_ERROR is returned. {H11307} This error |
|
4763 ** code is not remembered and will not be recalled by [sqlite3_errcode()] |
|
4764 ** or [sqlite3_errmsg()]. {A11308} The underlying xFileControl method might |
|
4765 ** also return SQLITE_ERROR. {A11309} There is no way to distinguish between |
|
4766 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying |
|
4767 ** xFileControl method. {END} |
|
4768 ** |
|
4769 ** See also: [SQLITE_FCNTL_LOCKSTATE] |
|
4770 */ |
|
4771 int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
|
4772 |
|
4773 /* |
|
4774 ** CAPI3REF: Testing Interface {H11400} <S30800> |
|
4775 ** |
|
4776 ** The sqlite3_test_control() interface is used to read out internal |
|
4777 ** state of SQLite and to inject faults into SQLite for testing |
|
4778 ** purposes. The first parameter is an operation code that determines |
|
4779 ** the number, meaning, and operation of all subsequent parameters. |
|
4780 ** |
|
4781 ** This interface is not for use by applications. It exists solely |
|
4782 ** for verifying the correct operation of the SQLite library. Depending |
|
4783 ** on how the SQLite library is compiled, this interface might not exist. |
|
4784 ** |
|
4785 ** The details of the operation codes, their meanings, the parameters |
|
4786 ** they take, and what they do are all subject to change without notice. |
|
4787 ** Unlike most of the SQLite API, this function is not guaranteed to |
|
4788 ** operate consistently from one release to the next. |
|
4789 */ |
|
4790 int sqlite3_test_control(int op, ...); |
|
4791 |
|
4792 /* |
|
4793 ** CAPI3REF: Testing Interface Operation Codes {H11410} <H11400> |
|
4794 ** |
|
4795 ** These constants are the valid operation code parameters used |
|
4796 ** as the first argument to [sqlite3_test_control()]. |
|
4797 ** |
|
4798 ** These parameters and their meanings are subject to change |
|
4799 ** without notice. These values are for testing purposes only. |
|
4800 ** Applications should not use any of these parameters or the |
|
4801 ** [sqlite3_test_control()] interface. |
|
4802 */ |
|
4803 #define SQLITE_TESTCTRL_PRNG_SAVE 5 |
|
4804 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 |
|
4805 #define SQLITE_TESTCTRL_PRNG_RESET 7 |
|
4806 #define SQLITE_TESTCTRL_BITVEC_TEST 8 |
|
4807 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
|
4808 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 |
|
4809 #define SQLITE_TESTCTRL_PENDING_BYTE 11 |
|
4810 |
|
4811 /* |
|
4812 ** CAPI3REF: SQLite Runtime Status {H17200} <S60200> |
|
4813 ** EXPERIMENTAL |
|
4814 ** |
|
4815 ** This interface is used to retrieve runtime status information |
|
4816 ** about the preformance of SQLite, and optionally to reset various |
|
4817 ** highwater marks. The first argument is an integer code for |
|
4818 ** the specific parameter to measure. Recognized integer codes |
|
4819 ** are of the form [SQLITE_STATUS_MEMORY_USED | SQLITE_STATUS_...]. |
|
4820 ** The current value of the parameter is returned into *pCurrent. |
|
4821 ** The highest recorded value is returned in *pHighwater. If the |
|
4822 ** resetFlag is true, then the highest record value is reset after |
|
4823 ** *pHighwater is written. Some parameters do not record the highest |
|
4824 ** value. For those parameters |
|
4825 ** nothing is written into *pHighwater and the resetFlag is ignored. |
|
4826 ** Other parameters record only the highwater mark and not the current |
|
4827 ** value. For these latter parameters nothing is written into *pCurrent. |
|
4828 ** |
|
4829 ** This routine returns SQLITE_OK on success and a non-zero |
|
4830 ** [error code] on failure. |
|
4831 ** |
|
4832 ** This routine is threadsafe but is not atomic. This routine can |
|
4833 ** called while other threads are running the same or different SQLite |
|
4834 ** interfaces. However the values returned in *pCurrent and |
|
4835 ** *pHighwater reflect the status of SQLite at different points in time |
|
4836 ** and it is possible that another thread might change the parameter |
|
4837 ** in between the times when *pCurrent and *pHighwater are written. |
|
4838 ** |
|
4839 ** See also: [sqlite3_db_status()] |
|
4840 */ |
|
4841 SQLITE_EXPERIMENTAL int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); |
|
4842 |
|
4843 |
|
4844 /* |
|
4845 ** CAPI3REF: Status Parameters {H17250} <H17200> |
|
4846 ** EXPERIMENTAL |
|
4847 ** |
|
4848 ** These integer constants designate various run-time status parameters |
|
4849 ** that can be returned by [sqlite3_status()]. |
|
4850 ** |
|
4851 ** <dl> |
|
4852 ** <dt>SQLITE_STATUS_MEMORY_USED</dt> |
|
4853 ** <dd>This parameter is the current amount of memory checked out |
|
4854 ** using [sqlite3_malloc()], either directly or indirectly. The |
|
4855 ** figure includes calls made to [sqlite3_malloc()] by the application |
|
4856 ** and internal memory usage by the SQLite library. Scratch memory |
|
4857 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache |
|
4858 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in |
|
4859 ** this parameter. The amount returned is the sum of the allocation |
|
