SQLite

**  ------------------------------
**  'a'            TEXT
**  'b'            NONE
**  'c'            NUMERIC
**  'd'            INTEGER
**  'e'            REAL
**
** An extra 'd' is appended to the end of the string to cover the
** rowid that appears as the last column in every index.
**
** Memory for the buffer containing the column index affinity string
** is managed along with the rest of the Index structure. It will be
** released when sqlite3DeleteIndex() is called.
*/
const char *sqlite3IndexAffinityStr(Vdbe *v, Index *pIdx){

    if( !pIdx->zColAff ){
      db->mallocFailed = 1;
      return 0;
    }
    for(n=0; n<pIdx->nColumn; n++){
      pIdx->zColAff[n] = pTab->aCol[pIdx->aiColumn[n]].affinity;
    }
    pIdx->zColAff[n++] = SQLITE_AFF_INTEGER;
    pIdx->zColAff[n] = 0;
  }
 
  return pIdx->zColAff;
}

/*

  if( ALWAYS(pC->pCursor!=0) ){
    assert( pC->deferredMoveto==0 );
    assert( pOp->p5==0 || pOp->p5==1 );
    assert( pOp->p4type==P4_INT32 );
    r.pKeyInfo = pC->pKeyInfo;
    r.nField = (u16)pOp->p4.i;
    if( pOp->p5 ){
      r.flags = UNPACKED_INCRKEY | UNPACKED_PREFIX_MATCH;
    }else{
      r.flags = UNPACKED_PREFIX_MATCH;
    }
    r.aMem = &aMem[pOp->p3];
#ifdef SQLITE_DEBUG
    { int i; for(i=0; i<r.nField; i++) assert( memIsValid(&r.aMem[i]) ); }
#endif
    rc = sqlite3VdbeIdxKeyCompare(pC, &r, &res);
    if( pOp->opcode==OP_IdxLT ){

    return SQLITE_CORRUPT_BKPT;
  }
  memset(&m, 0, sizeof(m));
  rc = sqlite3VdbeMemFromBtree(pC->pCursor, 0, (int)nCellKey, 1, &m);
  if( rc ){
    return rc;
  }
  assert( pUnpacked->flags & UNPACKED_PREFIX_SEARCH );
  *res = sqlite3VdbeRecordCompare(m.n, m.z, pUnpacked);
  sqlite3VdbeMemRelease(&m);
  return SQLITE_OK;
}

/*
** This routine sets the value to be returned by subsequent calls to

  for(; pWC; pWC=pWC->pOuter){
    for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
      if( pTerm->leftCursor==iCur
         && (pTerm->prereqRight & notReady)==0
         && pTerm->u.leftColumn==iColumn
         && (pTerm->eOperator & op)!=0
      ){
        if( iColumn>=0 && pIdx && pTerm->eOperator!=WO_ISNULL ){
          Expr *pX = pTerm->pExpr;
          CollSeq *pColl;
          char idxaff;
          int j;
          Parse *pParse = pWC->pParse;
  
          idxaff = pIdx->pTable->aCol[iColumn].affinity;

        wsFlags |= WHERE_COLUMN_NULL;
      }
#ifdef SQLITE_ENABLE_STAT3
      if( nEq==0 && pProbe->aSample ) pFirstTerm = pTerm;
#endif
      used |= pTerm->prereqRight;
    }
 
    /* If the index being considered is UNIQUE, and there is an equality 
    ** constraint for all columns in the index, then this search will find
    ** at most a single row. In this case set the WHERE_UNIQUE flag to 
    ** indicate this to the caller.
    **
    ** Otherwise, if the search may find more than one row, test to see if
    ** there is a range constraint on indexed column (nEq+1) that can be 
    ** optimized using the index. 
    */
    if( nEq==pProbe->nColumn && pProbe->onError!=OE_None ){
      testcase( wsFlags & WHERE_COLUMN_IN );
      testcase( wsFlags & WHERE_COLUMN_NULL );
      if( (wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
        wsFlags |= WHERE_UNIQUE;
      }
    }else if( pProbe->bUnordered==0 ){
      int j = (nEq==pProbe->nColumn ? -1 : pProbe->aiColumn[nEq]);
      if( findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){
        WhereTerm *pTop = findTerm(pWC, iCur, j, notReady, WO_LT|WO_LE, pIdx);
        WhereTerm *pBtm = findTerm(pWC, iCur, j, notReady, WO_GT|WO_GE, pIdx);
        whereRangeScanEst(pParse, pProbe, nEq, pBtm, pTop, &rangeDiv);
        if( pTop ){
          nBound = 1;
          wsFlags |= WHERE_TOP_LIMIT;
          used |= pTop->prereqRight;
          testcase( pTop->pWC!=pWC );
        }
        if( pBtm ){
          nBound++;
          wsFlags |= WHERE_BTM_LIMIT;
          used |= pBtm->prereqRight;
          testcase( pBtm->pWC!=pWC );
        }
        wsFlags |= (WHERE_COLUMN_RANGE|WHERE_ROWID_RANGE);
      }






