public override object InternalExecute(Program program)
{
object leftValue = Nodes[0].Execute(program);
object rightValue = Nodes[1].Execute(program);
#if NILPROPOGATION
if ((leftValue == null) || (rightValue == null))
{
return(null);
}
#endif
if (_comparisonNode != null)
{
program.Stack.PushWindow(0);
try
{
program.Stack.Push(leftValue);
try
{
program.Stack.Push(rightValue);
try
{
return(_comparisonNode.Execute(program));
}
finally
{
program.Stack.Pop();
}
}
finally
{
program.Stack.Pop();
}
}
finally
{
program.Stack.PopWindow();
}
}
else
{
RowEqualNode node = new RowEqualNode();
node.Nodes.Add(new ValueNode(((IRow)leftValue).DataType, leftValue));
node.Nodes.Add(new ValueNode(((IRow)rightValue).DataType, rightValue));
node.DetermineDataType(program.Plan);
return(node.Execute(program));
}
}
protected bool IsSuperset(Program program, ITable leftTable, ITable rightTable)
{
Row leftRow = new Row(program.ValueManager, LeftTableNode.DataType.RowType);
try
{
Row rightRow = new Row(program.ValueManager, RightTableNode.DataType.RowType);
try
{
if (rightTable.Supports(CursorCapability.BackwardsNavigable))
{
rightTable.First();
}
else
{
rightTable.Reset();
}
while (rightTable.Next())
{
rightTable.Select(rightRow);
bool hasRow = false;
if (leftTable.Supports(CursorCapability.BackwardsNavigable))
{
leftTable.First();
}
else
{
leftTable.Reset();
}
while (leftTable.Next())
{
leftTable.Select(leftRow);
program.Stack.PushWindow(0);
try
{
program.Stack.Push(leftRow);
try
{
program.Stack.Push(rightRow);
try
{
object result = RowEqualNode.Execute(program);
if ((result != null) && (bool)result)
{
hasRow = true;
break;
}
}
finally
{
program.Stack.Pop();
}
}
finally
{
program.Stack.Pop();
}
}
finally
{
program.Stack.PopWindow();
}
}
if (!hasRow)
{
return(false);
}
}
return(true);
}
finally
{
rightRow.Dispose();
}
}
finally
{
leftRow.Dispose();
}
}