+-----------------+---------------------+
| date_time | vale |
+-----------------+---------------------+
| 12/13/2015 0:00 | 56.75 |
| 12/13/2015 0:15 | 208.75 |
| 12/13/2015 0:30 | 58.8 |
| 12/13/2015 0:45 | 61.79 |
| 12/13/2015 1:00 | 288.65 |
| 12/13/2015 1:15 | 89.1 |
| 12/13/2015 1:30 | 28.9 |
| 12/13/2015 1:45 | 57.04 |
| 12/14/2015 1:00 | 63.87 |
| 12/14/2015 1:15 | 219.83 |
| 12/14/2015 1:30 | 64.95 |
| 12/14/2015 1:45 | 65.24 |
| 12/14/2015 2:00 | 55.67 |
| 12/14/2015 2:15 | 21.63 |
| 12/14/2015 2:30 | 56.75 |
| 12/14/2015 2:45 | 57.04 |
+-----------------+---------------------+
我有 date_time 及其各自的值,现在如何根据日、周和小时取平均值,如下所示:
+-----------------+-----------------+-----------+----------+
| date_time | hour_avg | day_avg | week_avg |
+-----------------+-----------------+-----------+----------+
| 12/13/2015 0:00 | 96.52 | 106.2 | 90.9 |
| 12/13/2015 1:00 | 115.9 | 106.2 | 90.9 |
| 12/14/2015 1:00 | 103.4 | 75.6 | 90.9 |
| 12/14/2015 2:00 | 47.7 | 75.6 | 90.9 |
+-----------------+-----------------+-----------+----------+
最佳答案
实现它的一种方法是使用 GROUP BY
日期和小时 + 整天/周的相关子查询:
SELECT
DATE_ADD(CAST(date_time AS DATE), INTERVAL HOUR(date_time) HOUR) AS date_time
,ROUND(AVG(vale),1) AS hour_avg
,ROUND((SELECT AVG(vale) FROM tab t2 WHERE DATE(t2.date_time) = DATE(t.date_time) GROUP BY DATE(date_time)),1) AS day_avg
,ROUND((SELECT AVG(vale) FROM tab t2 WHERE WEEK(t2.date_time) = WEEK(t.date_time) AND YEAR(t.date_time) = YEAR(t2.date_time) GROUP BY WEEK(date_time)),1) AS week_avg
FROM tab t
GROUP BY DATE(date_time), HOUR(date_time);
输出:
╔═════════════════════════════╦═══════════╦══════════╦══════════╗
║ date_time ║ hour_avg ║ day_avg ║ week_avg ║
╠═════════════════════════════╬═══════════╬══════════╬══════════╣
║ December, 13 2015 00:00:00 ║ 96.5 ║ 106.2 ║ 90.9 ║
║ December, 13 2015 01:00:00 ║ 115.9 ║ 106.2 ║ 90.9 ║
║ December, 14 2015 01:00:00 ║ 103.5 ║ 75.6 ║ 90.9 ║
║ December, 14 2015 02:00:00 ║ 47.8 ║ 75.6 ║ 90.9 ║
╚═════════════════════════════╩═══════════╩══════════╩══════════╝
关于mysql - 如何在 MySQL 中对三个具有不同平均值的变量进行分组?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/34450057/