ALTER TABLE tetel
  ADD CONSTRAINT tetel_fk6 FOREIGN KEY (fajta4)
      REFERENCES tetel_fajtak (kod) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION;

ALTER TABLE tetel
  ADD CONSTRAINT tetel_fk7 FOREIGN KEY (fajta5)
      REFERENCES tetel_fajtak (kod) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION;

ALTER TABLE tetel
  ADD CONSTRAINT tetel_fk8 FOREIGN KEY (fajta6)
      REFERENCES tetel_fajtak (kod) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE NO ACTION;