Database: flight_2

Question: Which flight numbers correspond to United Airlines flights?
SQL: SELECT T1.FlightNo FROM FLIGHTS AS T1 JOIN AIRLINES AS T2 ON T2.uid  =  T1.Airline WHERE T2.Airline  =  "United Airlines"

Question: Give the flight numbers of flights leaving from APG.
SQL: SELECT FlightNo FROM FLIGHTS WHERE SourceAirport  =  "APG"

Question: Give the flight numbers of flights landing at APG.
SQL: SELECT FlightNo FROM FLIGHTS WHERE DestAirport  =  "APG"

Question: Give the flight numbers of flights leaving from Aberdeen.
SQL: SELECT T1.FlightNo FROM FLIGHTS AS T1 JOIN AIRPORTS AS T2 ON T1.SourceAirport   =  T2.AirportCode WHERE T2.City  =  "Aberdeen"

Question: Give the flight numbers of flights arriving in Aberdeen.
SQL: SELECT T1.FlightNo FROM FLIGHTS AS T1 JOIN AIRPORTS AS T2 ON T1.DestAirport   =  T2.AirportCode WHERE T2.City  =  "Aberdeen"

Question: How many flights land in Aberdeen or Abilene?
SQL: SELECT count(*) FROM Flights AS T1 JOIN Airports AS T2 ON T1.DestAirport  =  T2.AirportCode WHERE T2.city  =  "Aberdeen" OR T2.city  =  "Abilene"

Question: Which airports do not have departing or arriving flights?
SQL: SELECT AirportName FROM Airports WHERE AirportCode NOT IN (SELECT SourceAirport FROM Flights UNION SELECT DestAirport FROM Flights)