MYSQL無法創建表：錯誤150

Question

我正在嘗試使用外鍵創建一些表，但是我無法通過錯誤150.它還說錯誤1005無法創建表別名。

這是我的腳本：

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.';

錯誤說它的第29行是：

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

所有表都是InnoDB。 我真的被卡住了，不確定它是什么？

Answer 1

去掉

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

在create table命令中。

創建表后添加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

您的第一個表有一個約束，它引用第二個表。 因此切換創建順序。

當然，您的第二個表有一個約束，它引用了您在問題中未提及的其他一些表Users 。 因此，您必須首先創建Users ，然后創建Mailboxes ，然后創建Aliases 。

或者，您可以從表定義中刪除CONSTRAINT子句，然后在表全部可用之后創建約束，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;

（我認為第29行不相關。）