4860 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd> |
|
4861 ** |
|
4862 ** <dt>SQLITE_STATUS_MALLOC_SIZE</dt> |
|
4863 ** <dd>This parameter records the largest memory allocation request |
|
4864 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their |
|
4865 ** internal equivalents). Only the value returned in the |
|
4866 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
|
4867 ** The value written into the *pCurrent parameter is undefined.</dd> |
|
4868 ** |
|
4869 ** <dt>SQLITE_STATUS_PAGECACHE_USED</dt> |
|
4870 ** <dd>This parameter returns the number of pages used out of the |
|
4871 ** [pagecache memory allocator] that was configured using |
|
4872 ** [SQLITE_CONFIG_PAGECACHE]. The |
|
4873 ** value returned is in pages, not in bytes.</dd> |
|
4874 ** |
|
4875 ** <dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> |
|
4876 ** <dd>This parameter returns the number of bytes of page cache |
|
4877 ** allocation which could not be statisfied by the [SQLITE_CONFIG_PAGECACHE] |
|
4878 ** buffer and where forced to overflow to [sqlite3_malloc()]. The |
|
4879 ** returned value includes allocations that overflowed because they |
|
4880 ** where too large (they were larger than the "sz" parameter to |
|
4881 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because |
|
4882 ** no space was left in the page cache.</dd> |
|
4883 ** |
|
4884 ** <dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> |
|
4885 ** <dd>This parameter records the largest memory allocation request |
|
4886 ** handed to [pagecache memory allocator]. Only the value returned in the |
|
4887 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
|
4888 ** The value written into the *pCurrent parameter is undefined.</dd> |
|
4889 ** |
|
4890 ** <dt>SQLITE_STATUS_SCRATCH_USED</dt> |
|
4891 ** <dd>This parameter returns the number of allocations used out of the |
|
4892 ** [scratch memory allocator] configured using |
|
4893 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not |
|
4894 ** in bytes. Since a single thread may only have one scratch allocation |
|
4895 ** outstanding at time, this parameter also reports the number of threads |
|
4896 ** using scratch memory at the same time.</dd> |
|
4897 ** |
|
4898 ** <dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> |
|
4899 ** <dd>This parameter returns the number of bytes of scratch memory |
|
4900 ** allocation which could not be statisfied by the [SQLITE_CONFIG_SCRATCH] |
|
4901 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values |
|
4902 ** returned include overflows because the requested allocation was too |
|
4903 ** larger (that is, because the requested allocation was larger than the |
|
4904 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer |
|
4905 ** slots were available. |
|
4906 ** </dd> |
|
4907 ** |
|
4908 ** <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> |
|
4909 ** <dd>This parameter records the largest memory allocation request |
|
4910 ** handed to [scratch memory allocator]. Only the value returned in the |
|
4911 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
|
4912 ** The value written into the *pCurrent parameter is undefined.</dd> |
|
4913 ** |
|
4914 ** <dt>SQLITE_STATUS_PARSER_STACK</dt> |
|
4915 ** <dd>This parameter records the deepest parser stack. It is only |
|
4916 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd> |
|
4917 ** </dl> |
|
4918 ** |
|
4919 ** New status parameters may be added from time to time. |
|
4920 */ |
|
4921 #define SQLITE_STATUS_MEMORY_USED 0 |
|
4922 #define SQLITE_STATUS_PAGECACHE_USED 1 |
|
4923 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 |
|
4924 #define SQLITE_STATUS_SCRATCH_USED 3 |
|
4925 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 |
|
4926 #define SQLITE_STATUS_MALLOC_SIZE 5 |
|
4927 #define SQLITE_STATUS_PARSER_STACK 6 |
|
4928 #define SQLITE_STATUS_PAGECACHE_SIZE 7 |
|
4929 #define SQLITE_STATUS_SCRATCH_SIZE 8 |
|
4930 |
|
4931 /* |
|
4932 ** CAPI3REF: Database Connection Status {H17500} <S60200> |
|
4933 ** EXPERIMENTAL |
|
4934 ** |
|
4935 ** This interface is used to retrieve runtime status information |
|
4936 ** about a single [database connection]. The first argument is the |
|
4937 ** database connection object to be interrogated. The second argument |
|
4938 ** is the parameter to interrogate. Currently, the only allowed value |
|
4939 ** for the second parameter is [SQLITE_DBSTATUS_LOOKASIDE_USED]. |
|
4940 ** Additional options will likely appear in future releases of SQLite. |
|
4941 ** |
|
4942 ** The current value of the requested parameter is written into *pCur |
|
4943 ** and the highest instantaneous value is written into *pHiwtr. If |
|
4944 ** the resetFlg is true, then the highest instantaneous value is |
|
4945 ** reset back down to the current value. |
|
4946 ** |
|
4947 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. |
|
4948 */ |
|
4949 SQLITE_EXPERIMENTAL int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); |
|
4950 |
|
4951 /* |
|
4952 ** CAPI3REF: Status Parameters for database connections {H17520} <H17500> |
|
4953 ** EXPERIMENTAL |
|
4954 ** |
|
4955 ** Status verbs for [sqlite3_db_status()]. |
