SQL select from date ranges - mysql

Question

I have a table of RADIUS session records that includes start time, stop time, and MAC address. I have a requirement to collect a list of users that were online during two time ranges. I believe I'm getting a list of all users online during the time ranges with the following query:
SELECT s_session_id, s_start_time, s_stop_time, s_calling_station_id
FROM sessions
WHERE (
("2015-10-01 08:00:00" BETWEEN s_start_time AND s_stop_time OR "2015-10-01 08:30:00" BETWEEN s_start_time AND s_stop_time)
OR
("2015-10-01 12:00:00" BETWEEN s_start_time AND s_stop_time OR "2015-10-01 12:30:00" BETWEEN s_start_time AND s_stop_time)
)
ORDER BY s_start_time;
But the next step, isolating details for only those users online during both periods, is eluding me. The closest I get is adding
GROUP BY s_calling_station_id HAVING COUNT(s_calling_station_id) > 1
but that doesn't provide me with all the session details.
Fiddle is here: http://sqlfiddle.com/#!9/1df471/1
Thanks for any assistance!

Answer 1

Use a self-join. Use column aliases so you can access the columns from each session with different names.
SELECT s1.s_calling_station_id,
s1.s_session_id AS s1_session_id, s1.s_start_time AS s1_start_time, s1.s_stop_time AS s1_stop_time,
s2.s_session_id AS s2_session_id, s2.s_start_time AS s2_start_time, s2.s_stop_time AS s2_stop_time
FROM sessions AS s1
JOIN sessions AS s2
ON s1.s_calling_station_id = s2.s_calling_station_id
AND s1.s_session_id != s2.s_session_id
WHERE ("2015-10-01 08:00:00" BETWEEN s1.s_start_time AND s1.s_stop_time OR "2015-10-01 08:30:00" BETWEEN s1.s_start_time AND s1.s_stop_time)
AND
("2015-10-01 12:00:00" BETWEEN s2.s_start_time AND s2.s_stop_time OR "2015-10-01 12:30:00" BETWEEN s2.s_start_time AND s2.s_stop_time)
DEMO

Answer 2

Although this question already has an accepted answer, I'd like to add this one (it avoids duplicates and pulls the data from the sessions table of all sessions that fulfill the condition):
First, create a table that holds the filtered data (the MAC addresses that have connections on both intervals:
create table temp_sessions
select s1.s_calling_station_id
, if(#t1_1 between s1.s_start_time and s1.s_stop_time or #t1_2 between s1.s_start_time and s1.s_stop_time, s1.s_session_id, null) as s_1
, if(#t2_1 between s2.s_start_time and s2.s_stop_time or #t2_2 between s2.s_start_time and s2.s_stop_time, s2.s_session_id, null) as s_2
from -- I use user variables because it will make easier to modify the time intervals if needed
(select #t1_1 := '2015-10-01 08:00:00', #t1_2 := '2015-10-01 08:30:00'
, #t2_1 := '2015-10-01 12:00:00', #t2_2 := '2015-10-01 12:30:00') as init
, sessions as s1
inner join sessions as s2
on s1.s_calling_station_id = s2.s_calling_station_id
and s1.s_session_id != s2.s_session_id
having s_1 is not null and s_2 is not null;
And now, simply use this table to get what you need:
select sessions.*
from sessions
inner join (
select s_calling_station_id, s_1 as s_session_id
from temp_sessions
union
select s_calling_station_id, s_2 as s_session_id
from temp_sessions
) as a using (s_calling_station_id, s_session_id);
Here's the SQL fiddle