Restrictions for current version of Data Service :

--EF provider

1. Opertaion methods can only returns collections of Model Entitities, Model Complex Types or simple types.

2. Even if operation return IQueriable type all aux filter conditions wont be suppported.

Ie :

//This is model's entity or complex type

class Thing

{

int Val {get;set;}

}

[WebGet]

IQueriable GetThings()

You can't use this request :

...MyService.svc?GetThings$filter = Val eq 1

3. No operation method overridens