title: Can you select all child collections of a collection of entities as a single collection?
body: <p>I have a collection of "ParentEntity", each one of which has a collection of "ChildEntity".</p>
  
  <p>I'd like to select ALL of the ChildEntity as a single collection.</p>
  
  <pre><code>var children = from p in parents
   select p.Children;
  </code></pre>
  
  <p>Returns a collection of ChildEntity collections?</p>
  
  <p>I'd like to get a single collection of all the Children, rather than a collection of collections.</p>