加入2计数查询与GROUP BY子句

Question

我有2个查询
第一个是：

SELECT UserId, COUNT(CustomerId) AS Total 
    FROM (SELECT * 
      FROM Customer 
     WHERE JoinYear = 2016 
      AND JoinMonth = 1 
      AND JoinWeek = 2 
      AND JoinDay = 1) x 
GROUP BY UserId 

第二个是：

SELECT UserId, COUNT(CustomerId) AS Joined 
    FROM (SELECT * 
      FROM Customer 
     WHERE JoinYear = 2016 
      AND JoinMonth = 1 
      AND JoinWeek = 2 
      AND JoinDay = 1 
      AND JoinStatus = 2) x 
GROUP BY UserId 

他们每个人都将产生

(first query)    (second query) 

UserId | Total    UserId | Total 
--------------    -------------- 
    1 | 10     1 | 2 
    2 | 15     2 | 5 

我的问题是如何加入他们这样的桌子？

Userid | Total | Joined 
----------------------- 
    1 | 10 | 2 
    2 | 15 | 5 

Answer 1

您的查询是没有道理极其复杂。

试试这个：

SELECT UserID, COUNT(*) Total, SUM(CASE WHEN JoinStatus = 2 THEN 1 END) Joined 
FROM Customer 
WHERE JoinYear = 2016 AND JoinMonth = 1 AND JoinWeek = 2 AND JoinDay = 1 
GROUP BY UserID 

这里是一个展示SQLFiddle这种技术。

每当你发现自己有嵌套的子查询时，问问自己是否真的是强制性的。

Answer 2

其他oprion：

select UserID, count(Total) as Total, count(Joind) as Joined 
from (
      select UserId,COUNT(CustomerId) as Total, cast(0 as int) as Joined 
      from Customer 
      where JoinYear = 2016 and JoinMonth = 1 and JoinWeek = 2 and JoinDay = 1 
      group by UserID 
      union all 
      select UserId, 
        cast(0 as int) as Total, count(CustomerId) as Joined Customer 
      where JoinYear = 2016 and JoinMonth = 1 and JoinWeek = 2 and JoinDay = 1 and JoinStatus = 2 
      group by UserId 
     ) x 
group by x.UserID