CREATE TABLE city (city_id DECIMAL, city TEXT, hanzi TEXT, hanyu_pinyin TEXT, regional_population DECIMAL, gdp DECIMAL)
CREATE TABLE match (match_id DECIMAL, date TEXT, venue TEXT, score TEXT, result TEXT, competition TEXT)
CREATE TABLE temperature (city_id DECIMAL, jan DECIMAL, feb DECIMAL, mar DECIMAL, apr DECIMAL, jun DECIMAL, jul DECIMAL, aug DECIMAL, sep DECIMAL, oct DECIMAL, nov DECIMAL, dec DECIMAL)
CREATE TABLE hosting_city (year DECIMAL, match_id DECIMAL, host_city TEXT)

Which three cities have the largest regional population?
SELECT city FROM city ORDER BY regional_population DESC LIMIT 3
SELECT "city" FROM "city" ORDER BY "regional_population" DESC NULLS LAST LIMIT 3