title: Most recent post does not come above post if there was already made an comment
body: <p>@Dianuj solved my issue a week ago, when I asked how I can get a <code>recent comment</code> above a <code>post</code>. That all worked very well, but yesterday, when I tested it, I saw a little issue, which I not want on my <code>Wordpress</code> site. Let me explain it to you...</p>
  
  <p>If someone makes a comment on a post that has none comments before you comment, then the function on this page <a href="https://stackoverflow.com/questions/17501490/how-to-get-most-recent-commented-post-above-new-submitted-post-in-wordpress">How to get most recent commented post above new submitted post in Wordpress?</a> will work flawlessly. I thank Dianuj for making my life easier.</p>
  
  <p><strong>The problem starts when a user makes a comment on a post that ALREADY has a comment in it. So for instance, you make the second comment on a post. In that case, the post title won't go up and show 'his' face on the page</strong>. That is the big problem and I hope someone can help me out with the snippets that are on this link <a href="https://stackoverflow.com/questions/17501490/how-to-get-most-recent-commented-post-above-new-submitted-post-in-wordpress">How to get most recent commented post above new submitted post in Wordpress?</a></p>
  
  <p>PS: for the lazy ones, here it goes --> </p>
  
  <pre><code>&lt;?php
  global $wpdb;
  $results = $wpdb-&gt;get_results("    SELECT p.*,
      (CASE WHEN c.comment_date IS NULL THEN p.`post_date` ELSE c.comment_date END) order_column
       FROM `wp_posts` p
      LEFT  JOIN `wp_comments` c  ON (p.ID = c.`comment_post_ID` ) WHERE p.post_type='post' AND p.post_status='publish'
      GROUP BY p.ID
       ORDER BY order_column   DESC"); 
  ?&gt;
  </code></pre>