From Class to Linq

   Queries in Silverlight (which I assume you're using since you posted in this forum) must be asynchronous unless directed against the local cache.  So the basic query would look something like this:

      var vendorsQuery = entityManager.Vendors

        .OrderBy(v => v.VendorName);

      _em1.ExecuteQueryAsync<Vendor>(vendorsQuery, GotVendors, null);

...

    private void GotVendors(EntityQueryOperation<Vendor> op) {

      ObservableCollection<Vendor> vendors = 

        new ObservableCollection<Vendor>();

      op.Results.ForEach(v => vendors.Add(v));

    }

or using the anonymous method syntax,

      var vendorsQuery = entityManager.Vendors

        .OrderBy(v => v.VendorName);

      entityManager.ExecuteQueryAsync<Vendor>(vendorsQuery, op => {

        ObservableCollection<Vendor> vendors =

          new ObservableCollection<Vendor>();

        op.Results.ForEach(v => vendors.Add(v));

      },

      null);

    }

If you want write a FetchVendors method, you'll need to pass it a callback method so it can "phone" your calling method back when the results have been returned from the asynchronous query operation. For an example of that, see the GetEmployeeWithTotalOrderRevenueAsyncMethod() mini-demo in the Silvermight MiniDemos solution for Object Persistence, described here:

DevForce 2010 Documentation � Business Object Persistence � Code Sample - Mini-Demos (Silverlight)