我的目标是将属于同一时间窗口（例如10秒）的日期时间值集群到SQL Server 2008 R2中属于同一个类的子组（每个类可以有1-n子组）。这是我的第一次尝试：
DECLARE @TimeWindowInSeconds INT
SET @TimeWindowInSeconds = 10
IF OBJECT_ID('tempdb..#Temp') IS NOT NULL
DROP TABLE #Temp
CREATE TABLE #Temp ( Class INT, DT DATETIME )
INSERT INTO #Temp
( Class, DT )
VALUES ( 1, '2014-11-05 10:55:00:00' ),
( 1, '2014-11-05 10:55:01:00' ),
( 1, '2014-11-05 10:55:02:00' ),
( 1, '2014-11-05 10:55:03:00' ),
( 1, '2014-11-05 10:55:04:00' ),
( 1, '2014-11-05 10:55:05:00' ),
( 1, '2014-11-05 10:55:06:00' ),
( 1, '2014-11-05 10:55:07:00' ),
( 1, '2014-11-05 10:55:08:00' ),
( 1, '2014-11-05 10:55:09:00' ),
( 1, '2014-11-05 10:55:10:00' ),
( 1, '2014-11-05 10:55:11:00' ),
( 1, '2014-11-05 11:55:12:00' ),
( 1, '2014-11-05 11:55:13:00' ),
( 1, '2014-11-05 11:55:14:00' ),
( 1, '2014-11-05 11:55:15:00' ),
( 1, '2014-11-05 11:55:16:00' ),
( 1, '2014-11-05 11:55:17:00' ),
( 1, '2014-11-05 11:55:18:00' ),
( 1, '2014-11-05 11:55:19:00' ),
( 1, '2014-11-05 11:55:21:00' ),
( 1, '2014-11-05 11:55:22:00' ),
( 1, '2014-11-05 11:55:23:00' ),
( 1, '2014-11-05 11:55:24:00' ),
( 1, '2014-11-05 11:55:25:00' ),
( 1, '2014-11-05 11:55:26:00' ),
( 1, '2014-11-05 11:55:27:00' ),
( 2, '2014-11-05 10:55:10:00' ),
( 2, '2014-11-05 10:55:11:00' );
;
WITH CTE1
AS ( SELECT Class ,
DT ,
ROW_NUMBER() OVER ( ORDER BY Class, DT ) AS RowNumber
FROM #Temp
),
CTE2
AS (
-- A is the successor
SELECT A.Class ,
A.RowNumber ,
B.RowNumber AS RowNumber1 ,
A.DT ,
B.DT AS DT2 ,
DATEDIFF(SECOND, B.DT, A.DT) AS DifferenceInSeconds ,
CASE WHEN B.DT IS NULL THEN 1
END z
FROM CTE1 AS A
LEFT OUTER JOIN CTE1 AS B ON A.RowNumber = B.RowNumber
+ 1
AND A.Class = B.Class
AND DATEDIFF(SECOND, B.DT,
A.DT) < @TimeWindowInSeconds
),
CTE3
AS ( SELECT CTE2.Class ,
CTE2.DT ,
( SELECT SUM(z)
FROM CTE2 c
WHERE c.DT <= CTE2.DT
AND c.Class = CTE2.Class
) AS SubGroup
FROM CTE2
)
SELECT
*
FROM CTE3
WHERE CAST(CTE3.Class AS NVARCHAR(100)) + '-'
+ CAST(CTE3.SubGroup AS NVARCHAR(100)) IN (
SELECT CAST(CTE3.Class AS NVARCHAR(100)) + '-'
+ CAST(CTE3.SubGroup AS NVARCHAR(100))
FROM CTE3
GROUP BY CTE3.Class ,
CTE3.SubGroup
HAVING COUNT(*) > 1 )
ORDER BY Class, DT
不幸的是，它会产生错误的结果：
Class DT SubGroup
1 2014-11-05 10:55:00.000 1
1 2014-11-05 10:55:01.000 1
1 2014-11-05 10:55:02.000 1
1 2014-11-05 10:55:03.000 1
1 2014-11-05 10:55:04.000 1
1 2014-11-05 10:55:05.000 1
1 2014-11-05 10:55:06.000 1
1 2014-11-05 10:55:07.000 1
1 2014-11-05 10:55:08.000 1
1 2014-11-05 10:55:09.000 1
1 2014-11-05 10:55:10.000 1
1 2014-11-05 10:55:11.000 1
1 2014-11-05 11:55:12.000 2
1 2014-11-05 11:55:13.000 2
1 2014-11-05 11:55:14.000 2
1 2014-11-05 11:55:15.000 2
1 2014-11-05 11:55:16.000 2
1 2014-11-05 11:55:17.000 2
1 2014-11-05 11:55:18.000 2
1 2014-11-05 11:55:19.000 2
1 2014-11-05 11:55:21.000 2
1 2014-11-05 11:55:22.000 2
1 2014-11-05 11:55:23.000 2
1 2014-11-05 11:55:24.000 2
1 2014-11-05 11:55:25.000 2
1 2014-11-05 11:55:26.000 2
1 2014-11-05 11:55:27.000 2
2 2014-11-05 10:55:10.000 1
2 2014-11-05 10:55:11.000 1
正确的结果应该是（参见CorrectSubGroup）：
Class DT SubGroup CorrectSubGroup
1 05/11/2014 10:55:00 1 1
