/ Check-in [09834279]
Login

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

Overview
Comment:Move the generation of output column names earlier, to right after name resolution and before query transformations such as flattening. This prevents the names from getting mangled by query transformations, and obviates hacks in the query flattener that attempt to work around the name mangling. The resulting code is smaller and faster and gives more consistent output. This is an alternative fix to ticket [de3403bf5ae5f72ed].
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | early-column-names
Files: files | file ages | folders
SHA3-256:09834279aeca3bda63de684a369ed64f2cbf587b5f5df1454c0a3c009a1337ad
User & Date: drh 2017-07-29 16:01:55
References
2017-07-31
17:40
More consistent column names. Cherry-pick of [09834279] and [0c38dde45] as a fix for ticket [de3403bf5ae]. check-in: be0e24a0 user: drh tags: branch-3.20
13:11
Move the generation of output column names earlier, to right after name resolution and before query transformations such as flattening. This prevents the names from getting mangled by query transformations, and obviates hacks in the query flattener that attempt to work around the name mangling. The resulting code is smaller and faster and gives more consistent output. This is a fix for ticket [de3403bf5ae5f72ed] and a cherry-pick of check-in [09834279aeca3bda] check-in: 499942b3 user: drh tags: branch-3.19
2017-07-29
17:47 Ticket [de3403bf] Column name shift due to LEFT JOIN query flattening status still Open with 6 other changes artifact: 84cc8ca4 user: drh
Context
2017-07-29
17:02
New test cases for column name generation interacting with the query flattener. Closed-Leaf check-in: 0c38dde4 user: drh tags: early-column-names
16:01
Move the generation of output column names earlier, to right after name resolution and before query transformations such as flattening. This prevents the names from getting mangled by query transformations, and obviates hacks in the query flattener that attempt to work around the name mangling. The resulting code is smaller and faster and gives more consistent output. This is an alternative fix to ticket [de3403bf5ae5f72ed]. check-in: 09834279 user: drh tags: early-column-names
2017-07-28
22:22
Update Tcl version used by the TclKit batch tool for MSVC. check-in: bcec155e user: mistachkin tags: trunk
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/select.c.

1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
....
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
....
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607


1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619




1620
1621
1622
1623
1624
1625
1626
....
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639


1640
1641
1642
1643
1644
1645
1646
....
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
....
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
....
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
....
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
....
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
....
5214
5215
5216
5217
5218
5219
5220








5221
5222
5223
5224
5225
5226
5227
....
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
....
6054
6055
6056
6057
6058
6059
6060
6061
6062
6063
6064
6065
6066
6067
6068
6069
6070
6071
6072
6073
6074

      assert( pTab && pExpr->pTab==pTab );
      if( pS ){
        /* The "table" is actually a sub-select or a view in the FROM clause
        ** of the SELECT statement. Return the declaration type and origin
        ** data for the result-set column of the sub-select.
        */
        if( iCol>=0 && ALWAYS(iCol<pS->pEList->nExpr) ){
          /* If iCol is less than zero, then the expression requests the
          ** rowid of the sub-select or view. This expression is legal (see 
          ** test case misc2.2.2) - it always evaluates to NULL.
          **
          ** The ALWAYS() is because iCol>=pS->pEList->nExpr will have been
          ** caught already by name resolution.
          */
          NameContext sNC;
          Expr *p = pS->pEList->a[iCol].pExpr;
          sNC.pSrcList = pS->pSrc;
          sNC.pNext = pNC;
          sNC.pParse = pNC->pParse;
          zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); 
................................................................................
    zType = columnType(&sNC, p, 0, 0, 0, 0);
#endif
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
  }
#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
}

/*
** Return the Table objecct in the SrcList that has cursor iCursor.
** Or return NULL if no such Table object exists in the SrcList.
*/
static Table *tableWithCursor(SrcList *pList, int iCursor){
  int j;
  for(j=0; j<pList->nSrc; j++){
    if( pList->a[j].iCursor==iCursor ) return pList->a[j].pTab;
  }
  return 0;
}


/*
** Compute the column names for a SELECT statement.
**
** The only guarantee that SQLite makes about column names is that if the
** column has an AS clause assigning it a name, that will be the name used.
** That is the only documented guarantee.  However, countless applications
................................................................................
**
**    full=ON, short=ANY:       If the result refers directly to a table column,
**                              then the result column name with the table name
**                              prefix, ex: TABLE.COLUMN.  Otherwise use zSpan.
*/
static void generateColumnNames(
  Parse *pParse,      /* Parser context */
  SrcList *pTabList,  /* The FROM clause of the SELECT */
  ExprList *pEList    /* Expressions defining the result set */
){
  Vdbe *v = pParse->pVdbe;
  int i;
  Table *pTab;


  sqlite3 *db = pParse->db;
  int fullName;      /* TABLE.COLUMN if no AS clause and is a direct table ref */
  int srcName;       /* COLUMN or TABLE.COLUMN if no AS clause and is direct */

#ifndef SQLITE_OMIT_EXPLAIN
  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  if( pParse->colNamesSet || db->mallocFailed ) return;




  assert( v!=0 );
  assert( pTabList!=0 );
  pParse->colNamesSet = 1;
  fullName = (db->flags & SQLITE_FullColNames)!=0;
  srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
................................................................................
    Expr *p = pEList->a[i].pExpr;

    assert( p!=0 );
    if( pEList->a[i].zName ){
      /* An AS clause always takes first priority */
      char *zName = pEList->a[i].zName;
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
    }else if( srcName
           && (p->op==TK_COLUMN || p->op==TK_AGG_COLUMN)
           && (pTab = tableWithCursor(pTabList, p->iTable))!=0
    ){
      char *zCol;
      int iCol = p->iColumn;


      if( iCol<0 ) iCol = pTab->iPKey;
      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
      if( iCol<0 ){
        zCol = "rowid";
      }else{
        zCol = pTab->aCol[iCol].zName;
      }
................................................................................
      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */
      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
      if( dest.eDest!=priorOp ){
        int iCont, iBreak, iStart;
        assert( p->pEList );
        if( dest.eDest==SRT_Output ){
          Select *pFirst = p;
          while( pFirst->pPrior ) pFirst = pFirst->pPrior;
          generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
        }
        iBreak = sqlite3VdbeMakeLabel(v);
        iCont = sqlite3VdbeMakeLabel(v);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
        iStart = sqlite3VdbeCurrentAddr(v);
        selectInnerLoop(pParse, p, p->pEList, unionTab,
                        0, 0, &dest, iCont, iBreak);
................................................................................
      p->pLimit = pLimit;
      p->pOffset = pOffset;

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );
      if( dest.eDest==SRT_Output ){
        Select *pFirst = p;
        while( pFirst->pPrior ) pFirst = pFirst->pPrior;
        generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
      }
      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
      computeLimitRegisters(pParse, p, iBreak);
      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
      r1 = sqlite3GetTempReg(pParse);
      iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
      sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v);
................................................................................
  sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);

  /* Jump to the this point in order to terminate the query.
  */
  sqlite3VdbeResolveLabel(v, labelEnd);

  /* Set the number of output columns
  */
  if( pDest->eDest==SRT_Output ){
    Select *pFirst = pPrior;
    while( pFirst->pPrior ) pFirst = pFirst->pPrior;
    generateColumnNames(pParse, pFirst->pSrc, pFirst->pEList);
  }

