Mysql 查询/存储过程根据所选月份范围逐列获取数据

Question

我选择月份和年份，范围为 1 月 23 日到 3 月 23 日。使用 mysql 查询或存储过程的预期输出应如下所示。

	1 月 23 日礼物	1 月 23 日缺席	2 月 23 日现在	2 月 23 日缺席
A级	22	23	10	30
B级	22	23	10	30
C级	15	2	12	35

我尝试使用以下查询：

SELECT class  as 'Class', 
  sum(if(Attendance='Present',1,0))as 'Present', 
  sum(if(Attendance='Absent',1,0))as 'Absent' 
FROM attendance_data  
where date(attendance_date) between '2023-09-01' and '2023-11-01'  
group by class

这导致：

	现在	缺席
A级	1	2
B级	3	4

我尽早需要解决方案。 谢谢你。

Answer 1

您应该能够在条件和中添加另一个条件，并使用

MONTH()

函数来检查日期：

SELECT class AS 'Class', 
  SUM(Attendance = 'Present' AND MONTH(attendance_date) = 1) AS 'Jan-23Present', 
  SUM(Attendance = 'Absent' AND MONTH(attendance_date) = 1) AS 'Jan-23Absent', 
  SUM(Attendance = 'Present' AND MONTH(attendance_date) = 2) AS 'Feb-23Present', 
  SUM(Attendance = 'Absent' AND MONTH(attendance_date) = 2) AS 'Feb-23Absent'
FROM attendance_data  
WHERE DATE(attendance_date) BETWEEN '2023-01-01' AND '2023-02-28'  
GROUP BY class