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

Show the names and main services for train stations that have the top three total number of passengers.
SELECT name, main_services FROM station ORDER BY total_passengers DESC LIMIT 3
SELECT "name", "main_services" FROM "station" ORDER BY "total_passengers" DESC NULLS LAST LIMIT 3