SQLite

  u16 c;
  assert( allowedOp(op) );
  if( op==TK_IN ){
    c = WO_IN;
  }else if( op==TK_ISNULL ){
    c = WO_ISNULL;
  }else if( op==TK_IS ){
    c = WO_EQ;  /* IS works like ==, just without the IsNull tests */
  }else{
    assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff );
    c = (u16)(WO_EQ<<(op-TK_EQ));
  }
  assert( op!=TK_ISNULL || c==WO_ISNULL );
  assert( op!=TK_IN || c==WO_IN );
  assert( op!=TK_EQ || c==WO_EQ );

      testcase( j==1 );

      /* We have found a candidate table and column.  Check to see if that
      ** table and column is common to every term in the OR clause */
      okToChngToIN = 1;
      for(; i>=0 && okToChngToIN; i--, pOrTerm++){
        assert( pOrTerm->eOperator & WO_EQ );
        testcase( pOrTerm->pExpr->op==TK_IS );
        if( pOrTerm->leftCursor!=iCursor ){
          pOrTerm->wtFlags &= ~TERM_OR_OK;
        }else if( pOrTerm->u.leftColumn!=iColumn ){
          okToChngToIN = 0;
        }else{
          int affLeft, affRight;
          /* If the right-hand side is also a column, then the affinities

      Expr *pNew;            /* The complete IN operator */

      for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){
        if( (pOrTerm->wtFlags & TERM_OR_OK)==0 ) continue;
        assert( pOrTerm->eOperator & WO_EQ );
        assert( pOrTerm->leftCursor==iCursor );
        assert( pOrTerm->u.leftColumn==iColumn );
        testcase( pOrTerm->pExpr->op==TK_IS );
        pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
        pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
        pLeft = pOrTerm->pExpr->pLeft;
      }
      assert( pLeft!=0 );
      pDup = sqlite3ExprDup(db, pLeft, 0);
      pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0, 0);

  char aff;
  if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
  if( (pTerm->eOperator & WO_EQ)==0 ) return 0;
  if( (pTerm->prereqRight & notReady)!=0 ) return 0;
  if( pTerm->u.leftColumn<0 ) return 0;
  aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
  if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
  testcase( pTerm->pExpr->op==TK_IS );
  return 1;
}
#endif


#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
/*

        sqlite3VdbeAddOp2(v, OP_SCopy, r1, regBase+j);
      }
    }
    testcase( pTerm->eOperator & WO_ISNULL );
    testcase( pTerm->eOperator & WO_IN );
    if( (pTerm->eOperator & (WO_ISNULL|WO_IN))==0 ){
      Expr *pRight = pTerm->pExpr->pRight;
      testcase( pTerm->pExpr->op==TK_IS );
      if( (pTerm->wtFlags & TERM_NULLOK)==0
       && sqlite3ExprCanBeNull(pRight)
      ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+j, pLevel->addrBrk);
        VdbeCoverage(v);
      }
      if( zAff ){

    /* Seek the index cursor to the start of the range. */
    nConstraint = nEq;
    if( pRangeStart ){
      Expr *pRight = pRangeStart->pExpr->pRight;
      sqlite3ExprCode(pParse, pRight, regBase+nEq);
      whereLikeOptimizationStringFixup(v, pLevel, pRangeStart);
      testcase( pRangeStart->pExpr->op==TK_IS );
      if( (pRangeStart->wtFlags & TERM_NULLOK)==0
       && sqlite3ExprCanBeNull(pRight)
      ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
        VdbeCoverage(v);
      }
      if( zStartAff ){

    */
    nConstraint = nEq;
    if( pRangeEnd ){
      Expr *pRight = pRangeEnd->pExpr->pRight;
      sqlite3ExprCacheRemove(pParse, regBase+nEq, 1);
      sqlite3ExprCode(pParse, pRight, regBase+nEq);
      whereLikeOptimizationStringFixup(v, pLevel, pRangeEnd);
      testcase( pRangeEnd->pExpr->op==TK_IS );
      if( (pRangeEnd->wtFlags & TERM_NULLOK)==0
       && sqlite3ExprCanBeNull(pRight)
      ){
        sqlite3VdbeAddOp2(v, OP_IsNull, regBase+nEq, addrNxt);
        VdbeCoverage(v);
      }
      if( sqlite3CompareAffinity(pRight, cEndAff)!=SQLITE_AFF_NONE

