Question

我觉得这是一个非常基本的问题，但这让我很沮丧！想象一下，我有一个表格（收入），大致是这样的：

Month     Product      Revenue
2019-01   Networking   1.00
2019-01   Computing    2.53
2019-01   Storage      4.88
2019-02   Networking   5.32
2019-02   Storage      6.20
...

我想做的就是总结每月总收入和每月网络收入，但是对于我来说，我无法全神贯注于d这样做（不编写两个查询）。因此结果应类似于：

Month     TotalRevenue  NetworkingRevenue
2019-01   8.41          1.00
2019-02   11.52         5.32
...

任何帮助将不胜感激。

Answer 1

使用情况

 select month,
 sum(case when Product='Networking' then Revenue else 0 end) as NetworkingRevenue,
 sum(Revenue) as TotalRevenue from table_name group by month

Answer 2

尝试一下：

SELECT 
  Month, 
  SUM(revenue) AS Revenue, 
  SUM(CASE WHEN Product = 'Networking' THEN Revenue ELSE 0 END) AS Revenue_Networking
FROM MyTable
GROUP BY Month
ORDER BY Month

SQL Fiddle

SQL：汇总和已过滤汇总

2 个答案: