Coming from pre-WM7 systems, I’m quite used to having support for some breed of SQL Server (SQL CE) on devices. Well – it is not supported (in V1) on WM7. A number of alternatives exists here:
1) Sterling http://sterling.codeplex.com/
A Isolated Storage located database functionality.
”Sterling is a lightweight object-oriented database implementation for Silverlight and Windows Phone 7 that works with your existing class structures. Sterling supports full LINQ to Object queries over keys and indexes for fast retrieval of information from large data sets.”
2) PERST (Object database)
See Andy Wigley’s blog for additional info http://mobileworld.appamundi.com/blogs/andywigley/archive/2010/06/07/perst-a-database-for-windows-phone-7-silverlight.aspx
Haven’t tried them out at this time, but as time permits – I surely will!
Update: See this post: http://blog.clauskonrad.net/2010/10/how-to-database-for-wp7.html