CREATE OR REPLACE TRIGGER Order_trg
BEFORE INSERT ON "Order"
FOR EACH ROW
DECLARE
err_early EXCEPTION;
BEGIN
        IF :NEW.Deadline < SYSDATE
                THEN RAISE err_early;
                ROLLBACK;
        END IF;
EXCEPTION
        WHEN err_early THEN RAISE_APPLICATION_ERROR(-20857,'Слишком рано!');
END Order_trg;
/