title: Trying to order a query after using ROLLUP
body: <p>In mysql, I need to order the result bellow by the year/month desc:</p>
  
  <pre><code>Month          Mod1    Mod2    Mod3
  Jan/2013        5       4       2
  Jan/2013        1       5       3
  Total           6       9       5
  Feb/2013        6       3       2
  Feb/2013        2       1       4
  Total           8       4       6
  Mar/2014        6       3       2
  Mar/2014        2       1       4
  Total           8       4       6
  </code></pre>
  
  <p>Ordering by year/month desc should be:</p>
  
  <pre><code>Month          Mod1    Mod2    Mod3
  Mar/2014        6       3       2
  Mar/2014        2       1       4
  Total           8       4       6
  Feb/2013        6       3       2
  Feb/2013        2       1       4
  Total           8       4       6
  Jan/2013        5       4       2
  Jan/2013        1       5       3
  Total           6       9       5
  </code></pre>
  
  <p>The query is:</p>
  
  <pre><code>SELECT
     month,
     year,
     SUM(IF(mod = 1, 1, 0)) AS mod1,
     SUM(IF(mod = 2, 1, 0)) AS mod2,
     SUM(IF(mod = 3, 1, 0)) AS mod3
  FROM
     DW_RM_Log
  WHERE
     ...
  GROUP BY
     year, month
  WITH ROLLUP
  HAVING year IS NOT NULL AND month IS NOT NULL
  </code></pre>
  
  <p>I can't just insert ORDER BY year, month DESC at the end, because I get the following error: 'SQLSTATE[HY000]: General error: 1221 Incorrect usage of CUBE/ROLLUP and ORDER BY'. Any suggestions?</p>