sql - 为另一列sql的每个值计算列的百分比

Question

I want to calculate the percentage of elected people for each member type, I was able to do this:

SELECT Member, COUNT(Name) * 100 / 
    (SELECT COUNT(*) FROM 'results' WHERE Member= '1' ) AS 'perc' 
FROM 'results' 
    WHERE elected='yes' AND Member = '1'

但我想为所有成员值做这件事（也是'0'）

我的表如下所示：

Name     member     Elected
----------------------------
joe      0          yes
ann      1          no
jef      0          no

这是我想要的结果：

Member    Percentage
---------------------
0         50%
1         0%

Answer 1

你应该能够使用这样的东西：

select member,
  coalesce(count(case when elected = 'yes' then 1 end)/count(*), 0) * 100 Percentage
from results
group by member

请参阅带有演示的 SQL Fiddle

结果：

| MEMBER | PERCENTAGE |
-----------------------
|      0 |         50 |
|      1 |          0 |

Answer 2

SELECT Member, 
   Sum(Case When elected='yes' Then 1 
            Else 0 End) / COUNT(*) 'perc' 
FROM 'results' 
group by Member

Answer 3

您的查询应该是

SELECT Member, 
(COUNT(Case When elected='yes' Then 1 Else NULL End) / COUNT(*)) * 100 'perc' 
FROM 'results'     
group by Member

Answer 4

尝试Group By Member

如果您使用sqlfiddle.com，那么很容易为您提供帮助。

从bluefeet偷东西给你

select member,
  concat(FLOOR(coalesce(count(case when elected = 'yes' then 1 end)/count(*), 0) * 100), '%')  Percentage
from results
group by member