这是“分组和窗口”的一个示例。
;with x as
(
select Id, Status, StartDate, EndDate,
iif (lag(Status) over (order by Id, StartDate) = Status,
null, 1) rst from emp ), y as ( select Id, Status, StartDate, EndDate, sum(rst) over (order by Id, StartDate) grp from x )
select Id,
MIN(Status) as Status,
MIN(StartDate) StartDate,
MAX(EndDate) EndDate
from y
group by Id, grp
order by Id, grp
GO
Id | Status | StartDate | EndDate
-: | :----- | :------------------ | :------------------
1 | Active | 01/09/2007 00:00:00 | 15/10/2016 00:00:00
1 | Sick | 16/10/2016 00:00:00 | 31/12/2016 00:00:00
1 | Active | 01/01/2017 00:00:00 | 04/02/2017 00:00:00
1 | Unpaid | 05/02/2017 00:00:00 | 09/02/2017 00:00:00
1 | Active | 10/02/2017 00:00:00 | 11/02/2017 00:00:00
1 | Unpaid | 12/02/2017 00:00:00 | 30/04/2017 00:00:00
1 | Active | 01/05/2017 00:00:00 | 13/10/2017 00:00:00
1 | Sick | 14/10/2017 00:00:00 | 11/11/2017 00:00:00
1 | Active | 12/11/2017 00:00:00 | null
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