For Oracle, Sybase and Informix, setting SQLWARN0 to "W" triggers the SQLWARNING clause.
Oracle
When no data is returned from a SELECT or FETCH statement, the condition NOT FOUND is triggered, regardless of the setting of the Oracle precompiler directive MODE.
Informix
Informix allows you to perform a STOP or a CALL from within a WHENEVER statement. These are additions to the ANSI standard and are documented in the Informix ESQL/COBOL programmers manual.