/ Check-in [92724260]
Login
SQLite training in Houston TX on 2019-11-05 (details)
Part of the 2019 Tcl Conference

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

Overview
Comment:Code simplification in sqlite3ColumnsFromExprList(). Update the %z format code so that it works with buffers obtained from sqlite3DbMalloc(). Add a testcase for the slow column name uniquifier.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: 9272426057b6cb2d913519ff4c97aa6e211f7d51
User & Date: drh 2015-11-14 22:04:22
Context
2015-11-15
11:13
Fix the column name uniquifier so that it works with zero-length column names. check-in: 791761eb user: drh tags: trunk
2015-11-14
22:04
Code simplification in sqlite3ColumnsFromExprList(). Update the %z format code so that it works with buffers obtained from sqlite3DbMalloc(). Add a testcase for the slow column name uniquifier. check-in: 92724260 user: drh tags: trunk
20:52
Use a hash table to improve the preformance of column name uniqueness checking. check-in: 5b08f29f user: drh tags: trunk
Changes
Hide Diffs Unified Diffs Show Whitespace Changes Patch

Changes to src/printf.c.

722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
    */
    width -= length;
    if( width>0 && !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
    sqlite3StrAccumAppend(pAccum, bufpt, length);
    if( width>0 && flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');

    if( zExtra ){
      sqlite3_free(zExtra);
      zExtra = 0;
    }
  }/* End for loop over the format string */
} /* End of function */

/*
** Enlarge the memory allocation on a StrAccum object so that it is







|







722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
    */
    width -= length;
    if( width>0 && !flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');
    sqlite3StrAccumAppend(pAccum, bufpt, length);
    if( width>0 && flag_leftjustify ) sqlite3AppendChar(pAccum, width, ' ');

    if( zExtra ){
      sqlite3DbFree(pAccum->db, zExtra);
      zExtra = 0;
    }
  }/* End for loop over the format string */
} /* End of function */

/*
** Enlarge the memory allocation on a StrAccum object so that it is

Changes to src/select.c.

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
1647

1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668

  for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
    if( (zName = pEList->a[i].zName)!=0 ){
      /* If the column contains an "AS <name>" phrase, use <name> as the name */
      zName = sqlite3DbStrDup(db, zName);
    }else{
      Expr *pColExpr = p;  /* The expression that is the result column name */
      Table *pTab;         /* Table associated with this expression */
      while( pColExpr->op==TK_DOT ){
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
      if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){
        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
        pTab = pColExpr->pTab;
        if( iCol<0 ) iCol = pTab->iPKey;
        zName = sqlite3MPrintf(db, "%s",
                 iCol>=0 ? pTab->aCol[iCol].zName : "rowid");
      }else if( pColExpr->op==TK_ID ){
        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
        zName = sqlite3MPrintf(db, "%s", pColExpr->u.zToken);
      }else{
        /* Use the original text of the column expression as its name */
        zName = sqlite3MPrintf(db, "%s", pEList->a[i].zSpan);
      }
    }


    /* Make sure the column name is unique.  If the name is not unique,
    ** append an integer to the name so that it becomes unique.
    */
    cnt = 0;
    while( zName && sqlite3HashFind(&ht, zName)!=0 ){
      char *zNewName;
      nName = sqlite3Strlen30(zName);
      for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}
      if( zName[j]==':' ) nName = j;
      zName[nName] = 0;
      zNewName = sqlite3MPrintf(db, "%s:%u", zName, ++cnt);
      sqlite3DbFree(db, zName);
      zName = zNewName;
      if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
    }
    pCol->zName = zName;
    if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
      db->mallocFailed = 1;
    }
  }







<












<
|


|


|


>






<



<
|
<
<







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
1647
1648
1649
1650
1651
1652

1653
1654
1655

1656


1657
1658
1659
1660
1661
1662
1663

  for(i=0, pCol=aCol; i<nCol && !db->mallocFailed; i++, pCol++){
    /* Get an appropriate name for the column
    */
    p = sqlite3ExprSkipCollate(pEList->a[i].pExpr);
    if( (zName = pEList->a[i].zName)!=0 ){
      /* If the column contains an "AS <name>" phrase, use <name> as the name */

    }else{
      Expr *pColExpr = p;  /* The expression that is the result column name */
      Table *pTab;         /* Table associated with this expression */
      while( pColExpr->op==TK_DOT ){
        pColExpr = pColExpr->pRight;
        assert( pColExpr!=0 );
      }
      if( pColExpr->op==TK_COLUMN && ALWAYS(pColExpr->pTab!=0) ){
        /* For columns use the column name name */
        int iCol = pColExpr->iColumn;
        pTab = pColExpr->pTab;
        if( iCol<0 ) iCol = pTab->iPKey;

        zName = iCol>=0 ? pTab->aCol[iCol].zName : "rowid";
      }else if( pColExpr->op==TK_ID ){
        assert( !ExprHasProperty(pColExpr, EP_IntValue) );
        zName = pColExpr->u.zToken;
      }else{
        /* Use the original text of the column expression as its name */
        zName = pEList->a[i].zSpan;
      }
    }
    zName = sqlite3MPrintf(db, "%s", zName);

    /* Make sure the column name is unique.  If the name is not unique,
    ** append an integer to the name so that it becomes unique.
    */
    cnt = 0;
    while( zName && sqlite3HashFind(&ht, zName)!=0 ){

      nName = sqlite3Strlen30(zName);
      for(j=nName-1; j>0 && sqlite3Isdigit(zName[j]); j--){}
      if( zName[j]==':' ) nName = j;

      zName = sqlite3MPrintf(db, "%.*z:%u", nName, zName, ++cnt);


      if( cnt>3 ) sqlite3_randomness(sizeof(cnt), &cnt);
    }
    pCol->zName = zName;
    if( zName && sqlite3HashInsert(&ht, zName, pCol)==pCol ){
      db->mallocFailed = 1;
    }
  }

Changes to test/misc1.test.

696
697
698
699
700
701
702
703









704

# At one point, running this would read one byte passed the end of a 
# buffer, upsetting valgrind.
#
do_test misc1-24.0 {
  list [catch { sqlite3_prepare_v2 db ! -1 dummy } msg] $msg
} {1 {(1) unrecognized token: "!}}










finish_test








>
>
>
>
>
>
>
>
>

696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713

# At one point, running this would read one byte passed the end of a 
# buffer, upsetting valgrind.
#
do_test misc1-24.0 {
  list [catch { sqlite3_prepare_v2 db ! -1 dummy } msg] $msg
} {1 {(1) unrecognized token: "!}}

# The following query (provided by Kostya Serebryany) used to take 25
# minutes to prepare.  This has been speeded up to about 250 milliseconds.
#
do_catchsql_test misc1-25.0 {
SELECT-1 UNION  SELECT 5 UNION SELECT 0 UNION SElECT*from(SELECT-5) UNION SELECT*from(SELECT-0) UNION  SELECT:SELECT-0 UNION SELECT-1 UNION SELECT 1 UNION SELECT 1 ORDER BY S  in(WITH K AS(WITH K AS(select'CREINDERcharREADEVIRTUL5TABLECONFLICT !1 USIN'' MFtOR(b38q,eWITH K AS(selectCREATe TABLE t0(a,b,c,d,e, PRIMARY KEY(a,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,b,c,d,c,a,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d'CEIl,k'',ab, g, a,b,o11b, i'nEX/charREDE IVT LR!VABLt5SG',N  ,N in rement,l_vacuum,M&U,'te3(''5l' a,bB,b,l*e)SELECT:SELECT, *,*,*from(( SELECT
$group,:conc ap0,1)fro,(select"",:PBAG,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,c,d,c,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d, foreign_keysc,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,c,d,c,a,b,d,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,c,a,b,b,c,d,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,d,c,e,d,d,c,a,b,b,c,c,a,b,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,bb,b,E,d,c,d,c,b,c,d,c,d,c,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,a,b,c,e,d,d,c,a,b,b,c,d,d,c,a,b,c,e,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,c,d,c,a,b,d,d,c,a,a,b,d,d,c,a,b,b,c,d,c,a,b,e,e,d,b,c,d,c,a,b,b,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,c,a,b,c,e,d,d,c,a,b,b,c,d,c,d,c,a,b,c,e,c,d,c,a,b,b,c,d,MAato_aecSELEC,+?b," "O,"i","a",""b  ,5 ))KEY)SELECT*FROM((k()reaC,k,K) eA,k '' )t ,K  M);
} {1 {too many columns in result set}}


finish_test