title: How to join DBRef objects in mongo
body: <p>Hi I am having my first collection</p>
  
  <pre><code>    students 
  {
   "name" : "abc"
   "class" : "1"
   "subjects" : DBRef("subjects","class1")
  }
  </code></pre>
  
  <p>and my second collection</p>
  
  <pre><code> subjects
  {
   "_id" : "class1"
   "sub1" : "english"
   "sub2" : "physics"
  }
  </code></pre>
  
  <p>I want to achieve my output as below my joining the above two collections</p>
  
  <pre><code>   {
   "name" : "abc"
   "class" : "1"
   "subjects" : {sub1 : "english",sub2 : "physics"}
  }
  </code></pre>
  
  <p>Is it possible,if yes how?</p>