1 05/11/2014 10:55:01 1 1
1 05/11/2014 10:55:02 1 1
1 05/11/2014 10:55:03 1 1
1 05/11/2014 10:55:04 1 1
1 05/11/2014 10:55:05 1 1
1 05/11/2014 10:55:06 1 1
1 05/11/2014 10:55:07 1 1
1 05/11/2014 10:55:08 1 1
1 05/11/2014 10:55:09 1 1
1 05/11/2014 10:55:10 1 2
1 05/11/2014 10:55:11 1 2
1 05/11/2014 11:55:12 2 2
1 05/11/2014 11:55:13 2 2
1 05/11/2014 11:55:14 2 2
1 05/11/2014 11:55:15 2 2
1 05/11/2014 11:55:16 2 2
1 05/11/2014 11:55:17 2 2
1 05/11/2014 11:55:18 2 2
1 05/11/2014 11:55:19 2 2
1 05/11/2014 11:55:21 2 3
1 05/11/2014 11:55:22 2 3
1 05/11/2014 11:55:23 2 3
1 05/11/2014 11:55:24 2 3
1 05/11/2014 11:55:25 2 3
1 05/11/2014 11:55:26 2 3
1 05/11/2014 11:55:27 2 3
2 05/11/2014 10:55:10 1 1
2 05/11/2014 10:55:11 1 1
任何帮助表示赞赏。感谢。
答案 0 :(得分：1)
这应该可以解决问题，希望有所帮助。
DECLARE @TimeWindowInSeconds INT
DECLARE @TimePartitioner INT
--Define the time window (e.g. 10 seconds)
SET @TimeWindowInSeconds = 10
--Calculate the sub group based on the Time Window
SET @TimePartitioner = 60 / @TimeWindowInSeconds;
IF OBJECT_ID('tempdb..##Temp') IS NOT NULL
DROP TABLE ##Temp
CREATE TABLE ##Temp ( Class INT, DT DATETIME )
INSERT INTO ##Temp
( Class, DT )
VALUES ( 1, '2014-11-05 10:55:00:00' ),
( 1, '2014-11-05 10:55:01:00' ),
( 1, '2014-11-05 10:55:02:00' ),
( 1, '2014-11-05 10:55:03:00' ),
( 1, '2014-11-05 10:55:04:00' ),
( 1, '2014-11-05 10:55:05:00' ),
( 1, '2014-11-05 10:55:06:00' ),
( 1, '2014-11-05 10:55:07:00' ),
( 1, '2014-11-05 10:55:08:00' ),
( 1, '2014-11-05 10:55:09:00' ),
( 1, '2014-11-05 10:55:10:00' ),
( 1, '2014-11-05 10:55:11:00' ),
( 1, '2014-11-05 11:55:12:00' ),
( 1, '2014-11-05 11:55:13:00' ),
( 1, '2014-11-05 11:55:14:00' ),
( 1, '2014-11-05 11:55:15:00' ),
( 1, '2014-11-05 11:55:16:00' ),
( 1, '2014-11-05 11:55:17:00' ),
( 1, '2014-11-05 11:55:18:00' ),
( 1, '2014-11-05 11:55:19:00' ),
( 1, '2014-11-05 11:55:21:00' ),
( 1, '2014-11-05 11:55:22:00' ),
( 1, '2014-11-05 11:55:23:00' ),
( 1, '2014-11-05 11:55:24:00' ),
( 1, '2014-11-05 11:55:25:00' ),
( 1, '2014-11-05 11:55:26:00' ),
( 1, '2014-11-05 11:55:27:00' ),
( 2, '2014-11-05 10:55:10:00' ),
( 2, '2014-11-05 10:55:11:00' );
WITH cte_secondraingebuild (seconds)
AS (SELECT 0 AS Seconds
UNION ALL
SELECT o.seconds + 1
FROM cte_secondraingebuild o
WHERE o.seconds < 59),
cte_secondrainge (seconds, SubGroup)
AS (SELECT seconds,
Ntile(@TimePartitioner)
OVER(
ORDER BY Cast(seconds AS INT))
FROM cte_secondraingebuild),
cte_distinctdates (datetimes)
AS (SELECT DISTINCT CONVERT(VARCHAR(17), dt, 120)
FROM ##temp),
cte_datetimegapless (datetimesfull, SubGroup)
AS (SELECT Cast(dd.datetimes + RIGHT('00'+Cast(sr.seconds AS VARCHAR(2)), 2) AS DATETIME),
SubGroup
FROM cte_distinctdates dd
CROSS JOIN cte_secondrainge sr),
cte_resultstaging
AS (SELECT tp.class,
tp.dt,
datetimesfull,
SubGroup
FROM ##temp tp
JOIN cte_datetimegapless dtgl
ON dtgl.datetimesfull = tp.dt)
SELECT Class,DT,SubGroup
FROM cte_resultstaging
ORDER BY class,dt
答案 1 :(得分：0)
试试这个..
SELECT class,
dt,
( Datepart(second, DT) / 10 ) + 1
FROM #Temp
GROUP BY class,
dt,
Datepart(second, DT) / 10