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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 ** An tokenizer for SQL |
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13 ** |
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14 ** This file contains C code that implements the sqlite3_complete() API. |
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15 ** This code used to be part of the tokenizer.c source file. But by |
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16 ** separating it out, the code will be automatically omitted from |
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17 ** static links that do not use it. |
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18 ** |
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19 ** $Id: complete.c,v 1.7 2008/06/13 18:24:27 drh Exp $ |
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20 */ |
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21 #include "sqliteInt.h" |
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22 #ifndef SQLITE_OMIT_COMPLETE |
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23 |
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24 /* |
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25 ** This is defined in tokenize.c. We just have to import the definition. |
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26 */ |
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27 #ifndef SQLITE_AMALGAMATION |
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28 #ifdef SQLITE_ASCII |
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29 extern const char sqlite3IsAsciiIdChar[]; |
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30 #define IdChar(C) (((c=C)&0x80)!=0 || (c>0x1f && sqlite3IsAsciiIdChar[c-0x20])) |
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31 #endif |
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32 #ifdef SQLITE_EBCDIC |
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33 extern const char sqlite3IsEbcdicIdChar[]; |
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34 #define IdChar(C) (((c=C)>=0x42 && sqlite3IsEbcdicIdChar[c-0x40])) |
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35 #endif |
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36 #endif /* SQLITE_AMALGAMATION */ |
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37 |
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38 |
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39 /* |
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40 ** Token types used by the sqlite3_complete() routine. See the header |
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41 ** comments on that procedure for additional information. |
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42 */ |
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43 #define tkSEMI 0 |
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44 #define tkWS 1 |
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45 #define tkOTHER 2 |
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46 #define tkEXPLAIN 3 |
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47 #define tkCREATE 4 |
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48 #define tkTEMP 5 |
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49 #define tkTRIGGER 6 |
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50 #define tkEND 7 |
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51 |
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52 /* |
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53 ** Return TRUE if the given SQL string ends in a semicolon. |
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54 ** |
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55 ** Special handling is require for CREATE TRIGGER statements. |
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56 ** Whenever the CREATE TRIGGER keywords are seen, the statement |
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57 ** must end with ";END;". |
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58 ** |
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59 ** This implementation uses a state machine with 7 states: |
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60 ** |
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61 ** (0) START At the beginning or end of an SQL statement. This routine |
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62 ** returns 1 if it ends in the START state and 0 if it ends |
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63 ** in any other state. |
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64 ** |
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65 ** (1) NORMAL We are in the middle of statement which ends with a single |
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66 ** semicolon. |
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67 ** |
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68 ** (2) EXPLAIN The keyword EXPLAIN has been seen at the beginning of |
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69 ** a statement. |
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70 ** |
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71 ** (3) CREATE The keyword CREATE has been seen at the beginning of a |
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72 ** statement, possibly preceeded by EXPLAIN and/or followed by |
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73 ** TEMP or TEMPORARY |
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74 ** |
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75 ** (4) TRIGGER We are in the middle of a trigger definition that must be |
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76 ** ended by a semicolon, the keyword END, and another semicolon. |
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77 ** |
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78 ** (5) SEMI We've seen the first semicolon in the ";END;" that occurs at |
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79 ** the end of a trigger definition. |
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80 ** |
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81 ** (6) END We've seen the ";END" of the ";END;" that occurs at the end |
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82 ** of a trigger difinition. |
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83 ** |
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84 ** Transitions between states above are determined by tokens extracted |
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85 ** from the input. The following tokens are significant: |
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86 ** |
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87 ** (0) tkSEMI A semicolon. |
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88 ** (1) tkWS Whitespace |
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89 ** (2) tkOTHER Any other SQL token. |
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90 ** (3) tkEXPLAIN The "explain" keyword. |
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91 ** (4) tkCREATE The "create" keyword. |
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92 ** (5) tkTEMP The "temp" or "temporary" keyword. |
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93 ** (6) tkTRIGGER The "trigger" keyword. |
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94 ** (7) tkEND The "end" keyword. |
