แสดงเที่ยวบินทั้งหมดที่มาถึงดัลลาให้ฉันดู ไม่จำเป็นต้องใช้ตารางทั้งหมด
show me all flights arriving at DALLASIt is not neccessary to use all the tables.
 airport_service:  city_code [ varchar]  airport_code [ varchar]  miles_distant [ int]  direction [ varchar]  minutes_distant [ int] 
SELECT DISTINCT flight.flight_id FROM airport_service, city, flight WHERE city.city_code = airport_service.city_code AND city.city_name = 'DALLAS' AND flight.to_airport = airport_service.airport_code