SQL 服务器并发 5 个时间戳列

Question

我想得到一个 SQL 查询，它可以帮助我获取连续的时间，以 5 分钟内的时间为准，并且注意到的次数应该大于或等于 5？

例如：

Column A
17:22:23
17:44:31
17:25:36
17:24:11
17:47:39
17:26:22
17:22:44

我的结果应该只获取以下值？

17:22:23
17:25:36
17:24:11
17:26:22
17:22:44

Answer 1

您可以使用 lag 和 lead，如下所示：

SELECT [ColumnA]
FROM   (SELECT [ColumnA],
               PrevVal = LAG([ColumnA]) OVER (ORDER BY [ColumnA]),
               NextVal = LEAD([ColumnA]) OVER (ORDER BY [ColumnA])
        FROM   YourTable) a
WHERE  DATEDIFF(MINUTE, PrevVal, [ColumnA]) <= 5
        OR DATEDIFF(MINUTE, [ColumnA], NextVal) <= 5;

Answer 2

the exact ask is to fetch something that lies 5 mins between each other and has repeated more than 5 times

应该这样做

WITH T1
     AS (SELECT *,
                KeepPreceding = IIF(DATEDIFF(MINUTE,  LAG(ColumnA, 4) OVER (ORDER BY ColumnA), ColumnA) <= +5, 1, 0),
                KeepFollowing = IIF(DATEDIFF(MINUTE, LEAD(ColumnA, 4) OVER (ORDER BY ColumnA), ColumnA) >= -5, 1, 0)
         FROM   YourTable),
     T2
     AS (SELECT *,
                /*If at least one of the 4 following rows or this one has the KeepPreceding flag then preserve this row*/
                MAX(KeepPreceding) OVER (ORDER BY ColumnA ROWS BETWEEN CURRENT ROW AND 4 FOLLOWING) AS KeptForPreceding,
                /*If at least one of the 4 preceding rows or this one has the KeepFollowing flag then preserve this row*/
                MAX(KeepFollowing) OVER (ORDER BY ColumnA ROWS BETWEEN 4 PRECEDING AND CURRENT ROW) AS KeptForFollowing
         FROM   T1)
SELECT ColumnA
FROM   T2
WHERE  1 IN ( KeptForPreceding, KeptForFollowing )
ORDER  BY ColumnA;

SQL 服务器并发 5 个时间戳列

SQL Server concurrent 5 timestamps in a columns

sql-server

sql-server-2012

gaps-and-islands