pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    if( pLoop->prereq==0
     && (pTerm->wtFlags & TERM_VIRTUAL)==0

     && sqlite3ExprIsTableConstant(pTerm->pExpr, pSrc->iCursor) ){
      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
                                sqlite3ExprDup(pParse->db, pTerm->pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol = pTerm->u.leftColumn;
      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
................................................................................
/* Check to see if a partial index with pPartIndexWhere can be used
** in the current query.  Return true if it can be and false if not.
*/
static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){
  int i;
  WhereTerm *pTerm;
  for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( sqlite3ExprImpliesExpr(pTerm->pExpr, pWhere, iTab) ) return 1;




  }
  return 0;
}

/*
** Add all WhereLoop objects for a single table of the join where the table
** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be

  pTable = pSrc->pTab;
  pWCEnd = &pWC->a[pWC->nTerm];
  pLoop = pLevel->pWLoop;
  idxCols = 0;
  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
    if( pLoop->prereq==0
     && (pTerm->wtFlags & TERM_VIRTUAL)==0
     && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
     && sqlite3ExprIsTableConstant(pTerm->pExpr, pSrc->iCursor) ){
      pPartial = sqlite3ExprAnd(pParse->db, pPartial,
                                sqlite3ExprDup(pParse->db, pTerm->pExpr, 0));
    }
    if( termCanDriveIndex(pTerm, pSrc, notReady) ){
      int iCol = pTerm->u.leftColumn;
      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
................................................................................
/* Check to see if a partial index with pPartIndexWhere can be used
** in the current query.  Return true if it can be and false if not.
*/
static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){
  int i;
  WhereTerm *pTerm;
  for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
    if( sqlite3ExprImpliesExpr(pTerm->pExpr, pWhere, iTab)
     && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
    ){
      return 1;
    }
  }
  return 0;
}

/*
** Add all WhereLoop objects for a single table of the join where the table
** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be

  CREATE TABLE t3(e,f);
  INSERT INTO t3 VALUES(123,654),(555,444),(234,987);

  SELECT (SELECT count(*) FROM t1, t2 WHERE a=e AND x=f), e, f, '|'
    FROM t3
   ORDER BY rowid;
} {1 123 654 | 0 555 444 | 4 234 987 |}
































finish_test

  CREATE TABLE t3(e,f);
  INSERT INTO t3 VALUES(123,654),(555,444),(234,987);

  SELECT (SELECT count(*) FROM t1, t2 WHERE a=e AND x=f), e, f, '|'
    FROM t3
   ORDER BY rowid;
} {1 123 654 | 0 555 444 | 4 234 987 |}

# Ticket [2326c258d02ead33d]
# Two joins, one with and the other without an ORDER BY clause.
# The one without ORDER BY correctly returns two rows of result.
# The one with ORDER BY returns no rows. 
#
do_execsql_test autoindex4-3.0 {
  CREATE TABLE A(Name text);
  CREATE TABLE Items(ItemName text , Name text);
  INSERT INTO Items VALUES('Item1','Parent');
  INSERT INTO Items VALUES('Item2','Parent');
  CREATE TABLE B(Name text);
  
  SELECT Items.ItemName
    FROM Items
      LEFT JOIN A ON (A.Name = Items.ItemName and Items.ItemName = 'dummy')
      LEFT JOIN B ON (B.Name = Items.ItemName)
    WHERE Items.Name = 'Parent'
    ORDER BY Items.ItemName;
} {Item1 Item2}
do_execsql_test autoindex4-3.1 {
  CREATE INDEX Items_x1 ON Items(ItemName,Name) WHERE ItemName = 'dummy';
  
  SELECT Items.ItemName
    FROM Items
      LEFT JOIN A ON (A.Name = Items.ItemName and Items.ItemName = 'dummy')
      LEFT JOIN B ON (B.Name = Items.ItemName)
    WHERE Items.Name = 'Parent'
    ORDER BY Items.ItemName;
} {Item1 Item2}


finish_test

  UPDATE OR REPLACE t6 SET b=789;
  SELECT * FROM t6;
} {123 789}
do_execsql_test index6-6.2 {
  PRAGMA integrity_check;
} {ok}






























finish_test

  UPDATE OR REPLACE t6 SET b=789;
  SELECT * FROM t6;
} {123 789}
do_execsql_test index6-6.2 {
  PRAGMA integrity_check;
} {ok}

# Test case for ticket [2326c258d02ead33d69faa63de8f4686b9b1b9d9] on
# 2015-02-24.  Any use of a partial index qualifying constraint inside
# the ON clause of a LEFT JOIN was causing incorrect results for all
# versions of SQLite 3.8.0 through 3.8.8.
#
do_execsql_test index6-7.0 {
  CREATE TABLE t7a(x);
  CREATE TABLE t7b(y);
  INSERT INTO t7a(x) VALUES(1);
  CREATE INDEX t7ax ON t7a(x) WHERE x=99;
  PRAGMA automatic_index=OFF;
  SELECT * FROM t7a LEFT JOIN t7b ON (x=99) ORDER BY x;
} {1 {}}
do_execsql_test index6-7.1 {
  INSERT INTO t7b(y) VALUES(2);
  SELECT * FROM t7a JOIN t7b ON (x=99) ORDER BY x;
} {}
do_execsql_test index6-7.2 {
  INSERT INTO t7a(x) VALUES(99);
  SELECT * FROM t7a LEFT JOIN t7b ON (x=99) ORDER BY x;
} {1 {} 99 2}
do_execsql_test index6-7.3 {
  SELECT * FROM t7a JOIN t7b ON (x=99) ORDER BY x;
} {99 2}
do_execsql_test index6-7.4 {
  EXPLAIN QUERY PLAN
  SELECT * FROM t7a JOIN t7b ON (x=99) ORDER BY x;
} {/USING COVERING INDEX t7ax/}

finish_test