Oracle 触发器

 
create table emp2_log(
 uname varchar2(20),
 action varchar(10),
 atime date
);
create or replace trigger trig
   after insert or delete or update on emp2 for each row  //绑在一张表上,before after 都可
以,before是 插数据之前，after是之后
begin
   if inserting then
       insert into emp2_log values(USER,'insert',sysdate);
   elsif updating then
       insert into emp2_log values(USER,'update',sysdate);
   elsif deleting then
       insert into emp2_log values(USER,'delete',sysdate);
   end if;
end;
----------------
create or replace trigger trig
   after  update on emp2 for each row
begin
  update emp set deptno=:NEW.deptno where deptno=:OLD.deptno;  //  对有外键约束进行设置
end;