以15分钟为间隔对mysql进行分组查询

Question

我有一个监控系统,每隔n秒收集一次数据(n大约是10但是有变化).我想以15分钟的间隔汇总收集的数据.有没有办法将时间戳值合并为15分钟块以允许分组工作？

Answer 1

SELECT   FLOOR(UNIX_TIMESTAMP(timestamp)/(15 * 60)) AS timekey
FROM     table
GROUP BY timekey;

Answer 2

试试这个,15分钟间隔的记录分组,你可以改变15*60到你需要的间隔

SELECT sec_to_time(time_to_sec(datefield)- time_to_sec(datefield)%(15*60)) as intervals from tablename
group by intervals

Answer 3

以下方法 1) 的改编：

select Round(date_format(date, "%i") / (15*60)) AS interval  
from table
group by interval 

以下方法 3) 的改编：

SELECT Round(Convert(substring(date_column, 14, 2), UNSIGNED) / (15*60)) AS interval /* e.g. 2009-01-04 12:20:00 */
FROM table 
GROUP BY interval;

我在这里找到了一些方法：

1）

select date_format(date, "%W") AS `Day of the week`, sum(cost)
from daily_cost
group by `Day of the week` 
order by date_format(date, "%w")

2）

select count(*) as 'count', 
  date_format(min(added_on), '%Y-%M-%d') as 'week commencing',
  date_format(added_on, '%Y%u') as 'week' 
from system 
where added_on >= '2007-05-16' 
group by week 
order by 3 desc;

3）

SELECT substring(postdate, 1,10) AS dd, COUNT(id) FROM MyTable GROUP BY dd;

（也在这里：http ://www.bradino.com/mysql/dayparting-on-datetime-field-using-substring/ ）

编辑：所有解决方案在具有大量记录的表上都会表现不佳。