  /* Reassembly the compound query so that it will be freed correctly
  ** by the calling function */
  if( p->pPrior ){
    sqlite3SelectDelete(db, p->pPrior);
  }
  p->pPrior = pPrior;
  pPrior->pNext = p;
................................................................................
){
  const char *zSavedAuthContext = pParse->zAuthContext;
  Select *pParent;    /* Current UNION ALL term of the other query */
  Select *pSub;       /* The inner query or "subquery" */
  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
  SrcList *pSrc;      /* The FROM clause of the outer query */
  SrcList *pSubSrc;   /* The FROM clause of the subquery */
  ExprList *pList;    /* The result set of the outer query */
  int iParent;        /* VDBE cursor number of the pSub result set temp table */
  int iNewParent = -1;/* Replacement table for iParent */
  int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    
  int i;              /* Loop counter */
  Expr *pWhere;                    /* The WHERE clause */
  struct SrcList_item *pSubitem;   /* The subquery */
  sqlite3 *db = pParse->db;
................................................................................
    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
    **   \                     \_____________ subquery __________/          /
    **    \_____________________ outer query ______________________________/
    **
    ** We look at every expression in the outer query and every place we see
    ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
    */
    pList = pParent->pEList;
    for(i=0; i<pList->nExpr; i++){
      if( pList->a[i].zName==0 ){
        char *zName = sqlite3DbStrDup(db, pList->a[i].zSpan);
        sqlite3Dequote(zName);
        pList->a[i].zName = zName;
      }
    }
    if( pSub->pOrderBy ){
      /* At this point, any non-zero iOrderByCol values indicate that the
      ** ORDER BY column expression is identical to the iOrderByCol'th
      ** expression returned by SELECT statement pSub. Since these values
      ** do not necessarily correspond to columns in SELECT statement pParent,
      ** zero them before transfering the ORDER BY clause.
      **
................................................................................
  isAgg = (p->selFlags & SF_Aggregate)!=0;
#if SELECTTRACE_ENABLED
  if( sqlite3SelectTrace & 0x100 ){
    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif









  /* Try to flatten subqueries in the FROM clause up into the main query
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];
    Select *pSub = pItem->pSelect;
................................................................................
    if( db->mallocFailed ) goto select_end;
    if( !IgnorableOrderby(pDest) ){
      sSort.pOrderBy = p->pOrderBy;
    }
  }
#endif

  /* Get a pointer the VDBE under construction, allocating a new VDBE if one
  ** does not already exist */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto select_end;

#ifndef SQLITE_OMIT_COMPOUND_SELECT
  /* Handle compound SELECT statements using the separate multiSelect()
  ** procedure.
  */
  if( p->pPrior ){
    rc = multiSelect(pParse, p, pDest);
    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
................................................................................

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  explainSetInteger(pParse->iSelectId, iRestoreSelectId);

  /* Identify column names if results of the SELECT are to be output.
  */
  if( rc==SQLITE_OK && pDest->eDest==SRT_Output ){
    generateColumnNames(pParse, pTabList, pEList);
  }

  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
#if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p,("end processing\n"));
  pParse->nSelectIndent--;
#endif
  return rc;
}







|



<
<
<







 







<
<
<
<
<
<
<
<
<
<
<
<







 







|
<




>
>

|
|









>
>
>
>







 







|
<
<
<


>
>







 







<
<
<
<
<







 







<
<
<
<
<







 







<
<
<
<
<
<
<
<







 







<







 







<
<
<
<
<
<
<
<







 







>
>
>
>
>
>
>
>







 







<
<
<
<
<







 







<
<
<
<
<
<








1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444



1445
1446
1447
1448
1449
1450
1451
....
1547
1548
1549
1550
1551
1552
1553












1554
1555
1556
1557
1558
1559
1560
....
1580
1581
1582
1583
1584
1585
1586
1587

1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
....
1617
1618
1619
1620
1621
1622
1623
1624



1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
....
2453
2454
2455
2456
2457
2458
2459





2460
2461
2462
2463
2464
2465
2466
....
2523
2524
2525
2526
2527
2528
2529





2530
2531
2532
2533
2534
2535
2536
....
3130
3131
3132
3133
3134
3135
3136








3137
3138
3139
3140
3141
3142
3143
....
3424
3425
3426
3427
3428
3429
3430

3431
3432
3433
3434
3435
3436
3437
....
3748
3749
3750
3751
3752
3753
3754








3755
3756
3757
3758
3759
3760
3761
....
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
....
5220
5221
5222
5223
5224
5225
5226





5227
5228
5229
5230
5231
5232
5233
....
6019
6020
6021
6022
6023
6024
6025






6026
6027
6028
6029
6030
6031
6032
6033

      assert( pTab && pExpr->pTab==pTab );
      if( pS ){
        /* The "table" is actually a sub-select or a view in the FROM clause
        ** of the SELECT statement. Return the declaration type and origin
        ** data for the result-set column of the sub-select.
        */
        if( iCol>=0 && iCol<pS->pEList->nExpr ){
          /* If iCol is less than zero, then the expression requests the
          ** rowid of the sub-select or view. This expression is legal (see 
          ** test case misc2.2.2) - it always evaluates to NULL.



          */
          NameContext sNC;
          Expr *p = pS->pEList->a[iCol].pExpr;
          sNC.pSrcList = pS->pSrc;
          sNC.pNext = pNC;
          sNC.pParse = pNC->pParse;
          zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); 
................................................................................
    zType = columnType(&sNC, p, 0, 0, 0, 0);
#endif
    sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT);
  }
#endif /* !defined(SQLITE_OMIT_DECLTYPE) */
}














/*
** Compute the column names for a SELECT statement.
**
** The only guarantee that SQLite makes about column names is that if the
** column has an AS clause assigning it a name, that will be the name used.
** That is the only documented guarantee.  However, countless applications
................................................................................
**
**    full=ON, short=ANY:       If the result refers directly to a table column,
**                              then the result column name with the table name
**                              prefix, ex: TABLE.COLUMN.  Otherwise use zSpan.
*/
static void generateColumnNames(
  Parse *pParse,      /* Parser context */
  Select *pSelect     /* Generate column names for this SELECT statement */

){
  Vdbe *v = pParse->pVdbe;
  int i;
  Table *pTab;
  SrcList *pTabList;
  ExprList *pEList;
  sqlite3 *db = pParse->db;
  int fullName;    /* TABLE.COLUMN if no AS clause and is a direct table ref */
  int srcName;     /* COLUMN or TABLE.COLUMN if no AS clause and is direct */

#ifndef SQLITE_OMIT_EXPLAIN
  /* If this is an EXPLAIN, skip this step */
  if( pParse->explain ){
    return;
  }
#endif

  if( pParse->colNamesSet || db->mallocFailed ) return;
  /* Column names are determined by the left-most term of a compound select */
  while( pSelect->pPrior ) pSelect = pSelect->pPrior;
  pTabList = pSelect->pSrc;
  pEList = pSelect->pEList;
  assert( v!=0 );
  assert( pTabList!=0 );
  pParse->colNamesSet = 1;
  fullName = (db->flags & SQLITE_FullColNames)!=0;
  srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName;
  sqlite3VdbeSetNumCols(v, pEList->nExpr);
  for(i=0; i<pEList->nExpr; i++){
................................................................................
    Expr *p = pEList->a[i].pExpr;

    assert( p!=0 );
    if( pEList->a[i].zName ){
      /* An AS clause always takes first priority */
      char *zName = pEList->a[i].zName;
      sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT);
    }else if( srcName && p->op==TK_COLUMN ){



      char *zCol;
      int iCol = p->iColumn;
      pTab = p->pTab;
      assert( pTab!=0 );
      if( iCol<0 ) iCol = pTab->iPKey;
      assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) );
      if( iCol<0 ){
        zCol = "rowid";
      }else{
        zCol = pTab->aCol[iCol].zName;
      }
................................................................................
      /* Convert the data in the temporary table into whatever form
      ** it is that we currently need.
      */
      assert( unionTab==dest.iSDParm || dest.eDest!=priorOp );
      if( dest.eDest!=priorOp ){
        int iCont, iBreak, iStart;
        assert( p->pEList );





        iBreak = sqlite3VdbeMakeLabel(v);
        iCont = sqlite3VdbeMakeLabel(v);
        computeLimitRegisters(pParse, p, iBreak);
        sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v);
        iStart = sqlite3VdbeCurrentAddr(v);
        selectInnerLoop(pParse, p, p->pEList, unionTab,
                        0, 0, &dest, iCont, iBreak);
................................................................................
      p->pLimit = pLimit;
      p->pOffset = pOffset;

