Question

当我向MySQL表添加约束时，我有这种奇怪的行为：

[...] add constraint qrtz_blob_triggers_ibfk_1 foreign key [...]

现在SHOW CREATE TABLE显示两次约束：

CONSTRAINT `qrtz_blob_triggers_ibfk_1` FOREIGN KEY [...]
CONSTRAINT `QRTZ_BLOB_TRIGGERS_ibfk_1` FOREIGN KEY [...]

以下是完整的会话：

mysql> DROP DATABASE IF EXISTS my_test; CREATE DATABASE my_test default character set utf8 collate utf8_bin;
Query OK, 2 rows affected (0.07 sec)

Query OK, 1 row affected (0.00 sec)

mysql> use my_test;
Database changed
mysql> 
mysql> DROP TABLE IF EXISTS `QRTZ_TRIGGERS`;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> 
mysql> CREATE TABLE `QRTZ_TRIGGERS` (
       `TRIGGER_NAME` varchar(80) NOT NULL,
       `TRIGGER_GROUP` varchar(80) NOT NULL,
       PRIMARY KEY (`TRIGGER_NAME`,`TRIGGER_GROUP`)
     ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.08 sec)

mysql> 
mysql> DROP TABLE IF EXISTS `QRTZ_BLOB_TRIGGERS`;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> 
mysql> create table `QRTZ_BLOB_TRIGGERS` (`TRIGGER_NAME` varchar(80) not null, `TRIGGER_GROUP` varchar(80) not null, `BLOB_DATA` longblob, primary key (`TRIGGER_NAME`, `TRIGGER_GROUP`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;
Query OK, 0 rows affected (0.08 sec)

mysql> 
mysql> alter table `QRTZ_BLOB_TRIGGERS`  add index qrtz_blob_triggers_ibfk_1 (`TRIGGER_NAME`, `TRIGGER_GROUP`), add constraint qrtz_blob_triggers_ibfk_1 foreign key (`TRIGGER_NAME`, `TRIGGER_GROUP`) references `QRTZ_TRIGGERS` (`TRIGGER_NAME`, `TRIGGER_GROUP`) ON UPDATE RESTRICT ON DELETE RESTRICT;
Query OK, 0 rows affected (0.18 sec)
Records: 0  Duplicates: 0  Warnings: 0

mysql> 
mysql> show create table QRTZ_BLOB_TRIGGERS \G
*************************** 1. row ***************************
       Table: QRTZ_BLOB_TRIGGERS
Create Table: CREATE TABLE `QRTZ_BLOB_TRIGGERS` (
  `TRIGGER_NAME` varchar(80) NOT NULL,
  `TRIGGER_GROUP` varchar(80) NOT NULL,
  `BLOB_DATA` longblob,
  PRIMARY KEY (`TRIGGER_NAME`,`TRIGGER_GROUP`),
  KEY `qrtz_blob_triggers_ibfk_1` (`TRIGGER_NAME`,`TRIGGER_GROUP`),
  CONSTRAINT `qrtz_blob_triggers_ibfk_1` FOREIGN KEY (`TRIGGER_NAME`, `TRIGGER_GROUP`) REFERENCES `QRTZ_TRIGGERS` (`TRIGGER_NAME`, `TRIGGER_GROUP`),
  CONSTRAINT `QRTZ_BLOB_TRIGGERS_ibfk_1` FOREIGN KEY (`TRIGGER_NAME`, `TRIGGER_GROUP`) REFERENCES `QRTZ_TRIGGERS` (`TRIGGER_NAME`, `TRIGGER_GROUP`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
1 row in set (0.00 sec)

使用

[...] add constraint QRTZ_BLOB_TRIGGERS_ibfk_1 foreign key [...]

工作正常。

我正在使用Ubuntu 12.04 LTS和MySQL 5.5：

mysql-server-5.5     5.5.32-0ubuntu0.12.04.1

有没有人知道那里发生了什么？

Answer 1

这是一个known bug，修正在upcoming release：

InnoDB将重命名用户定义的外键约束，该约束在其名称中包含字符串“ ibfk ”，从而导致重复约束。“

错误报告建议修复版本5.1.72,5.5.32,5.6.14,5.7.2，但我怀疑5.5分支的拼写错误。考虑到发布日期，我希望修复为v5.5。 34 。

MySQL - 添加约束一次用不同的情况添加两次

1 个答案: