Find overlapping (date/time) rows within one table

Question

I have a table which stores in each row a meeting with start date/time and end date/time.

meetingID int
meetingStart datetime
meetingEnd datetime

De

Answer 1

Probably something like this:

SELECT m1.meetingID, m2.meetingID
FROM meeting AS m1, meeting AS m2
WHERE m1.meetingID < m2.meetingID
    AND m1.meetingStart BETWEEN m2.meetingStart AND m2.meetingEnd
    OR m1.meetingEnd BETWEEN m2.meetingStart AND m2.meetingEnd

By selecting only m1.meetingID < m2.meetingID you dont compare rows with itself and don't get duplicates because every row would be joined twice (m1, m2) and (m2, m1)