New subject: [Mediawiki-l] Database error - LinkHolderArray::replaceInternal

8 Dec 2010

 Hi,

 I am migrating our wiki to another server, and upgrading the Mediawiki 
 version in the process (from 1.13.3 to 1.16.0)

 But at some pages I now get the following error message;

 --------
 A database query syntax error has occurred. This may indicate a bug in 
 the software. The last attempted database query was:
     (SQL query hidden)
 from within function "LinkHolderArray::replaceInternal". Database 
 returned error "1271: Illegal mix of collations for operation ' IN ' 
 (localhost)".
 --------

 I have already determined this has to do with some characters being in 
 article titles/wiki links (the Czech 'č' for instance, see 

http://wiki.scramble.nl/index.php?title=Fokker_F.XVIII&action=historysu…)oldid=14823).
 Having the same characters in the main text is not an issue (compare 
 [[Česká Letecká Společnost|ČLS]] which doesn't work, with [[Ceská 
 Letecká Spolecnost|ČLS]] which does).
 What surprised me, was that the error also occurred when I tried to 
 preview this page, at which point there there is no database query (yet) 
 I would imagine. But I may be wrong on that :-)

 So it seems it has something to do with the character sets used, but as 
 my expertise on that is rather basic, I have not a clue what exactly.

 What did I do so far;
 - dumped the databases on the old server with mysqldump
 - installed MW 1.16.0 on the new server
 - imported the database dump on the new server (completely, dropping 
 the 'newly created tables' from last step first)
 - ran the update.php script
 - uploaded the images directories (OK, this has nothing to do with 
 above issue, just being complete ;-) )
 - installed the current versions of all extensions we used on the old 
 server

 Could anybody tell what I did wrong, or point me to a solution? I would 
 like being able to use those characters, as is the case on our old 
 server.

 Thanks in advance!

 Regards,

 Hans