错误信息:Cannot drop index 'energy_type_id': needed in a foreign key constraint 创建device表的信息 CREATE TABLE `device` ( `id` int(11) NOT NULL AUTO_INCREMENT, `name` char(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL, `device_type_id` int(16) NOT N
梳理mysql外键约束的知识点. 1.mysql外键约束只对InnoDb引擎有效: 2.创建外键约束如下: DROP TABLE IF EXISTS t_demo_product; CREATE TABLE IF NOT EXISTS t_demo_product( proid ), proname ), price ), PRIMARY KEY(proid) )ENGINE=InnoDB DEFAULT CHARSET=gbk; DROP TABLE IF EXISTS t_demo_oper