SQL Server 分区窗口中多个属性的 Min() 和 Max()

Question

我在 SQL Server 中有一个时间表，其中包含公共交通工具的 [SERV_ID]（服务 ID）、[STATION]（车站）、[ARR]（到达时间）、[DEP]（出发时间）。每个服务都可以每天都在[SERV_DAY]。

目标是总结Serviceday、Service-line、First-station、Last-station以及相应的时间戳。 --> 每天每服务一行。

对于[SERV_ID] N170，这将是：

SERV_DAY                SERV_ID     FIRST_STATION   MIN_DEP                 LAST_STATION        MAX_ARR
2019-08-14 00:00:00     N170        Downtown        2019-08-14 06:06:00     CentralStation      2019-08-14 07:11:00

我尝试通过([SERV_DAY], [SERV_ID]) 进行分区，然后为每个分区获取MAX([ARR]) 和MIN([DEP])。这工作了很长时间，但现在我想为每个最小值和最大值获取对应的 Station。

SELECT 
       [SERV_DAY],[SERV_ID],
       MAX([ARR]) OVER(PARTITION BY [SERV_DAY],[SERV_ID]) AS MAX_ARR,
       MIN([DEP]) OVER(PARTITION BY [SERV_DAY],[SERV_ID]) AS MIN_DEP 
FROM #demo

稍后我需要在最后一站添加延迟，该延迟在数据集的扩展版本中可用，为 [ARR_EFFECTIVE] 和 [DEP_EFFECTIVE]。希望一旦我知道如何总结如上所述的每日线路，我就能够添加这些属性。

这个话题很接近，但我不明白如何适应“差距和孤岛问题” Min() and Max() based on partition in sql server

我在 dbfiddle 中设置了一个演示数据集 https://dbfiddle.uk/?rdbms=sqlserver_2016&fiddle=52e53d43a49ddb8f67454e576bfa7d74

谁能帮我完成查询？

Answer 1

SELECT 
       [SERV_DAY]
       ,[SERV_ID],
       FIRST_VALUE(STATION) over (Partition by [SERV_DAY],[SERV_ID] Order by ARR DESC) Station1
       , FIRST_VALUE(STATION) over (Partition by [SERV_DAY],[SERV_ID] Order by DEP ASC) Station2
FROM #demo

Answer 2

如果您有大量数据，我想我会使用临时表而不是 CTE，但这里有一个关于它应该如何工作的快速想法：

WITH CTE AS
(
    SELECT * 
    , ROW_NUMBER() OVER(PARTITION BY [SERV_DAY],[SERV_ID] ORDER BY ARR  ) RN
    , ROW_NUMBER() OVER(PARTITION BY [SERV_DAY],[SERV_ID] ORDER BY DEP  ) RN2
    from #demo
)
SELECT t1.[SERV_DAY],t1.[SERV_ID],t1.[STATION] FIRST_STATION, t1.[DEP] MIN_DEP, t2.STATION LAST_STATION
FROM CTE t1
INNER JOIN CTE t2 on t1.SERV_DAY = t2.SERV_DAY and t1.SERV_ID = t2.SERV_ID and t2.RN2 = 1
WHERE t1.RN = 1

Answer 3

您可以分两步完成： 首先添加一个按ARR 降序排序的row_number 和另一个按dep 排序的row_number。然后，您可以过滤 row_number = 1 的行以选择其他列。 下面是一个如何检索 max_arr 和 min_dep 的站的示例：

WITH T AS (
SELECT 
       [SERV_DAY], [SERV_ID],
       MAX([ARR]) OVER(PARTITION BY [SERV_DAY],[SERV_ID]) AS MAX_ARR,
       MIN([DEP]) OVER(PARTITION BY [SERV_DAY],[SERV_ID]) AS MIN_DEP,
       ROW_NUMBER() OVER(PARTITION BY [SERV_DAY],[SERV_ID] ORDER BY [ARR] DESC) AS RN_ARR,
       ROW_NUMBER() OVER(PARTITION BY [SERV_DAY],[SERV_ID] ORDER BY [DEP]) AS RN_DEP,
       *
  FROM #demo
)
SELECT MAX(CASE WHEN RN_ARR = 1 THEN [STATION] END) MAX_ARR_STATION,
       MAX(CASE WHEN RN_DEP = 1 THEN [STATION] END) MIN_DEP_STATION,
       *
  FROM T

Answer 4

作为对@casenonsensitive 的回复，它可以使用他的代码并稍作修改！

WITH T AS (

SELECT 
       [SERV_DAY], [SERV_ID], [STATION],
       MAX([ARR]) OVER(PARTITION BY [SERV_DAY],[SERV_ID]) AS MAX_ARR,
       MIN([DEP]) OVER(PARTITION BY [SERV_DAY],[SERV_ID]) AS MIN_DEP,
       ROW_NUMBER() OVER(PARTITION BY [SERV_DAY],[SERV_ID] ORDER BY [ARR] ) AS RN_ARR,
       ROW_NUMBER() OVER(PARTITION BY [SERV_DAY],[SERV_ID] ORDER BY [DEP] ) AS RN_DEP
  FROM #demo
  )
  
 SELECT MAX(CASE WHEN RN_ARR = 1 THEN [STATION] END) MIN_DEP_STATION,
       MAX(CASE WHEN RN_DEP = 1 THEN [STATION] END) MAX_ARR_STATION, [SERV_DAY], [SERV_ID], MAX_ARR, MIN_DEP from T
       group by [SERV_DAY], [SERV_ID], MIN_DEP, MAX_ARR