FreeTDS Development Group

[Norbert Matzke <matzke AT geopp.de>]

ZIGLIO, Frediano, VF-IT wrote:
> > Problem: My client ODBC application needs to bind parameters which are
> > UTF-8 encoded to SQL insert/update statements.
> > I have set ClientCharset to UTF-8 in freetds.conf.
> >
> > I did some tests with Version 0.82 of FreeTDS and SQL Server 2005.
> > Seemed to work, but not with a short UTF-8 String like '€'.
> > '€' is 3 bytes long in UTF-8 encoding.
> >
> > If I called
> > SQLBindParameter( , ,SQL_C_CHAR, SQL_WVARCHAR, n, 0, , , &ind )
> > with n=1 and *ind=3 I got an error message. iconv was not able to
> > convert '€' and SQL Server complains also ...
> >
> > Calling with n=3 and *ind=3 succeeds but inserts the string '€  ' into
> > the database because the Server pads with 2 blanks to the 
> > requested size
> > of 3 CHARS.
> >
> > Setting *ind=SQL_NTS did not help.
> >
> > I have tested version 0.83dev 2008-10-09 also: It did not work at
> > all using UTF-8 strings with non single byte UTF-8 characters.
> >
> > So I have had a look at what is going on inside the FreeTDS code
> > (ver. 0.83dev) and found that the problem arises due to insufficient
> > buffer space for the bounded parameter.
> >
> > I solved the problem with very small changes to tds/mem.c and
> > odbc/sql2tds.c (see attached patch). For me it works now.
> >
> > Any comments on this issue ?
> >
> > Best regards,
> > Norbert
>
> It's strange that every time you implement a feature someone ask for 
> another... well, this means that previous works as expected I hope :)
> WVARCHAR is currently in progress. I don't think is supported by 0.82 and 
> have some problems (there is a failing test) under CVS HEAD. Test related to 
> your problem should be utf8, I'll test with your string.
>
> Actually I'm quite busy so I have no timeline for this issue.
>
> freddy77

I was not aware of the fact that utf-8 support is quite new to FreeTDS.
I have had a look at the documentation before I tried to use it, a few
days ago, and it seemed to me that by setting the Client Charset to
UTF-8 one can use a MS SQL Server like any other UTF-8 capable DMBS --
though MS SQL Server itself is not UTF-8 capable ! This is a very
valuable feature of FreeTDS !

Besides, if I understand correctly, requesting SQL_WVARCHAR vs. 
SQL_VARCHAR as SQL parameter type does not make any diffence to FreeTDS 
? Only the server will not_do/do a USC-2 --> CP1252 --> UCS-2
conversion with the data ? (assuming CREATE TABLE ... NVARCHAR() ..)

Norbert