How can I fix this "SQL Statement ignored" error?
CREATE OR REPLACE FUNCTION f_query_01 RETURN NUMBERISBEGIN DECLARE c_query_number NUMBER DEFAULT NULL; start_time DATE DEFAULT NULL; end_time DATE DEFAULT NULL; time_diff NUMBER DEFAULT NULL; BEGIN SELECT CAST (SYSTIMESTAMP AS DATE) INTO start_time FROM DUAL; SELECT COUNT (*) INTO c_query_number FROM ws; SELECT CAST (SYSTIMESTAMP AS DATE) INTO end_time FROM DUAL; time_diff := start_time - end_time; RETURN time_diff; END;END f_query_01;