We have released a new sample on our Sync code gallery site that demonstrates use of Sql Express database for offline caching and synchronization purposes. Sync Services for ADO.Net (a.k.a Occasionaly Connected Systems OCS) lets users take a database offline and enabled synchronization with the server in a hub-spoke topology. The released version shipped a full client provider implementation for Sql CE database. Users have been very eager to use SQL Express as their client and this sample ships an express client provider implementation and a test client demonstrating its usage. From our Sync blog.

"In this sample, two tables (orders and order_details) are on the server database and also on the local client database.  The sample synchronizes edits to these table to keep their data identical.
This sample demonstrates:

  • Using SQL Express to cache changes for a client application.
  • A customized SQLExpressClientSyncProvider class that wraps around Microsoft.Synchronization.Data.Server.DbServerSyncProvider.

I would like to point out that even though we have done a fair amount of testing in house with this sample, it is still only posted as a sample.  In the future we certainly plan of including a fully supported version of a SQL Express client provider within a future release of Sync Services for ADO.NET.  "

The sample Express provider does not support schema initialization so your client schema should be pre populated. The sample uses triggers for change tracking on server and client. Please take the sample for a spin and provide feedback at our forum.