What is the lost income from unoccupied rooms at each hotel today?

Question

What will be an ideal response?

Answer 1

SELECT hotelNo, SUM(price) FROM Room r
WHERE roomNo NOT IN
(SELECT roomNo FROM Booking b, Hotel h
WHERE (dateFrom <= CURRENT_DATE AND
dateTo >= CURRENT_DATE) AND
b.hotelNo = h.hotelNo)

GROUP BY hotelNo;