我有一张 table :
<表类=“s-表”>
<标题>
ID
PROJECT_ID
月
MEMBER_ID
<正文>
1
1
1
1
2
1
1
2
3
1
2
1
4
1
2
2
5
1
3
1
6
2
1
3
7
2
2
3
8
2
3
2
7
2
3
3
我想创建一个像这样的表:
<表类=“s-表”>
<标题>
PROJECT_ID
标题
MONTH_1
MONTH_2
MONTH_3
<正文>
1
标题1
2
2
1
2
标题2
1
1
2
每个月我都有成员(member)总数。我怎样才能实现它？
谢谢!
最佳答案
@Arth 的更简单回答
select project_id,
CONCAT('title', project_id) title,
SUM(month=1) month_1,
SUM(month=2) month_2,
SUM(month=3) month_3
from table1 test
group by project_id;
<强> Fiddle
select
`PROJECT_ID`,Title,
coalesce(count(`MONTH_1`),0) as `MONTH_1`,
coalesce(count(`MONTH_2`),0) as `MONTH_2`,
coalesce(count(`MONTH_3`),0) as `MONTH_3`
from
(select
`PROJECT_ID`, concat('Title', `PROJECT_ID`) as Title,
case when `MONTH` = 1 then `MEMBER_ID` end as `MONTH_1`,
case when `MONTH` = 2 then `MEMBER_ID` end as `MONTH_2`,
case when `MONTH` = 3 then `MEMBER_ID` end as `MONTH_3`
from Table1) test
group by PROJECT_ID;
<强> fiddle
关于mysql - Mysql 数据透视表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25324963/