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

List the names of people that are not employed by any company
SELECT name FROM people WHERE NOT people_id IN (SELECT people_id FROM employment)
SELECT "name" FROM "people" WHERE NOT "people_id" IN (SELECT "people_id" FROM "employment")