예제 #1
0
        // requires: caseForOuterJoins corresponds the slot "slotNum"
        // effects: Adds a WhenThen corresponding to child to caseForOuterJoins.
        private void AddCaseForOuterJoins(CaseStatement caseForOuterJoins, CqlBlock child, int slotNum, CqlIdentifiers identifiers)
        {
            // Determine the cells that the slot comes from
            // and make an OR expression, e.g., WHEN _from0 or _from2 or ... THEN child[slotNum]

            var childSlot    = child.SlotValue(slotNum);
            var constantSlot = childSlot as ConstantProjectedSlot;

            if (constantSlot != null &&
                constantSlot.CellConstant.IsNull())
            {
                // NULL being generated by a child - don't need to project
                return;
            }

            var originBool = BoolExpression.False;

            for (var i = 0; i < NumBoolSlots; i++)
            {
                var boolSlotNum = BoolIndexToSlot(i);
                if (child.IsProjected(boolSlotNum))
                {
                    // OR it to the expression
                    var boolExpr = new QualifiedCellIdBoolean(child, identifiers, i);
                    originBool = BoolExpression.CreateOr(originBool, BoolExpression.CreateLiteral(boolExpr, RightDomainMap));
                }
            }
            // Qualify the slotNum with the child.CqlAlias for the THEN
            var slot = child.QualifySlotWithBlockAlias(slotNum);

            caseForOuterJoins.AddWhenThen(originBool, slot);
        }
        private void AddCaseForOuterJoins(
            CaseStatement caseForOuterJoins,
            CqlBlock child,
            int slotNum,
            CqlIdentifiers identifiers)
        {
            ConstantProjectedSlot constantProjectedSlot = child.SlotValue(slotNum) as ConstantProjectedSlot;

            if (constantProjectedSlot != null && constantProjectedSlot.CellConstant.IsNull())
            {
                return;
            }
            BoolExpression or = BoolExpression.False;

            for (int index = 0; index < this.NumBoolSlots; ++index)
            {
                int slot = this.BoolIndexToSlot(index);
                if (child.IsProjected(slot))
                {
                    QualifiedCellIdBoolean qualifiedCellIdBoolean = new QualifiedCellIdBoolean(child, identifiers, index);
                    or = BoolExpression.CreateOr(or, BoolExpression.CreateLiteral((BoolLiteral)qualifiedCellIdBoolean, this.RightDomainMap));
                }
            }
            QualifiedSlot qualifiedSlot = child.QualifySlotWithBlockAlias(slotNum);

            caseForOuterJoins.AddWhenThen(or, (ProjectedSlot)qualifiedSlot);
        }