What are the total number of domestic passengers of airports that contain the word "London"?
select sum ( domestic_passengers ) from airport where airport_name like "%london%"
What about with a name like 'Heathrow'?
select sum ( domestic_passengers ) from airport where airport_name like "%heathrow%"
what about international passengers?
select sum ( international_passengers ) from airport where airport_name like "%heathrow%"