CREATE TABLE region (region_id NUMBER, region_code CLOB, region_name CLOB)
CREATE TABLE storm (storm_id NUMBER, name CLOB, dates_active CLOB, max_speed NUMBER, damage_millions_usd NUMBER, number_deaths NUMBER)
CREATE TABLE affected_region (region_id NUMBER, storm_id NUMBER, number_city_affected NUMBER)

What are the names of regions that were not affected?
SELECT region_name FROM region WHERE NOT region_id IN (SELECT region_id FROM affected_region)
SELECT "region_name" FROM "region" WHERE NOT "region_id" IN (SELECT "region_id" FROM "affected_region")