Room booking sql query

Question

I have a problem in writing the sql to get the available rooms from the tables. my table structures are given below.

table : booking

boo         


        

Answer 1

This should do it; if there is a reservation that does not end before or start after the reservation we want, the room is considered busy.

SELECT r.room_id
FROM rooms r
WHERE r.room_id NOT IN (
    SELECT b.room_id FROM bookings b
    WHERE NOT (b.end_datetime   < '2012-09-14T18:00'
               OR
               b.start_datetime > '2012-09-21T09:00'))
ORDER BY r.room_id;

SQLFiddle here.