title: LINQ2SQL vs EF4: Entity retrieval and usage from different contexts
body: <p>I am long time user of LINQ2SQL, but have not used the Entity Framework yet.</p>
  
  <p>One thing that is not possible in LINQ2SQL is to use tracked entities in different data contexts, or 'link' objects from different data contexts. </p>
  
  <p>Example:</p>
  
  <pre><code>Foo f = null;
  
  using (var dc = new DB()) 
    f = dc.Foos.Single(x =&gt; x.ID = 1);
  
  using (var dc = new DB()) 
  {
    var b = new Baz();
    dc.Bazs.InsertOnSubmit(b);
    f.Baz = b;
    dc.SubmitChanges();
  }
  </code></pre>
  
  <p>Note: IIRC, this <strong>can</strong> work if using disconnected objects (but IMO that is pretty useless).</p>
  
  <p>Today, I saw an <a href="http://www.primaryobjects.com/CMS/Article122.aspx" rel="nofollow">article on EF4</a> implying that the pattern above <strong>can</strong> be used with EF4. </p>
  
  <p>So the question is: Is this in fact possible?</p>