What trains go to station ID 1?
SELECT * FROM train_station AS T1 JOIN station AS T2 ON T1.station_id   =   T2.station_id JOIN train AS T3 ON T3.train_id   =   T1.train_id where T1.station_id  =  1
trains going to station ID 1 refers to filtering results where station_id = 1; JOIN is used to combine rows from two or more tables based on a related column between them;