title: want to make relations(between Event and Files)
body: <p>I am using <code>plupload</code> plugin to upload multiple files. That works fine. </p>
  
  <p>In <code>Files</code> Model, I am storing the <code>user_id</code> and <code>blob_key</code>.
  Here is <a href="http://imgur.com/ywpXP" rel="nofollow">a form</a>.  </p>
  
  <p>Suppose User's uploaded the files using plugin. That files are successfully saved in <code>FILES</code>. Then he submit the form. Now <code>description</code> field saved to <code>Event</code>. how do I know that event has this this files? There is no any relationship between <code>Event</code> and <code>Files</code> models. I am confused. So Will you please help me to create a relationship? thanks alot :-) </p>
  
  <pre><code> class Files(db.Model):
        blob_key = blobstore.BlobReferenceProperty(required=True)
        created_by = xxxxxx
  </code></pre>
  
  <p>Here is my second Model</p>
  
  <pre><code>class Event(db.Model):
    description = db.StringProperty(required=True)
  </code></pre>