SELECT DeviceId, CAST(ROUND(AVG(distance / time_diff),5,1) as decimal(18,5)) AS '移动速率' FROM ( SELECT DeviceId, DATEDIFF(second, LAG(StartTime) OVER (PARTITION BY DeviceId ORDER BY StartTime), StartTime) AS time_diff, SQRT(POWER(V1 - LAG(V1) OVER (PARTITION BY DeviceId ORDER BY StartTime), 2) + POWER(V2 - LAG(V2) OVER (PARTITION BY DeviceId ORDER BY StartTime), 2) + POWER(V3 - LAG(V3) OVER (PARTITION BY DeviceId ORDER BY StartTime), 2)) AS distance FROM T_BMWY_ResolveDeviceData WHERE StartTime >= DATEADD(day, -5, GETDATE()) ) t WHERE time_diff > 0 GROUP BY DeviceId 把这个语句改成sqlserver2008 版本的语句

在 SQL Server 2008 中，不支持 LAG 和 DATEDIFF 函数，需要使用其他方法来编写相同的查询。以下是一种可能的替代方法：

SELECT DeviceId, CAST(ROUND(AVG(distance / time_diff), 5, 1) AS decimal(18,5)) AS '移动速率'
FROM (
    SELECT t1.DeviceId, t1.StartTime, t1.V1, t1.V2, t1.V3,
           DATEDIFF(SECOND, t2.StartTime, t1.StartTime) AS time_diff,
           SQRT(POWER(t1.V1 - t2.V1, 2) + POWER(t1.V2 - t2.V2, 2) + POWER(t1.V3 - t2.V3, 2)) AS distance
    FROM T_BMWY_ResolveDeviceData t1
    JOIN T_BMWY_ResolveDeviceData t2 ON t1.DeviceId = t2.DeviceId AND t1.StartTime > t2.StartTime
    WHERE t1.StartTime >= DATEADD(DAY, -5, GETDATE())
) t
WHERE time_diff > 0
GROUP BY DeviceId

上述查询使用了自连接和 WHERE 语句来模拟 LAG 函数。它还使用了 POWER 函数来计算距离，而不是 SQRT 函数中的平方根。如果需要，可以根据具体情况进行调整。