title: MongoDB - manual references example
body: <p>I was reading the <a href="http://docs.mongodb.org/manual/reference/database-references/#document-references" rel="noreferrer">manual references</a> part from the MongoDB Database References documentation, but I don't really understand the part of the "second query to resolve the referenced fields". Could you give me an example of this query, so i can get a better idea of what they are talking about.</p>
  
  <blockquote>
    <p>"Manual references refers to the practice of including one document’s _id field in another document. The application can then issue a second query to resolve the referenced fields as needed."</p>
  </blockquote>