Solution is already provided, but I am wondering about the reason why this won't work.

Could it have something to do with the 'problem' in the 'SQL POP Quiz' thread?

The AccountNO...

Maybe a different approach...

Suppose an error occurs in the 'Update' statement in your procedure. In that case you return an empty recordset from the procedure.

So I am wondering if maybe...

Not sure this is a solution for your problem, but I'll give it a go anyway.

You could try to convert the quantities in the Trades table to the quantity taking...

Got a solution, provided you have some sort of incremental column in the table (like an identity). If that's not the case, I guess a cursor is the easiest solution.

First...