SQLite

Check-in [7344e791b9]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Better resolution of table and column names in joins where some of the terms of the FROM clause are parenthesized.
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | name-resolution-fix
Files: files | file ages | folders
SHA1: 7344e791b9456286ecdca6d45f2f5260fb3f10e2
User & Date: drh 2012-12-19 02:36:45.854
Context
2012-12-19
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
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
Unified Diff Ignore Whitespace Patch
Changes to src/resolve.c.
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
  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;
        int iDb;
        Column *pCol;
  
        pTab = pItem->pTab;
        assert( pTab!=0 && pTab->zName!=0 );
        iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
        assert( pTab->nCol>0 );
        if( zTab ){


          if( pItem->zAlias ){
            char *zTabName = pItem->zAlias;


            if( sqlite3StrICmp(zTabName, zTab)!=0 ) continue;
          }else{
            char *zTabName = pTab->zName;
            if( NEVER(zTabName==0) || sqlite3StrICmp(zTabName, zTab)!=0 ){






              continue;
            }



            if( zDb!=0 && sqlite3StrICmp(db->aDb[iDb].zName, zDb)!=0 ){
              continue;
            }
          }
        }
        if( 0==(cntTab++) ){
          pExpr->iTable = pItem->iCursor;
          pExpr->pTab = pTab;
          pSchema = pTab->pSchema;
          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++;
            pExpr->iTable = pItem->iCursor;
            pExpr->pTab = pTab;
            pMatch = pItem;
            pSchema = pTab->pSchema;
            /* Substitute the rowid (column -1) for the INTEGER PRIMARY KEY */
            pExpr->iColumn = j==pTab->iPKey ? -1 : (i16)j;
            break;
          }
        }
      }




    }


#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;







>
>
>
>
>
>
>
>
>
>
>
>
>
>









<




<

|
>
>
|
|
>
>
|
<
<
|
>
>
>
>
>
>
|
|
>
>
>
|
|
|
|
<

<
<
<













<
<

<






>
>
>
>
|
>







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;
Changes to src/select.c.
3388
3389
3390
3391
3392
3393
3394
3395

3396
3397
3398
3399
3400
3401
3402
    ** 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;


    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.
        */







|
>







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.
        */
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{