missing time range in a day - sql

Question

I have a table like this:
create table time_sheet
(
StatusCode char(1),
start_time datetime,
end_time datetime
)
insert into time_sheet values
('W','2012-08-01 10:00:00','2012-08-01 12:00:00'),
('D','2012-08-01 12:00:00','2012-08-01 14:00:00'),
('N','2012-08-01 16:00:00','2012-08-01 18:00:00')
The output should be like this:
StatusCode start_time end_time
B 2012-08-01 08:00:00.000 2012-08-01 10:00:00.000
W 2012-08-01 10:00:00.000 2012-08-01 12:00:00.000
D 2012-08-01 12:00:00.000 2012-08-01 14:00:00.000
B 2012-08-01 14:00:00.000 2012-08-01 16:00:00.000
N 2012-08-01 16:00:00.000 2012-08-01 18:00:00.000
B 2012-08-01 18:00:00.000 2012-08-01 20:00:00.000
The beging and end of the day are declared as below.
declare #begingOfDay datetime='2012-08-01 08:00:00.000'
declare #endOfDay datetime='2012-08-01 20:00:00.000'
Basically I want to have missing time range records in the result set between begingOfDay and endOfDay with statusCode B . Please see that in the output there are 3 records added with StatusCode B
Could anybody help with this?

Answer 1

Your sample data (note, Ts added to strings to enforce unambiguous date conversions):
create table time_sheet
(
StatusCode char(1),
start_time datetime,
end_time datetime
)
insert into time_sheet values
('W','2012-08-01T10:00:00','2012-08-01T12:00:00'),
('D','2012-08-01T12:00:00','2012-08-01T14:00:00'),
('N','2012-08-01T16:00:00','2012-08-01T18:00:00')
declare #begingOfDay datetime='2012-08-01T08:00:00.000'
declare #endOfDay datetime='2012-08-01T20:00:00.000'
And the query:
;with AllDTs as (
select #begingOfDay as TimePoint
union
select #endOfDay
union
select start_time from time_sheet
union
select end_time from time_sheet
), OrderedDTs as (
select TimePoint,ROW_NUMBER() OVER (ORDER BY TimePoint) as rn
from AllDTs
), Periods as (
select o1.TimePoint as start_time,o2.TimePoint as end_time
from
OrderedDTs o1
inner join
OrderedDTs o2
on
o1.rn = o2.rn-1
)
select
COALESCE(ts.StatusCode,'B') as StatusCode,
p.start_time,
p.end_time
from
Periods p
left join
time_sheet ts
on
p.start_time = ts.start_time and
p.end_time = ts.end_time
Result:
StatusCode start_time end_time
---------- ----------------------- -----------------------
B 2012-08-01 08:00:00.000 2012-08-01 10:00:00.000
W 2012-08-01 10:00:00.000 2012-08-01 12:00:00.000
D 2012-08-01 12:00:00.000 2012-08-01 14:00:00.000
B 2012-08-01 14:00:00.000 2012-08-01 16:00:00.000
N 2012-08-01 16:00:00.000 2012-08-01 18:00:00.000
B 2012-08-01 18:00:00.000 2012-08-01 20:00:00.000
Note, I've proceeded on the assumption that there are no overlapping time periods in the original table. The first CTE (AllDTs) just finds all unique datetime values that are of interest to us. OrderedDTs and Periods than arrange all of these datetime values into successive periods. The final query then takes each of these periods, and attempts to match them back to the original table, if possible. If not, then it's obviously a B period.

Answer 2

Try This one:
declare #begingOfDay datetime='2012-08-01 08:00:00.000'
declare #endOfDay datetime='2012-08-01 20:00:00.000'
declare #begingOfDay datetime='2012-08-01 08:00:00.000'
declare #endOfDay datetime='2012-08-01 20:00:00.000'
;WITH CTEMain as (select ROW_NUMBER() over (order by (select 0)) as id,StatusCode,start_time,end_time from time_sheet)
,CTE2 as (
select * from (
select CASE WHEN start_time > #begingOfDay then 'B' else StatusCode end as statusCode,
CASE WHEN start_time > #begingOfDay then #begingOfDay else start_time end as start_time,
CASE WHEN start_time > #begingOfDay then start_time else end_time end as end_time
FROM CTEMain where id=1
UNION
select StatusCode,start_time,end_time from CTEMain
union
select 'B'
,CASE WHEN CAST(((select c.start_time from CTEMain c where c.id=t1.id+1)-t1.end_time) as time) > '00:00:00' then end_time else null end as start_time
,CASE WHEN CAST(((select c.start_time from CTEMain c where c.id=t1.id+1)-t1.end_time) as time) > '00:00:00' then end_time+((select c.start_time from CTEMain c where c.id=t1.id+1)-t1.end_time) else null end as start_time
from CTEMain t1
) a)
select * from (
select * from CTE2 where start_time is not null
union all
select 'B',CASE WHEN MAX(end_time) = #endOfDay then null else MAX(end_time) end as start_time,#endOfDay as end_time from CTE2) a order by start_time