MySQL表創建錯誤

Question

我有兩個表名為

成員-列ID（主鍵），名稱，電子郵件和

主題-列ID，topic_type，created_by 。

我想創建它映射成員話題，其中有MEMBERID列（member表ID的外鍵 ）的新表MEMBER_TO_TOPICS，topicid（ 主題表ID的外鍵 ），CREATED_TIME。
這是我要執行的查詢。

CREATE TABLE `gsraisin`.`member_to_topics` (
`member_id` VARCHAR(50) NOT NULL,
`topic_id` VARCHAR(50) NOT NULL,
`created_date` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
PRIMARY KEY (`member_id`, `topic_id`),
CONSTRAINT `FK_member_to_topics_memberid` FOREIGN KEY `FK_member_to_topics_memberid`   
(`member_id`)
REFERENCES `member` (`id`)
ON DELETE CASCADE
ON UPDATE NO ACTION,
CONSTRAINT `FK_member_to_topics_topicid` FOREIGN KEY `FK_member_to_topics_topicid` 
(`topic_id`)
REFERENCES `topics` (`id`)
ON DELETE CASCADE
ON UPDATE NO ACTION
)
ENGINE = InnoDB;

但是在執行時出現以下錯誤-MYSQL錯誤號1005無法創建表member_to_topics（errno：121）

Answer 1

我在我的本地計算機上嘗試了一下，效果很好。

mysql> show create table member;
+--------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table  | Create Table                                                                                                                                                                                       |
+--------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| member | CREATE TABLE `member` (
  `id` varchar(50) NOT NULL DEFAULT '',
  `name` varchar(50) DEFAULT NULL,
  `email` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+--------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)


mysql> show create table topics;
+--------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table  | Create Table                                                                                                                                                                                                  |
+--------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| topics | CREATE TABLE `topics` (
  `id` varchar(50) NOT NULL DEFAULT '',
  `topic_type` varchar(50) DEFAULT NULL,
  `created_by` varchar(50) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+--------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql> show create table member_to_topics;
+------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Table            | Create Table                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
+------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| member_to_topics | CREATE TABLE `member_to_topics` (
  `member_id` varchar(50) NOT NULL,
  `topic_id` varchar(50) NOT NULL,
  `created_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`member_id`,`topic_id`),
  KEY `FK_member_to_topics_topicid` (`topic_id`),
  CONSTRAINT `FK_member_to_topics_memberid` FOREIGN KEY (`member_id`) REFERENCES `member` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION,
  CONSTRAINT `FK_member_to_topics_topicid` FOREIGN KEY (`topic_id`) REFERENCES `topics` (`id`) ON DELETE CASCADE ON UPDATE NO ACTION
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+------------------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

錯誤代碼121用於重復密鑰。

[matthewh@kookaburra ~]$ perror 121
OS error code 121:  Remote I/O error
MySQL error code 121: Duplicate key on write or update

我懷疑您可能有重復的約束名稱？