Question

using the following LINQ query:

EntityQuery<Questions> query = context.GetQuestionsQuery()
                  .Where(o => o.SurveyQuestions.Any(o2 => o2.SurveyID == 3));

However when using LINQPad…it works fine.

Questions.Where(o => o.SurveyQuestions.Any(o2 => o2.SurveyID == 3)).Dump();

is this a limitation of Silverlight? If so How can i do the same thing in a silverlight friendly way? On a little more investigation this looks like its being caused in the DomainContext.Load operation.

Webpage error details

User Agent: Mozilla/4.0 (compatible;
MSIE 7.0; Windows NT 5.1; Trident/4.0;
.NET CLR 2.0.50727; .NET CLR
3.0.4506.2152; .NET CLR 3.5.30729; .NET4.0C; .NET4.0E; .NET CLR 1.1.4322)
Timestamp: Mon, 28 Feb 2011 18:06:11
UTC

Message: Unhandled Error in
Silverlight 2 Application Query
operator ‘Any’ is not supported. at
System.ServiceModel.DomainServices.Client.WebDomainClient1.BeginQueryCore(EntityQuery
query, AsyncCallback callback, Object
userState) at
System.ServiceModel.DomainServices.Client.DomainClient.BeginQuery(EntityQuery
query, AsyncCallback callback, Object
userState) at
System.ServiceModel.DomainServices.Client.DomainContext.Load(EntityQuery
query, LoadBehavior loadBehavior,
Action1 callback, Object userState)
at
System.ServiceModel.DomainServices.Client.DomainContext.Load[TEntity](EntityQuery1
query, LoadBehavior loadBehavior,
Action1 callback, Object userState)
at
System.ServiceModel.DomainServices.Client.DomainContext.Load[TEntity](EntityQuery1
query, Action1 callback, Object
userState) at
ReadmissionTrackingApplication.Client.ViewModel.QuestionairreViewModel.ReceiveNewQuestionairreRequest(fnReadmitPatientList_Result
request) at
GalaSoft.MvvmLight.Helpers.WeakAction1.Execute(T
parameter) at
GalaSoft.MvvmLight.Helpers.WeakAction1.ExecuteWithObject(Object
parameter) at
GalaSoft.MvvmLight.Messaging.Messenger.SendToList[TMessage](TMessage
message, IEnumerable`1 list, Type
messageTargetType, Object token) at
GalaSoft.MvvmLight.Messaging.Messenger.SendToTargetOrType[TMessage](TMessage
message, Type messageTargetType,
Object token) at
GalaSoft.MvvmLight.Messaging.Messenger.Send[TMessage](TMessage
message) at
ReadmissionTrackingApplication.Client.ViewModel.PrimarySearchViewModel.OpenSurveyCommand_Execute()
at
ReadmissionTrackingApplication.Client.ViewModel.PrimarySearchViewModel.b__2()
at
GalaSoft.MvvmLight.Command.RelayCommand.Execute(Object
parameter) at
System.Windows.Controls.Primitives.ButtonBase.ExecuteCommand()
at
System.Windows.Controls.Primitives.ButtonBase.OnClick()
at
System.Windows.Controls.Button.OnClick()
at
System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs
e) at
System.Windows.Controls.Control.OnMouseLeftButtonUp(Control
ctrl, EventArgs e) at
MS.Internal.JoltHelper.FireEvent(IntPtr
unmanagedObj, IntPtr unmanagedObjArgs,
Int32 argsTypeIndex, Int32
actualArgsTypeIndex, String eventName)
Line: 1 Char: 1 Code: 0 URI:
http://localhost/readdtrackapp/Silverlight.js

Answer 1

Its because not all the LINQ queries are supported by EntityQuery class. Only the following operators would work with EntityQuery:

• Where
• OrderBy
• ThenBy
• Skip
• Take

http://msdn.microsoft.com/en-us/library/system.servicemodel.domainservices.client.entityquery%28v=vs.91%29.aspx