title: OData POST entity creation with expand
body: <p>I'm attempting to create an instance of an entity and two child entities at the same time. </p>
  
  <p>If I post the following JSON to the /user_objects resource it happily creates the parent user_object entity and the linked User_object_attribute entity. The only problem is that I can't seem to expand the result set to include the new user_object_attribute so I effectively have the most uptodate version of the user_object but I have to then go and read from the OData service i.e. another server hit in order to retrieve the user_object_attributes.</p>
  
  <p>Upon returning I have the id that would go neatly into the child user_object_attribute object but what if the child had a further server-side generated field like created_date? Then I still have to hit the OData repo again? </p>
  
  <p>I've tried the correct $expand query ?$expand=user_objects_attributes and while the creation succeeds I still am not returned the expanded result set. </p>
  
  <p>Would anyone have any idea if this is possible? Or is it a case that it isn't because hte only way to do it would be to return all the child user_object_attributes? </p>
  
  <pre><code>{
     "annotator_id":1,
     "content_type":"content_type",
     "created_date":"2013-02-15T17:20:09.191",
     "guid":"GUID",
     "size_kb":100,
     "title":"Title",
     "updated_date":null,
     "url":"URL",
     "user_object_id":0,
     "user_objects_attributes":[
        {
           "attribute_id":0,
           "name":"name191",
           "user_object_id":0,
           "value":"value191"
        }
     ]
  }
  </code></pre>
  
  <p>Thanks,
  Mark.</p>