डेटा मौजूद न होने पर भी मैसकल महीने-वार रिकॉर्ड का चयन करेगा

मैं दक्षता के बारे में ज्यादा कुछ नहीं कहूंगा क्योंकि मैंने इसे अन्य तरीकों के खिलाफ परीक्षण नहीं किया है, लेकिन एक अस्थायी तालिका के बिना यह जाने का एक उचित तरीका प्रतीत होता है।

   SELECT COUNT(u.userID) AS total, m.month
     FROM (
           SELECT 'Jan' AS MONTH
           UNION SELECT 'Feb' AS MONTH
           UNION SELECT 'Mar' AS MONTH
           UNION SELECT 'Apr' AS MONTH
           UNION SELECT 'May' AS MONTH
           UNION SELECT 'Jun' AS MONTH
           UNION SELECT 'Jul' AS MONTH
           UNION SELECT 'Aug' AS MONTH
           UNION SELECT 'Sep' AS MONTH
           UNION SELECT 'Oct' AS MONTH
           UNION SELECT 'Nov' AS MONTH
           UNION SELECT 'Dec' AS MONTH
          ) AS m
LEFT JOIN users u 
ON MONTH(STR_TO_DATE(CONCAT(m.month, ' 2013'),'%M %Y')) = MONTH(u.userRegistredDate)
   AND YEAR(u.userRegistredDate) = '2013'
GROUP BY m.month
ORDER BY 1+1;

यदि आप एक तिथि प्रारूप के आधार पर संघ बनाते हैं तो आप काम को कम भी कर सकते हैं और क्वेरी पर लोड कर सकते हैं।

   SELECT COUNT(u.userID) AS total, DATE_FORMAT(merge_date,'%b') AS month, YEAR(m.merge_date) AS year
     FROM (
           SELECT '2013-01-01' AS merge_date
           UNION SELECT '2013-02-01' AS merge_date
           UNION SELECT '2013-03-01' AS merge_date
           UNION SELECT '2013-04-01' AS merge_date
           UNION SELECT '2013-05-01' AS merge_date
           UNION SELECT '2013-06-01' AS merge_date
           UNION SELECT '2013-07-01' AS merge_date
           UNION SELECT '2013-08-01' AS merge_date
           UNION SELECT '2013-09-01' AS merge_date
           UNION SELECT '2013-10-01' AS merge_date
           UNION SELECT '2013-11-01' AS merge_date
           UNION SELECT '2013-12-01' AS merge_date
          ) AS m
LEFT JOIN users u 
       ON MONTH(m.merge_date) = MONTH(u.userRegistredDate)
          AND YEAR(m.merge_date) = YEAR(u.userRegistredDate)
GROUP BY m.merge_date
ORDER BY 1+1;

दोनों प्रश्नों का लाइव डेमो।