CREATE TABLE people (people_id DECIMAL, age DECIMAL, name TEXT, nationality TEXT, graduation_college TEXT)
CREATE TABLE employment (company_id DECIMAL, people_id DECIMAL, year_working DECIMAL)
CREATE TABLE company (company_id DECIMAL, name TEXT, headquarters TEXT, industry TEXT, sales_in_billion DECIMAL, profits_in_billion DECIMAL, assets_in_billion DECIMAL, market_value_in_billion DECIMAL)

How many companies are headquartered in the US?
SELECT COUNT(*) FROM company WHERE headquarters = 'USA'
SELECT COUNT(*) FROM "company" WHERE "headquarters" = 'USA'