CREATE TABLE farm_competition (competition_id NUMBER, year NUMBER, theme CLOB, host_city_id NUMBER, hosts CLOB)
CREATE TABLE farm (farm_id NUMBER, year NUMBER, total_horses NUMBER, working_horses NUMBER, total_cattle NUMBER, oxen NUMBER, bulls NUMBER, cows NUMBER, pigs NUMBER, sheep_and_goats NUMBER)
CREATE TABLE city (city_id NUMBER, official_name CLOB, status CLOB, area_km_2 NUMBER, population NUMBER, census_ranking CLOB)
CREATE TABLE competition_record (competition_id NUMBER, farm_id NUMBER, rank NUMBER)

What are the official names of cities that have not hosted a farm competition?
SELECT official_name FROM city WHERE NOT city_id IN (SELECT host_city_id FROM farm_competition)
SELECT "official_name" FROM "city" WHERE NOT "city_id" IN (SELECT "host_city_id" FROM "farm_competition")