CREATE TABLE farm_competition (Official_Name VARCHAR2, City_ID VARCHAR2, Host_city_ID VARCHAR2)
CREATE TABLE city (Official_Name VARCHAR2, City_ID VARCHAR2, Host_city_ID VARCHAR2)

List the official names of cities that have not held any 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")