create trigger wyzwalacz on employees
AFTER UPDATE
AS
BEGIN
DECLARE @id_managera_old int;
DECLARE @id_managera_new int;
select @id_managera_old = delted.mnaager_id form deleted;
select @id_managera_new = inserted.mnaager_id form inserted;
IF (@id_managera_old <>  id_managera_new)
BEGIN
 UPDATE Employees SET salary = salary - 0.10*salary from where employee_id = id_managera_old;
 UPDATE Employees SET salary = salary + 0.10*salary from where employee_id = id_managera_new ;
END
END
GO
-- test przyklad
UPDATE employees set manager_id=20 where employee_id=2;
GO
Drop trigger wyzwalacz;
GO