Question

我正在尝试使用外键创建一些表，但是我无法通过错误150.它还说错误1005无法创建表别名。

这是我的剧本：

DROP TABLE IF EXISTS `Aliases`;
CREATE TABLE `Aliases` (
  `aliasnum` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `usernum` bigint(20) unsigned NOT NULL DEFAULT '0',
  `address` varchar(255) NOT NULL DEFAULT '',
  `display` varchar(255) NOT NULL DEFAULT '',
  `selected` tinyint(1) NOT NULL DEFAULT '0',
  `created` datetime NOT NULL,
  PRIMARY KEY (`aliasnum`),
  UNIQUE KEY `UNIQ_DISPLAY` (`usernum`,`address`,`display`),
  KEY `IX_USERNUM` (`usernum`),
  KEY `IX_USERNUM_ADDRESS` (`usernum`,`address`),
  CONSTRAINT `Aliases_fk_1` FOREIGN KEY (`usernum`, `address`) REFERENCES `Mailboxes` (`usernum`, `address`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=latin1 MAX_ROWS=4294967295 AVG_ROW_LENGTH=100 COMMENT='Store mailbox display aliases and default status information.';

DROP TABLE IF EXISTS `Mailboxes`;
CREATE TABLE `Mailboxes` (
  `address` varchar(255) NOT NULL DEFAULT '',
  `usernum` bigint(20) unsigned NOT NULL DEFAULT '0',
  PRIMARY KEY (`address`),
  KEY `IX_USERNUM` (`usernum`),
  KEY `IX_USERNUM_ADDRESS` (`usernum`,`address`),
  CONSTRAINT `Mailboxes_ibfk_1` FOREIGN KEY (`usernum`) REFERENCES `Users` (`usernum`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=latin1 MAX_ROWS=4294967295 AVG_ROW_LENGTH=100 COMMENT='All mailboxes for which we accept e-mail.';

错误表明第29行是：

`selected` tinyint(1) NOT NULL DEFAULT '0',

所有表格都是InnoDB。我真的被困住了，不确定它是什么？

Answer 1

删除

CONSTRAINT `Aliases_fk_1` FOREIGN KEY (`usernum`, `address`) REFERENCES `Mailboxes` (`usernum`, `address`) ON DELETE CASCADE ON UPDATE CASCADE

和

CONSTRAINT `Mailboxes_ibfk_1` FOREIGN KEY (`usernum`) REFERENCES `Users` (`usernum`) ON DELETE CASCADE ON UPDATE CASCADE

create table命令中的

。

创建表格后添加FOREIGN KEY

ALTER TABLE `Aliases` 
ADD CONSTRAINT `Aliases_fk_1` 
FOREIGN KEY (`usernum`, `address`) 
REFERENCES `Mailboxes` (`usernum`, `address`) 
ON DELETE CASCADE 
ON UPDATE CASCADE;

和

ALTER TABLE `Mailboxes`
ADD CONSTRAINT `Mailboxes_ibfk_1` 
FOREIGN KEY (`usernum`)
REFERENCES `Users` (`usernum`)
ON DELETE CASCADE
ON UPDATE CASCADE;

Answer 2

您的第一个表有一个约束，它引用第二个表。所以改变创作顺序。

当然，你的第二个表有一个约束，它引用了你在问题中没有提到的其他一些表Users。因此，您必须先创建Users，然后Mailboxes，然后Aliases。

或者，您可以从表定义中删除CONSTRAINT子句，然后在表格全部可用之后创建约束，如下所示。

CREATE TABLE Users
CREATE TABLE Aliases ...
CREATE TABLE Mailboxes ...

ALTER TABLE Aliases ADD
  CONSTRAINT `Aliases_fk_1` FOREIGN KEY (`usernum`, `address`) REFERENCES `Mailboxes` (`usernum`, `address`) ON DELETE CASCADE ON UPDATE CASCADE;

ALTER TABLE Mailboxes ADD
  CONSTRAINT `Mailboxes_ibfk_1` FOREIGN KEY (`usernum`) REFERENCES `Users` (`usernum`) ON DELETE CASCADE ON UPDATE CASCADE;

（我认为第29行不相关。）

MYSQL无法创建表：错误150

2 个答案: