I have this weird behaviour when I add a constraint to a MySQL table:
[...] add constraint qrtz_blob_triggers_ibfk_1 foreign key [...]
Now SHOW CREATE TABLE shows the constraint twice:
CONSTRAINT `qrtz_blob_triggers_ibfk_1` FOREIGN KEY [...]
CONSTRAINT `QRTZ_BLOB_TRIGGERS_ibfk_1` FOREIGN KEY [...]
Here is the complete session:
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)
Using
[...] add constraint QRTZ_BLOB_TRIGGERS_ibfk_1 foreign key [...]
works fine.
I am using Ubuntu 12.04 LTS with MySQL 5.5:
mysql-server-5.5 5.5.32-0ubuntu0.12.04.1
Does anyone have a clue what's going on there?