ALTER TABLE vn.travel DROP FOREIGN KEY IF EXISTS travel_FK_1 ;
ALTER TABLE vn.travel DROP COLUMN IF EXISTS awbFk;

ALTER TABLE vn.travel 
	ADD awbFk SMALLINT(11) UNSIGNED;

ALTER TABLE vn.travel 
	ADD CONSTRAINT travel_FK_1 FOREIGN KEY (awbFk) REFERENCES vn.awb(id) 
		ON DELETE CASCADE ON UPDATE CASCADE;