[freetds] Character conversion errorwithspecialcharacters(umlauts)

James K. Lowden jklowden at freetds.org
Mon Jul 21 10:44:33 EDT 2008

Stefan Axelsson wrote:
> Just tested something else, as I realized I hadn't. isql lets me update
> the records with åäö in them just fine. Checking on the server and the
> updated data is as it should be. Getting the records back through isql
> (SELECT * FROM tablename) works fine. Using my Perl-script returns ?
> Where the åäö should be.
> Unfortunately I'm still rather confused about what talks to what, and
> how. And I'm even more in the dark when it comes to how to track what
> happens step-by-step. All I've gotten to work so far is the logging I
> can enable in odbcinst.ini-file. So if you, or anyone else, have any
> ideas, hints, tricks...do tell. I'd so prefere to solve this and not
> just install some other distro/port to Windows.

Ledsen att säga, det är inte enkelt.  :-(

The server announces its encoding during the login sequence.  For non-UCS2
columns, the encoding is set by server or database defaults, or (in SQL
Server 200[05]) by column.  sp_helpsort should show you yours (although I
think you know yours already). 

The client's encoding is determined first by the locale.  It can be
overridden in freetds.conf.  To use the override feature for an ODBC
connection, you must cause the ODBC driver to read freetds.conf.  To do
that, use the "Servername" (not "server") property in the DSN entry,
naming the section in freetds.conf where the encoding ("client charset")
is specified.  (I think you could set the client charset in the "[global]"
section, instead, if you prefer.)  

As long as both encodings can represent all the characters you need,
you're OK.  It is not necessary to use USC-2 on the server.  It is
necessary only that the intersection of the two encodings satisfies your

Now, who's the "client" here?  You're running a webserver producing HTML,
normally encoded as UTF-8.  And you seem to want UTF-8.  So I think you
want either to set your locale to UTF-8 or use and ODBC-Combined
configuration to take advantage of the freetds.conf override feature.  

HTH.  I can provide more if you need it.   Ta det lungt.  


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