SQLite

    /* If X is the column in the index and ORDER BY clause, check to see
    ** if there are any X= or X IS NULL constraints in the WHERE clause. */
    pConstraint = findTerm(p->pWC, base, iColumn, p->notReady,
                           WO_EQ|WO_ISNULL|WO_IN, pIdx);
    if( pConstraint==0 ){
      isEq = 0;
    }else if( (pConstraint->eOperator & WO_IN)!=0 ){
#if 0
      /* Constraints of the form: "X IN ..." cannot be used with an ORDER BY
      ** because we do not know in what order the values on the RHS of the IN
      ** operator will occur. */
      break;
#else
      if( termSortOrder ) break;
      isEq = 0;
#endif
    }else if( (pConstraint->eOperator & WO_ISNULL)!=0 ){
      uniqueNotNull = 0;
      isEq = 1;  /* "X IS NULL" means X has only a single value */
    }else if( pConstraint->prereqRight==0 ){
      isEq = 1;  /* Constraint "X=constant" means X has only a single value */
    }else{
      Expr *pRight = pConstraint->pExpr->pRight;

 
    /* 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 (pc.plan.nEq+1) that
    ** can be optimized using the index. 
    */
    if( pc.plan.nEq==pProbe->nColumn && pProbe->onError!=OE_None ){
      testcase( pc.plan.wsFlags & WHERE_COLUMN_IN );
      testcase( pc.plan.wsFlags & WHERE_COLUMN_NULL );
      if( (pc.plan.wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
        pc.plan.wsFlags |= WHERE_UNIQUE;
        if( p->i==0 || (p->aLevel[p->i-1].plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){

    }
  } {1 0 4 2 1 9 3 1 16 4}
  do_test where-5.2 {
    count {
      SELECT * FROM t1 WHERE rowid+0 IN (1,2,3,1234) order by 1;
    }
  } {1 0 4 2 1 9 3 1 16 102}
  do_test where-5.3a {
    count {
      SELECT * FROM t1 WHERE w IN (-1,1,2,3) order by 1;
    }
  } {1 0 4 2 1 9 3 1 16 13}
  do_test where-5.3b {
    count {
      SELECT * FROM t1 WHERE w IN (3,-1,1,2) order by 1;
    }
  } {1 0 4 2 1 9 3 1 16 13}
  do_test where-5.3c {
    count {
      SELECT * FROM t1 WHERE w IN (3,2,-1,1,2) order by 1;
    }
  } {1 0 4 2 1 9 3 1 16 13}
  do_test where-5.3d {
    count {
      SELECT * FROM t1 WHERE w IN (-1,1,2,3) order by 1 DESC;
    }
  } {3 1 16 2 1 9 1 0 4 14}
  do_test where-5.4 {
    count {
      SELECT * FROM t1 WHERE w+0 IN (-1,1,2,3) order by 1;
    }
  } {1 0 4 2 1 9 3 1 16 102}
  do_test where-5.5 {
    count {

} {1 100 4 2 99 9 3 98 16 nosort}
do_test where-6.7 {
  cksort {
    SELECT * FROM t3 WHERE b>0 ORDER BY a LIMIT 3
  }
} {1 100 4 2 99 9 3 98 16 nosort}
ifcapable subquery {
  do_test where-6.8a {
    cksort {
      SELECT * FROM t3 WHERE a IN (3,5,7,1,9,4,2) ORDER BY a LIMIT 3
    }
  } {1 100 4 2 99 9 3 98 16 nosort}
  do_test where-6.8b {
    cksort {
      SELECT * FROM t3 WHERE a IN (3,5,7,1,9,4,2) ORDER BY a DESC LIMIT 3
    }
  } {9 92 100 7 94 64 5 96 36 sort}
}
do_test where-6.9.1 {
  cksort {
    SELECT * FROM t3 WHERE a=1 AND c>0 ORDER BY a LIMIT 3
  }
} {1 100 4 nosort}
do_test where-6.9.1.1 {

        SELECT * FROM t1 WHERE z IN (SELECT 10207 UNION SELECT 10006)
                         AND y IN (SELECT 10000 UNION SELECT 10201)
                         AND x>0 AND x<10
        ORDER BY w
      }
    } {99 6 10000 10006 100 6 10201 10207 sort t1 i1zyx}
  }
  do_test where2-4.6a {
    queryplan {
      SELECT * FROM t1
       WHERE x IN (1,2,3,4,5,6,7,8)
         AND y IN (10000,10001,10002,10003,10004,10005)
       ORDER BY x
    }
  } {99 6 10000 10006 nosort t1 i1xy}
  do_test where2-4.6b {
    queryplan {
      SELECT * FROM t1
       WHERE x IN (1,2,3,4,5,6,7,8)
         AND y IN (10000,10001,10002,10003,10004,10005)
       ORDER BY x DESC
    }
  } {99 6 10000 10006 sort t1 i1xy}
  do_test where2-4.6c {
    queryplan {
      SELECT * FROM t1
       WHERE x IN (1,2,3,4,5,6,7,8)
         AND y IN (10000,10001,10002,10003,10004,10005)
       ORDER BY x, y
    }
  } {99 6 10000 10006 nosort t1 i1xy}
  do_test where2-4.6d {
    queryplan {
      SELECT * FROM t1
       WHERE x IN (1,2,3,4,5,6,7,8)
         AND y IN (10000,10001,10002,10003,10004,10005)
       ORDER BY x, y DESC
    }
  } {99 6 10000 10006 sort t1 i1xy}

  # Duplicate entires on the RHS of an IN operator do not cause duplicate
  # output rows.
  #
  do_test where2-4.6x {
    queryplan {
      SELECT * FROM t1 WHERE z IN (10207,10006,10006,10207)
      ORDER BY w
    }
  } {99 6 10000 10006 100 6 10201 10207 sort t1 i1zyx}
  do_test where2-4.6y {
    queryplan {
      SELECT * FROM t1 WHERE z IN (10207,10006,10006,10207)
      ORDER BY w DESC
    }
  } {100 6 10201 10207 99 6 10000 10006 sort t1 i1zyx}
  ifcapable compound {
    do_test where2-4.7 {
      queryplan {
        SELECT * FROM t1 WHERE z IN (
           SELECT 10207 UNION ALL SELECT 10006
           UNION ALL SELECT 10006 UNION ALL SELECT 10207)
        ORDER BY w

do_test where2-5.1 {
  queryplan {
    SELECT * FROM t1 WHERE w=99 ORDER BY w
  }
} {99 6 10000 10006 nosort t1 i1w}

ifcapable subquery {
  do_test where2-5.2a {
    queryplan {
      SELECT * FROM t1 WHERE w IN (99) ORDER BY w
    }
  } {99 6 10000 10006 nosort t1 i1w}
  do_test where2-5.2b {
    queryplan {
      SELECT * FROM t1 WHERE w IN (99) ORDER BY w DESC
    }
  } {99 6 10000 10006 sort t1 i1w}
}

# Verify that OR clauses get translated into IN operators.
#
set ::idx {}
ifcapable subquery {set ::idx i1w}