Re: DB2 UTF-8 ODBC double conversion

From:

"Tom Serface" <tom@camaswood.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Fri, 20 Nov 2009 09:55:21 -0800

Message-ID:

<OeyOvqgaKHA.5544@TK2MSFTNGP02.phx.gbl>

Is the data in the DB/2 database Unicode? If you're getting two bytes for
each then maybe there is a conversion being done some where. I don't think
this is necessarily a bad thing since it might save you some conversion
headaches if you just convert your MFC app to Unicode and use that all the
time.

My guess is the conversion is happening somewhere before it gets to the
database. Are you sure there is nothing like MultiByteToWideChar() being
called in your code somewhere?

Of course, doing ANSI and counting on codepage would be the worst way to
handle strings in a database that could be accessed from any language
install of the OS. In my experience going to Unicode hasn't really affected
the performance much.

Tom

"Mihajlo Cvetanovi??" <mcvetanovic@gmail> wrote in message
news:e9XxarfaKHA.4668@TK2MSFTNGP06.phx.gbl...

I inherited a non-Unicode MFC project that connects to DB2 database through
ODBC. The application uses UTF-8 strings for database transactions because
the the strings are multilingual. In DB2 Control Center I see those strings
as "raw", but when calling SELECT LENGTH(<some_column>) FROM <some_table> I
see that each UTF-8 byte occupies two bytes in database, as if there is
extra conversion to UTF-8 taking place between ODBC and database. It seems
that DB2 doesn't understand that I'm working with UTF-8 strings and thinks
that those strings coming from ODBC are in system code page.

Is there a way to disable this extra conversion to UTF-8, and make DB2
aware that strings from ODBC are already UTF-8?

I realize this is more the question for some DB2 newsgroup, but it
involves MFC as well.