##触发器示例：

删除触发

create trigger del_deptid after delete on deptmentfor each row begindelete form emp where id=:old.id;end del_dept id;/

插入触发

create or replace trigger insert_a_bafter insert on afor each rowbegininsert into b(id) values('d');end/

更新触发

create or replace trigger update_a_bafter insert on afor each row begininsert into b(id) values( '1');end/

综合案例：

--表create table mylog(curr_user varchar2(100),curr_date date,act char(1));

create or replace trigger mylog_aaafter insert or delete or update on a--for each rowbeginif inserting theninsert into mylog values(user,sysdate,'1');else deleting theninsert into mylog values(user,sysdate,'d');else insert into mylog values(user,sysdate,'u');end;/

create or replace trigger mylog_aaafter insert or delete or update on a--for each rowbegininsert into mylog values(user,sysdate,'1');end;/