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?