เที่ยวบิน UA 281 จากบอสตันไปเดนเวอร์เป็นสายการบินประเภทใดไม่จำเป็นต้องใช้ตารางทั้งหมด
what kind of airline is flight UA 281 from BOSTON to DENVERIt is not neccessary to use all the tables.
 month:  month_number [ int]  month_name [ text] 
SELECT DISTINCT airline.airline_code FROM airline, airport_service AS AIRPORT_SERVICE_0, airport_service AS AIRPORT_SERVICE_1, city AS CITY_0, city AS CITY_1, flight WHERE ((CITY_0.city_code = AIRPORT_SERVICE_0.city_code AND CITY_0.city_name = 'BOSTON' AND CITY_1.city_code = AIRPORT_SERVICE_1.city_code AND CITY_1.city_name = 'DENVER' AND flight.from_airport = AIRPORT_SERVICE_0.airport_code AND flight.to_airport = AIRPORT_SERVICE_1.airport_code) AND flight.flight_number = 281) AND flight.airline_code = 'UA' AND flight.airline_code = airline.airline_code