trigger_emp_dept.txt

orale培训教材包括了所有的sql说明和实例

CREATE OR REPLACE TRIGGER cascade_updates
  AFTER UPDATE OF deptno on emp
  FOR EACH ROW
   BEGIN
   	DBMS_OUTPUT.PUT_LINE('TRIGGER FILRE');
 	UPDATE dept
 	SET    dept.deptno = :new.deptno
	WHERE  dept.deptno = :old.deptno;
   END;


UPDATE emp SET    deptno = 20
WHERE  deptno = 30;

UPDATE emp SET    deptno = 2
WHERE  deptno = 30;