SELECT LOCATION FROM station EXCEPT SELECT LOCATION FROM station WHERE number_of_platforms  >=  15
Show all locations which don't have a train station with at least 15 platforms.
SELECT LOCATION FROM station EXCEPT SELECT LOCATION FROM station WHERE number_of_platforms > = 15
select location from station except select location from station where number_of_platforms > = value
Show all locations which do n't have a train station with at least 15 platforms .