FreeTDS Development Group

["Brian Bruns" <camber AT ais.org>]

TDS 4.2 transfers data using a single byte character set as specified by
the client.  One can pass different character sets and the SQL Server will
attempt to use that set.

TDS 7.0 on the other hand has no notion of a character set, everything is
passed as UCS-2 (2 byte unicode).  By default the FreeTDS driver strips
the high order byte which leaves something resembling the iso_1 charset.
If all your data in the nchar field is western character set compatible,
then don't worry and you're all set.  If on the other hand you have
character data outside of that range (greek, arabic, CJKV) you'll need to
accomadate that data on a unix system.  That's where the 'client charset'
comes in.

Even if you store nothing but english text in a unicode column, you still
can't query it with TDS 4.2 (well, you can run convert() on it...but that
is another story), TDS 7.0 is the only protocol version that supports it.

So, that's why TDS 4.2 wasn't working for you, now TDS 7.0 is a different
matter all together...i need to go double check what the story was there.

Brian

> >>> camber AT ais.org 12/03/01 07:04PM >>>
> 
> As far as the unicode table goes, the log is showing:
> 
> 2001-12-03 16:06:23 Msg 4004, Level 16, State 1, Server SCC-NT-IVR, Line 1
> ntext data cannot be sent to clients using DB-Library (such as ISQL) or=20
> ODBC version 3.7 or earlier.
> 
> Which basically means that TDS version 4.2 does not support unicode=20
> fields.  I need to look into why the error is not propagating up to the=20
> ODBC driver.  Unicode support in general in freetds is a little spotty,=20
> look at the 'client charset' settings in freetds.conf (see:
> http://www.freetds.org/userguide/unicode.html )
> 
> So, by specifying tds version =3D 7.0 in freetds.conf I am not actually =
> accomplishing anything? it was my understanding that I need to compile =
> with tdsver=3D4.2 and then add 7.0 to the conf file.
> 
> What should i have in the client charset? I was thinking it defaults to =
> something that fits US.
> 
> As far as non-unicode goes, I'm not seeing anything strange in the log,=20
> can you post either the ddl for your table or the output of sp_help on it?
> 
> sp_help?=20
> 
> Paivi