What airports have "London" in its name?
select airport_name from airport where airport_name like "%london%"
What aircraft names are associated with these airports?
select t1.aircraft from aircraft as t1 join airport_aircraft as t2 on t1.aircraft_id = t2.aircraft_id join airport as t3 on t2.airport_id = t3.airport_id where t3.airport_name like "%london%"
Which ones are associated with an airport with "London Heathrow"
select t1.aircraft from aircraft as t1 join airport_aircraft as t2 on t1.aircraft_id = t2.aircraft_id join airport as t3 on t2.airport_id = t3.airport_id where t3.airport_name = "London Gatwick"
Which of these aircrafts are also associated with an airport named "London Gatwick"
select t1.aircraft from aircraft as t1 join airport_aircraft as t2 on t1.aircraft_id = t2.aircraft_id join airport as t3 on t2.airport_id = t3.airport_id where t3.airport_name = "London Heathrow" intersect select t1.aircraft from aircraft as t1 join airport_aircraft as t2 on t1.aircraft_id = t2.aircraft_id join airport as t3 on t2.airport_id = t3.airport_id where t3.airport_name = "London Gatwick"