|
4956 ** |
|
4957 ** <dl> |
|
4958 ** <dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> |
|
4959 ** <dd>This parameter returns the number of lookaside memory slots currently |
|
4960 ** checked out.</dd> |
|
4961 ** </dl> |
|
4962 */ |
|
4963 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 |
|
4964 |
|
4965 |
|
4966 /* |
|
4967 ** CAPI3REF: Prepared Statement Status {H17550} <S60200> |
|
4968 ** EXPERIMENTAL |
|
4969 ** |
|
4970 ** Each prepared statement maintains various |
|
4971 ** [SQLITE_STMTSTATUS_SORT | counters] that measure the number |
|
4972 ** of times it has performed specific operations. These counters can |
|
4973 ** be used to monitor the performance characteristics of the prepared |
|
4974 ** statements. For example, if the number of table steps greatly exceeds |
|
4975 ** the number of table searches or result rows, that would tend to indicate |
|
4976 ** that the prepared statement is using a full table scan rather than |
|
4977 ** an index. |
|
4978 ** |
|
4979 ** This interface is used to retrieve and reset counter values from |
|
4980 ** a [prepared statement]. The first argument is the prepared statement |
|
4981 ** object to be interrogated. The second argument |
|
4982 ** is an integer code for a specific [SQLITE_STMTSTATUS_SORT | counter] |
|
4983 ** to be interrogated. |
|
4984 ** The current value of the requested counter is returned. |
|
4985 ** If the resetFlg is true, then the counter is reset to zero after this |
|
4986 ** interface call returns. |
|
4987 ** |
|
4988 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. |
|
4989 */ |
|
4990 SQLITE_EXPERIMENTAL int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); |
|
4991 |
|
4992 /* |
|
4993 ** CAPI3REF: Status Parameters for prepared statements {H17570} <H17550> |
|
4994 ** EXPERIMENTAL |
|
4995 ** |
|
4996 ** These preprocessor macros define integer codes that name counter |
|
4997 ** values associated with the [sqlite3_stmt_status()] interface. |
|
4998 ** The meanings of the various counters are as follows: |
|
4999 ** |
|
5000 ** <dl> |
|
5001 ** <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> |
|
5002 ** <dd>This is the number of times that SQLite has stepped forward in |
|
5003 ** a table as part of a full table scan. Large numbers for this counter |
|
5004 ** may indicate opportunities for performance improvement through |
|
5005 ** careful use of indices.</dd> |
|
5006 ** |
|
5007 ** <dt>SQLITE_STMTSTATUS_SORT</dt> |
|
5008 ** <dd>This is the number of sort operations that have occurred. |
|
5009 ** A non-zero value in this counter may indicate an opportunity to |
|
5010 ** improvement performance through careful use of indices.</dd> |
|
5011 ** |
|
5012 ** </dl> |
|
5013 */ |
|
5014 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 |
|
5015 #define SQLITE_STMTSTATUS_SORT 2 |
|
5016 |
|
5017 /* |
|
5018 ** CAPI3REF: Custom Page Cache Object |
|
5019 ** EXPERIMENTAL |
|
5020 ** |
|
5021 ** The sqlite3_pcache type is opaque. It is implemented by |
|
5022 ** the pluggable module. The SQLite core has no knowledge of |
|
5023 ** its size or internal structure and never deals with the |
|
5024 ** sqlite3_pcache object except by holding and passing pointers |
|
5025 ** to the object. |
|
5026 ** |
|
5027 ** See [sqlite3_pcache_methods] for additional information. |
|
5028 */ |
|
5029 typedef struct sqlite3_pcache sqlite3_pcache; |
|
5030 |
|
5031 /* |
|
5032 ** CAPI3REF: Application Defined Page Cache. |
|
5033 ** EXPERIMENTAL |
|
5034 ** |
|
5035 ** The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can |
|
5036 ** register an alternative page cache implementation by passing in an |
|
5037 ** instance of the sqlite3_pcache_methods structure. The majority of the |
|
5038 ** heap memory used by sqlite is used by the page cache to cache data read |
|
5039 ** from, or ready to be written to, the database file. By implementing a |
|
5040 ** custom page cache using this API, an application can control more |
|
5041 ** precisely the amount of memory consumed by sqlite, the way in which |
|
5042 ** said memory is allocated and released, and the policies used to |
|
5043 ** determine exactly which parts of a database file are cached and for |
|
5044 ** how long. |
|
5045 ** |
|
5046 ** The contents of the structure are copied to an internal buffer by sqlite |
|
5047 ** within the call to [sqlite3_config]. |
|
5048 ** |
|
5049 ** The xInit() method is called once for each call to [sqlite3_initialize()] |
|
5050 ** (usually only once during the lifetime of the process). It is passed |
|
5051 ** a copy of the sqlite3_pcache_methods.pArg value. It can be used to set |
|
5052 ** up global structures and mutexes required by the custom page cache |
|
5053 ** implementation. The xShutdown() method is called from within |
|
5054 ** [sqlite3_shutdown()], if the application invokes this API. It can be used |
|
5055 ** to clean up any outstanding resources before process shutdown, if required. |
|
5056 ** |
|
5057 ** The xCreate() method is used to construct a new cache instance. The |
|
5058 ** first parameter, szPage, is the size in bytes of the pages that must |
