problems with DSN for MS Acess database

[kdv09]

Hi!
I'm looking for some help in fixing my screwup:

I've got C++ app which reads MDB database, using MFC CDatabase and
CRecordset derived classes. I had it working OK on development PC (Win
XP SP2) with MS Access 2000 installed (the app itself does not use MS
Access). I moved the app on another PC (also Win XP SP2) without MS
Access. After some poking around I've figured out that the app does not
work because DSN it is using was not available. So I created System DSN
for MS Access Database by hand and my app was working OK.

After that by silly mistake User DSN for MS Access Database was created
on the development PC (the one with existing and working MS Access).
This upset performance of database access very badly - it takes very
long time to read and move through the records.
I've (1) unrolled XP to earlier date, (2) reinstalled MS Access - still
have the problem.

MS Access itself seems to be OK, no noticeable degradation of speed,
but CDatabase.Open and ExecuteSQL, CRecordset::Mov eFirst MoveNext, etc
take very long time. It also looks like increased disk activity during
those operations.

So, any hints on what's going on and how stop it from going on like
that?

Many thanks
kdv09

[Sky]

<kd***@excite.c om> wrote in message
news:11******** **************@ g44g2000cwa.goo glegroups.com.. .

Cool! I was just thinking there might be some API like CreateDSN or
something. But distributing and importing reg file with installation is
OK
Thank you for your help
kdv09

I believe the ODBC library does have functions to create DSNs at run time,
but I have never used them. I find it easer to simply write to the registry.
And if you use a static ODBC connection that does not change, then it is
easier to make the ODBC setup part of your install procedure, not part of
your program itself.

- Steve

[Sky]

<kd***@excite.c om> wrote in message
news:11******** *************@g 47g2000cwa.goog legroups.com...

David,
thanks for the suggestions! As a matter of fact, I had no particular
preference, just used some code from example i saw somewhere and it
worked. But now, after you've mentioned the issue I can see that using
DSN might be somewhat limiting in my application and DSN-less
connection could be a bettter choice - I will investigate and try to
use DSN less connection
Many thanks
kdv09

My understanding was that this is an existing C++ program that calls the
standard ODBC library directly, not the ADO interface and not an Access
application with table links.

- Steve

[Bernard Peek]

In message <11************ **********@g14g 2000cwa.googleg roups.com>,
kd***@excite.co m writes

Hi!
I'm looking for some help in fixing my screwup:

I've got C++ app which reads MDB database, using MFC CDatabase and
CRecordset derived classes. I had it working OK on development PC (Win
XP SP2) with MS Access 2000 installed (the app itself does not use MS
Access). I moved the app on another PC (also Win XP SP2) without MS
Access. After some poking around I've figured out that the app does not
work because DSN it is using was not available. So I created System DSN
for MS Access Database by hand and my app was working OK.

I notice you got the problem fixed. Other people working with file DSNs
may like to know that the File DSN is a simple text file that can be
hand-edited if necessary. The only problem is that they appear to use
UNIX style line-end codes, so Notepad and other text editors can't edit
them. But Wordpad can edit UNIX text files and so can be used to edit a
File DSN.

--
Bernard Peek
London, UK. DBA, Manager, Trainer & Author.

[David W. Fenton]

"Sky" <sk*@NOSPAMstan leyassociates.c om> wrote in
news:LK0qf.4249 7$eI5.3953@trnd dc05:

<kd***@excite. com> wrote in message
news:11******** *************@g 47g2000cwa.goog legroups.com...

David,
thanks for the suggestions! As a matter of fact, I had no
particular preference, just used some code from example i saw
somewhere and it worked. But now, after you've mentioned the
issue I can see that using DSN might be somewhat limiting in my
application and DSN-less connection could be a bettter choice - I
will investigate and try to use DSN less connection

My understanding was that this is an existing C++ program that
calls the standard ODBC library directly, not the ADO interface
and not an Access application with table links.

I don't know anything about C++, but many programming environments
have db libraries that would allow DSN-less connections. However,
the only ones I know about are much further from the metal than C++.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

[David W. Fenton]

kd***@excite.co m wrote in
news:11******** **************@ g44g2000cwa.goo glegroups.com:

But distributing and importing reg file with installation is
OK

Might not work on a machine with the registry permissions locked
down. You could probably avoid that by making sure the registry
entry you write is in the current user hive, and not in local
machine (which would be accessible only to users running with
administrative permissions, or with custom registry permissions that
allow users to write to it).

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/