Mysql时间数据分段累加求和案例之子查询与SUM窗口函数

Posted 2021-08-29 ShenLiang2025

mysql时间段数分段据累加求和

简介

时间段数据的分段可以根据义务逻辑来划分，累加求和在mysql8.0及以上可以通过sum结合窗口函数来实现，低版本用子查询实现。

需求

对原始数据按照时间点3点前、6点前、12点前对数值的累计得到如下结果：

时间段 累计
3 6
6 17
12 39

原始数据附录如下：

id inserttime num

1 2020-07-30 00:00:00 1

2 2020-07-30 01:00:00 2

3 2020-07-30 02:00:00 3

4 2020-07-30 03:00:00 2

5 2020-07-30 04:00:00 3

6 2020-07-30 05:00:00 6

7 2020-07-30 06:00:00 1

8 2020-07-30 07:00:00 5

9 2020-07-30 08:00:00 7

10 2020-07-30 09:00:00 2

11 2020-07-30 10:00:00 4

12 2020-07-30 11:00:00 3

 解决方法

-- Ⅰ关于问题,如果是Mysql 8.0用sum结合窗口函数，Mysql5.7及以下用子查询。

-- Ⅱ详细过程 Step By Step见代码处
-- Step 1 初始化表及数据
create table tb_shenliang2025(
id int,
inserttime datetime,
num int
);
INSERT INTO tb_shenliang2025
		SELECT 1 id,'2020-07-30 00:00:00' inserttime,'1' num UNION ALL
		SELECT 2 id,'2020-07-30 01:00:00' inserttime,'2' num UNION ALL
		SELECT 3 id,'2020-07-30 02:00:00' inserttime,'3' num UNION ALL
		SELECT 4 id,'2020-07-30 03:00:00' inserttime,'2' num UNION ALL
		SELECT 5 id,'2020-07-30 04:00:00' inserttime,'3' num UNION ALL
		SELECT 6 id,'2020-07-30 05:00:00' inserttime,'6' num UNION ALL
		SELECT 7 id,'2020-07-30 06:00:00' inserttime,'1' num UNION ALL
		SELECT 8 id,'2020-07-30 07:00:00' inserttime,'5' num UNION ALL
		SELECT 9 id,'2020-07-30 08:00:00' inserttime,'7' num UNION ALL
		SELECT 10 id,'2020-07-30 09:00:00' inserttime,'2' num UNION ALL
		SELECT 11 id,'2020-07-30 10:00:00' inserttime,'4' num UNION ALL
		SELECT 12 id,'2020-07-30 11:00:00' inserttime,'3' num

-- Step 2 Mysql8.0及以上结合窗口函数编写累计求和SQL 
 SELECT DISTINCT "时间段",
 SUM(num)OVER(ORDER BY flag RANGE BETWEEN UNBOUNDED PRECEDING AND CURRENT ROW) AS "累计"
 --SUM(num)OVER(ORDER BY flag) AS "累计" --默认即上述参数
 FROM
 (
		SELECT 
		CASE WHEN hour(inserttime)>=0 AND hour(inserttime)<3 THEN 3 
		 WHEN hour(inserttime)>=3 AND hour(inserttime)<6 THEN 6
		ELSE 12 END flag,
		num FROM tb_shenliang2025 A
 )A
 
-- Step 3 Mysql 5.7及以下版本(同样适用于Mysql8.0)
SELECT A.flag "时间段",(
	SELECT SUM(num) FROM 
			(
				SELECT flag,SUM(num) num FROM
					(SELECT 
					CASE WHEN hour(inserttime)>=0 AND hour(inserttime)<3 THEN 3 
					 WHEN hour(inserttime)>=3 AND hour(inserttime)<6 THEN 6
					ELSE 12 END flag,num FROM tb_shenliang2025
					)A
				GROUP BY flag
			)B
	WHERE B.flag<=A.flag) "累计"
FROM 
	(
			SELECT flag,SUM(num) num FROM
				(SELECT 
				CASE WHEN hour(inserttime)>=0 AND hour(inserttime)<3 THEN 3 
				 WHEN hour(inserttime)>=3 AND hour(inserttime)<6 THEN 6
				ELSE 12 END flag,num FROM tb_shenliang2025
				)A
			GROUP BY flag
		)A

-- Step 4 延展阅读,如果Step3的代码看上去麻烦,可以看如下简略版
-- 该辅助解释代码仅适用于Mysql8.0,因CTE在mysql低版本不支持
WITH CTE AS(
SELECT 1 id,6 num UNION ALL
SELECT 2 id,11 num UNION ALL
SELECT 3 id,22 num UNION ALL
SELECT 4 id,19 num
)
 
SELECT A.id,(
	SELECT SUM(num) FROM CTE B
	WHERE B.id<=A.id) total
FROM CTE A

-- 这里的CTE相当于Step3里按时间段分组统计。
			SELECT flag,SUM(num) num FROM
				(SELECT 
				CASE WHEN hour(inserttime)>=0 AND hour(inserttime)<3 THEN 3 
				 WHEN hour(inserttime)>=3 AND hour(inserttime)<6 THEN 6
				ELSE 12 END flag,num FROM tb_shenliang2025
				)A
			GROUP BY flag
-- 执行结果