如果日期列在TSQL中重叠，则合并行

Question

我有一个以下格式的表格

Id  StartDate   EndDate Type
1   2012-02-18  2012-03-18  1
1   2012-03-17  2012-06-29  1
1   2012-06-27  2012-09-27  1
1   2014-08-23  2014-09-24  3
1   2014-09-23  2014-10-24  3
1   2014-10-23  2014-11-24  3
2   2015-07-04  2015-08-06  1
2   2015-08-04  2015-09-06  1
3   2013-11-01  2013-12-01  0
3   2018-01-09  2018-02-09  0

我在这里找到了类似的问题，但没有找到可以帮助我解决问题的问题。我想合并具有相同行Id，Type和重叠的日期时间。

上表的结果应为

Id  StartDate   EndDate Type
1   2012-02-18  2012-09-27  1
1   2014-08-23  2014-11-24  3
2   2015-07-04  2015-09-06  1
3   2013-11-01  2013-12-01  0
3   2018-01-09  2018-02-09  0

在另一台服务器上，我能够做到以下限制和以下查询：

• 不在乎该Type列，而是在Id
• 有了SQL Server（2012）的较新版本，但是现在我的代码不兼容的是2008

---

SELECT Id
     , MIN(StartDate) AS StartDate
     , MAX(EndDate) AS EndDate
FROM (
    SELECT *
         , SUM(CASE WHEN a.EndDate = a.StartDate THEN 0
                    ELSE 1
               END
           ) OVER (ORDER BY Id, StartDate) sm
    FROM (
        SELECT Id
             , StartDate
             , EndDate
             , LAG(EndDate, 1, NULL) OVER (PARTITION BY Id ORDER BY Id, EndDate) EndDate
        FROM #temptable
    ) a
) b
GROUP BY Id, sm

任何建议我怎么能

• 在流程中包括类型
• 使它在SQL Server 2008上运行

Answer 1

此方法使用附加的临时表来标识重叠日期的组，然后根据这些组执行快速汇总。

SELECT *, ROW_NUMBER() OVER (ORDER BY Id, Type) AS UID,
    ROW_NUMBER() OVER (ORDER BY Id, Type) AS GroupId INTO #G FROM #TempTable
WHILE @@ROWCOUNT <> 0 BEGIN
    UPDATE T1 SET
        GroupId = T2.GroupId
    FROM #G T1
        INNER JOIN (
            SELECT T1.UID, CASE WHEN T1.GroupId  < T2.GroupId THEN T1.GroupId ELSE T2.GroupId END
            FROM #G T1
                LEFT OUTER JOIN #G T2
                    ON T1.Id = T2.Id AND T1.Type = T2.Type AND T1.GroupId <> T2.GroupId
                        AND T1.StartDate <= T2.EndDate AND T2.StartDate <= T1.EndDate
            ) T2 (UID, GroupId)
            ON T1.UID = T2.UID
    WHERE T1.GroupId <> T2.GroupId
END
SELECT Id, MIN(StartDate) AS StartDate, MAX(EndDate) AS EndDate, Type
FROM #G G GROUP BY GroupId, Id, Type

这将返回期望值

Id          StartDate  EndDate    Type
----------- ---------- ---------- -----------
1           2012-02-18 2012-09-27 1
1           2014-08-23 2014-11-24 3
2           2015-07-04 2015-09-06 1
3           2013-11-01 2013-12-01 0
3           2018-01-09 2018-02-09 0