Which countries in europe have at least 3 car manufacturers?
create table countries (countryname varchar, continent varchar, countryid varchar, PRIMARY KEY (countryname)); create table continents (contid varchar, continent varchar, PRIMARY KEY (contid)); create table car_makers (country varchar, PRIMARY KEY (country))
select t1.countryname from countries as t1 join continents as t2 on t1.continent = t2.contid join car_makers as t3 on t1.countryid = t3.country where t2.continent = 'europe' group by t1.countryname having count(*) >= 3