Mysql 创建外键时出错（检查数据类型）

我试图在两个表之间创建一个关系。这是每个表的查询和外键创建

CREATE TABLE IF NOT EXISTS `quotes` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `quote` text COLLATE utf8_unicode_ci NOT NULL,
  `author` int(11) NOT NULL,
  `topic` int(11) NOT NULL,
  `language` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  KEY `topic` (`topic`)
) ENGINE=InnoDB  DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;


CREATE TABLE IF NOT EXISTS `authors` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `author` int(11) NOT NULL,
  `period` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `photo` text COLLATE utf8_unicode_ci NOT NULL,
  `references` text COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1 ;

ALTER TABLE `quotes` ADD FOREIGN KEY ( `author` ) REFERENCES `mytestdb`.`authors` (
`id`
) ON DELETE RESTRICT ON UPDATE RESTRICT ;

但它抛出了以下错误

Error creating foreign key on author (check data types)

---

我不确定这个错误是怎么回事。在此方面的任何帮助都将不胜感激。

数据类型和符号必须相同

int

与

unsigned int

显示宽度不相关

---

author

是有符号整数

id

是一个无符号整数

从：

外键和引用键中的相应列必须 具有相似的数据类型。整数类型的大小和符号必须为 相同的。字符串类型的长度不必相同。对于 非二进制（字符）字符串列、字符集和排序规则 一定是一样的

它们的大小相同（int）。他们的星座不一样

10和11的显示宽度无关

演示 工作正常

CREATE TABLE IF NOT EXISTS `quotes` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `quote` text COLLATE utf8_unicode_ci NOT NULL,
  `author` int(11) NOT NULL,
  `topic` int(11) NOT NULL,
  `language` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  KEY `topic` (`topic`)
) ENGINE=InnoDB;


CREATE TABLE IF NOT EXISTS `authors` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `author` int(11) NOT NULL,
  `period` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `photo` text COLLATE utf8_unicode_ci NOT NULL,
  `references` text COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  CONSTRAINT fk_blah222 FOREIGN KEY (author) REFERENCES quotes(id)
) ENGINE=InnoDB;

---

工作正常

数据类型和符号必须相同

CREATE TABLE IF NOT EXISTS `quotes` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `quote` text COLLATE utf8_unicode_ci NOT NULL,
  `author` int(11) NOT NULL,
  `topic` int(11) NOT NULL,
  `language` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  KEY `topic` (`topic`)
) ENGINE=InnoDB;


CREATE TABLE IF NOT EXISTS `authors` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `author` int(11) NOT NULL,
  `period` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `photo` text COLLATE utf8_unicode_ci NOT NULL,
  `references` text COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  CONSTRAINT fk_blah222 FOREIGN KEY (author) REFERENCES quotes(id)
) ENGINE=InnoDB;

int

与

unsigned int

显示宽度不相关

---

author

是有符号整数

id

是一个无符号整数

从：

外键和引用键中的相应列必须 具有相似的数据类型。整数类型的大小和符号必须为 相同的。字符串类型的长度不必相同。对于 非二进制（字符）字符串列、字符集和排序规则 一定是一样的

它们的大小相同（int）。他们的星座不一样

10和11的显示宽度无关

演示 工作正常

CREATE TABLE IF NOT EXISTS `quotes` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `quote` text COLLATE utf8_unicode_ci NOT NULL,
  `author` int(11) NOT NULL,
  `topic` int(11) NOT NULL,
  `language` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  KEY `topic` (`topic`)
) ENGINE=InnoDB;


CREATE TABLE IF NOT EXISTS `authors` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `author` int(11) NOT NULL,
  `period` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `photo` text COLLATE utf8_unicode_ci NOT NULL,
  `references` text COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  CONSTRAINT fk_blah222 FOREIGN KEY (author) REFERENCES quotes(id)
) ENGINE=InnoDB;

---

可以正常工作

错误消息很清楚：

mytestdb.authors.id

是无符号整数（10），而

mytestdb.quotes.author

是有符号整数（11）与无符号整数（11）。Chg oneerror消息很清楚：

mytestdb.authors.id

是无符号int（10），而

mytestdb.quotes.author

是有符号int（11）与无符号int（11）。作者的大小应与引号id int size相同。不，它们的大小相同。它们的符号不同。慢慢读（答案）这里有三件事让人困惑。只有2个是相关的。两个相关的是尺寸和标志。第三个（不相关）是显示宽度10和11。作者的大小应与引号id int size相同。不，它们的大小相同。它们的符号不同。慢慢读（答案）这里有三件事让人困惑。只有2个是相关的。两个相关的是尺寸和标志。第三个（不相关）是显示宽度10和11。

CREATE TABLE IF NOT EXISTS `quotes` (
  `id` int(10) NOT NULL AUTO_INCREMENT,
  `quote` text COLLATE utf8_unicode_ci NOT NULL,
  `author` int(11) NOT NULL,
  `topic` int(11) NOT NULL,
  `language` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  KEY `topic` (`topic`)
) ENGINE=InnoDB;


CREATE TABLE IF NOT EXISTS `authors` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `author` int(11) NOT NULL,
  `period` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
  `photo` text COLLATE utf8_unicode_ci NOT NULL,
  `references` text COLLATE utf8_unicode_ci NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  PRIMARY KEY (`id`),
  KEY `author` (`author`),
  CONSTRAINT fk_blah222 FOREIGN KEY (author) REFERENCES quotes(id)
) ENGINE=InnoDB;