title: selecting between date range and forcing empty rows to be 0?
body: <p>I have a table that looks like</p>
  
  <pre><code>expires    | value  
  -------------------
  2011-06-15 | 15  
  2011-06-15 | 15  
  2011-06-25 | 15  
  2011-07-15 | 15  
  2011-07-15 | 15  
  2011-07-25 | 15  
  2011-08-15 | 15  
  2011-08-15 | 15  
  2011-08-25 | 15
  </code></pre>
  
  <p>I want to run a query that will spit out</p>
  
  <pre><code>June   | 45  
  July   | 45  
  August | 45  
  </code></pre>
  
  <p>So my query is </p>
  
  <pre><code>  SELECT SUM(amount) AS `amount`, 
           DATE_FORMAT(expires , '%M') AS `month`  
      FROM dealDollars 
     WHERE DATE(expires) BETWEEN DATE(NOW()) 
                             AND LAST_DAY(DATE(NOW()+INTERVAL 3 MONTH)) 
  GROUP BY MONTH(expires)
  </code></pre>
  
  <p>Which works fine.  But with the result, if there were no rows in say July, July would not show up.</p>
  
  <p>How can I force July to show up with 0 as its value?</p>