title: Storing a collection of IWhatever in MongoDB via NoRM
body: <p>I'm having a very hard time getting this working; not even totally sure that it's possible.</p>
  
  <p>Let's imagine a simple scenario:</p>
  
  <pre><code>class Employee {
     List&lt;ITask&gt; Tasks {get;set;}
  }
  </code></pre>
  
  <p>And say we have two different implementations of tasks.</p>
  
  <p>If I want to save the Employee object in MongoDB as a single document (the right way to do it I think), I'm getting completely stuck on being able to do any useful querying.  For instance, if a certain kind of ITask has categories and I want to pull ITasks in category A.  Or if a task is referenced in another document and I need to go pull it back.  I keep running into "not supported" problems (SelectMany, OfType) and then things go downhill from there.</p>
  
  <p>Anyone have some insight on how to accomplish either of those scenarios?</p>