Mine

create table bestelling
(
  bestel_id number(10) constraint c_t_bestelling_pk_bestel_id
            primary key,
  klant_id number (10),
  product_id number(10),
  aantal_besteld number (6) not null,
  datum_besteld timestamp default sysdate,
  bestel_status number(10) constraint c_t_bestelling_ck_bestel_status
                check (bestel_status IN ('1', '2', '3', '101', '102', '103', '201', '202', '203')),
	constraint c_t_bestelling_fk_klant_id
          foreign key (klant_id) references klant (klant_id),
	constraint c_t_bestelling_fk_product_id
          foreign key (product_id) references product (product_id)
);