MySQL删除外键列_MySQL
Mysql外键
bitsCN.com 今天遇到一个要删除外键列的问题,我发现:
Sql代码
show create table userfans;
Java代码
| userfans | CREATE TABLE `userfans` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`status` int(11) DEFAULT NULL,
`update_time` datetime DEFAULT NULL,
`user` int(11) DEFAULT NULL,
`fllower` int(11) DEFAULT NULL,
`follower` int(11) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY
`FKF025E60B81E8743E
` (`fllower`),
KEY `FKF025E60BAFF2360E` (`user`),
KEY `FKF025E60BC1B86A61` (`follower`),
CONSTRAINT
`FKF025E60B81E8743E
` FOREIGN
KEY
(`fllower`) REFERENCES `user` (`id`),
CONSTRAINT `FKF025E60BAFF2360E` FOREIGN KEY (`user`) REFERENCES `user` (`id`),
CONSTRAINT `FKF025E60BC1B86A61` FOREIGN KEY (`follower`) REFERENCES `user` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8 |
刚开始我想:是不是先删除KEY,再删除constraint,最后删除列?因为MySQL的外键列和Oracle不一样,MySQL的都是有KEY的;结果试了半天一直失败,最后发现,删除外键列竟然出奇的简单:
Sql代码
alter table userfans drop foreign key FKF025E60B81E8743E
;
显示:
Sql代码
Query OK, 2 rows affected (0.32 sec)
Records: 2 Duplicates: 0 Warnings: 0
真的是踏破铁鞋,白费功夫!
作者“绝尘”

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