Got it solved, with the update of the Char(1) field that I tried to set to 'N' I also updated a string field. The string field containd something like "A boolean field contains 'N' or 'Y'". It was this 'N' character it complaind about.

So conclusion setString("N") on a char(1) database field works fine.

Sorry for my mistake, thanks for the support.

--- In firebird-support@yahoogroups.com, Helen Borrie <helebor@...> wrote:
>
> At 09:45 AM 14/04/2011, you wrote:
> >Updated to Firebird 2.5. Problem still exsists. Tried a lot of options but still no succes. Also searched a lot on the internet but still no solution.
> >
> >If I try directly with JDBC to update a char(1) column I still get the error:
> >
> > at org.firebirdsql.gds.GDSException: Dynamic SQL Error
> > SQL error code = -104
> > Token unknown - line 1, column 68
> > N
> >
> >Also use Hibernate. Hibernate is able to update this column. What is wrong with simple JDBC code or configuration.
>
> Sounds like a problem in the Java layers, interpreting your SQL wrongly - but this is the wrong list. Subscribe to firebird-java - can subscribe here: http://firebirdsql.org/index.php?op=lists
>
> ^heLen^
> (Moderator)
>