I18N

Ex-web.de Colleague Markus asked me: I have been writing a german language article on character sets in MySQL and this is the translation of it.

For a migration, I needed a latin1_german1_cs collation, that is, I needed German umlauts to sort as their base characters.

Here is what to do: Find your charsets directory with "SHOW VARIABLES LIKE 'char%dir%'".

Inside that directory will be a file Index.xml. Find a free id and add your new collation using an unused id. Add a description and a name.

Inside the same directory is a file latin1.xml. Inside that file, copy the block of the collation matching your new collation most closely, and adapt it as needed. In my case, I changed latin1_german1_ci to _cs, and modified the character values to match.

Patch attached after the break.

How to use:

After applying the patch, the server must be restarted. "SHOW COLLATION" will now show the new latin1_german1_cs collation. "ALTER TABLE t CHANGE COLUMN oldcol newcol varchar(80) CHARSET latin1 COLLATE latin1_german1_cs NOT NULL" will change any old column to the new collation and recreate indices as needed.

Because we changed a single byte character set, we do not need to recomple anything. Try sorting by latin1_bin, latin1_german1_ci and latin1_german1_cs to observe how things are different with each collation.