Feature request: In/Not In

[Njanderson]

Hey! Could we get these features added? This is a query found when grading CSEP 544, HW3.

select distinct F2.dest_city as city
from Flights F1, Flights F2
where F1.origin_city = 'Seattle WA' and 
      F1.dest_city = F2.origin_city and F2.dest_city != F1.origin_city and 
      F2.dest_city not in (select F.dest_city as dest_city 
                           from Flights F 
                           where F.origin_city = 'Seattle WA');