q8.sql

SELECT hotel_name 
FROM hotels
WHERE
  city = 'Waterford' AND
  hotel_num IN (
    SELECT r.hotel_num 
    FROM rooms AS r
    WHERE r.room_num NOT IN (
      SELECT b.room_num 
      FROM bookings AS b
      WHERE 
        b.hotel_num = r.hotel_num AND
        '2016-10-05' BETWEEN b.arr_date AND b.dep_date
    )
    GROUP BY hotel_num
    HAVING COUNT(*) >= 5
);