Question

我有一个包含时间段的表

StartDate               CancelDate
2014-01-01 00:00:00.000 2014-01-15 00:00:00.000
2014-01-16 00:00:00.000 2014-01-31 00:00:00.000
2014-02-05 00:00:00.000 2014-02-15 00:00:00.000

您可以看到前两行中的句点已连接，并且它们正在创建从2014-01-01到2014-01-31的一个更大的句点，并且在第三行中有一段未连接的句点。

如何从上面的表中获取此表？

    StartDate               CancelDate
    2014-01-01 00:00:00.000 2014-01-31 00:00:00.000
    2014-02-05 00:00:00.000 2014-02-15 00:00:00.000

Answer 1

这些方面的内容应该有效：

SELECT MIN(startdate) StartDate, CancelDate
FROM
(
SELECT a.startdate, 
COALESCE(b.canceldate, a.canceldate) canceldate
FROM dt a
LEFT JOIN dt b ON
(b.startdate=DATEADD(d,1,a.canceldate) OR a.canceldate=b.startdate)
) x
GROUP BY CancelDate

dt是您的数据表

Answer 2

declare @t table (start VARCHAR(10),enddate VARCHAR(10))
insert into @t (start,enddate)values
('2014-01-01','2014-01-15'),
('2012-01-01','2012-01-15'),
('2014-01-15','2014-01-31'),
('2014-02-02','2014-02-15'),
('2014-02-15','2014-02-28')

Select MIN(CAST (start AS DATE)),MAX(CAST (enddate AS DATE)) 
from @t 
group by LEFT(start,7),LEFT(enddate,7)

或使用CTE

   ;WITH CTE AS 
(
select DISTINCT

    (select min(start) from @t
        where LEFT(start,7) = LEFT(m.start,7)
        ) as StartDate,
    (select max(enddate) from @t
        where LEFT(enddate,7) = LEFT(m.enddate,7)
        ) as EndDate,
        ROW_NUMBER()OVER(PARTITION BY LEFT(STart,7) ORDER BY  LEFT(STart,7) DESC)RN 
from
    @t m
    )
    Select DISTINCT StartDate,EndDate from CTE

如何从多个较小的时间段创造更大的时间段？

2 个答案: