Вывести сообщение с применением триггеров

CREATE OR REPLACE FUNCTION sertificate()
RETURNS TRIGGER
AS $$DECLARE
rec record; 
BEGIN
SELECT INTO rec *
FROM student, exams WHERE id_student = NEW.student
AND exam_type IN ('ВТ', 'ВВ', 'ГТ', 'ГВ') AND (passed IN ('Да'));
IF NOT found THEN
RAISE EXCEPTION 'Студента с таким id не существует!';
ELSE
RAISE NOTICE 'Результат успешно изменен!';
RETURN NEW;
END IF;  
END;
$$ LANGUAGE 'plpgsql';
 
DROP TRIGGER IF EXISTS tr_sertificate ON exams;
CREATE TRIGGER tr_sertificate BEFORE UPDATE OF student ON exams
FOR EACH ROW EXECUTE PROCEDURE sertificate();
--
UPDATE exams SET passed = 'Да' WHERE id_exam = 20;

CREATE OR REPLACE FUNCTION sertificate()
RETURNS TRIGGER
AS $$DECLARE
rec record; 
BEGIN
SELECT INTO rec *
FROM exams WHERE id_exam = NEW.passed
AND student = 10
AND exam_type IN ('ВТ', 'ВВ', 'ГТ', 'ГВ') AND (passed IN ('Да'));
IF NOT found THEN
RAISE EXCEPTION 'Несуществующий ID --> %', id_exam;
ELSE
RAISE NOTICE 'Все экзамены сданы. Студент может получить водительское удостоверение';
RETURN NEW;
END IF;  
END;
$$ LANGUAGE 'plpgsql';
 
DROP TRIGGER IF EXISTS tr_sertificate ON exams;
CREATE TRIGGER tr_sertificate BEFORE UPDATE OF student ON exams
FOR EACH ROW EXECUTE PROCEDURE sertificate();
 
UPDATE exams SET passed = 'Нет' WHERE id_exam = 20;