Ciao Criric ho fatto come mi hai detto questo e' il messaggio della query:
SELECT idhotel, room, price, (3 * price) as total FROM rooms WHERE '2014-05-15' BETWEEN data_start AND data_end && id = 1
Errore query : SELECT idhotel, room, price, (3 * price) as total FROM rooms WHERE '2014-05-15'...