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Overview
Comment: | Better resolution of table and column names in joins where some of the terms of the FROM clause are parenthesized. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | name-resolution-fix |
Files: | files | file ages | folders |
SHA1: |
7344e791b9456286ecdca6d45f2f5260 |
User & Date: | drh 2012-12-19 02:36:45.854 |
Context
2012-12-19
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13:41 | Add commentary to the ExprList object to explain how zSpan is overloaded. Add test cases for the new name resolution functionality. (check-in: 3e7d84db78 user: drh tags: name-resolution-fix) | |
02:36 | Better resolution of table and column names in joins where some of the terms of the FROM clause are parenthesized. (check-in: 7344e791b9 user: drh tags: name-resolution-fix) | |
2012-12-18
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19:36 | Optimize the degenerate case of a FROM clause table name enclosed all by itself inside parentheses. Generate code as if the parentheses did not exist, rather than the old behavior of manifesting the parenthesized table into a transient table. Also, tag every FROM-clause SELECT subquery that is generated by a parenthesized FROM-clause expression using the SF_NestedFrom flag. The new SF_NestedFrom flag is not yet used for anything. (check-in: 7fecced466 user: drh tags: trunk) | |
Changes
Changes to src/resolve.c.
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201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 | assert( zCol ); /* The Z in X.Y.Z cannot be NULL */ assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) ); /* Initialize the node to no-match */ pExpr->iTable = -1; pExpr->pTab = 0; ExprSetIrreducible(pExpr); /* Start at the inner-most context and move outward until a match is found */ while( pNC && cnt==0 ){ ExprList *pEList; SrcList *pSrcList = pNC->pSrcList; if( pSrcList ){ for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ Table *pTab; | > > > > > > > > > > > > > > < < | > > | | > > | < < | > > > > > > | | > > > | | | | < < < < < < < > > > > | > | 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 | assert( zCol ); /* The Z in X.Y.Z cannot be NULL */ assert( !ExprHasAnyProperty(pExpr, EP_TokenOnly|EP_Reduced) ); /* Initialize the node to no-match */ pExpr->iTable = -1; pExpr->pTab = 0; ExprSetIrreducible(pExpr); /* Translate the schema name in zDb into a pointer to the corresponding ** schema. If not found, pSchema will remain NULL and nothing will match ** resulting in an appropriate error message toward the end of this routine */ if( zDb ){ for(i=0; i<db->nDb; i++){ assert( db->aDb[i].zName ); if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){ pSchema = db->aDb[i].pSchema; break; } } } /* Start at the inner-most context and move outward until a match is found */ while( pNC && cnt==0 ){ ExprList *pEList; SrcList *pSrcList = pNC->pSrcList; if( pSrcList ){ for(i=0, pItem=pSrcList->a; i<pSrcList->nSrc; i++, pItem++){ Table *pTab; Column *pCol; pTab = pItem->pTab; assert( pTab!=0 && pTab->zName!=0 ); assert( pTab->nCol>0 ); if( zDb && pTab->pSchema!=pSchema ){ continue; } if( pItem->pSelect && (pItem->pSelect->selFlags & SF_NestedFrom)!=0 ){ ExprList *pEList = pItem->pSelect->pEList; int hit = 0; for(j=0; j<pEList->nExpr; j++){ if( zTab && sqlite3StrICmp(pEList->a[j].zSpan, zTab)!=0 ) continue; if( sqlite3StrICmp(pEList->a[j].zName, zCol)==0 ){ cnt++; cntTab = 2; pMatch = pItem; pExpr->iColumn = j; } } if( hit || zTab==0 ) continue; } if( zTab ){ const char *zTabName = pItem->zAlias ? pItem->zAlias : pTab->zName; assert( zTabName!=0 ); if( sqlite3StrICmp(zTabName, zTab)!=0 ){ continue; } } if( 0==(cntTab++) ){ pMatch = pItem; } for(j=0, pCol=pTab->aCol; j<pTab->nCol; j++, pCol++){ if( sqlite3StrICmp(pCol->zName, zCol)==0 ){ /* If there has been exactly one prior match and this match ** is for the right-hand table of a NATURAL JOIN or is in a ** USING clause, then skip this match. */ if( cnt==1 ){ if( pItem->jointype & JT_NATURAL ) continue; if( nameInUsingClause(pItem->pUsing, zCol) ) continue; } cnt++; pMatch = pItem; /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */ pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j; break; } } } if( pMatch ){ pExpr->iTable = pMatch->iCursor; pExpr->pTab = pMatch->pTab; pSchema = pExpr->pTab->pSchema; } } /* if( pSrcList ) */ #ifndef SQLITE_OMIT_TRIGGER /* If we have not already resolved the name, then maybe ** it is a new.* or old.* trigger argument reference */ if( zDb==0 && zTab!=0 && cnt==0 && pParse->pTriggerTab!=0 ){ int op = pParse->eTriggerOp; |
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Changes to src/select.c.
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3388 3389 3390 3391 3392 3393 3394 | ** operators that need to be expanded. Loop through each expression ** in the result set and expand them one by one. */ struct ExprList_item *a = pEList->a; ExprList *pNew = 0; int flags = pParse->db->flags; int longNames = (flags & SQLITE_FullColNames)!=0 | | > | 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 | ** operators that need to be expanded. Loop through each expression ** in the result set and expand them one by one. */ struct ExprList_item *a = pEList->a; ExprList *pNew = 0; int flags = pParse->db->flags; int longNames = (flags & SQLITE_FullColNames)!=0 && (flags & SQLITE_ShortColNames)==0 && (p->selFlags & SF_NestedFrom)==0; for(k=0; k<pEList->nExpr; k++){ Expr *pE = a[k].pExpr; assert( pE->op!=TK_DOT || pE->pRight!=0 ); if( pE->op!=TK_ALL && (pE->op!=TK_DOT || pE->pRight->op!=TK_ALL) ){ /* This particular expression does not need to be expanded. */ |
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3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 | }else{ pExpr = pRight; } pNew = sqlite3ExprListAppend(pParse, pNew, pExpr); sColname.z = zColname; sColname.n = sqlite3Strlen30(zColname); sqlite3ExprListSetName(pParse, pNew, &sColname, 0); sqlite3DbFree(db, zToFree); } } if( !tableSeen ){ if( zTName ){ sqlite3ErrorMsg(pParse, "no such table: %s", zTName); }else{ | > > > | 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 | }else{ pExpr = pRight; } pNew = sqlite3ExprListAppend(pParse, pNew, pExpr); sColname.z = zColname; sColname.n = sqlite3Strlen30(zColname); sqlite3ExprListSetName(pParse, pNew, &sColname, 0); if( pNew && (p->selFlags & SF_NestedFrom)!=0 ){ pNew->a[pNew->nExpr-1].zSpan = sqlite3DbStrDup(db, zTabName); } sqlite3DbFree(db, zToFree); } } if( !tableSeen ){ if( zTName ){ sqlite3ErrorMsg(pParse, "no such table: %s", zTName); }else{ |
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