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95 ** |
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96 ** Whitespace never causes a state transition and is always ignored. |
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97 ** |
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98 ** If we compile with SQLITE_OMIT_TRIGGER, all of the computation needed |
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99 ** to recognize the end of a trigger can be omitted. All we have to do |
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100 ** is look for a semicolon that is not part of an string or comment. |
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101 */ |
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102 int sqlite3_complete(const char *zSql){ |
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103 u8 state = 0; /* Current state, using numbers defined in header comment */ |
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104 u8 token; /* Value of the next token */ |
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105 |
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106 #ifndef SQLITE_OMIT_TRIGGER |
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107 /* A complex statement machine used to detect the end of a CREATE TRIGGER |
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108 ** statement. This is the normal case. |
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109 */ |
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110 static const u8 trans[7][8] = { |
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111 /* Token: */ |
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112 /* State: ** SEMI WS OTHER EXPLAIN CREATE TEMP TRIGGER END */ |
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113 /* 0 START: */ { 0, 0, 1, 2, 3, 1, 1, 1, }, |
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114 /* 1 NORMAL: */ { 0, 1, 1, 1, 1, 1, 1, 1, }, |
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115 /* 2 EXPLAIN: */ { 0, 2, 1, 1, 3, 1, 1, 1, }, |
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116 /* 3 CREATE: */ { 0, 3, 1, 1, 1, 3, 4, 1, }, |
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117 /* 4 TRIGGER: */ { 5, 4, 4, 4, 4, 4, 4, 4, }, |
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118 /* 5 SEMI: */ { 5, 5, 4, 4, 4, 4, 4, 6, }, |
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119 /* 6 END: */ { 0, 6, 4, 4, 4, 4, 4, 4, }, |
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120 }; |
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121 #else |
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122 /* If triggers are not suppored by this compile then the statement machine |
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123 ** used to detect the end of a statement is much simplier |
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124 */ |
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125 static const u8 trans[2][3] = { |
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126 /* Token: */ |
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127 /* State: ** SEMI WS OTHER */ |
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128 /* 0 START: */ { 0, 0, 1, }, |
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129 /* 1 NORMAL: */ { 0, 1, 1, }, |
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130 }; |
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131 #endif /* SQLITE_OMIT_TRIGGER */ |
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132 |
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133 while( *zSql ){ |
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134 switch( *zSql ){ |
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135 case ';': { /* A semicolon */ |
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136 token = tkSEMI; |
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137 break; |
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138 } |
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139 case ' ': |
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140 case '\r': |
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141 case '\t': |
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142 case '\n': |
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143 case '\f': { /* White space is ignored */ |
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144 token = tkWS; |
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145 break; |
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146 } |
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147 case '/': { /* C-style comments */ |
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148 if( zSql[1]!='*' ){ |
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149 token = tkOTHER; |
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150 break; |
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151 } |
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152 zSql += 2; |
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153 while( zSql[0] && (zSql[0]!='*' || zSql[1]!='/') ){ zSql++; } |
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154 if( zSql[0]==0 ) return 0; |
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155 zSql++; |
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156 token = tkWS; |
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157 break; |
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158 } |
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159 case '-': { /* SQL-style comments from "--" to end of line */ |
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160 if( zSql[1]!='-' ){ |
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161 token = tkOTHER; |
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162 break; |
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163 } |
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164 while( *zSql && *zSql!='\n' ){ zSql++; } |
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165 if( *zSql==0 ) return state==0; |
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166 token = tkWS; |
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167 break; |
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168 } |
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169 case '[': { /* Microsoft-style identifiers in [...] */ |
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170 zSql++; |
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171 while( *zSql && *zSql!=']' ){ zSql++; } |
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172 if( *zSql==0 ) return 0; |
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173 token = tkOTHER; |
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174 break; |
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175 } |
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176 case '`': /* Grave-accent quoted symbols used by MySQL */ |
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177 case '"': /* single- and double-quoted strings */ |
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178 case '\'': { |
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179 int c = *zSql; |
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180 zSql++; |
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181 while( *zSql && *zSql!=c ){ zSql++; } |
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182 if( *zSql==0 ) return 0; |
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183 token = tkOTHER; |
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184 break; |
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185 } |
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186 default: { |
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187 int c; |
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188 if( IdChar((u8)*zSql) ){ |
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189 /* Keywords and unquoted identifiers */ |
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190 int nId; |
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191 for(nId=1; IdChar(zSql[nId]); nId++){} |
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192 #ifdef SQLITE_OMIT_TRIGGER |
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193 token = tkOTHER; |
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194 #else |
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195 switch( *zSql ){ |
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196 case 'c': case 'C': { |
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197 if( nId==6 && sqlite3StrNICmp(zSql, "create", 6)==0 ){ |
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198 token = tkCREATE; |
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199 }else{ |
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200 token = tkOTHER; |
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201 } |
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202 break; |
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203 } |
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204 case 't': case 'T': { |
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205 if( nId==7 && sqlite3StrNICmp(zSql, "trigger", 7)==0 ){ |
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206 token = tkTRIGGER; |
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207 }else if( nId==4 && sqlite3StrNICmp(zSql, "temp", 4)==0 ){ |
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208 token = tkTEMP; |
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209 }else if( nId==9 && sqlite3StrNICmp(zSql, "temporary", 9)==0 ){ |
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210 token = tkTEMP; |
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211 }else{ |
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212 token = tkOTHER; |
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213 } |
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214 break; |
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215 } |
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216 case 'e': case 'E': { |
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217 if( nId==3 && sqlite3StrNICmp(zSql, "end", 3)==0 ){ |
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218 token = tkEND; |
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219 }else |
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220 #ifndef SQLITE_OMIT_EXPLAIN |
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221 if( nId==7 && sqlite3StrNICmp(zSql, "explain", 7)==0 ){ |
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222 token = tkEXPLAIN; |
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223 }else |
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224 #endif |
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225 { |
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226 token = tkOTHER; |
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227 } |
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228 break; |
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229 } |
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230 default: { |
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231 token = tkOTHER; |
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232 break; |
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233 } |
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234 } |
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235 #endif /* SQLITE_OMIT_TRIGGER */ |
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236 zSql += nId-1; |
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237 }else{ |
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238 /* Operators and special symbols */ |
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239 token = tkOTHER; |
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240 } |
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241 break; |
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242 } |
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243 } |
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244 state = trans[state][token]; |
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245 zSql++; |
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246 } |
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247 return state==0; |
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248 } |
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249 |
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250 #ifndef SQLITE_OMIT_UTF16 |
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251 /* |
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252 ** This routine is the same as the sqlite3_complete() routine described |
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253 ** above, except that the parameter is required to be UTF-16 encoded, not |
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254 ** UTF-8. |
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255 */ |
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256 int sqlite3_complete16(const void *zSql){ |
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257 sqlite3_value *pVal; |
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258 char const *zSql8; |
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259 int rc = SQLITE_NOMEM; |
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260 |
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261 #ifndef SQLITE_OMIT_AUTOINIT |
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262 rc = sqlite3_initialize(); |
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263 if( rc ) return rc; |
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264 #endif |
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265 pVal = sqlite3ValueNew(0); |
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266 sqlite3ValueSetStr(pVal, -1, zSql, SQLITE_UTF16NATIVE, SQLITE_STATIC); |
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267 zSql8 = sqlite3ValueText(pVal, SQLITE_UTF8); |
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268 if( zSql8 ){ |
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269 rc = sqlite3_complete(zSql8); |
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270 }else{ |
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271 rc = SQLITE_NOMEM; |
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272 } |
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273 sqlite3ValueFree(pVal); |
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274 return sqlite3ApiExit(0, rc); |
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275 } |
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276 #endif /* SQLITE_OMIT_UTF16 */ |
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277 #endif /* SQLITE_OMIT_COMPLETE */ |