      /* Generate code to take the intersection of the two temporary
      ** tables.
      */
      assert( p->pEList );





      iBreak = sqlite3VdbeMakeLabel(v);
      iCont = sqlite3VdbeMakeLabel(v);
      computeLimitRegisters(pParse, p, iBreak);
      sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v);
      r1 = sqlite3GetTempReg(pParse);
      iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1);
      sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v);
................................................................................
  sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE);
  sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v);

  /* Jump to the this point in order to terminate the query.
  */
  sqlite3VdbeResolveLabel(v, labelEnd);









  /* Reassembly the compound query so that it will be freed correctly
  ** by the calling function */
  if( p->pPrior ){
    sqlite3SelectDelete(db, p->pPrior);
  }
  p->pPrior = pPrior;
  pPrior->pNext = p;
................................................................................
){
  const char *zSavedAuthContext = pParse->zAuthContext;
  Select *pParent;    /* Current UNION ALL term of the other query */
  Select *pSub;       /* The inner query or "subquery" */
  Select *pSub1;      /* Pointer to the rightmost select in sub-query */
  SrcList *pSrc;      /* The FROM clause of the outer query */
  SrcList *pSubSrc;   /* The FROM clause of the subquery */

  int iParent;        /* VDBE cursor number of the pSub result set temp table */
  int iNewParent = -1;/* Replacement table for iParent */
  int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */    
  int i;              /* Loop counter */
  Expr *pWhere;                    /* The WHERE clause */
  struct SrcList_item *pSubitem;   /* The subquery */
  sqlite3 *db = pParse->db;
................................................................................
    **   SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b;
    **   \                     \_____________ subquery __________/          /
    **    \_____________________ outer query ______________________________/
    **
    ** We look at every expression in the outer query and every place we see
    ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10".
    */








    if( pSub->pOrderBy ){
      /* At this point, any non-zero iOrderByCol values indicate that the
      ** ORDER BY column expression is identical to the iOrderByCol'th
      ** expression returned by SELECT statement pSub. Since these values
      ** do not necessarily correspond to columns in SELECT statement pParent,
      ** zero them before transfering the ORDER BY clause.
      **
................................................................................
  isAgg = (p->selFlags & SF_Aggregate)!=0;
#if SELECTTRACE_ENABLED
  if( sqlite3SelectTrace & 0x100 ){
    SELECTTRACE(0x100,pParse,p, ("after name resolution:\n"));
    sqlite3TreeViewSelect(0, p, 0);
  }
#endif

  /* Get a pointer the VDBE under construction, allocating a new VDBE if one
  ** does not already exist */
  v = sqlite3GetVdbe(pParse);
  if( v==0 ) goto select_end;
  if( pDest->eDest==SRT_Output ){
    generateColumnNames(pParse, p);
  }

  /* Try to flatten subqueries in the FROM clause up into the main query
  */
#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW)
  for(i=0; !p->pPrior && i<pTabList->nSrc; i++){
    struct SrcList_item *pItem = &pTabList->a[i];
    Select *pSub = pItem->pSelect;
................................................................................
    if( db->mallocFailed ) goto select_end;
    if( !IgnorableOrderby(pDest) ){
      sSort.pOrderBy = p->pOrderBy;
    }
  }
#endif






#ifndef SQLITE_OMIT_COMPOUND_SELECT
  /* Handle compound SELECT statements using the separate multiSelect()
  ** procedure.
  */
  if( p->pPrior ){
    rc = multiSelect(pParse, p, pDest);
    explainSetInteger(pParse->iSelectId, iRestoreSelectId);
................................................................................

  /* Control jumps to here if an error is encountered above, or upon
  ** successful coding of the SELECT.
  */
select_end:
  explainSetInteger(pParse->iSelectId, iRestoreSelectId);







  sqlite3DbFree(db, sAggInfo.aCol);
  sqlite3DbFree(db, sAggInfo.aFunc);
#if SELECTTRACE_ENABLED
  SELECTTRACE(1,pParse,p,("end processing\n"));
  pParse->nSelectIndent--;
#endif
  return rc;
}