เที่ยวบินใดที่เดินทางจากซานฟรานซิสโกไปเดนเวอร์ในวันจันทร์ไม่จำเป็นต้องใช้ตารางทั้งหมด
what flights go from SAN FRANCISCO to DENVER on MONDAYIt is not neccessary to use all the tables.
 city:  city_code [ varchar]  city_name [ varchar]  state_code [ varchar]  country_name [ varchar]  time_zone_code [ varchar] 
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, days, flight WHERE (CITY_1.city_code = AIRPORT_SERVICE_1.city_code AND CITY_1.city_name = 'DENVER' AND days.day_name = 'MONDAY' AND flight.flight_days = days.days_code AND flight.to_airport = AIRPORT_SERVICE_1.airport_code) AND CITY_0.city_code = AIRPORT_SERVICE_0.city_code AND CITY_0.city_name = 'SAN FRANCISCO' AND flight.from_airport = AIRPORT_SERVICE_0.airport_code