Good morning. The application is Java. The database version is : Server version: 5.1.49-3 (Debian)
This is an example of the problem: ______________________________ mysql> SET collation_connection = utf8_unicode_ci; Query OK, 0 rows affected (0.00 sec) mysql> 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) mysql> update MY_TABLE set USER_ID = LOWER(USER_ID) where USER_ID = 'XXYYZZ'; ERROR 1451 (23000): Cannot delete or update a parent row: a foreign key constraint fails etc. etc. ______________________________ Since the used collation is "_ci" (I suppose it means case insensitive) I don't understand why it is giving an error trying to change a value to lowercase. I did try on a test environment to use the trick (SET foreign_key_checks=0;) but I don't understand why I should disable the foreign key checks when I am NOT violating them. The application was able to write in some other tables the USER_ID in lowercase. And I think that was an expected behaviour because the collation is case insensitive! Why now I can't set some values from uppercase to lowercase? There is not any weird character in the USER_ID column, just from A to Z. Thank you. On Wed, May 16, 2012 at 5:35 PM, Shawn Green <shawn.l.gr...@oracle.com> wrote: > Hello Ananda, > > > On 5/16/2012 6:42 AM, Ananda Kumar wrote: >> >> why are not using any where condition in the update statment >> > > WHERE clauses are not required. Performing a command without one will affect > ever row on the table. > >> On Wed, May 16, 2012 at 1:24 PM, GF<gan...@gmail.com> wrote: >> >>> Good morning, >>> I have an application where the user ids were stored lowercase. >>> Some batch import, in the user table some users stored a uppercase >>> id, and for some applicative logic, in other tables that have a >>> foreign key to the user table, their user ids are stored lowercase. >>> ... >>> >>> Have you any idea how to solve this situation without >>> stopping/recreating the DB? (it's a production environment) >>> Thanks >>> > > Have you tried ? > > SET foreign_key_checks=0; > http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html#sysvar_foreign_key_checks > > If that does not work, you would need to first un-create your Foreign Key > relationships, update your key values (the USER_ID fields), then re-create > your Foreign Key relationships. > > Regards, > -- > Shawn Green > MySQL Principal Technical Support Engineer > Oracle USA, Inc. - Hardware and Software, Engineered to Work Together. > Office: Blountville, TN > > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: http://lists.mysql.com/mysql > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql
