Re: SQL Server 2019: CHAR(N) using UTF-8 is seen as SQL_NVARCHAR by SQLDescribeCol()

I don't know anything about SQL Server 2019, but if they added the option
to allow UTF-8 encoding of character strings, it would seem natural that
said strings would be variable-length, even if declared CHAR(n). Strings
encoded in UTF-8 are inherently variable length.

Craig Jackson

On Wed, Feb 27, 2019 at 10:27 AM Sebastien FLAESCH <[email protected]> wrote:

> Hi,
>
> Just tried with TDS 7.4, it did not help.
>
> I have tested the MS ODBC driver 17.3.1.1, it works as expected
> ( I get 1/SQL_CHAR from SQLDescribeCol() )
>
> You may know that it's very easy to setup an SQL Server 2019 with
> docker, do you?
>
> Cheers,
> Seb
>
> On 2/27/19 3:08 PM, Frediano Ziglio wrote:
> > Hi,
> >    I would try to use TDS 7.4, not 7.3.
> > Also I would try to use Microsoft ODBC driver and a network analyzer
> > (like wireshark).
> >
> > Regards,
> >    Frediano
> >
> > Il giorno mar 26 feb 2019 alle ore 11:26 Sebastien FLAESCH
> > <[email protected]> ha scritto:
> >>
> >> Testing FreeTDS 1.1rc3 with SQL Server 2019:
> >>
> >> I get an unexpected SQL type code with a CHAR(10) column, when the
> >> database collation is using UTF-8.
> >>
> >> Instead of SQL_CHAR (or SQL_WCHAR), I get SQL_WVARCHAR.
> >>
> >> I have created a database with this collation:
> >>
> >>     Latin1_General_100_CI_AS_SC_UTF8
> >>
> >> Then created a table like this:
> >>
> >>     CREATE TABLE mytab1 ( col1 CHAR(10) )
> >>
> >> and inserted a row:
> >>
> >>     INSERT INTO mytab1 VALUES ( 'abc' )
> >>
> >> Then in the ODBC program:
> >>
> >>     SQLExecDirect(.."SELECT * FROM mytab1"..)
> >>     SQLDescribCol(...)
> >>
> >> Check the TDSDUMP trace in attachment (freetds-2019-1.log)
> >>
> >> token.c:1541:tds7_get_data_info:
> >>           colname = col1
> >>           type = 39 (varchar)
> >>           server's type = 231 (x UCS-2 varchar)           <-- 231 ?
> >>           column_varint_size = 2
> >>           column_size = 20 (20 on server)
> >>
> >>
> >> The same program, connecting to SQL Server 2017 (were DB collation is
> Latin1
> >> without UTF-8):
> >>
> >>
> >> token.c:1541:tds7_get_data_info:
> >>           colname = col1
> >>           type = 47 (char)
> >>           server's type = 175 (xchar)          <-- 175
> >>           column_varint_size = 2
> >>           column_size = 10 (10 on server)
> >>
> >> With SQL Server 2019, when using another collation (non-UTF-8)
> >>
> >>      CREATE TABLE mytab2 ( col1 CHAR(10) COLLATE Latin1_General_CI_AS )
> >>
> >> I get the expected tds type code...
> >>
> >> Seb
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> >
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