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 match (match_id DECIMAL, date TEXT, venue TEXT, score TEXT, result TEXT, competition TEXT)
CREATE TABLE city (city_id DECIMAL, city TEXT, hanzi TEXT, hanyu_pinyin TEXT, regional_population DECIMAL, gdp DECIMAL)
CREATE TABLE hosting_city (year DECIMAL, match_id DECIMAL, host_city TEXT)

What is the city with the smallest GDP? Return the city and its GDP.
SELECT city, gdp FROM city ORDER BY gdp LIMIT 1
SELECT "city", "gdp" FROM "city" ORDER BY "gdp" NULLS FIRST LIMIT 1