|
5059 ** be allocated by the cache. szPage will not be a power of two. The |
|
5060 ** second argument, bPurgeable, is true if the cache being created will |
|
5061 ** be used to cache database pages read from a file stored on disk, or |
|
5062 ** false if it is used for an in-memory database. The cache implementation |
|
5063 ** does not have to do anything special based on the value of bPurgeable, |
|
5064 ** it is purely advisory. |
|
5065 ** |
|
5066 ** The xCachesize() method may be called at any time by SQLite to set the |
|
5067 ** suggested maximum cache-size (number of pages stored by) the cache |
|
5068 ** instance passed as the first argument. This is the value configured using |
|
5069 ** the SQLite "[PRAGMA cache_size]" command. As with the bPurgeable parameter, |
|
5070 ** the implementation is not required to do anything special with this |
|
5071 ** value, it is advisory only. |
|
5072 ** |
|
5073 ** The xPagecount() method should return the number of pages currently |
|
5074 ** stored in the cache supplied as an argument. |
|
5075 ** |
|
5076 ** The xFetch() method is used to fetch a page and return a pointer to it. |
|
5077 ** A 'page', in this context, is a buffer of szPage bytes aligned at an |
|
5078 ** 8-byte boundary. The page to be fetched is determined by the key. The |
|
5079 ** mimimum key value is 1. After it has been retrieved using xFetch, the page |
|
5080 ** is considered to be pinned. |
|
5081 ** |
|
5082 ** If the requested page is already in the page cache, then a pointer to |
|
5083 ** the cached buffer should be returned with its contents intact. If the |
|
5084 ** page is not already in the cache, then the expected behaviour of the |
|
5085 ** cache is determined by the value of the createFlag parameter passed |
|
5086 ** to xFetch, according to the following table: |
|
5087 ** |
|
5088 ** <table border=1 width=85% align=center> |
|
5089 ** <tr><th>createFlag<th>Expected Behaviour |
|
5090 ** <tr><td>0<td>NULL should be returned. No new cache entry is created. |
|
5091 ** <tr><td>1<td>If createFlag is set to 1, this indicates that |
|
5092 ** SQLite is holding pinned pages that can be unpinned |
|
5093 ** by writing their contents to the database file (a |
|
5094 ** relatively expensive operation). In this situation the |
|
5095 ** cache implementation has two choices: it can return NULL, |
|
5096 ** in which case SQLite will attempt to unpin one or more |
|
5097 ** pages before re-requesting the same page, or it can |
|
5098 ** allocate a new page and return a pointer to it. If a new |
|
5099 ** page is allocated, then the first sizeof(void*) bytes of |
|
5100 ** it (at least) must be zeroed before it is returned. |
|
5101 ** <tr><td>2<td>If createFlag is set to 2, then SQLite is not holding any |
|
5102 ** pinned pages associated with the specific cache passed |
|
5103 ** as the first argument to xFetch() that can be unpinned. The |
|
5104 ** cache implementation should attempt to allocate a new |
|
5105 ** cache entry and return a pointer to it. Again, the first |
|
5106 ** sizeof(void*) bytes of the page should be zeroed before |
|
5107 ** it is returned. If the xFetch() method returns NULL when |
|
5108 ** createFlag==2, SQLite assumes that a memory allocation |
|
5109 ** failed and returns SQLITE_NOMEM to the user. |
|
5110 ** </table> |
|
5111 ** |
|
5112 ** xUnpin() is called by SQLite with a pointer to a currently pinned page |
|
5113 ** as its second argument. If the third parameter, discard, is non-zero, |
|
5114 ** then the page should be evicted from the cache. In this case SQLite |
|
5115 ** assumes that the next time the page is retrieved from the cache using |
|
5116 ** the xFetch() method, it will be zeroed. If the discard parameter is |
|
5117 ** zero, then the page is considered to be unpinned. The cache implementation |
|
5118 ** may choose to reclaim (free or recycle) unpinned pages at any time. |
|
5119 ** SQLite assumes that next time the page is retrieved from the cache |
|
5120 ** it will either be zeroed, or contain the same data that it did when it |
|
5121 ** was unpinned. |
|
5122 ** |
|
5123 ** The cache is not required to perform any reference counting. A single |
|
5124 ** call to xUnpin() unpins the page regardless of the number of prior calls |
|
5125 ** to xFetch(). |
|
5126 ** |
|
5127 ** The xRekey() method is used to change the key value associated with the |
|
5128 ** page passed as the second argument from oldKey to newKey. If the cache |
|
5129 ** previously contains an entry associated with newKey, it should be |
|
5130 ** discarded. Any prior cache entry associated with newKey is guaranteed not |
|
5131 ** to be pinned. |
|
5132 ** |
|
5133 ** When SQLite calls the xTruncate() method, the cache must discard all |
|
5134 ** existing cache entries with page numbers (keys) greater than or equal |
|
5135 ** to the value of the iLimit parameter passed to xTruncate(). If any |
|
5136 ** of these pages are pinned, they are implicitly unpinned, meaning that |
|
5137 ** they can be safely discarded. |
|
5138 ** |
|
5139 ** The xDestroy() method is used to delete a cache allocated by xCreate(). |
