DROP TABLE IF EXISTS #Groups;
CREATE TABLE #Groups
(
[entity] nvarchar(30),
[workItem] nvarchar(255),
[CreatedDate] datetime
)
INSERT INTO #Groups ([entity], [workItem], [CreatedDate])
VALUES
( N'5002', N'AG', N'2020-09-04T13:24:00.823' ),
( N'5002', N'AG', N'2020-09-04T13:23:05.103' ),
( N'5002', N'AG', N'2020-09-04T14:23:05.103' ),
( N'5002', N'SH', N'2020-09-04T13:26:42.367' ),
( N'5002', N'SH', N'2020-09-04T13:27:17.25' ),
( N'5003', N'SH', N'2020-10-04T15:36:42.367' ),
( N'5003', N'SH', N'2020-10-04T15:37:17.25' );
预期结果:
entity workItem CreatedDate
--------------------------------------------
5002 AG 2020-09-04 13:24:00.823
5002 AG 2020-09-04 14:23:05.103
5002 SH 2020-09-04 13:27:17.250
5003 SH 2020-10-04 15:37:17.250
基本上,我需要按实体,工作项和日期分组,且公差为一分钟。
这是我的尝试(尽管我没有走太远):
SELECT
t1.entity,
t1.workItem,
t1.CreatedDate,
LAG(t1.CreatedDate, 1) OVER (PARTITION BY t1.entity, t1.workItem ORDER BY t1.CreatedDate) AS CreateDate_new
FROM
#Groups t1
LEFT JOIN
#Groups t2 ON t2.entity = t1.entity
AND t2.workItem = t1.workItem
AND t2.CreatedDate >= t1.CreatedDate
AND (DATEDIFF(MINUTE, t1.CreatedDate, t2.CreatedDate) < 1)
GROUP BY
t1.entity, t1.workItem, t1.CreatedDate
ORDER BY
t1.workItem
答案 0 :(得分:2)
我认为这被称为“缺口和孤岛”问题,因此在SO上很少有这些问题。
下面的方法是
这是执行此操作的一种方法
WITH Groups_Flagged AS
(SELECT [Entity], [workItem], [CreatedDate],
CASE WHEN DATEDIFF(second, LAG([CreatedDate], 1) OVER (PARTITION BY [Entity], [workItem] ORDER BY [CreatedDate]), [CreatedDate]) < 60 THEN 0 ELSE 1 END AS NewGrp_Flag
FROM #Groups
),
Groups_Grouped AS
(SELECT [Entity], [workItem], [CreatedDate], SUM(NewGrp_Flag) OVER (ORDER BY [Entity], [workItem], [CreatedDate]) AS GrpNum
FROM Groups_Flagged
)
SELECT [Entity], [workItem], MAX([CreatedDate]) AS [CreatedDate]
FROM Groups_Grouped
GROUP BY [Entity], [workItem], [GrpNum]
ORDER BY [Entity], [workItem];
Groups_Flagged
CTE标记哪些记录是“新的”,例如,不在该实体/工作项组合的先前记录的1分钟(60秒)之内。它将新记录标记为“ 1”,其他标记为“ 0”。
然后,Groups_Grouped
CTE使用这些1和0的运行总数来为每个集群创建组号。
最终选择的实体是按Entity,WorkItem和新的组编号分组的,并为其获得最大的CreatedDate。
请注意,尽管这会将一系列活动视为一个组(例如,如果您有5个被创建对象,相隔50s,则视为一个活动)。如果您不希望这种情况发生,则需要明确指定如何处理这些链。
(PS感谢您具有创建数据的脚本,它使回答这些问题变得更加容易!)