oracle sql tigger

create or replace trigger triger_test

before

update on dept

for each row

begin

dbms_output.put_line('변경 전 컬럼 값:'|| :old.dname);

dbms_output.put_line('변경 후 컬럼 값:'|| :new.dname);

end;

/

update dept set dname='총무부' where deptno='30';

create or replace trigger check_delete

before delete on emp

begin

if to_char(sysdate,'DY') in ('목','금') then

raise_application_error(-20007,'목,금요일은 안됨');

end if;

end;

/

delete from emp;

select to_char(sysdate,'DY') from dual

create or replace trigger sum_trigger

before

insert or update on emp

for each row

declare

avg_sal number;

begin

select round(avg(sal),3)

into avg_sal

from emp;

dbms_output.put_line('급여평균:'|| avg_sal);

end;

/

insert into emp(empno,ename,sal,hiredate,deptno) values(1001,'KIM',3000,sysdate,30);

create or replace trigger emp_sal_chk

before insert or update of sal on emp

for each row

begin

if :new.job='CLERK' and :new.sal > 2000 then

raise_application_error(-20002,'너무 높음');

end if;

end;

/

update emp set sal=sal+2000 where empno=7369;

update emp set sal=sal+2000 where empno=7876;