Question

Does WCF Data Services support working with Entity Framework Code First (4.1)? It seems like it’s having a hard time understanding what to do with DbSet or DbContext. I suppose this shouldn’t be too surprising since EFCF was released after Data Services.

internal class Context:DbContext {
    public Context(String nameOrConnectionString) : base(nameOrConnectionString) { }

    public DbSet<AlertQueue> Alerts { get; set; }
}

public class EntitySet:Abstract.EntitySet {
    public EntitySet(String nameOrConnectionString) {
        var context = new Context(nameOrConnectionString);

        this.AlertQueueRepository = new Concrete.AlertQueueRepository(new Repository<AlertQueue>(context, context.Alerts));
    }
}

public class AlertQueueRepository:EntityRepository<AlertQueue> {
    public AlertQueueRepository(IEntityRepository<AlertQueue> entityRepository):base(entityRepository) { }

    public IQueryable<AlertQueue> Pending {
        get {
            return (from alert in this.All
                    where alert.ReviewMoment == null
                    select alert);
        }
    }
}

EntityRepository and IEntityRepository provide generic methods for All and other CRUD functions. This is the WCF Data Service that isn’t working:

public class WcfDataService1:DataService<Domain.Concrete.AlertQueueRepository> {
    public static void InitializeService(DataServiceConfiguration config) {
        config.SetEntitySetAccessRule("All", EntitySetRights.AllRead);
        config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;
    }
}

Answer 1

You need to install Microsoft WCF Data Services 2011 CTP2.

Here is a good step by step article from the ADO.NET Team Blog: Using WCF Data Services with Entity Framework 4.1 and Code First

You will need to change the reference for “System.Data.Services” and “System.Data.Services.Client”
to “Microsoft.Data.Services” and “Microsoft.Data.Services.Client” after installing the CTP and then you will have a new V3 protocol version (DataServiceProtocolVersion.V3)

Add a constructor like below to pass in a connection string or database name

public class HospitalContext : DbContext
{
    public HospitalContext(string dbname) : base(dbname)
    {
    }

    public DbSet<Patient> Patients { get; set; }
    public DbSet<LabResult> LabResults { get; set; }
}