5.38.txt

delphi renyuanguanlixinxioxitong

CREATE OR REPLACE TRIGGER tr_emp_sal 
BEFORE UPDATE OF sal ON employee  FOR EACH ROW
BEGIN
  IF :new.sal<:old.sal THEN
     raise_application_error(-20010,'工资只涨不降');
  END IF;
END tr_emp_sal;
/
update employee set sal=800 where employeeno='1990-003';