我有一张这样的桌子:
CREATE TABLE `articles`
(
`article_id` INT(10) NOT NULL auto_increment,
`pubsrc_id` INT(10) NOT NULL,
`pub_id` VARCHAR(16) NOT NULL
PRIMARY KEY (`article_id`),
UNIQUE KEY `pubsrc_id` (`pubsrc_id`,`pub_id`),
CONSTRAINT `pub_articles_ibfk_1` FOREIGN KEY (`pubsrc_id`) REFERENCES `pub_sources` (`pubsrc_id`) ON
DELETE RESTRICT
ON
UPDATE RESTRICT,
CONSTRAINT `pub_articles_ibfk_2` FOREIGN KEY (`pubsrc_id`) REFERENCES `pub_sources` (`pubsrc_id`)
)
有另一个表,前一个表有一个键:
CREATE TABLE `pub_sources`
(
`pubsrc_id` INT(11) NOT NULL,
`pubsrc_name` VARCHAR(32) NOT NULL
PRIMARY KEY (`pubsrc_id`)
)
我正试着用命令放下外国钥匙:
SET SESSION SQL_SAFE_UPDATES = 0;
SET FOREIGN_KEY_CHECKS = 0;
ALTER TABLE `articles` DROP FOREIGN KEY `pubsrc_id`;
但得到以下错误:
Error Code: 1091. Can't DROP 'pubsrc_id'; check that column/key exists
最佳答案
您需要根据外键的约束名(而不是定义它的列的名称)删除外键。
不好:
mysql> ALTER TABLE `articles` DROP FOREIGN KEY `pubsrc_id`;
ERROR 1091 (42000): Can't DROP 'pubsrc_id'; check that column/key exists
可以:
mysql> ALTER TABLE `articles` DROP FOREIGN KEY `pub_articles_ibfk_1`;
Query OK, 0 rows affected (0.03 sec)