I think the following might give complete information (I removed some columns not involved in the problem)
Server version: 5.1.49-3 (Debian) SET collation_connection = utf8_unicode_ci; Query OK, 0 rows affected (0.00 sec) show variables like '%colla%'; +----------------------+-----------------+ | Variable_name | Value | +----------------------+-----------------+ | collation_connection | utf8_unicode_ci | | collation_database | utf8_unicode_ci | | collation_server | utf8_unicode_ci | +----------------------+-----------------+ 3 rows in set (0.00 sec) show variables like '%char%'; +--------------------------+----------------------------+ | Variable_name | Value | +--------------------------+----------------------------+ | character_set_client | utf8 | | character_set_connection | utf8 | | character_set_database | utf8 | | character_set_filesystem | binary | | character_set_results | utf8 | | character_set_server | utf8 | | character_set_system | utf8 | | character_sets_dir | /usr/share/mysql/charsets/ | +--------------------------+----------------------------+ 8 rows in set (0.00 sec) select USER_ID from TBL_USER where USER_ID = 'GIUSEPPE'; +----------+ | USER_ID | +----------+ | GIUSEPPE | +----------+ 1 row in set (0.00 sec) select USER_ID from TBL_USER where USER_ID = 'giuseppe'; +----------+ | USER_ID | +----------+ | GIUSEPPE | +----------+ 1 row in set (0.00 sec) update TBL_USER set USER_ID = LOWER(USER_ID) where USER_ID = 'GIUSEPPE'; ERROR 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails (`myschema`.`TBL_COMMENT`, CONSTRAINT `FK4F6E52581590B46E` FOREIGN KEY (`USER_ID`) REFERENCES `TBL_USER` (`USER_ID`)) | TBL_USER | CREATE TABLE `TBL_USER` ( `USER_ID` varchar(50) COLLATE utf8_unicode_ci NOT NULL, << cut >> PRIMARY KEY (`USER_ID`), << cut >> ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci | | TBL_COMMENT | CREATE TABLE `TBL_COMMENT` ( << cut >> `ID` bigint(20) NOT NULL AUTO_INCREMENT, << cut >> `USER_ID` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL, << cut >> PRIMARY KEY (`ID`), << cut >> KEY `FK4F6E52581590B46E` (`USER_ID`), << cut >> CONSTRAINT `FK4F6E52581590B46E` FOREIGN KEY (`USER_ID`) REFERENCES `TBL_USER` (`USER_ID`), << cut >> ) ENGINE=InnoDB AUTO_INCREMENT=7876 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci | -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