    if( pLevel->iLeftJoin ) continue;
    pE = pTerm->pExpr;
    assert( !ExprHasProperty(pE, EP_FromJoin) );
    assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
    pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
    if( pAlt==0 ) continue;
    if( pAlt->wtFlags & (TERM_CODED) ) continue;
    testcase( (pAlt->eOperator & WO_EQ)!=0 && pAlt->pExpr->op==TK_IS );
    testcase( pAlt->eOperator & WO_IN );
    VdbeModuleComment((v, "begin transitive constraint"));
    pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
    if( pEAlt ){
      *pEAlt = *pAlt->pExpr;
      pEAlt->pLeft = pE->pLeft;
      sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);

        pLoop->nOut += pTerm->truthProb;
      }else{
        /* In the absence of explicit truth probabilities, use heuristics to
        ** guess a reasonable truth probability. */
        pLoop->nOut--;
        if( pTerm->eOperator&WO_EQ ){
          Expr *pRight = pTerm->pExpr->pRight;
          testcase( pTerm->pExpr->op==TK_IS );
          if( sqlite3ExprIsInteger(pRight, &k) && k>=(-1) && k<=1 ){
            k = 10;
          }else{
            k = 20;
          }
          if( iReduce<k ) iReduce = k;
        }

        if( nInMul==0 
         && pProbe->nSample 
         && pNew->u.btree.nEq<=pProbe->nSampleCol
         && ((eOp & WO_IN)==0 || !ExprHasProperty(pTerm->pExpr, EP_xIsSelect))
        ){
          Expr *pExpr = pTerm->pExpr;
          if( (eOp & (WO_EQ|WO_ISNULL))!=0 ){
            testcase( (eOp & WO_EQ)!=0 && pExpr->op==TK_IS );
            testcase( eOp & WO_ISNULL );
            rc = whereEqualScanEst(pParse, pBuilder, pExpr->pRight, &nOut);
          }else{
            rc = whereInScanEst(pParse, pBuilder, pExpr->x.pList, &nOut);
          }
          if( rc==SQLITE_NOTFOUND ) rc = SQLITE_OK;
          if( rc!=SQLITE_OK ) break;          /* Jump out of the pTerm loop */

        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
        if( !pColl ) pColl = db->pDfltColl;
        z1 = pColl->zName;
        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
        if( !pColl ) pColl = db->pDfltColl;
        z2 = pColl->zName;
        if( sqlite3StrICmp(z1, z2)!=0 ) continue;
        testcase( pTerm->pExpr->op==TK_IS );
      }
      obSat |= MASKBIT(i);
    }

    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
      if( pLoop->wsFlags & WHERE_IPK ){
        pIndex = 0;

       || pIdx->pPartIdxWhere!=0 
       || pIdx->nKeyCol>ArraySize(pLoop->aLTermSpace) 
      ) continue;
      for(j=0; j<pIdx->nKeyCol; j++){
        pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
        if( pTerm==0 ) break;
        pLoop->aLTerm[j] = pTerm;
        testcase( pTerm->pExpr->op==TK_IS );
      }
      if( j!=pIdx->nKeyCol ) continue;
      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
      if( pIdx->isCovering || (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
        pLoop->wsFlags |= WHERE_IDX_ONLY;
      }
      pLoop->nLTerm = j;

# "sqlite_search_count" which tallys the number of executions of MoveTo
# and Next operators in the VDBE.  By verifing that the search count is
# small we can be assured that indices are being used properly.
#
do_test where-1.1.1 {
  count {SELECT x, y, w FROM t1 WHERE w=10}
} {3 121 10 3}
do_test where-1.1.1b {
  count {SELECT x, y, w FROM t1 WHERE w IS 10}
} {3 121 10 3}
do_eqp_test where-1.1.2 {
  SELECT x, y, w FROM t1 WHERE w=10
} {*SEARCH TABLE t1 USING INDEX i1w (w=?)*}
do_eqp_test where-1.1.2b {
  SELECT x, y, w FROM t1 WHERE w IS 10
} {*SEARCH TABLE t1 USING INDEX i1w (w=?)*}
do_test where-1.1.3 {
  db status step
} {0}
do_test where-1.1.4 {
  db eval {SELECT x, y, w FROM t1 WHERE +w=10}
} {3 121 10}
do_test where-1.1.5 {

} {3 144 11 3}
do_test where-1.3.1 {
  count {SELECT x, y, w AS abc FROM t1 WHERE 11=w}
} {3 144 11 3}
do_test where-1.3.2 {
  count {SELECT x, y, w AS abc FROM t1 WHERE 11=abc}
} {3 144 11 3}
do_test where-1.3.3 {
  count {SELECT x, y, w AS abc FROM t1 WHERE 11 IS abc}
} {3 144 11 3}
do_test where-1.4.1 {
  count {SELECT w, x, y FROM t1 WHERE 11=w AND x>2}
} {11 3 144 3}
do_test where-1.4.1b {
  count {SELECT w, x, y FROM t1 WHERE 11 IS w AND x>2}
} {11 3 144 3}
do_eqp_test where-1.4.2 {
  SELECT w, x, y FROM t1 WHERE 11=w AND x>2
} {*SEARCH TABLE t1 USING INDEX i1w (w=?)*}
do_eqp_test where-1.4.2b {
  SELECT w, x, y FROM t1 WHERE 11 IS w AND x>2
} {*SEARCH TABLE t1 USING INDEX i1w (w=?)*}
do_test where-1.4.3 {
  count {SELECT w AS a, x AS b, y FROM t1 WHERE 11=a AND b>2}
} {11 3 144 3}
do_eqp_test where-1.4.4 {
  SELECT w AS a, x AS b, y FROM t1 WHERE 11=a AND b>2
} {*SEARCH TABLE t1 USING INDEX i1w (w=?)*}
do_test where-1.5 {

} {3 144 3}
do_test where-1.10 {
  count {SELECT x, y FROM t1 WHERE x=3 AND w>=10 AND y=121}
} {3 121 3}
do_test where-1.11 {
  count {SELECT x, y FROM t1 WHERE x=3 AND y=100 AND w<10}
} {3 100 3}
do_test where-1.11b {
  count {SELECT x, y FROM t1 WHERE x IS 3 AND y IS 100 AND w<10}
} {3 100 3}

# New for SQLite version 2.1: Verify that that inequality constraints
# are used correctly.
#
do_test where-1.12 {
  count {SELECT w FROM t1 WHERE x=3 AND y<100}
} {8 3}
do_test where-1.12b {
  count {SELECT w FROM t1 WHERE x IS 3 AND y<100}
} {8 3}
do_test where-1.13 {
  count {SELECT w FROM t1 WHERE x=3 AND 100>y}
} {8 3}
do_test where-1.14 {
  count {SELECT w FROM t1 WHERE 3=x AND y<100}
} {8 3}
do_test where-1.14b {
  count {SELECT w FROM t1 WHERE 3 IS x AND y<100}
} {8 3}
do_test where-1.15 {
  count {SELECT w FROM t1 WHERE 3=x AND 100>y}
} {8 3}
do_test where-1.16 {
  count {SELECT w FROM t1 WHERE x=3 AND y<=100}
} {8 9 5}
do_test where-1.17 {
  count {SELECT w FROM t1 WHERE x=3 AND 100>=y}
} {8 9 5}
do_test where-1.18 {
  count {SELECT w FROM t1 WHERE x=3 AND y>225}
} {15 3}
do_test where-1.18b {
  count {SELECT w FROM t1 WHERE x IS 3 AND y>225}
} {15 3}
do_test where-1.19 {
  count {SELECT w FROM t1 WHERE x=3 AND 225<y}
} {15 3}
do_test where-1.20 {
  count {SELECT w FROM t1 WHERE x=3 AND y>=225}
} {14 15 5}
do_test where-1.21 {
  count {SELECT w FROM t1 WHERE x=3 AND 225<=y}
} {14 15 5}
do_test where-1.22 {
  count {SELECT w FROM t1 WHERE x=3 AND y>121 AND y<196}
} {11 12 5}
do_test where-1.22b {
  count {SELECT w FROM t1 WHERE x IS 3 AND y>121 AND y<196}
} {11 12 5}
do_test where-1.23 {
  count {SELECT w FROM t1 WHERE x=3 AND y>=121 AND y<=196}
} {10 11 12 13 9}
do_test where-1.24 {
  count {SELECT w FROM t1 WHERE x=3 AND 121<y AND 196>y}
} {11 12 5}
do_test where-1.25 {