I'm talking about the new SQL function in the newest version of QlikView.
Here is a document talking about it, the function in question is on page 8.
thanks for the document about this interesting new feature.
As I read it, one can only use aggregation functions in the function sql().
"The expression functions that are supported with this initial release are; Sum, Avg, Count, Min, Max." (page 12)
The string in the bracets of sql() seems to be handed down to the database, so the aggregation function in that string must be supported by the underlying db.
In the function no filtering is possible, filtering is done via the explicit attributes defined in the DIRECT SELECT statement.