CREATE TABLE station_company (station_id DECIMAL, company_id DECIMAL, rank_of_the_year DECIMAL)
CREATE TABLE gas_station (station_id DECIMAL, open_year DECIMAL, location TEXT, manager_name TEXT, vice_manager_name TEXT, representative_name TEXT)
CREATE TABLE company (company_id DECIMAL, rank DECIMAL, company TEXT, headquarters TEXT, main_industry TEXT, sales_billion DECIMAL, profits_billion DECIMAL, assets_billion DECIMAL, market_value DECIMAL)

Show all main industry and total market value in each industry.
SELECT main_industry, SUM(market_value) FROM company GROUP BY main_industry
SELECT "main_industry", SUM("market_value") FROM "company" GROUP BY "main_industry"