mySQL数据库--增加、删除、更改外键关联

删除外键关联

增加外键 关联

ALTER TABLE tblorder DROP FOREIGN KEY `FK_order_consignee_cityid`;ALTER TABLE tblorder ADD CONSTRAINT `FK_tblgtt_order_consignee_cityid` FOREIGN KEY(`consignee_cityid`) REFERENCES `tblcontact` (`cont_id`);

ALTER TABLE tblorder DROP FOREIGN KEY `FK_tblorder_shipper_cityid`;ALTER TABLE tblorder ADD CONSTRAINT `FK_tblorder_shipper_cityid` FOREIGN KEY(`shipper_cityid`) REFERENCES `tblcontact` (`cont_id`);

查了一下没有找到更改外键关联的命令，就使用傻办法，先删除后增加