一、如果表已建主要进行子表操作
1.先删除约束值(如果存在)ALTER TABLE `子表`DROP FOREIGN KEY `唯一约束值`;2.更新子表ALTER TABLE `子表`ADD CONSTRAINT `唯一约束值` FOREIGN KEY (`id`) REFERENCES `主表` (`id`) ON DELETE CASCADE ON UPDATE RESTRICT;
二、新建表
CREATETABLE`子表`(`id`INT(11)UNSIGNEDAUTO_INCREMENTNOTNULLPRIMARYKEY(`id`),CONSTRAINT `唯一约束值` FOREIGN KEY (`id`) REFERENCES `主表` (`id`) ON DELETE CASCADE)TYPE=InnoDB;