Show me the station names.
select network_name from station;
How about the name of trains and the number of stations each runs through?
select t1.name, count(*) from train as t1 join route as t2 on t1.id = t2.train_id group by t2.train_id;
Of these, return the name with the greatest number of stations.
select t1.name from train as t1 join route as t2 on t1.id = t2.train_id group by t2.train_id order by count(*) desc limit 1;