按消息類型分組，每個消息組之間的持續時間以分鐘爲單位

Question

我有一個存儲主機消息的表，我試圖按類型對消息進行分組，並顯示它們發生的分鐘數。我需要顯示每個組的最短消息日期和最大消息日期。我有以下查詢，並且我可以按照最短時間和消息時間的類型獲取消息，但是我需要最短時間爲上一行的最大時間。

;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) 

我的輸出是這樣的：

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 

我想它喜歡這個

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 

我已經與查詢玩弄了一會兒現在和任何幫助將不勝感激。

Answer 1

在sqlserver中，窗口函數LAG(column) OVER(order by x)可用於返回上一行中列的值，其中ORDER BY x定義了什麼是「上一個」行。請記住，您可能還想要PARTITION BY your_grouping以確保組的第一行不會從另一個組中拉出以前的值