-- pay_change.sql

CREATE TABLE pay_change_log
(
   id NUMERIC,
   old_amount NUMERIC(9, 2),
   new_amount NUMERIC(9, 2),
   date_changed DATE,
   changed_by VARCHAR(30)
);
CREATE TRIGGER pay_change
   AFTER UPDATE ON employee
   FOR EACH ROW
      INSERT INTO pay_change_log
         (id, old_amount, new_amount, date_changed, changed_by)
      VALUES
          (OLD.id, OLD.pay_amount, NEW.pay_amount, CURDATE(), USER());
