Select between two dates when there is overlapping - sql

Question

I have these data in my view
ID event_start event_end
499 2021-07-13 00:00:00.000 2021-07-13 00:00:00.000
499 2021-07-15 00:00:00.000 2021-07-15 00:00:00.000
499 2021-07-14 05:00:00.000 2021-07-14 06:00:00.000
499 2021-07-14 02:00:00.000 2021-07-14 03:00:00.000
499 2021-07-14 07:00:00.000 2021-07-14 09:00:00.000
So I have parameters as #date_start and #date_end and would like to select like this:
DECLARE #date_start datetime2 = '2021-07-14 07:00', #date_end datetime2 = '2021-07-14 08:10'
Select ID, t1.event_start, t1.event_end from Table1
WHERE event_start >= #date_start AND event_end <= #date_end
AND ID=499
That will give me no returned result. But my goal is to get the last row.
499 2021-07-14 07:00:00.000 2021-07-14 09:00:00.000
since this row starts at 7 and finishes at 9 which will cover the #date_start and #date_end period. How could I do that?
Also if I changed #date_start and #date_end to this:
DECLARE #date_start datetime2 = '2021-07-14', #date_end datetime2 = '2021-07-14'
It should return
499 2021-07-14 05:00:00.000 2021-07-14 06:00:00.000
499 2021-07-14 02:00:00.000 2021-07-14 03:00:00.000
499 2021-07-14 07:00:00.000 2021-07-14 09:00:00.000
because all three row happened on the same day but just different time.
Thank you

Answer 1

It seems you actually want to check for any overlaps of the date ranges in the table with the date range specified in the parameters.
Assuming that it doesn't matter if two intervals butt-end each other (say 07:00-08:00 and 08:00-09:00), you need to do an interval check like this start1 < end2 AND end1 > start2
DECLARE #date_start datetime2 = '2021-07-14 07:00', #date_end datetime2 = '2021-07-14 08:10'
SELECT
ID,
t1.event_start,
t1.event_end
FROM Table1
WHERE event_start < #date_end AND event_end > #date_start
AND ID = 499;

Answer 2

First thing to bear in mind, are your datetimes in DATETIME type?
If so, let's check the first case.
1.To see whether a datetime/timestamp is contained in a range, we specify the following WHERE clause:
WHERE
event_start <= '2021-07-14 07:00:00' and
event_end >= '2021-07-14 08:10:00'
1. OUTPUT
id event_start event_end
--- ----------------------- -----------------------
499 2021-07-14 07:00:00.000 2021-07-14 09:00:00.000
In case your data is not in DATETIME/TIMESTAMP type, this might not work.
2.Here, you change the condition, since you want all the stuff that happened during a whole day. Therefore, the WHERE clause looks like this:
WHERE
event_start >= '2021-07-14' and
event_end < '2021-07-15'
2. OUTPUT
id event_start event_end
--- ----------------------- -----------------------
499 2021-07-14 05:00:00.000 2021-07-14 06:00:00.000
499 2021-07-14 02:00:00.000 2021-07-14 03:00:00.000
499 2021-07-14 07:00:00.000 2021-07-14 09:00:00.000
Hope it helped!