title: mySQL order by date field not working
body: <p>I am trying to get a data sorted from 2 tables posts and postmeta</p>
  
  <p>Example wp_posts Table</p>
  
  <pre><code>ID      post_title          post_name
  328   Test Event Five   test-event-five
  326   Test Event Four   test-event-four
  324   Test Event Three  test-event-three 
  321   Test Event  Two   test-event-two 
  320   Test Event One    test-event-one
  </code></pre>
  
  <p>Example wp_postmeta Table</p>
  
  <pre><code>id  post_id       meta_key                    meta_value
  1    328      calendar_start-date            August 08, 2012
  2    326      calendar_start-date            August 09, 2012
  3    324      calendar_start-date            September 06, 2012
  4    321      calendar_start-date            August 23, 2012  
  5    320      calendar_start-date            September 17, 2012
  </code></pre>
  
  <p>In order to output the data ordered by the dates in the meta value, I am using the query</p>
  
  <pre><code>SELECT wp_posts.ID, 
         wp_posts.post_title, 
         wp_posts.post_name, 
         wp_postmeta.post_id,
         wp_postmeta.meta_value as event_date 
  FROM wp_posts, wp_postmeta 
  WHERE wp_posts.ID = wp_postmeta.post_id 
  AND wp_postmeta.meta_key = 'calendar_start-date' 
  AND wp_posts.post_status = 'publish' 
  AND wp_posts.post_type = 'calendar' 
  ORDER BY DATE_FORMAT( event_date, '%M %d, %Y' ) DESC 
  LIMIT 0 , 30
  </code></pre>
  
  <p>But the result is not ordered by the dates, instead it is coming as</p>
  
  <pre><code>ID     post_title          post_name      post_id   event_date
  328  Test Event Five    test-event-five     328     August 08, 2012
  326  Test Event Four    test-event-four     326     August 09, 2012
  324  Test Event Three   test-event-three    324     September 06, 2012
  321  Test Event  Two    test-event-two      321     August 23, 2012
  320  Test Event One     test-event-one      320     September 17, 2012
  </code></pre>
  
  <p>Where am I going wrong in the query and how can I display the records ordered properly by the event_date. The input format of the date is MM dd, yy through UI/Datepicker.</p>