Re: Replacement for Dao

From: Roy Fine (rlfine_at_twt.obfuscate.net)
Date: 05/10/04 

Date: Sun, 9 May 2004 22:39:52 -0400

Rajas

I have to make sure that I was runing with a "real" 2003 format database, so
I created a new databse using Access 2003, and imported some data. I then
wrote a quick hack of a program to create a CDaoDatabase object and a
CDaoRecordset object, then open both and fetch from the database. All seems
to work ok - but I was using VC++ 7.1 (VS 2003).

regards
roy fine

(note - DAO is still available - but it has officially been moved to the
deprecated category - i.e. you should move to a new/supported technology
soon. There is no native support for Jet in .Net, so one could expect the
Jet Engine to be deprecated soon - in fact Jet will not be available at all
on 64 bit platforms, rather you have MSDE as the backend database engine)
   rlf

Here is a snip of the code that I used:

/* ******************************************* */
BOOL CDAODoc::OnNewDocument()
{
 if (!CDocument::OnNewDocument())
  return FALSE;

 CDaoDatabase *db;
 CString db_2003_Path = "C:\\Documents and Settings\\Administrator\\My
Documents\\FastTalk3000_vA.mdb";
 db = new CDaoDatabase();
 db->Open(db_2003_Path);

 CDaoRecordset *daorec = new CDaoRecordset(db);
 daorec->Open(AFX_DAO_USE_DEFAULT_TYPE,"Select count(*) FROM names_master");
 int reccnt = daorec->GetFieldValue(0).lVal;

 daorec->Close();
 db->Close();

 delete daorec;
 delete db;

 return TRUE;
}
/* ************************************************** */

"rajas" <rajas@cox.net> wrote in message
news:EfAnc.19083$ph.708@fed1read07...
> Roy,
> Thanks for the input.
>
> The application (an MFC app) that I am looking at actually works well with
> Access2000 - in fact the application checks to see if jet 4.0 is available
> and uses AfxGetModuleState()->m_dwVersion = 0x0601; to work around the
hard
> coding in MFC. However, something in Office 2003 seems to break it.
>
> As I wrote earlier, the application uses Jet database or SQL server. I
read
> that Jet actually provides ADO support through its ODBC (I am still
looking
> through examples in ODBC for Autonumber - seems a pain with need for
> multiple accessor macros , as well as BLOB support for large text
strings -
> was straight forward in Dao) and hence ODBC may perform better than ADO.
> Have not made a decision yet - but looks like I need to real soon.
>
> "Roy Fine" <rlfine@twt.obfuscate.net> wrote in message
> news:uouV1qSNEHA.892@TK2MSFTNGP09.phx.gbl...
> > Rajas,
> >
> > you may have gotten a bit of bad info -- DAO still works, it is MFC that
> is
> > hardcoded to the DAO 3.5 version. DAO 3.6 works well with Jet 4
database
> > versions through Access 2000 for sure.
> >
> > If you want to move away from DAO, then you should seriously consider
> ADO -
> > there are capabilities in ADO and ADOX that match DAO, while the ODBC
> > support is a bit weak (like not being able to create autonumber column,
> and
> > not being able to access the @@IDENTITY column, etc...)
> >
> > regards
> > roy fine
> >
> >
> > "rajas" <rajas@cox.net> wrote in message
> > news:H2tmc.17865$ph.13348@fed1read07...
> > > Hello,
> > >
> > > I need to 'update' an application that uses MFC Dao database classes -
> it
> > > appears that this will not work in newer Windows & no longer
supported.
> > The
> > > application uses Access or SQL server depending on the circumstances.
> > >
> > > What is the best alternative - Still need to use VC 6 (not .Net).
> Need
> > to
> > > taking into account learning curve & 'longevity' of support.
> Performance
> > is
> > > also a consideration - though secondary. Most ADO examples in MSDN
> > seem
> > > to be .Net or VB, and OLE DB examples are even more limited.
> > >
> > > I would appreciate any and all input. If there is already a place
where
> > > this has been discussed - I would appreciate if someone would point me
> to
> > > it.
> > >
> > > Thanks
> > >
> > >
> >
> >
>
>

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