human
Schema:
station (Station_ID, Name, Annual_entry_exit, Annual_interchanges, Total_Passengers, Location, Main_Services, Number_of_Platforms)
train (Train_ID, Name, Time, Service)
train_station (Train_ID, Station_ID)
Please answer with SQL.
assistant
Sure, I understand.
human
Show station id for all stations with a train.
assistant
SELECT station_id FROM train_station;
human
Show the name of stations without any train.
assistant
SELECT name FROM station WHERE station_id NOT IN ( SELECT station_id FROM train_station ) ;