Puoi selezionare le camere prenotate e invertire:
SELECT * FROM tbRoom WHERE RoomID NOT IN (SELECT RoomID FROM tbReservationDetail WHERE ArrvialDate < yourDate AND DepartureDate > yourDate)
Puoi selezionare le camere prenotate e invertire:
SELECT * FROM tbRoom WHERE RoomID NOT IN (SELECT RoomID FROM tbReservationDetail WHERE ArrvialDate < yourDate AND DepartureDate > yourDate)