Is it possible to use WCF Data Services to provide CRUD access to an entity that is stored in a federation member on SQL Azure Federation?
Assuming the federation key is stored in the security principal and is readily available in the application context, is there a way to intercept the service operations and issue the appropriate USE FEDERATION commands, opening the connection at the right time, as one would do if explicitly developing for ADO.NET Entity Framework?
I solved this issue by attaching an event handler to the "Connection.StateChange" property of the DbContext used by the WCF Data Service.
In this event handler, when the ConnectionState changes to Open I execute a "USE FEDERATION" command with the appropriate arguments (partition key and filter).
This way, every time the service is opening a new database connection, I make sure the first command issued in this connection is "USE FEDERATION". All subsequent commands on that connection operate in this context.