หมายเลขเที่ยวบินสำหรับเที่ยวบิน CO ซึ่งออกจากเดนเวอร์เวลา 12.20 น. และไปยังซานฟรานซิสโกคือเท่าใด ไม่จำเป็นต้องใช้ตารางทั้งหมด
what is the flight number for the CO flight which leaves DENVER at 1220pm and goes to SAN FRANCISCOIt is not neccessary to use all the tables.
 time_zone:  time_zone_code [ text]  time_zone_name [ text]  hours_from_gmt [ int] 
SELECT DISTINCT flight.flight_id FROM airport_service AS AIRPORT_SERVICE_0, airport_service AS AIRPORT_SERVICE_1, city AS CITY_0, city AS CITY_1, flight WHERE ((CITY_1.city_code = AIRPORT_SERVICE_1.city_code AND CITY_1.city_name = 'SAN FRANCISCO' AND flight.departure_time = 1220 AND flight.to_airport = AIRPORT_SERVICE_1.airport_code) AND CITY_0.city_code = AIRPORT_SERVICE_0.city_code AND CITY_0.city_name = 'DENVER' AND flight.from_airport = AIRPORT_SERVICE_0.airport_code) AND flight.airline_code = 'CO'