>(the learning curve I have currently is like climbing a steep mountain of loose gravel)... > >OK. I have a silverlight 4 app. EF datamodel of my SQL database. Domain DataService making my Entities visible. > >Two entity tables are Projects and Change_Requests. Projects has primary key Project_ID. Change Requests has FK Product_ID. Change Requests have a SubdivisionID (int) field. > >They seem to be functioning as entities correctly. The GetProjectsQuery and GetChange_RequestQuery queries seem to be functional (all built automatically when creating the datamodel and domainservice). > >This works fine.. > > EntityQuery<Project> query = (from P in _Context.GetProjectsQuery() > where P.Proj_Name.Contains(txtFilterProjectName.Text.Trim()) > orderby P.Proj_Name > select P); > LoadOperation<Project> lo = _Context.Load<Project>(query); > > DataGridProjects.ItemsSource = lo.Entities; > >GetChange_RequestQuery works ok too. > >Now I'm trying to do the equivalent of a join or subquery to get Projects that have Change_Requests in a specific Change_Request.SubdivisionID. > >I've tried.. > > EntityQuery<Project> query = (from p in _Context.Projects > from c in _Context.Change_Requests > where p.Project_ID == c.Project_ID && c.Subdivision == SubdivisionID > select p); > >I get an error .. >Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<ChangeManagement.Web.Project>' to 'System.ServiceModel.DomainServices.Client.EntityQuery<ChangeManagement.Web.Project>' > >OK, let's try using the Getmethods (like the one that worked above).. > > EntityQuery<Project> query = (from p in _Context.GetProjectsQuery() > from c in _Context.GetChange_RequestQuery() > where p.Project_ID == c.Project_ID > && c.Subdivision.Equals(SubdivisionID) > select p); > >Error.. >Could not find an implementation of the query pattern for source type 'System.ServiceModel.DomainServices.Client.EntityQuery<ChangeManagement.Web.Project>'. 'SelectMany' not found. > >OK - let's try a join.. > EntityQuery<Project> query = (from p in _Context.Projects > join c in _Context.Change_Requests on p.Project_ID equals c.Project_ID > where c.Subdivision.Equals(SubdivisionID) > select p); > >Error.. >Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<ChangeManagement.Web.Project>' to 'System.ServiceModel.DomainServices.Client.EntityQuery<ChangeManagement.Web.Project>' > >What am I missing?? Apparently working with more than one entity changes the query to IEnumerable rather than EntityQuery? > >How do I get by this? > >