title: Play! Morphia querying within Collection (i.e. Set or List) fields
body: <p>I have documents with a Set of Long values for their parent document IDs like so:</p>
  
  <pre><code>{..., "parentIDs" : [ 47, 49 ], ...}
  </code></pre>
  
  <p>In my Entity class this field is defined as:</p>
  
  <pre><code>@Embedded(concreteClass = java.util.TreeSet.class)
  @Indexed
  public Set&lt;Long&gt; parentIDs = new TreeSet&lt;Long&gt;();
  </code></pre>
  
  <p>What would be the Morphia query to return all documents with a specific parent ID (for example 47)?</p>
  
  <p>I'm using:</p>
  
  <pre><code>List&lt;Node&gt; nl = Node.find("type", "event").filter("parentIDs", id).asList();
  </code></pre>
  
  <p>with id being a correct and existing parent document id.
  But it does not work. What am I missing?</p>
  
  <p>thanks eriq</p>