ALTER TABLE vn.roadmap
	ADD COLUMN m3 INT UNSIGNED NULL,
	ADD COLUMN driver2Fk INT UNSIGNED NULL,
	ADD COLUMN driver1Fk INT UNSIGNED NULL,
	ADD CONSTRAINT roadmap_worker_FK FOREIGN KEY (driver1Fk) REFERENCES vn.worker(id) ON DELETE RESTRICT ON UPDATE CASCADE,
	ADD CONSTRAINT roadmap_worker_FK_2 FOREIGN KEY (driver2Fk) REFERENCES vn.worker(id) ON DELETE RESTRICT ON UPDATE CASCADE;