Cypris’ lookout

MS Access: upsizing to SQL Server 2008

Tuesday, March 17, 2009

I’m currently researching ways to move my main MS Access application from a simple local network client/backend setup to a global, multiple remote sites configuration using SQL Server.

One of the challenges is to upsize the current MS Access 2007 backend database to SQL Server 2008. If you try it from Access itself using the Upsizing Wizard, you may end up getting this error message:

The Upsizing Wizard only works with Microsoft SQL Server (Versions 6.50 SP5 or higher). Please log in to a SQL Server data source.

After spending some time fiddling around with SQL Server settings I couldn’t understand why I was still getting this error.
Turns out that the upsizing wizard is apparently sensitive to the version of SQL Server you’re using and it doesn’t consider SQL Server v10 (2008) as being later than v6.50…

This issue is in fact a blessing.
Microsoft provides a migration tool for upsizing MS Access database to SQL Server 2008 that’s orders of magnitude better than anything the basic wizard can do: the SQL Migration Assistant for Access, or SSMA.

SSMA lets you take a bunch of Access databases and move the tables and queries you choose to SQL Server, automatically linking them in your original database if you want.
It’s not just a one-off thing either: SSMA keeps track of the objects that where transferred and allows you to synchronise both schema and data as often as you need.

So here you are: do not use the basic MS Access Upsizing Wizard, download and use SSMA instead.

Strange COM Error

While SSMA works perfectly fine on my Windows 2008 x64 laptop, on my main Windows XP desktop it throws an exception when trying to load an Access database:

Unable to cast COM object of type ‘Microsoft.Office.Interop.Access.Dao.DBEngineClass’ to interface type ‘Microsoft.Office.Interop.Access.Dao._DBEngine’
… {00000021-0000-0010-8000-00AA006D2EA4}…

It was a COM error saying that the library for DAO couldn’t be loaded.

I couldn’t find any relevant information on the web.
After a while, I had a look at the DAO driver in
C:\Program Files\Common Files\Microsoft Shared\DAO\dao360.dll
and I noticed that the filename was in blue: that reminded me that I had set compression on the filesystem.

I disabled compression for the file and, magically, SSMA worked again…

Moral of the story: be careful about compressing your filesystem, some registered libraries and system files may work in unpredictable ways…

References

• SQL Server Migration Assistant for Access main page.
• SQL Server Migration Assistant download. Note that you will have to register to get a license file that you need to save on your PC before you can use this free tool.
• “Access 2007 Upsizing to SQL Server 2008 Express in SQL Upsizing” discussion on Microsoft groups.
• “KB838594: Error message when you try to upsize your Access database by using the Upsizing Wizard” is not the problem here, but some may find the reference useful if you’re trying to upsize your MS Access database to a SQL Server database on a network.
• My random thoughts on SQL Server Upsizing from Microsoft Access from Tony’s Access MVP website, and his list of links to other resources.

Updates

• 17MAR2009: Added section on the strange COM error.
• 14MAR2009 : Added links to Tony’s Access MVP website.
• 05JAN2009 : Original publication.

Entry Filed under  :  Database, MSAccess, Programming