mysql - 如何在mysql中实现这样的数据透视表？

Question

我有以下查询来显示学生的每月费用状态。

SELECT regd, Name_of_Student, Class, Section, Rollno,
If(Month = 'January', Status, 0) AS Jan,
If(Month = 'September', Status, 0) AS Sept  
FROM fee
where Class='XI(Art)' and Rollno='2';

此代码的问题如图所示：

我想输出如下：

在实际应用中，我会显示所有月份。

请在此处查看小提琴

Answer 1

SELECT regd, Name_of_Student, Class, Section, Rollno,
MAX(If(Month = 'January', Status, 0)) AS Jan,
MAX(If(Month = 'September', Status, 0)) AS Sept  
FROM fee
where Class='XI(Art)' and Rollno='2'
GROUP BY regd, Name_of_Student, Class, Section, Rollno;