    }

    /* If there is an ORDER BY clause and the index being considered will
    ** naturally scan rows in the required order, set the appropriate flags
    ** in wsFlags. Otherwise, if there is an ORDER BY clause but the index
    ** will scan rows in a different order, set the bSort variable.  */
    if( isSortingIndex(

  sqlite3StrAccumAppend(&txt, " (", 2);
  for(i=0; i<nEq; i++){
    explainAppendTerm(&txt, i, aCol[aiColumn[i]].zName, "=");
  }

  j = i;
  if( pPlan->wsFlags&WHERE_BTM_LIMIT ){
    char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName;
    explainAppendTerm(&txt, i++, z, ">");
  }
  if( pPlan->wsFlags&WHERE_TOP_LIMIT ){
    char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName;
    explainAppendTerm(&txt, i, z, "<");
  }
  sqlite3StrAccumAppend(&txt, ")", 1);
  return sqlite3StrAccumFinish(&txt);
}

/*
** This function is a no-op unless currently processing an EXPLAIN QUERY PLAN

    int nExtraReg = 0;           /* Number of extra registers needed */
    int op;                      /* Instruction opcode */
    char *zStartAff;             /* Affinity for start of range constraint */
    char *zEndAff;               /* Affinity for end of range constraint */

    pIdx = pLevel->plan.u.pIdx;
    iIdxCur = pLevel->iIdxCur;
    k = (nEq==pIdx->nColumn ? -1 : pIdx->aiColumn[nEq]);

    /* If this loop satisfies a sort order (pOrderBy) request that 
    ** was passed to this function to implement a "SELECT min(x) ..." 
    ** query, then the caller will only allow the loop to run for
    ** a single iteration. This means that the first row returned
    ** should not have a NULL value stored in 'x'. If column 'x' is
    ** the first one after the nEq equality constraints in the index,

    zEndAff = sqlite3DbStrDup(pParse->db, zStartAff);
    addrNxt = pLevel->addrNxt;

    /* If we are doing a reverse order scan on an ascending index, or
    ** a forward order scan on a descending index, interchange the 
    ** start and end terms (pRangeStart and pRangeEnd).
    */
    if( (nEq<pIdx->nColumn && bRev==(pIdx->aSortOrder[nEq]==SQLITE_SO_ASC))
     || (bRev && pIdx->nColumn==nEq)
    ){
      SWAP(WhereTerm *, pRangeEnd, pRangeStart);
    }

    testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
    testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
    testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
    testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );

# 2011 November 16
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl
set testprefix whereC

do_execsql_test 1.0 {
  CREATE TABLE t1(i INTEGER PRIMARY KEY, a, b INTEGER);

  INSERT INTO t1 VALUES(1, 1, 1);
  INSERT INTO t1 VALUES(2, 1, 1);
  INSERT INTO t1 VALUES(3, 1, 2);
  INSERT INTO t1 VALUES(4, 1, 2);
  INSERT INTO t1 VALUES(5, 1, 2);
  INSERT INTO t1 VALUES(6, 1, 3);
  INSERT INTO t1 VALUES(7, 1, 3);

  INSERT INTO t1 VALUES(8, 2, 1);
  INSERT INTO t1 VALUES(9, 2, 1);
  INSERT INTO t1 VALUES(10, 2, 2);
  INSERT INTO t1 VALUES(11, 2, 2);
  INSERT INTO t1 VALUES(12, 2, 2);
  INSERT INTO t1 VALUES(13, 2, 3);
  INSERT INTO t1 VALUES(14, 2, 3);

  INSERT INTO t1 VALUES(15, 2, 1);
  INSERT INTO t1 VALUES(16, 2, 1);
  INSERT INTO t1 VALUES(17, 2, 2);
  INSERT INTO t1 VALUES(18, 2, 2);
  INSERT INTO t1 VALUES(19, 2, 2);
  INSERT INTO t1 VALUES(20, 2, 3);
  INSERT INTO t1 VALUES(21, 2, 3);

  CREATE INDEX i1 ON t1(a, b);
}

foreach {tn sql res} {
  1   "SELECT i FROM t1 WHERE a=1 AND b=2 AND i>3"         {4 5}
  2   "SELECT i FROM t1 WHERE rowid='12'"                  {12}
  3   "SELECT i FROM t1 WHERE a=1 AND b='2'"               {3 4 5}
  4   "SELECT i FROM t1 WHERE a=1 AND b='2' AND i>'3'"     {4 5}
  5   "SELECT i FROM t1 WHERE a=1 AND b='2' AND i<5"       {3 4}
  6   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i<12"        {10 11}
  7   "SELECT i FROM t1 WHERE a IN(1, 2) AND b=2 AND i<11" {3 4 5 10}
  8   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i BETWEEN 10 AND 12" {10 11 12}
  9   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i BETWEEN 11 AND 12" {11 12}
 10   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i BETWEEN 10 AND 11" {10 11}
 11   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i BETWEEN 12 AND 10" {}
 12   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i<NULL"      {}
 13   "SELECT i FROM t1 WHERE a=2 AND b=2 AND i>=NULL"     {}
 14   "SELECT i FROM t1 WHERE a=1 AND b='2' AND i<4.5"     {3 4}
} {
  do_execsql_test 1.$tn.1 $sql $res
  do_execsql_test 1.$tn.2 "$sql ORDER BY i ASC"  [lsort -integer -inc  $res]
  do_execsql_test 1.$tn.3 "$sql ORDER BY i DESC" [lsort -integer -dec  $res]
}


finish_test