Question

我不是一个数据库家伙，但我一直在攻击这个，但似乎无法解决这个问题。我已经阅读了相关的文档页面（http://dev.mysql.com/doc/refman/5.5/en/innodb-foreign-key-constraints.html），我无法看到我的语法可能成为问题的位置

ERROR 1064 (42000) at line 84: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FOREIGN KEY (user_id) REFERENCES user(id)
    ON DELETE RESTRICT ON UPDATE C' at line 5

这是相关的SQL - order（id）和user（id）在各自的表中自动递增int（10）字段。

DROP TABLE IF EXISTS `user_orders`;
CREATE TABLE `user_orders` (
`user_id` int(10) unsigned NOT NULL default '0',
`order_id` int(10) unsigned NOT NULL default '0',
PRIMARY KEY (`user_orders_user_id`, `user_orders_order_id`)
FOREIGN KEY (user_id) REFERENCES user(id)
    ON DELETE RESTRICT ON UPDATE CASCADE,
FOREIGN KEY (order_id) REFERENCES order(id)
    ON DELETE RESTRICT ON UPDATE CASCADE,
) AUTO_INCREMENT=50;

帮助将不胜感激 - 特别是如果你能解释我错过了什么。

Answer 1

PK之后你错过了一个逗号：

PRIMARY KEY (`user_orders_user_id`, `user_orders_order_id`), -- <-------
FOREIGN KEY (user_id) REFERENCES user(id) ...

如果你想强制执行外键，你会想要使用InnoDB引擎：

) AUTO_INCREMENT=50 ENGINE=InnoDB;

Answer 2

我相信你不知道自己在做什么。您的代码充满了错误。

user_id int（10）unsigned NOT NULL默认＆＃39; 0＆＃39;， order_id int（10）unsigned NOT NULL默认＆＃39; 0＆＃39;， PRIMARY KEY（user_orders_user_id，user_orders_order_id）

user_orders_user_id来自哪里。为什么加倍。花点时间阅读你的代码。它应该是，PRIMARY KEY（user_id，order_id）

FOREIGN KEY（user_id）REFERENCES用户（id）关于更新级联的删除限制， FOREIGN KEY（order_id）REFERENCES order（id）关于更新级联的删除限制，）AUTO_INCREMENT = 50;

我建议你采取不同的方法。首先重新订购逗号，以便轻松切换它们。然后将＃放在你的FK线前面。

    DROP TABLE IF EXISTS `user_orders`;
CREATE TABLE `user_orders` 
( user_id int(10) unsigned NOT NULL default '0'
, order_id int(10) unsigned NOT NULL default '0'
, PRIMARY KEY (`user_id`, `order_id`)
#, FOREIGN KEY (user_id) REFERENCES userS(id)  ON DELETE RESTRICT ON UPDATE CASCADE
# , FOREIGN KEY (order_id) REFERENCES order_id) ON DELETE RESTRICT ON UPDATE CASCADE
) ENGINE=InnoDB 
# AUTO_INCREMENT=50 
DEFAULT CHARSET=utf8
;

简化。这至少会运行。然后一次取消注释1行。

输入

SHOW ENGINE INNODB状态;

每当你得到奇怪的mysql错误。寻找

------------------------
LATEST FOREIGN KEY ERROR
------------------------
160323 10:25:43 Error in foreign key constraint of table DEMO/user_orders:
FOREIGN KEY (user_id) REFERENCES userS(id)  ON DELETE RESTRICT ON UPDATE CASCADE

这导致以下解决方案。

    CREATE TABLE `USERS` 
( `ID` INT(10) UNSIGNED NOT NULL AUTO_INCREMENT
, `NAME` VARCHAR(10) NOT NULL
, `EMAIL` VARCHAR(20) NOT NULL
, `ACTIVE` BOOLEAN NOT NULL default 0
, CONSTRAINT PK PRIMARY KEY (`ID`) USING BTREE
, UNIQUE KEY `UK_ID` (`ID`) USING BTREE
, UNIQUE KEY `UK_NAME` (`NAME`)
, UNIQUE KEY `UK_EMAIL` (`EMAIL`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

DROP TABLE IF EXISTS `user_orders`;
CREATE TABLE `user_orders` 
( user_id int(10) unsigned NOT NULL # default '0'
, order_id int(10) unsigned NOT NULL # default '0'
, PRIMARY KEY (`user_id`, `order_id`)
, FOREIGN KEY (user_id) REFERENCES USERS(id)  ON DELETE RESTRICT ON UPDATE CASCADE
# , FOREIGN KEY (order_id) REFERENCES order_id ON DELETE RESTRICT ON UPDATE CASCADE
) ENGINE=InnoDB 
# AUTO_INCREMENT=50 
DEFAULT CHARSET=utf8
;

MySQL CREATE TABLE＆amp;外键错误

2 个答案: