sql - 选择重叠的时间范围

Question

T-SQL 日期时间问题。

我有一组时间范围。在这些时间范围内，可能会有一组重叠的时间范围，我称之为“阻塞”时间。被封锁的时间不会超过一天。我想要做的是分割时间以排除被封锁的时间，基本上给我未被“封锁”的时间范围。可以安全地假设阻塞时间不能落在时间范围之外。

示例:我从上午 9 点工作到下午 5 点，下午 1 点有 30 分钟的午休时间。我想要 2 行的结果:上午 9 点到下午 1 点和下午 1.30 到下午 5 点。

如前所述，我有一组时间范围，因此在上面的示例中，每天的工作时间可能不同，休息的次数和持续时间也可能不同。

我想在 SQL 方面，输入参数应该是这样的:

declare @timeranges table ( StartDateTime datetime, EndDateTime datetime )
declare @blockedtimes table ( StartDateTime datetime, EndDateTime datetime )

insert into @timeranges 
select '01 Jan 2009 09:00:00', '01 Jan 2009 17:00:00'
union select '02 Feb 2009 10:00:00', '02 Feb 2009 13:00:00'

insert into @blockedtimes 
select '01 Jan 2009 13:00:00', '01 Jan 2009 13:30:00'
union select '02 Feb 2009 10:30:00', '02 Feb 2009 11:00:00'
union select '02 Feb 2009 12:00:00', '02 Feb 2009 12:30:00'

结果集看起来像这样。

Start                   End
---------------------   ---------------------
'01 Jan 2009 09:00:00' '01 Jan 2009 13:00:00'
'01 Jan 2009 13:30:00' '01 Jan 2009 17:00:00'
'02 Feb 2009 10:00:00' '02 Feb 2009 10:30:00'
'02 Feb 2009 11:00:00' '02 Feb 2009 12:00:00'
'02 Feb 2009 12:30:00' '02 Feb 2009 13:00:00'

我可以用游标或 while 循环来做到这一点，但如果有人可以建议如何在没有迭代的情况下做到这一点，那就太好了 - 谢谢。

Answer 1

第一次剪辑，可能会有一些问题，但我会继续努力。
适用于给定的数据，只需要尝试其他场景

declare @timeranges table ( StartDateTime datetime, EndDateTime datetime )
declare @blockedtimes table ( StartDateTime datetime, EndDateTime datetime )

insert into @timeranges 
select '01 Jan 2009 09:00:00', '01 Jan 2009 17:00:00'
union select '02 Feb 2009 10:00:00', '02 Feb 2009 13:00:00'
--union select '03 Feb 2009 10:00:00', '03 Feb 2009 15:00:00'


insert into @blockedtimes 
select '01 Jan 2009 13:00:00', '01 Jan 2009 13:30:00'
union select '02 Feb 2009 10:30:00', '02 Feb 2009 11:00:00' 
union select '02 Feb 2009 12:00:00', '02 Feb 2009 12:30:00'

--build an ordered, time range table with an indicator
--to determine which ranges are timeranges 'tr'
--and which are blockedtimes 'bt'
--
declare @alltimes table (row int, rangetype varchar(10), StartDateTime datetime, EndDateTime datetime )
insert into @alltimes
select
    row_number() over (order by a.startdatetime), *
from
    (
    select 'tr' as rangetype ,startdatetime, enddatetime from @timeranges
    union
    select 'bt' as rangetype ,startdatetime, enddatetime from @blockedtimes
    )a

--what does the data look like  
--
select * from @alltimes


--
-- build up the results
select
    --start time is either the start time of a timerange, or the end of a blockedtime
    case 
        when at1.rangetype = 'tr' then at1.startdatetime
        when at1.rangetype = 'bt' then at1.enddatetime 
    end as [Start],
    case 
        --a time range followed by another time range : end time from the current time range
        when at1.rangetype = 'tr' and (select at2.rangetype from @alltimes at2 where at2.row = at1.row+1) = 'tr'
            then at1.enddatetime

        --a time range followed by nothing (last record) : end time from the currenttime range
        when at1.rangetype = 'tr' and (select at2.rangetype from @alltimes at2 where at2.row = at1.row+1) is null
            then at1.enddatetime

        --a time range followed by a blockedtime : end time is start time of blocked time
        when at1.rangetype = 'tr' and (select at2.rangetype from @alltimes at2 where at2.row = at1.row+1) = 'bt'
            then (select top 1 at2.startdatetime from @alltimes at2 where at2.row > at1.row and at2.rangetype = 'bt' order by row)

        --a blocked time followed by a blockedtime : end time is start time of next blocked time    
        when at1.rangetype = 'bt'  and (select at2.rangetype from @alltimes at2 where at2.row = at1.row+1) = 'bt'
            then (select top 1 at2.startdatetime from @alltimes at2 where at2.row > at1.row and at2.rangetype = 'bt' order by row)

        --a blocked time followed by a time range : end time is end time of previous time range     
        when at1.rangetype = 'bt'  and (select at2.rangetype from @alltimes at2 where at2.row = at1.row+1) = 'tr'
            then (select top 1 at2.enddatetime from @alltimes at2 where at2.row < at1.row and at2.rangetype = 'tr' order by row desc)

        --a blocked time followed by nothing (last record) : end time is end time of previous time range    
        when at1.rangetype = 'bt'  and (select at2.rangetype from @alltimes at2 where at2.row = at1.row+1) is null
            then (select top 1 at2.enddatetime from @alltimes at2 where at2.row < at1.row and at2.rangetype = 'tr' order by row desc)

    end as [End]

from @alltimes at1