public override IdSet GetIdSet( TableExpression te )
{
if ( Lhs is ExpName && Rhs.IsConstant() )
{
ExpName e = (ExpName)Lhs;
if ( e.ColName == "Id" ) // select ... from t where id in ( .... )
{
return Rhs.ListIdSet();
}
IndexFile ix = te.FindIndex( e.ColIx );
if ( ix != null ) // select ... from t where indexedcol in ( .... )
{
return new Lookup( ix, Rhs ); // For each value in the Rhs list, lookup it's ids, and return them in the IdSet.
}
}
return null;
}
public override IdSet GetIdSet( TableExpression te )
{
if ( Operator <= Token.Equal && Right.IsConstant() && Left is ExpName )
{
ExpName e = ((ExpName)Left);
if ( e.ColName == "Id" && Operator == Token.Equal ) return new SingleId( Right );
IndexFile ix = te.FindIndex( e.ColIx );
if ( ix != null ) return new IndexFrom( ix, Right, Operator );
}
else if ( Operator <= Token.Equal && Left.IsConstant() && Right is ExpName )
{
ExpName e = ((ExpName)Right);
if ( e.ColName == "Id" && Operator == Token.Equal ) return new SingleId( Left );
IndexFile ix = te.FindIndex( e.ColIx );
if ( ix != null ) return new IndexFrom( ix, Left, TokenInfo.Reflect( Operator ) );
}
else if ( Operator == Token.And )
{
var left = Left.GetIdSet( te ); if ( left != null ) return left;
var right = Right.GetIdSet( te ); if ( right != null ) return right;
}
return null;
}