Sql server 在时间轴SQL Server中对事件进行分组

我有一系列事件按照时间顺序依次发生。为了方便起见，我把比赛时间缩短到1分钟。有时，同一事件发生在同一事件之后，本质上使其成为同一事件

基本数据如下所示：

我想要一个如下所示的结果集：

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实现这一点的最佳方法是什么？

一种方法是使用行号的差异对活动岛进行分组。例如：

SELECT Start = MIN(StartTime), [End] = MAX(EndTime), Activity
FROM (
    SELECT *, RN = ROW_NUMBER() OVER (ORDER BY StartTime) - ROW_NUMBER() OVER (PARTITION BY Activity ORDER BY StartTime)
    FROM #Events
) AS E
GROUP BY Activity, RN;

---

我希望这是最好的方式：

SELECT  X.Start, Y.[End], X.Activity
FROM
(
    SELECT ROW_NUMBER() OVER (ORDER BY E1.StartTime) RN, E1.StartTime [Start], E1.Activity
    FROM (
        SELECT *, ROW_NUMBER() OVER (ORDER BY StartTime) RN
        FROM #Events
    ) AS E1
    LEFT JOIN
    (
        SELECT *, ROW_NUMBER() OVER (ORDER BY StartTime) RN
        FROM #Events
    ) AS E2
    ON E1.Activity=E2.Activity
    AND E1.RN=E2.RN+1
    WHERE E2.Activity IS NULL
) X
INNER JOIN
(
    SELECT ROW_NUMBER() OVER (ORDER BY E1.StartTime) RN, E1.EndTime [End], E1.Activity
    FROM (
        SELECT *, ROW_NUMBER() OVER (ORDER BY StartTime) RN
        FROM #Events
    ) AS E1
    LEFT JOIN
    (
        SELECT *, ROW_NUMBER() OVER (ORDER BY StartTime) RN
        FROM #Events
    ) AS E2
    ON E1.Activity=E2.Activity
    AND E1.RN=E2.RN-1
    WHERE E2.Activity IS NULL
) Y
ON X.RN=Y.RN

结果:

2017-09-19 10:01:00.000 2017-09-19 10:15:00.000 Play
2017-09-19 10:16:00.000 2017-09-19 11:12:00.000 Subject 1
2017-09-19 11:13:00.000 2017-09-19 11:25:00.000 Play
2017-09-19 11:26:00.000 2017-09-19 12:35:00.000 Subject 2
2017-09-19 12:36:00.000 2017-09-19 12:45:00.000 Play

---

真是聪明的解决方案！谢谢

2017-09-19 10:01:00.000 2017-09-19 10:15:00.000 Play
2017-09-19 10:16:00.000 2017-09-19 11:12:00.000 Subject 1
2017-09-19 11:13:00.000 2017-09-19 11:25:00.000 Play
2017-09-19 11:26:00.000 2017-09-19 12:35:00.000 Subject 2
2017-09-19 12:36:00.000 2017-09-19 12:45:00.000 Play