如何获得不同时间戳之间的平均值

Question

我有一个包含3列的表

ID | Teamid | Timestamp

我们知道由参与者驱动的一轮是2KM，每次他们通过控制点时都会添加一个时间戳

现在我们正在搜索所选团队计算每个时间戳之间的平均速度，以便我们将其放在折线图上。

ID  | Ploegnr| Tijdstamp

----------------------------------------

 1   |   1    | 2013-06-28 18:35:28

 2   |   1    | 2013-06-28 18:36:28

 3   |   2    | 2013-06-28 18:36:30

 4   |   3    | 2013-06-28 18:37:28

 5   |   2    | 2013-06-28 18:40:28

 6   |   1    | 2013-06-28 18:42:28

 8   |   3    | 2013-06-28 18:48:28

让某人知道或了解如何开始

这是另一个查询，它取最近2个时间戳的平均值

我已查询过去2个时间戳

SELECT a.*
 , 3600 / (UNIX_TIMESTAMP(a.Tijdstamp) - UNIX_TIMESTAMP(b.Tijdstamp)) * 2 snelheid 
FROM 
 ( SELECT x.*
    FROM Ronde x
    JOIN Ronde y
      ON y.Ploegnr = x.Ploegnr 
     AND y.Tijdstamp >= x.Tijdstamp
   GROUP
      BY x.ID
  HAVING COUNT(*) = 1
 ) a
 JOIN
 ( SELECT x.*
 , COUNT(*) rank
    FROM Ronde x
    JOIN Ronde y
      ON y.Ploegnr = x.Ploegnr 
     AND y.Tijdstamp >= x.Tijdstamp
   GROUP
      BY x.ID
  HAVING COUNT(*) = 2
 ) b
 ON b.Ploegnr = a.Ploegnr
 left join Ploeg as l on  l.id = b.ploegnr ;