How to turn Time Ranking data into a "Timeline" with T-SQL
I have a set of data below
Agent Rank START STOP CODE
Joey 52 11:30 11:45 BRK_Break1
Joey 53 17:30 17:45 BRK_Break2
开发者_运维百科 Joey 57 14:15 15:15 BRK_Lunch
Joey 152 09:40 19:00 CONT_Shift
which is a persons "status" throughout the data. The logic needs to be that there is one line for each "period" of time so it creates one contiunal "timeline" based upon the rank (lower = higher priority) so it looks like below
Agent Start Stop Code
Joey 09:40 11:30 CONT_Shift
Joey 11:30 11:45 BRK_Break1
Joey 11:45 14:15 CONT_Shift
Joey 14:15 15:15 BRK_Lunch
Joey 15:15 17:30 CONT_Shift
Joey 17:30 17:45 BRK_Break2
Joey 17:45 19:00 CONT_Shift
Any ideas how this can be achived? Ideally I would like to restrict the use of staging tables and do this through a CTE or maybe some self joins but not sure where to start?
It is a really good question, answering it was quite hard. first I waited for someone else to solve it, but since that didn't happen, I gave it a try, I discovered a mistake and gave it another try.
it is not pretty, but it seems there are no features in sql supporting the question. So the sql is quite complex. If someone else comes up with a different and better solution, I will be the first to give it a plus.
declare @t table (name varchar(10), rank int, start datetime, stop datetime, code varchar(12))
insert @t values ('Joey', 52, '2011-06-21 11:30', '2011-06-21 11:45', 'BRK_Break1')
insert @t values ('Joey', 53, '2011-06-21 17:30', '2011-06-21 17:45', 'BRK_Break2')
insert @t values ('Joey', 57, '2011-06-21 14:15', '2011-06-21 15:15', 'BRK_Lunch')
insert @t values ('Joey',152, '2011-06-21 09:40', '2011-06-21 19:00', 'CONT_Shift')
insert @t values ('Joey',152, '2011-06-22 09:40', '2011-06-22 19:00', 'CONT_Shift')
;with aa as
(
select name, rank, start, 'b' action, code from @t
union all
select name, rank, stop, 'e', code from @t
)
select * from (
select name,start,
(select min(start) from aa where start > a.start and a.name = name) stop,
(select code from (select rank() OVER (ORDER BY rank) as rank, code from @t where dateadd(second, 1, a.start) between start and stop and name = a.name) c where rank = 1) code
from aa a
where not exists (select 1 from @t where a.start between start and stop and a.rank > rank and a.name = name)
and exists (select 1 from @t where a.start between start and stop and a.name = name)
) d
where code is not null and
name = 'Joey'
order by start
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