錯誤：錯誤1005：無法創建表'網站。＃sql-3e5_102'（錯誤：150）

Question

我試圖設置3個表之間的外鍵，並在標題中收到錯誤，所有_id字段是未簽名的，並且與其父文件的格式相同。

表中的問題：

CREATE TABLE `Group` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT, 
    `name` varchar(250) COLLATE utf8_unicode_ci DEFAULT NULL, 
    `name_url` varchar(250) COLLATE utf8_unicode_ci DEFAULT NULL, 
    `enabled` tinyint(1) unsigned NOT NULL DEFAULT '1', 
    `order` int(11) NOT NULL DEFAULT '0', 
    `internal` tinyint(1) NOT NULL, 
    `updated` int(11) DEFAULT NULL, 
    `created` int(11) DEFAULT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=InnoDB AUTO_INCREMENT=12 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

CREATE TABLE `Permission` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT, 
    `description` tinytext COLLATE utf8_unicode_ci, 
    `controller` varchar(250) CHARACTER SET utf8 DEFAULT NULL, 
    `action` varchar(250) CHARACTER SET utf8 DEFAULT NULL, 
    `enabled` tinyint(1) unsigned NOT NULL DEFAULT '0', 
    `updated` int(11) DEFAULT NULL, 
    `created` int(11) DEFAULT NULL, 
    PRIMARY KEY (`id`) 
) ENGINE=InnoDB AUTO_INCREMENT=40 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

CREATE TABLE `Group_Permission` (
    `id` int(11) unsigned NOT NULL AUTO_INCREMENT, 
    `group_id` int(11) unsigned DEFAULT NULL, 
    `permission_id` int(11) unsigned DEFAULT NULL, 
    `enabled` tinyint(1) unsigned NOT NULL DEFAULT '1', 
    `use_client_id` tinyint(1) DEFAULT '0', 
    `updated` int(11) DEFAULT NULL, 
    `created` int(11) DEFAULT NULL, 
    PRIMARY KEY (`id`), 
    KEY `perm, group_id` (`permission_id`,`group_id`) 
) ENGINE=InnoDB AUTO_INCREMENT=58 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 

查詢被MySQL工作臺運行

SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0; 
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0; 
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL'; 

ALTER TABLE `website`.`Group` 
    ADD CONSTRAINT `fk_Group_Group_Permission1` 
    FOREIGN KEY (`id`) 
    REFERENCES `website`.`Group_Permission` (`group_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION; 

ALTER TABLE `website`.`Group_Permission` 
DROP INDEX `perm, group_id` 
, ADD INDEX `permission_id` (`group_id` ASC) 
, ADD INDEX `group_id` (`group_id` ASC) ; 

ALTER TABLE `website`.`Permission` 
    ADD CONSTRAINT `fk_Permission_Group_Permission1` 
    FOREIGN KEY (`id`) 
    REFERENCES `website`.`Group_Permission` (`permission_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION; 


SET SQL_MODE=@OLD_SQL_MODE; 
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS; 
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS; 

查詢創建外鍵：

New client connection 
client connection established 
Executing SQL script in server 

> ERROR: Error 1005: Can't create table 'website.#sql-3e5_102' (errno: 
> 150) 


ALTER TABLE `website`.`Group` 
    ADD CONSTRAINT `fk_Group_Group_Permission1` 
    FOREIGN KEY (`id`) 
    REFERENCES `website`.`Group_Permission` (`group_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION 

SQL script execution finished: statements: 3 succeeded, 1 failed 

Answer 1

它看起來像你對我有你的關係落後。 Group_Permission應該包括到Group的FK關係，而不是相反。同樣，Group_Permission.permission_id應參考Permission.id而不是其他方式。約束失敗，因爲id已經是您嘗試將其設爲外鍵時的主鍵。

ALTER TABLE `website`.`Group_Permission` 
    ADD CONSTRAINT `fk_Group_Group_Permission1` 
    FOREIGN KEY (`group_id`) 
    REFERENCES `website`.`Group` (`id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION 
    ADD CONSTRAINT `fk_Permission_Group_Permission1` 
    FOREIGN KEY (`permission_id`) 
    REFERENCES `website`.`Permission` (`id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION;