title: Postgres window function column with Rails
body: <p>I'd like to use the rank() function PostgreSQL on one of my columns.</p>
  
  
  
  <pre><code>Character.select("*, rank() OVER (ORDER BY points DESC)")
  </code></pre>
  
  <p>But since I don't have a rank column in my table rails doesn't include it with the query. What would be the correct way to get the rank included in my ActiveRecord object?</p>