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Overview
Comment: | Modify the sqlite3_stmt_readonly() interface so that it returns false for CREATE TABLE IF NOT EXISTS statements even if the table already exists and the statement is really a read-only no-op. Likewise for DROP TABLE, CREATE INDEX, and DROP INDEX. Update the documentation for sqlite3_stmt_readonly() to reflect this new behavior. |
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cf8eb465974e596a13df56f3efbc98e0 |
User & Date: | drh 2021-05-13 18:24:22.567 |
Context
2021-05-14
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13:32 | Fix an over-length source code comment in whereexpr.c. No logic changes. (check-in: af5eb902e7 user: drh tags: trunk) | |
2021-05-13
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18:24 | Modify the sqlite3_stmt_readonly() interface so that it returns false for CREATE TABLE IF NOT EXISTS statements even if the table already exists and the statement is really a read-only no-op. Likewise for DROP TABLE, CREATE INDEX, and DROP INDEX. Update the documentation for sqlite3_stmt_readonly() to reflect this new behavior. (check-in: cf8eb46597 user: drh tags: trunk) | |
13:43 | The content columns of the index-btree that implements a WITHOUT ROWID table are not ordered and so the query planner should not assume they are ordered. Fix for the issue identified by forum post 6c8960f545. (check-in: c21bc5a235 user: drh tags: trunk) | |
Changes
Changes to src/build.c.
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1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 | return pTab->nNVCol + i - n; }else{ /* iCol is a normal or stored column */ return n; } } #endif /* ** Begin constructing a new table representation in memory. This is ** the first of several action routines that get called in response ** to a CREATE TABLE statement. In particular, this routine is called ** after seeing tokens "CREATE" and "TABLE" and the table name. The isTemp ** flag is true if the table should be stored in the auxiliary database | > > > > > > > > > > > > > > > > | 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 | return pTab->nNVCol + i - n; }else{ /* iCol is a normal or stored column */ return n; } } #endif /* ** Insert a single OP_JournalMode query opcode in order to force the ** prepared statement to return false for sqlite3_stmt_readonly(). This ** is used by CREATE TABLE IF NOT EXISTS and similar if the table already ** exists, so that the prepared statement for CREATE TABLE IF NOT EXISTS ** will return false for sqlite3_stmt_readonly() even if that statement ** is a read-only no-op. */ static void sqlite3ForceNotReadOnly(Parse *pParse){ int iReg = ++pParse->nMem; Vdbe *v = sqlite3GetVdbe(pParse); if( v ){ sqlite3VdbeAddOp3(v, OP_JournalMode, 0, iReg, PAGER_JOURNALMODE_QUERY); } } /* ** Begin constructing a new table representation in memory. This is ** the first of several action routines that get called in response ** to a CREATE TABLE statement. In particular, this routine is called ** after seeing tokens "CREATE" and "TABLE" and the table name. The isTemp ** flag is true if the table should be stored in the auxiliary database |
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1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 | pTable = sqlite3FindTable(db, zName, zDb); if( pTable ){ if( !noErr ){ sqlite3ErrorMsg(pParse, "table %T already exists", pName); }else{ assert( !db->init.busy || CORRUPT_DB ); sqlite3CodeVerifySchema(pParse, iDb); } goto begin_table_error; } if( sqlite3FindIndex(db, zName, zDb)!=0 ){ sqlite3ErrorMsg(pParse, "there is already an index named %s", zName); goto begin_table_error; } | > | 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 | pTable = sqlite3FindTable(db, zName, zDb); if( pTable ){ if( !noErr ){ sqlite3ErrorMsg(pParse, "table %T already exists", pName); }else{ assert( !db->init.busy || CORRUPT_DB ); sqlite3CodeVerifySchema(pParse, iDb); sqlite3ForceNotReadOnly(pParse); } goto begin_table_error; } if( sqlite3FindIndex(db, zName, zDb)!=0 ){ sqlite3ErrorMsg(pParse, "there is already an index named %s", zName); goto begin_table_error; } |