|
5140 ** All resources associated with the specified cache should be freed. After |
|
5141 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] |
|
5142 ** handle invalid, and will not use it with any other sqlite3_pcache_methods |
|
5143 ** functions. |
|
5144 */ |
|
5145 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; |
|
5146 struct sqlite3_pcache_methods { |
|
5147 void *pArg; |
|
5148 int (*xInit)(void*); |
|
5149 void (*xShutdown)(void*); |
|
5150 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); |
|
5151 void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
|
5152 int (*xPagecount)(sqlite3_pcache*); |
|
5153 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
|
5154 void (*xUnpin)(sqlite3_pcache*, void*, int discard); |
|
5155 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); |
|
5156 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
|
5157 void (*xDestroy)(sqlite3_pcache*); |
|
5158 }; |
|
5159 |
|
5160 /* |
|
5161 ** CAPI3REF: Online Backup Object |
|
5162 ** EXPERIMENTAL |
|
5163 ** |
|
5164 ** The sqlite3_backup object records state information about an ongoing |
|
5165 ** online backup operation. The sqlite3_backup object is created by |
|
5166 ** a call to [sqlite3_backup_init()] and is destroyed by a call to |
|
5167 ** [sqlite3_backup_finish()]. |
|
5168 ** |
|
5169 ** See Also: [Using the SQLite Online Backup API] |
|
5170 */ |
|
5171 typedef struct sqlite3_backup sqlite3_backup; |
|
5172 |
|
5173 /* |
|
5174 ** CAPI3REF: Online Backup API. |
|
5175 ** EXPERIMENTAL |
|
5176 ** |
|
5177 ** This API is used to overwrite the contents of one database with that |
|
5178 ** of another. It is useful either for creating backups of databases or |
|
5179 ** for copying in-memory databases to or from persistent files. |
|
5180 ** |
|
5181 ** See Also: [Using the SQLite Online Backup API] |
|
5182 ** |
|
5183 ** Exclusive access is required to the destination database for the |
|
5184 ** duration of the operation. However the source database is only |
|
5185 ** read-locked while it is actually being read, it is not locked |
|
5186 ** continuously for the entire operation. Thus, the backup may be |
|
5187 ** performed on a live database without preventing other users from |
|
5188 ** writing to the database for an extended period of time. |
|
5189 ** |
|
5190 ** To perform a backup operation: |
|
5191 ** <ol> |
|
5192 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the |
|
5193 ** backup, |
|
5194 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer |
|
5195 ** the data between the two databases, and finally |
|
5196 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources |
|
5197 ** associated with the backup operation. |
|
5198 ** </ol> |
|
5199 ** There should be exactly one call to sqlite3_backup_finish() for each |
|
5200 ** successful call to sqlite3_backup_init(). |
|
5201 ** |
|
5202 ** <b>sqlite3_backup_init()</b> |
|
5203 ** |
|
5204 ** The first two arguments passed to [sqlite3_backup_init()] are the database |
|
5205 ** handle associated with the destination database and the database name |
|
5206 ** used to attach the destination database to the handle. The database name |
|
5207 ** is "main" for the main database, "temp" for the temporary database, or |
|
5208 ** the name specified as part of the [ATTACH] statement if the destination is |
|
5209 ** an attached database. The third and fourth arguments passed to |
|
5210 ** sqlite3_backup_init() identify the [database connection] |
|
5211 ** and database name used |
|
5212 ** to access the source database. The values passed for the source and |
|
5213 ** destination [database connection] parameters must not be the same. |
|
5214 ** |
|
5215 ** If an error occurs within sqlite3_backup_init(), then NULL is returned |
|
5216 ** and an error code and error message written into the [database connection] |
|
5217 ** passed as the first argument. They may be retrieved using the |
|
5218 ** [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()] functions. |
|
5219 ** Otherwise, if successful, a pointer to an [sqlite3_backup] object is |
|
5220 ** returned. This pointer may be used with the sqlite3_backup_step() and |
|
5221 ** sqlite3_backup_finish() functions to perform the specified backup |
|
5222 ** operation. |
|
5223 ** |
|
5224 ** <b>sqlite3_backup_step()</b> |
|
5225 ** |
|
5226 ** Function [sqlite3_backup_step()] is used to copy up to nPage pages between |
|
5227 ** the source and destination databases, where nPage is the value of the |
|
5228 ** second parameter passed to sqlite3_backup_step(). If nPage is a negative |
|
5229 ** value, all remaining source pages are copied. If the required pages are |
|
5230 ** succesfully copied, but there are still more pages to copy before the |
|
5231 ** backup is complete, it returns [SQLITE_OK]. If no error occured and there |
|
5232 ** are no more pages to copy, then [SQLITE_DONE] is returned. If an error |
|
5233 ** occurs, then an SQLite error code is returned. As well as [SQLITE_OK] and |
|
5234 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], |
|
5235 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an |
