title: SQL Group with Order by
body: <p>This feels like it should have a basic solution but I don't seem to be getting it.</p>
  
  <p>Take this query:</p>
  
  <pre><code>            SELECT Category FROM Article
              GROUP BY Category
  </code></pre>
  
  <p>I want to effectively do this:</p>
  
  <pre><code>            SELECT Category, DatePublished FROM Article 
              GROUP BY Category
              ORDER BY DatePublished DESC
  </code></pre>
  
  <p>I don't really want to select DatePublished, but it seemed to make sense to order by it. That doesn't work though.</p>
  
  <p>Basically I want to order categories by the most recent DatePublished article.</p>