对 SQL 查询中的分割范围求和

Question

我有一个包含我的服务器状态的表，

create table ServerStatus
(
    ServerId int, 
    StartTime datetime, 
    Seconds int,
    [State] char(8) 
)

我想要一个给定开始和结束日期的查询将总结服务器在此期间在每个状态下花费的时间。 我还希望查询返回服务器处于未知状态的时间量。

因此，例如为以下数据

1   2008-01-01 00:00:00.000 120 broken  
1   2008-01-02 00:00:00.000 120 off     
1   2008-01-03 00:00:00.000 240 burning 
1   2008-01-04 00:00:00.000 60  off     
1   2008-01-05 00:00:00.000 60  off     
2   2008-01-01 00:00:00.000 60  broken  
2   2008-01-02 00:00:00.000 30  off     
2   2008-01-03 00:00:00.000 20  burning 
2   2008-01-04 00:00:00.000 600 off     
3   2007-01-04 00:00:00.000 600 off     
4   2007-12-12 00:00:00.000 999999999   onfire  

提供了范围。

select  @start = dateadd(second, 60, '2008-01-01'), 
@fin = dateadd(second, 60, '2008-01-04')

我想返回结果：

1   broken      60
1   burning     240
1   off         180
1   unknown     258720
2   burning     20
2   off         90
2   unknown     259090
4   onfire      259200

这个问题与以下内容有些相关：组合SQL 查询中的分割日期范围

Answer 1

这是迄今为止我想到的最好的：

declare @start datetime
declare @fin datetime 

select  @start = dateadd(second, 60, '2008-01-01'), @fin = dateadd(second, 60, '2008-01-04')

select ServerId, State, Total = sum(
    case when StartTime > @start and DateAdd(second, Seconds, StartTime) <= @fin
        then Seconds
    when StartTime < @start and DateAdd(second, Seconds, StartTime) <= @fin
        then DateDiff(second, @start, DateAdd(second, Seconds, StartTime)) 
    when StartTime < @start and DateAdd(second, Seconds, StartTime) >= @fin
        then DateDiff(second, @start, @fin)
    else 
        DateDiff(second,StartTime,@fin)
    end)
into #t
from ServerStatus 
where @start < dateadd(second, Seconds, StartTime) 
and @fin > StartTime
group by ServerId, State

insert #t
select ServerId, 'unknown', DateDiff(second, @start, @fin) - sum(Total) 
from #t 
group by ServerId
having DateDiff(second, @start, @fin) > sum(Total)

select * from #t 
order by ServerId, State