|
5236 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. |
|
5237 ** |
|
5238 ** As well as the case where the destination database file was opened for |
|
5239 ** read-only access, sqlite3_backup_step() may return [SQLITE_READONLY] if |
|
5240 ** the destination is an in-memory database with a different page size |
|
5241 ** from the source database. |
|
5242 ** |
|
5243 ** If sqlite3_backup_step() cannot obtain a required file-system lock, then |
|
5244 ** the [sqlite3_busy_handler | busy-handler function] |
|
5245 ** is invoked (if one is specified). If the |
|
5246 ** busy-handler returns non-zero before the lock is available, then |
|
5247 ** [SQLITE_BUSY] is returned to the caller. In this case the call to |
|
5248 ** sqlite3_backup_step() can be retried later. If the source |
|
5249 ** [database connection] |
|
5250 ** is being used to write to the source database when sqlite3_backup_step() |
|
5251 ** is called, then [SQLITE_LOCKED] is returned immediately. Again, in this |
|
5252 ** case the call to sqlite3_backup_step() can be retried later on. If |
|
5253 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or |
|
5254 ** [SQLITE_READONLY] is returned, then |
|
5255 ** there is no point in retrying the call to sqlite3_backup_step(). These |
|
5256 ** errors are considered fatal. At this point the application must accept |
|
5257 ** that the backup operation has failed and pass the backup operation handle |
|
5258 ** to the sqlite3_backup_finish() to release associated resources. |
|
5259 ** |
|
5260 ** Following the first call to sqlite3_backup_step(), an exclusive lock is |
|
5261 ** obtained on the destination file. It is not released until either |
|
5262 ** sqlite3_backup_finish() is called or the backup operation is complete |
|
5263 ** and sqlite3_backup_step() returns [SQLITE_DONE]. Additionally, each time |
|
5264 ** a call to sqlite3_backup_step() is made a [shared lock] is obtained on |
|
5265 ** the source database file. This lock is released before the |
|
5266 ** sqlite3_backup_step() call returns. Because the source database is not |
|
5267 ** locked between calls to sqlite3_backup_step(), it may be modified mid-way |
|
5268 ** through the backup procedure. If the source database is modified by an |
|
5269 ** external process or via a database connection other than the one being |
|
5270 ** used by the backup operation, then the backup will be transparently |
|
5271 ** restarted by the next call to sqlite3_backup_step(). If the source |
|
5272 ** database is modified by the using the same database connection as is used |
|
5273 ** by the backup operation, then the backup database is transparently |
|
5274 ** updated at the same time. |
|
5275 ** |
|
5276 ** <b>sqlite3_backup_finish()</b> |
|
5277 ** |
|
5278 ** Once sqlite3_backup_step() has returned [SQLITE_DONE], or when the |
|
5279 ** application wishes to abandon the backup operation, the [sqlite3_backup] |
|
5280 ** object should be passed to sqlite3_backup_finish(). This releases all |
|
5281 ** resources associated with the backup operation. If sqlite3_backup_step() |
|
5282 ** has not yet returned [SQLITE_DONE], then any active write-transaction on the |
|
5283 ** destination database is rolled back. The [sqlite3_backup] object is invalid |
|
5284 ** and may not be used following a call to sqlite3_backup_finish(). |
|
5285 ** |
|
5286 ** The value returned by sqlite3_backup_finish is [SQLITE_OK] if no error |
|
5287 ** occurred, regardless or whether or not sqlite3_backup_step() was called |
|
5288 ** a sufficient number of times to complete the backup operation. Or, if |
|
5289 ** an out-of-memory condition or IO error occured during a call to |
|
5290 ** sqlite3_backup_step() then [SQLITE_NOMEM] or an |
|
5291 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] error code |
|
5292 ** is returned. In this case the error code and an error message are |
|
5293 ** written to the destination [database connection]. |
|
5294 ** |
|
5295 ** A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() is |
|
5296 ** not a permanent error and does not affect the return value of |
|
5297 ** sqlite3_backup_finish(). |
|
5298 ** |
|
5299 ** <b>sqlite3_backup_remaining(), sqlite3_backup_pagecount()</b> |
|
5300 ** |
|
5301 ** Each call to sqlite3_backup_step() sets two values stored internally |
|
5302 ** by an [sqlite3_backup] object. The number of pages still to be backed |
|
5303 ** up, which may be queried by sqlite3_backup_remaining(), and the total |
|
5304 ** number of pages in the source database file, which may be queried by |
|
5305 ** sqlite3_backup_pagecount(). |
|
5306 ** |
|
5307 ** The values returned by these functions are only updated by |
|
5308 ** sqlite3_backup_step(). If the source database is modified during a backup |
|
5309 ** operation, then the values are not updated to account for any extra |
|
5310 ** pages that need to be updated or the size of the source database file |
|
5311 ** changing. |
|
5312 ** |
|
5313 ** <b>Concurrent Usage of Database Handles</b> |
|
5314 ** |
|
5315 ** The source [database connection] may be used by the application for other |
|
5316 ** purposes while a backup operation is underway or being initialized. |
|
5317 ** If SQLite is compiled and configured to support threadsafe database |
|
5318 ** connections, then the source database connection may be used concurrently |
|
5319 ** from within other threads. |
|
5320 ** |
|
5321 ** However, the application must guarantee that the destination database |
|
5322 ** connection handle is not passed to any other API (by any thread) after |
|
5323 ** sqlite3_backup_init() is called and before the corresponding call to |
|
5324 ** sqlite3_backup_finish(). Unfortunately SQLite does not currently check |
|
5325 ** for this, if the application does use the destination [database connection] |
|
5326 ** for some other purpose during a backup operation, things may appear to |
|
5327 ** work correctly but in fact be subtly malfunctioning. Use of the |
|
5328 ** destination database connection while a backup is in progress might |
|
5329 ** also cause a mutex deadlock. |
|
5330 ** |
|
5331 ** Furthermore, if running in [shared cache mode], the application must |
|
5332 ** guarantee that the shared cache used by the destination database |
|
5333 ** is not accessed while the backup is running. In practice this means |
|
5334 ** that the application must guarantee that the file-system file being |
|
5335 ** backed up to is not accessed by any connection within the process, |
|
5336 ** not just the specific connection that was passed to sqlite3_backup_init(). |
|
5337 ** |
|
5338 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple |
|
5339 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). |
|
5340 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() |
|
5341 ** APIs are not strictly speaking threadsafe. If they are invoked at the |
|
5342 ** same time as another thread is invoking sqlite3_backup_step() it is |
|
5343 ** possible that they return invalid values. |
|
5344 */ |
|
5345 sqlite3_backup *sqlite3_backup_init( |
|
5346 sqlite3 *pDest, /* Destination database handle */ |
|
5347 const char *zDestName, /* Destination database name */ |
|
5348 sqlite3 *pSource, /* Source database handle */ |
|
5349 const char *zSourceName /* Source database name */ |
|
5350 ); |
|
5351 int sqlite3_backup_step(sqlite3_backup *p, int nPage); |
|
5352 int sqlite3_backup_finish(sqlite3_backup *p); |
|
5353 int sqlite3_backup_remaining(sqlite3_backup *p); |
|
5354 int sqlite3_backup_pagecount(sqlite3_backup *p); |
|
5355 |
|
5356 /* |
|
5357 ** CAPI3REF: Unlock Notification |
|
5358 ** EXPERIMENTAL |
|
5359 ** |
|
5360 ** When running in shared-cache mode, a database operation may fail with |
|
5361 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or |
|
5362 ** individual tables within the shared-cache cannot be obtained. See |
|
5363 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. |
|
5364 ** This API may be used to register a callback that SQLite will invoke |
|
5365 ** when the connection currently holding the required lock relinquishes it. |
|
5366 ** This API is only available if the library was compiled with the |
|
5367 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. |
|
5368 ** |
|
5369 ** See Also: [Using the SQLite Unlock Notification Feature]. |
|
5370 ** |
|
5371 ** Shared-cache locks are released when a database connection concludes |
|
5372 ** its current transaction, either by committing it or rolling it back. |
|
5373 ** |
|
5374 ** When a connection (known as the blocked connection) fails to obtain a |
|
5375 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the |
|
5376 ** identity of the database connection (the blocking connection) that |
|
5377 ** has locked the required resource is stored internally. After an |
|
5378 ** application receives an SQLITE_LOCKED error, it may call the |
|
5379 ** sqlite3_unlock_notify() method with the blocked connection handle as |
|
5380 ** the first argument to register for a callback that will be invoked |
|
5381 ** when the blocking connections current transaction is concluded. The |
|
5382 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] |
|
5383 ** call that concludes the blocking connections transaction. |
|
5384 ** |
|
5385 ** If sqlite3_unlock_notify() is called in a multi-threaded application, |
|
5386 ** there is a chance that the blocking connection will have already |
|
5387 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. |
|
5388 ** If this happens, then the specified callback is invoked immediately, |
|
5389 ** from within the call to sqlite3_unlock_notify(). |
|
5390 ** |
|
5391 ** If the blocked connection is attempting to obtain a write-lock on a |
|
5392 ** shared-cache table, and more than one other connection currently holds |
|
5393 ** a read-lock on the same table, then SQLite arbitrarily selects one of |
|
5394 ** the other connections to use as the blocking connection. |
|
5395 ** |
|
5396 ** There may be at most one unlock-notify callback registered by a |
|
5397 ** blocked connection. If sqlite3_unlock_notify() is called when the |
|
5398 ** blocked connection already has a registered unlock-notify callback, |
|
