按消息类型分组，每个消息组之间的持续时间以分钟为单位

Question

我有一个存储主机消息的表，我试图按类型对消息进行分组，并显示它们发生的分钟数。我需要显示每个组的最短消息日期和最大消息日期。我有以下查询，并且我可以按照最短时间和消息时间的类型获取消息，但是我需要最短时间为上一行的最大时间。

;WITH cte as (
SELECT CRS, WindowNumber, StateOfServiceReason, DateOfEntry, 
ROW_NUMBER() OVER(PARTITION BY StateOfServiceReason ORDER BY CRS, Windownumber, DateOfEntry) AS gn, 
ROW_NUMBER() OVER (ORDER BY CRS, WindowNumber, DateOfEntry) AS rn 
FROM [dbo].[ServiceLog] 
WHERE  1 = 1 
AND   CRS = 'BBP' 
AND   WindowNumber = 1), cte2 AS (
SELECT CRS, WindowNumber, StateOfServiceReason, DateOfEntry, gn, rn, gn - rn as gb 
FROM cte) , cte3 AS (
SELECT CRS, WindowNumber,StateOfServiceReason, MIN(DateOfEntry) AS MinMsgDate, MAX(DateOfEntry) As MaxMsgDate, 
DATEDIFF(MINUTE, MIN(DateOfEntry), Max(DateOfEntry)) as TotalMinutes 
FROM cte2 
GROUP BY CRS, WindowNumber,StateOfServiceReason, gb) 

我的输出是这样的：

CRS WindowNumber StateOfServiceReason MinMsgDate   MaxMsgDate  TotalMinutes 
BBP 1    Unknown     2017-07-01 00:07:46 2017-07-01 02:47:05 160 
BBP 1    OperatorMaintenance  2017-07-01 02:47:05 2017-07-01 03:01:10 0 
BBP 1    Unknown     2017-07-01 03:01:10 2017-07-01 08:37:26 336 
BBP 1    OperatorMaintenance  2017-07-01 08:37:26 2017-07-01 18:36:14 598 

我想它喜欢这个

CRS WindowNumber StateOfServiceReason MinMsgDate   MaxMsgDate   TotalMinutes 
BBP 1    Unknown     01/07/2017 00:07:46 01/07/2017 02:47:06 xx 
BBP 1    OperatorMaintenance  01/07/2017 02:47:06 01/07/2017 03:01:10 xx 
BBP 1    Unknown     01/07/2017 03:01:10 01/07/2017 08:37:27 xx 
BBP 1    OperatorMaintenance  01/07/2017 08:37:27 01/07/2017 18:36:14 xx 

我已经与查询玩弄了一会儿现在和任何帮助将不胜感激。

Answer 1

在sqlserver中，窗口函数LAG(column) OVER(order by x)可用于返回上一行中列的值，其中ORDER BY x定义了什么是“上一个”行。请记住，您可能还想要PARTITION BY your_grouping以确保组的第一行不会从另一个组中拉出以前的值