CREATE TABLE station (station_id NUMBER, name CLOB, annual_entry_exit NUMBER, annual_interchanges NUMBER, total_passengers NUMBER, location CLOB, main_services CLOB, number_of_platforms NUMBER)
CREATE TABLE train_station (train_id NUMBER, station_id NUMBER)
CREATE TABLE train (train_id NUMBER, name CLOB, time CLOB, service CLOB)

Show station names without any trains.
SELECT name FROM station WHERE NOT station_id IN (SELECT station_id FROM train_station)
SELECT "name" FROM "station" WHERE NOT "station_id" IN (SELECT "station_id" FROM "train_station")