5399 ** then the new callback replaces the old. If sqlite3_unlock_notify() is |
|
5400 ** called with a NULL pointer as its second argument, then any existing |
|
5401 ** unlock-notify callback is cancelled. The blocked connections |
|
5402 ** unlock-notify callback may also be canceled by closing the blocked |
|
5403 ** connection using [sqlite3_close()]. |
|
5404 ** |
|
5405 ** The unlock-notify callback is not reentrant. If an application invokes |
|
5406 ** any sqlite3_xxx API functions from within an unlock-notify callback, a |
|
5407 ** crash or deadlock may be the result. |
|
5408 ** |
|
5409 ** Unless deadlock is detected (see below), sqlite3_unlock_notify() always |
|
5410 ** returns SQLITE_OK. |
|
5411 ** |
|
5412 ** <b>Callback Invocation Details</b> |
|
5413 ** |
|
5414 ** When an unlock-notify callback is registered, the application provides a |
|
5415 ** single void* pointer that is passed to the callback when it is invoked. |
|
5416 ** However, the signature of the callback function allows SQLite to pass |
|
5417 ** it an array of void* context pointers. The first argument passed to |
|
5418 ** an unlock-notify callback is a pointer to an array of void* pointers, |
|
5419 ** and the second is the number of entries in the array. |
|
5420 ** |
|
5421 ** When a blocking connections transaction is concluded, there may be |
|
5422 ** more than one blocked connection that has registered for an unlock-notify |
|
5423 ** callback. If two or more such blocked connections have specified the |
|
5424 ** same callback function, then instead of invoking the callback function |
|
5425 ** multiple times, it is invoked once with the set of void* context pointers |
|
5426 ** specified by the blocked connections bundled together into an array. |
|
5427 ** This gives the application an opportunity to prioritize any actions |
|
5428 ** related to the set of unblocked database connections. |
|
5429 ** |
|
5430 ** <b>Deadlock Detection</b> |
|
5431 ** |
|
5432 ** Assuming that after registering for an unlock-notify callback a |
|
5433 ** database waits for the callback to be issued before taking any further |
|
5434 ** action (a reasonable assumption), then using this API may cause the |
|
5435 ** application to deadlock. For example, if connection X is waiting for |
|
5436 ** connection Y's transaction to be concluded, and similarly connection |
|
5437 ** Y is waiting on connection X's transaction, then neither connection |
|
5438 ** will proceed and the system may remain deadlocked indefinitely. |
|
5439 ** |
|
5440 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock |
|
5441 ** detection. If a given call to sqlite3_unlock_notify() would put the |
|
5442 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no |
|
5443 ** unlock-notify callback is registered. The system is said to be in |
|
5444 ** a deadlocked state if connection A has registered for an unlock-notify |
|
5445 ** callback on the conclusion of connection B's transaction, and connection |
|
5446 ** B has itself registered for an unlock-notify callback when connection |
|
5447 ** A's transaction is concluded. Indirect deadlock is also detected, so |
|
5448 ** the system is also considered to be deadlocked if connection B has |
|
5449 ** registered for an unlock-notify callback on the conclusion of connection |
|
5450 ** C's transaction, where connection C is waiting on connection A. Any |
|
5451 ** number of levels of indirection are allowed. |
|
5452 ** |
|
5453 ** <b>The "DROP TABLE" Exception</b> |
|
5454 ** |
|
5455 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost |
|
5456 ** always appropriate to call sqlite3_unlock_notify(). There is however, |
|
5457 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, |
|
5458 ** SQLite checks if there are any currently executing SELECT statements |
|
5459 ** that belong to the same connection. If there are, SQLITE_LOCKED is |
|
5460 ** returned. In this case there is no "blocking connection", so invoking |
|
5461 ** sqlite3_unlock_notify() results in the unlock-notify callback being |
|
5462 ** invoked immediately. If the application then re-attempts the "DROP TABLE" |
|
5463 ** or "DROP INDEX" query, an infinite loop might be the result. |
|
5464 ** |
|
5465 ** One way around this problem is to check the extended error code returned |
|
5466 ** by an sqlite3_step() call. If there is a blocking connection, then the |
|
5467 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in |
|
5468 ** the special "DROP TABLE/INDEX" case, the extended error code is just |
|
5469 ** SQLITE_LOCKED. |
|
5470 */ |
|
5471 int sqlite3_unlock_notify( |
|
5472 sqlite3 *pBlocked, /* Waiting connection */ |
|
5473 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ |
|
5474 void *pNotifyArg /* Argument to pass to xNotify */ |
|
5475 ); |
|
5476 |
|
5477 /* |
|
5478 ** Undo the hack that converts floating point types to integer for |
|
5479 ** builds on processors without floating point support. |
|
5480 */ |
|
5481 #ifdef SQLITE_OMIT_FLOATING_POINT |
|
5482 # undef double |
|
5483 #endif |
|
5484 |
|
5485 #ifdef __cplusplus |
|
5486 } /* End of the 'extern "C"' block */ |
|
5487 #endif |
|
5488 #endif |