Show the names of countries that have more than one roller coaster.
create table roller_coaster (country_id varchar, PRIMARY KEY (country_id)); create table country (name varchar, country_id varchar, PRIMARY KEY (name))
select t1.name from country as t1 join roller_coaster as t2 on t1.country_id = t2.country_id group by t1.name having count(*) > 1