Question

I have a table which contains my server status

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

I would like a query that given a start and end date will summarize the time the server spends in each state during that time. I would also like the query to return the amount of time the servers spend in an unknown state.

So, for example for the following data

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   

Provided the range.

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

I would like to return the results:

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

This question is somewhat related to: Combining split date ranges in a SQL query

Answer 1

This is the best I have come up with so far:

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