Re: SQLBindParameter() does not work with UTF-8 ?!

> 
> 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
> 

Well... SQL_WVARCHAR have problems. FreeTDS support UTF-8 as client encoding converting as best as it can but using SQL_VARCHAR. There is a big difference between SQL_VARCHAR and SQL_WVARCHAR cause FreeTDS should use VARCHAR or NVARCHAR on server. Currently not supporting SQL_WVARCHAR means that you have to use SQL_VARCHAR which lead to VARCHAR so you can't represent much characters. When FreeTDS will support SQL_WVARCHAR any UCS-2 characters will be available to your client.

freddy77

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