CVGIt คืออะไรไม่จำเป็นต้องใช้ตารางทั้งหมด
what is CVGIt is not neccessary to use all the tables.
 flight_stop:  flight_id [ int]  stop_number [ int]  stop_days [ text]  stop_airport [ text]  arrival_time [ int]  arrival_airline [ text]  arrival_flight_number [ int]  departure_time [ int]  departure_airline [ text]  departure_flight_number [ int]  stop_time [ int] 
SELECT DISTINCT airport_code FROM airport WHERE airport_code = 'CVG'