title: query that outputs that # of unique records per field in a model?
body: <p>Given a Model like:</p>
  
  <pre><code>Contact (id, user_id, xxx, xxxxxxx)
  </code></pre>
  
  <p>I would like to have a query that outputs that # of unique user_id records in the Contact model? Any thoughts on how to write this?</p>
  
  <p>Thanks</p>