title: Issues when querying multiple entities with LINQ and ObjectSet, type conversion errors?
body: <p>I have a model comprised of multiple entities. I am trying to write a LINQ statement in my controller to query some of these entities. Thanks in advance for any help offered, this is driving me crazy.</p>
  
  <p>For each ObjectSet statement (see below) I receive the following error:</p>
  
  <pre><code>Cannot implicitly convert type 'System.Data.Entity.DbSet&lt;MyApp.Models.MY_ENTITY_1&gt;' to 'System.Data.Objects.ObjectSet&lt;MyApp.Models.MY_ENTITY_1&gt;'
  </code></pre>
  
  <p>Here is my code: </p>
  
  <pre><code> public class MyController : ApiController
      {
      private MyEntities context = new MyEntities();
  
      public IQueryable &lt;string&gt; Get()
  
      {
          ObjectSet&lt;MY_ENTITY_1&gt; my_entity_1 = context.MY_ENTITY_1; //Error here
          ObjectSet&lt;MY_ENTITY_2&gt; my_entity_2 = context.MY_ENTITY_2; //Error here
          ObjectSet&lt;MY_ENTITY_3&gt; my_entity_3 = context.MY_ENTITY_3; //Error here
  
          var query =
              from MY_ENTITY_1 in my_entity_1
              from MY_ENTITY_2 in my_entity_2
              from MY_ENTITY_3 in my_entity_3
  
              where
                   MY_ENITITY_1.something == MY_ENTITY_2.something
  
              select new
                  {
                      Result1 = MY_ENTITY_1.FOO1,
                      Result2 = MY_ENTITY_2.FOO2,
                      Result3 = MY_ENTITY_3.FOO3
                  };
  
          foreach (var myResults in query)
          {
              Console.WriteLine(myResults);
          };
  
          return myResults;
      }
  </code></pre>