Trigger for validation of salary updated in emp table is within range

Question

Hi,
I need some help in correcting my fault in the below trigger as it is not working as expected.
. trigger should be invoked if while modifying the  sal in EMP table, it is not in the valid range as specified in the SALGRADE table (between lowest  losal and highest  hisal)
salgrade table
Column Name
Data Type
Nullable
Default
Primary Key
GRADE
NUMBER(2,0)
Yes
LOSAL
NUMBER
Yes
HISAL
NUMBER
Yes
I have created a trigger
create or replace trigger tr_validate_sal
before
insert or update on emp
for each row
declare
cursor c is select losal,hisal from salgrade;
begin
for i in c
loop
if :new.sal < i.losal and :new.sal > i.hisal
then
raise_application_error(-20400,'sal out of range');
end if;
end loop;
end;
after creating this trigger also i am able to insert or update salary not in range of salgrade (losal and hisal). please help.

Answer 1

/* Formatted on 2013/12/24 09:31 (Formatter Plus v4.8.8) */
CREATE OR REPLACE TRIGGER tr_validate_sal
   BEFORE INSERT OR UPDATE
   ON emp1
   FOR EACH ROW
DECLARE
  v_lowsal number;
  v_hisal number;
BEGIN
  SELECT min(losal) losal, max(hisal)
     INTO v_lowsal, v_hisal
        FROM salgrade;
      IF :NEW.sal not between v_lowsal and   v_hisal
      THEN
         raise_application_error (-20400, 'sal out of range');
      END IF;
END;