Help with how to use a user defined function in Universal Server

Say I have a user defined function like create function f() returning int; let rid = select rowid from .....; return rid; end function; Ok, the function does some sort of query, and returns a row id for the row that is found. Now, I'd like to use it like so maybe: select * from tbl where rowid = f(); This isn't good because f is invoked for each row in tbl. So, how to do it. The SPL would be something like execute function f() into rid; select * from tbl where rowid=rid; But is there no magic SQL select syntax that would get this done in one statement? Obviously, I'm pretty new to SQL3 and the idea of extended user types and functions. So far, I am not finding the Informix manuals to be particularly well written or organized, so any quality book references would be very much appreciated as well. Thanks. ============================================================ Roger S. Reynolds email: rsr@rogerware.com rsr@softix.com Web: http://www.rogerware.com