如何在MySQL中对多个子查询进行分组

Question

嗨我正在尝试对一系列子查询进行分组，但不断为每行获得相同的结果。

 SELECT Campaign_Name, 
        (SELECT COUNT(Bounce) 
        FROM `temp_Data`) AS Sent, (SELECT COUNT(Bounce) 
              FROM `temp_Data` 
              WHERE Bounce = '0') AS Delivered, (SELECT SUM(Opened) 
                 FROM `temp_Data` 
                 WHERE Opened = '1')AS Opened 
FROM temp_Data 

GROUP BY Campaign_Name 

结果是：

Campaign Name Sent Delivered Opened 
Campaign1  300 278  196 
Campaign2  300 278  196 

我的数据是0.1所以，即使我总结它仍然给了我同样的结果。

如何获得每个广告系列的个人计数？

Answer 1

这可以在一个单一的查询

SELECT 
    Campaign_Name, 
    COUNT(*) AS Sent, 
    COUNT(CASE WHEN Bounce = '0' THEN 1 ELSE NULL END) AS Delivered, 
    COUNT(CASE WHEN Opened = '1' THEN 1 ELSE NULL END) AS Opened 
FROM temp_Data 
GROUP BY Campaign_Name 

做看看control functions和COUNT。

棘手的部分是COUNT不增加NULL值，所以我用它来做一个选择性计数。