create or replace trigger tri_alert
before delete or insert or update on emp for each row
declare
 v_empno emp.empno%type;
begin
 v_empno := :old.empno;
 dbms_output.put_line('?????ú￡o'||v_empno);
end tri_alert;

create or replace trigger tri_rollback
after delete or insert or update on emp for each row
declare
 v_empno emp.empno%type;
 v_ename emp.ename%type;
 v_job emp.job%type;
 v_mgr emp.mgr%type;
 v_sal emp.sal%type;
 v_comm emp.comm%type;
 v_deptno emp.edeptno%type;
begin
 v_empno := :old.empno;
 v_ename := :old.ename;
 v_job := :old.job;
 v_mgr := :old.mgr;
 v_sal := :old.sal;
 v_comm := :old.comm;
 v_deptno := :old.deptno;
 insert into emp values(v_empno,v_ename,v_job,v_mgr,v_sal,v_comm,v_deptno);
 dbms_output.put_line('??1?'||v_empno||'DDêy?Y');
 
end tri_rollback;