title: Compare columns from SUM(CASE...END) in the same query
body: <p>I'm trying to add a column named <code>Ready</code> to my query that checks if the sum of <code>Complete</code> is = to the sum of <code>Total</code> and places 'Y' if True and 'N' if FALSE.</p>
  
  <p>Here is my query that works producing 4 columns</p>
  
  <pre><code> SELECT pc.Sub,
      SUM(CASE WHEN `SheetStatus` LIKE 'Complete' THEN 1 ELSE 0 END) AS 'Complete',
      SUM(CASE WHEN `SheetStatus` LIKE 'Not started' THEN 1 ELSE 0 END) AS 'Not Started',
      SUM(CASE WHEN `CheckSheet` LIKE '%' THEN 1 ELSE 0 END) AS 'Total'        
  FROM `pc`
  Group By pc.Sub WITH ROLLUP
  </code></pre>
  
  <p>I just cant figure out how to create the extra column if it is possible at all.
  Regards</p>