Find overlapping time ranges - tsql

Question

I'm surprised this hasn't come up yet.
In T-SQL, I need to find the intervals (defined by startDateTime and endDateTime) that overlap with daily interval (say 9am-5pm).
For example, with table:
CREATE TABLE [dbo].[Interval](
[startDateTime] [datetime] NOT NULL,
[endDateTime] [datetime] NOT NULL
)
Solution would be the procedure that returns only overlapping intervals:
CREATE PROCEDURE FindIntervals
-- Add the parameters for the stored procedure here
#from varchar(5) = '9:00',
#to varchar(5) = '17:00'
AS
BEGIN
select * from Interval
where ...
END
GO
EDIT:
Example intervals:
Sep 7 2011 8:00 AM - Sep 7 2011 8:30 PM
Sep 7 2011 11:00 AM - Sep 7 2011 1:00 PM
Sep 7 2011 1:00 PM - Sep 7 2011 6:00 PM
Sep 9 2011 8:00 AM - Sep 9 2011 8:30 PM
Sep 9 2011 11:00 AM - Sep 9 2011 1:00 PM
Sep 9 2011 1:00 PM - Sep 9 2011 6:00 PM
So, for given interval "nine to five", 2, 3, 5 and 6 should be returned, as they overlap the given input.
But,
Sep 9 2011 8:00 AM - Sep 10 2011 8:30 PM
also fits, because it includes entire day.
Please, I need help with matching string and datetime values in T-SQL, not abstract "less then"/"greater then" solutions.

Answer 1

declare #Interval table
(
startDateTime datetime,
endDateTime datetime
)
insert into #Interval values
('2011-09-07T08:00:00', '2011-09-07T08:30:00'),
('2011-09-07T11:00:00', '2011-09-07T13:00:00'),
('2011-09-07T13:00:00', '2011-09-07T18:00:00'),
('2011-09-09T08:00:00', '2011-09-09T08:30:00'),
('2011-09-09T11:00:00', '2011-09-09T13:00:00'),
('2011-09-09T13:00:00', '2011-09-09T18:00:00'),
('2011-09-09T08:00:00', '2011-09-10T08:30:00')
declare #from varchar(5) = '09:00'
declare #to varchar(5) = '17:00'
;with L(MinDate, MaxDate) as
(
select dateadd(day, datediff(day, 0, min(startDateTime)), 0),
dateadd(day, datediff(day, 0, max(endDateTime)), 0)
from #Interval
),
D(fromTime, endTime) as
(
select dateadd(day, Number.number, L.MinDate)+cast(#from as datetime),
dateadd(day, Number.number, L.MinDate)+cast(#to as datetime)
from L
inner join master..spt_values as Number
on Number.number <= datediff(day, L.MinDate, L.MaxDate)
where Number.type = 'P'
)
select I.startDateTime,
I.endDateTime
from #Interval as I
where exists (select *
from D
where I.startDateTime < D.endTime and
I.endDateTime > D.fromTime)
Result:
startDateTime endDateTime
----------------------- -----------------------
2011-09-07 11:00:00.000 2011-09-07 13:00:00.000
2011-09-07 13:00:00.000 2011-09-07 18:00:00.000
2011-09-09 11:00:00.000 2011-09-09 13:00:00.000
2011-09-09 13:00:00.000 2011-09-09 18:00:00.000
2011-09-09 08:00:00.000 2011-09-10 08:30:00.000
If you expect to have a date range of more than 2048 days you need to replace master..spt_values with a numbers table. Make sure the numbers table starts with 0.
SQL Server 2008 version
;with L(MinDate, MaxDate) as
(
select cast(min(startDateTime) as date),
cast(max(endDateTime) as date)
from #Interval
),
D(fromTime, endTime) as
(
select dateadd(day, Number.number, L.MinDate)+cast(#from as datetime),
dateadd(day, Number.number, L.MinDate)+cast(#to as datetime)
from L
inner join master..spt_values as Number
on Number.number <= datediff(day, L.MinDate, L.MaxDate)
where Number.type = 'P'
)
select I.startDateTime,
I.endDateTime
from #Interval as I
where exists (select *
from D
where I.startDateTime < D.endTime and
I.endDateTime > D.fromTime)