Mysql 将3分钟记录合并并汇总为一行记录

我有一个每分钟记录一次数据的表格。它看起来像：

time_stamp            wh   
2013-02-01 08:00:00  1700    
2013-02-01 08:01:00  1600    
2013-02-01 08:02:00  1800    
2013-02-01 08:03:00  1700    
2013-02-01 08:04:00  1900    
2013-02-01 08:05:00  1400    
2013-02-01 08:06:00  1500    
2013-02-01 08:07:00  1700    
2013-02-01 08:08:00  1700    
2013-02-01 08:09:00  1800    
2013-02-01 08:10:00  1800    
2013-02-01 08:11:00  1400 

等等

我想每3分钟总结一次wh数据，然后每3分钟找出平均值。 输出将如下所示：

time_stamp            SUM(wh)    AVG(wh)
2013-02-01 08:00:00    5100       1700
2013-02-01 08:03:00    5500       1833.3333
2013-02-01 08:06:00    4900       1633.3333
2013-02-01 08:09:00    5000       1666.6667

这似乎很容易，但我不能得到我想要的结果。这是我尝试的sql查询：

SELECT from_unixtime(ROUND(unix_timestamp(time_stamp) / 
       (60*3)) * 60 * 3) AS rounded_time,
       SUM(wh),
       AVG(wh)
FROM electrex_0
WHERE time_stamp BETWEEN '2013-02-01 08:00' AND '2013-02-01 09:00'
GROUP BY rounded_time

---

通过使用此sql代码，我成功地获得了正确的时间戳，但没有获得

SUM

和

AVG

的时间戳。我意识到它将以另一种方式进行汇总。例如：2013-02-01 08:03:00的

sum（wh）

是5100，它将从08:02,08:03,08:04获取数据并进行汇总

您想如何从以下渠道获得5500：

2013-02-01 08:03:00  1700    
2013-02-01 08:04:00  1900    
2013-02-01 08:05:00  1400  

总数是5000，不是吗

以下是用于返回正确数据的查询：

SELECT
  from_unixtime(ROUND((unix_timestamp(time_stamp) - 60) / (60*3)) * 60 * 3) AS rounded_time,
  SUM(wh),
  AVG(wh)
FROM electrex_0
WHERE time_stamp BETWEEN '2013-02-01 08:00'
    AND '2013-02-01 09:00'
GROUP BY rounded_time

返回：

ROUNDED_TIME                    SUM(WH) AVG(WH)
February, 01 2013 08:00:00+0000 5100    1700
February, 01 2013 08:03:00+0000 5000    1666.6667
February, 01 2013 08:06:00+0000 4900    1633.3333
February, 01 2013 08:09:00+0000 5000    1666.6667

---

以下是如何处理变量

SET @VAR:=1;
SET @group=0;
SELECT 
    time_stamp,
    SUM(wh) AS `TotalSum`,
    AVG(wh) AS `TotalAvg`
FROM 
  (
    SELECT 
        time_stamp,
        wh,
        @VAR AS Level,
        @group AS `TGroup`,
        @group := IF(@VAR = 3,@group + 1 ,@group) ,
        @VAR := IF(@VAR = 3,1,@VAR+1 )
    FROM electrex_0
  ) AS l
GROUP BY TGroup

输出

|     TIME_STAMP                  | TOTALSUM |  TOTALAVG |
----------------------------------------------------------
| February, 01 2013 08:00:00+0000 |     5100 |      1700 |
| February, 01 2013 08:03:00+0000 |     5000 | 1666.6667 |
| February, 01 2013 08:06:00+0000 |     4900 | 1633.3333 |
| February, 01 2013 08:09:00+0000 |     5000 | 1666.6667 |