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3193 3194 3195 3196 3197 3198 3199 | if( sqlite3ReadSchema(pParse) ) goto exit_drop_table; if( noErr ) db->suppressErr++; assert( isView==0 || isView==LOCATE_VIEW ); pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]); if( noErr ) db->suppressErr--; if( pTab==0 ){ | > | > > | 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 | if( sqlite3ReadSchema(pParse) ) goto exit_drop_table; if( noErr ) db->suppressErr++; assert( isView==0 || isView==LOCATE_VIEW ); pTab = sqlite3LocateTableItem(pParse, isView, &pName->a[0]); if( noErr ) db->suppressErr--; if( pTab==0 ){ if( noErr ){ sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase); sqlite3ForceNotReadOnly(pParse); } goto exit_drop_table; } iDb = sqlite3SchemaToIndex(db, pTab->pSchema); assert( iDb>=0 && iDb<db->nDb ); /* If pTab is a virtual table, call ViewGetColumnNames() to ensure ** it is initialized. |
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3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 | } if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){ if( !ifNotExist ){ sqlite3ErrorMsg(pParse, "index %s already exists", zName); }else{ assert( !db->init.busy ); sqlite3CodeVerifySchema(pParse, iDb); } goto exit_create_index; } } }else{ int n; Index *pLoop; | > | 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 | } if( sqlite3FindIndex(db, zName, pDb->zDbSName)!=0 ){ if( !ifNotExist ){ sqlite3ErrorMsg(pParse, "index %s already exists", zName); }else{ assert( !db->init.busy ); sqlite3CodeVerifySchema(pParse, iDb); sqlite3ForceNotReadOnly(pParse); } goto exit_create_index; } } }else{ int n; Index *pLoop; |
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4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294 | } pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase); if( pIndex==0 ){ if( !ifExists ){ sqlite3ErrorMsg(pParse, "no such index: %S", pName->a); }else{ sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase); } pParse->checkSchema = 1; goto exit_drop_index; } if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){ sqlite3ErrorMsg(pParse, "index associated with UNIQUE " "or PRIMARY KEY constraint cannot be dropped", 0); | > | 4302 4303 4304 4305 4306 4307 4308 4309 4310 4311 4312 4313 4314 4315 4316 | } pIndex = sqlite3FindIndex(db, pName->a[0].zName, pName->a[0].zDatabase); if( pIndex==0 ){ if( !ifExists ){ sqlite3ErrorMsg(pParse, "no such index: %S", pName->a); }else{ sqlite3CodeVerifyNamedSchema(pParse, pName->a[0].zDatabase); sqlite3ForceNotReadOnly(pParse); } pParse->checkSchema = 1; goto exit_drop_index; } if( pIndex->idxType!=SQLITE_IDXTYPE_APPDEF ){ sqlite3ErrorMsg(pParse, "index associated with UNIQUE " "or PRIMARY KEY constraint cannot be dropped", 0); |
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Changes to src/sqlite.h.in.
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4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 | ** sqlite3_stmt_readonly() to return true since, while those statements ** change the configuration of a database connection, they do not make ** changes to the content of the database files on disk. ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so ** sqlite3_stmt_readonly() returns false for those commands. */ int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); /* ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement ** METHOD: sqlite3_stmt ** | > > > > > > > > > | 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 | ** sqlite3_stmt_readonly() to return true since, while those statements ** change the configuration of a database connection, they do not make ** changes to the content of the database files on disk. ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so ** sqlite3_stmt_readonly() returns false for those commands. ** ** ^This routine returns false if there is any possibility that the ** statement might change the database file. ^A false return does ** not guarantee that the statement will change the database file. ** ^For example, an UPDATE statement might have a WHERE clause that ** makes it a no-op, but the sqlite3_stmt_readonly() result would still ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a ** read-only no-op if the table already exists, but ** sqlite3_stmt_readonly() still returns false for such a statement. */ int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); /* ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement ** METHOD: sqlite3_stmt ** |
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