Tom, Thanks. I found out the key issue it. It's because the truncate command can't have the "cascade". For the other people reference. The right funcitons are : *********************************************************** CREATE OR REPLACE FUNCTION truncate_t (IN tablename text) RETURNS VOID AS $$ BEGIN EXECUTE 'TRUNCATE TABLE ' || quote_ident(tablename) || ';'; EXCEPTION WHEN undefined_table THEN RAISE EXCEPTION 'Table "%" does not exists', tablename; END; $$ LANGUAGE plpgsql SECURITY DEFINER STRICT; *********************************************************** *********************************************************** CREATE OR REPLACE FUNCTION truncate_t (tablename text) RETURNS VOID AS $$ BEGIN EXECUTE 'TRUNCATE TABLE ' || quote_ident(tablename) || ';'; EXCEPTION WHEN undefined_table THEN RAISE EXCEPTION 'Table "%" does not exists', tablename; END; $$ LANGUAGE plpgsql SECURITY DEFINER STRICT; *********************************************************** usage : select truncate_t ('aaa'); Thanks everybody's help. Regards. Grace -- View this message in context: http://postgresql.1045698.n5.nabble.com/Please-help-me-to-take-a-look-of-the-erros-in-my-functions-Thanks-tp5613507p5615529.html Sent from the PostgreSQL - general mailing list archive at Nabble.com. -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general