Question

我试图从日期时间列中使用10分钟的间隔来获取平均值。这么胖我得到这个SQL来获取间隔

的数据

                        select 1 AS `location_id`,
        `raw_datas`.`parsing_at` AS `date`,
count(`raw_datas`.`station_mac`) AS `quantity`
                              FORM `raw_datas`
                             WHERE (timediff(`raw_datas`.`parsing_at`,`raw_datas`.`last_time_seen`) <= 20)
                          GROUP BY UNIX_TIMESTAMP(`raw_datas`.`parsing_at`) DIV 600
                          order by `raw_datas`.`parsing_at`;

但结果显示已添加

+-------------+---------------------+----------+
| location_id | date                | quantity |
+-------------+---------------------+----------+
|           1 | 2016-04-11 05:10:22 |      137 |
|           1 | 2016-04-11 05:20:02 |      121 |
|           1 | 2016-04-11 05:30:02 |       24 |
|           1 | 2016-04-11 06:06:11 |       20 |
|           1 | 2016-04-11 06:10:02 |       36 |
|           1 | 2016-04-11 06:20:02 |       37 |
|           1 | 2016-04-11 06:30:02 |       29 |
|           1 | 2016-04-11 08:46:10 |        7 |
|           1 | 2016-04-11 08:50:02 |       21 |
|           1 | 2016-04-11 09:00:22 |       16 |
|           1 | 2016-04-11 09:10:22 |       16 |
|           1 | 2016-04-11 09:20:02 |       15 |
|           1 | 2016-04-11 09:30:02 |        8 |
|           1 | 2016-04-11 09:41:01 |        1 |
|           1 | 2016-04-11 15:01:02 |       69 |
|           1 | 2016-04-11 15:10:02 |      106 |
|           1 | 2016-04-11 15:20:02 |       69 |
|           1 | 2016-04-11 23:18:02 |       20 |
|           1 | 2016-04-11 23:20:02 |      124 |
|           1 | 2016-04-11 23:30:02 |      105 |
|           1 | 2016-04-11 23:40:02 |       80 |
|           1 | 2016-04-12 22:00:35 |      224 |
|           1 | 2016-04-12 22:10:02 |      191 |
|           1 | 2016-04-12 22:20:02 |      193 |
|           1 | 2016-04-12 22:30:02 |       66 |
+-------------+---------------------+----------+

如何使数量列显示日期列上时间间隔的平均值？

Answer 1

您可以使用AVG（）函数代替count（）来获得平均值

MySQL按日期时间以10分钟为间隔获得平均值分组

1 个答案: