title: How to use COUNT(column) in Sequel?
body: <p>I'm trying to build this query:</p>
  
  <pre><code>SELECT name, COUNT(file) AS f FROM user GROUP BY name
  </code></pre>
  
  <p>This is what I'm doing:</p>
  
  <pre><code>db[:user].select(:name).count(:file).group(:name)
  </code></pre>
  
  <p>But it doesn't work. How can I add that <code>COUNT(file) AS f</code> to the list of <code>SELECT</code> operands?</p>