SQL

Question

我的查询有问题。

我想对员工位置进行分类并按地区统计，这里是我的查询：

SELECT
    (CASE 
        WHEN location = 'India' THEN 'Asia' 
        WHEN location  = 'Italy' THEN 'Europe' 
        WHEN location  = 'Singapore' THEN 'Asia' 
        WHEN location  = 'Australia' THEN 'Australia' 
        ELSE NULL 
     END) AS Region,  
    COUNT(location) AS Total_person 
FROM
    Location_tbl 
GROUP BY
    location

结果是这样的：

亚洲 = 1
欧洲 = 1
亚洲 = 1
澳大利亚 = 1

我想要的结果是这样的:

亚洲 = 2
欧洲 = 1
澳大利亚 = 1

你们能帮我解决一下我的查询，这样我就能得到我想要的结果吗？

Answer 1

您需要在group by-

中添加自定义组

select 
CASE WHEN location in( 'India','Singapore') THEN 'Asia' WHEN location  = 'Italy' THEN 'Europe' WHEN location  = 'Australia' THEN 'Australia' END as Region, 
count(location) as Total_person from Location_tbl 
group by CASE WHEN location in( 'India','Singapore') THEN 'Asia' WHEN location  = 'Italy' THEN 'Europe' WHEN location  = 'Australia' THEN 'Australia' END

Answer 2

select 
    Region, 
    count(Region) 
from 
    (select (CASE WHEN location = 'India' THEN 'Asia' WHEN location  = 'Italy' THEN 'Europe' WHEN location  = 'Singapore' THEN 'Asia' WHEN location  = 'Australia' THEN 'Australia' ELSE null END) as Region 
     from Location_tbl) tab 
group by 
    tab.Region

Answer 3

SELECT 
    location,
    CASE
        WHEN location = 'India' or 'Singapore' THEN 'Asia' 
        WHEN location = 'Italy' THEN 'Europe'
        WHEN location = 'Australia' THEN 'Australia'
        ELSE NULL
    END AS Region
FROM 
    Location_tbl
GROUP BY 
    location
ORDER BY 
    SUM(location);

SQL - 如何对重复计数结果求和

SQL - How to sum duplicate count result

qsqlquery