CREATE TABLE country (country VARCHAR, country_id VARCHAR)
CREATE TABLE city (country_id VARCHAR)

Which countries have at least 3 cities?
SELECT T2.country FROM city AS T1 JOIN country AS T2 ON T1.country_id = T2.country_id GROUP BY T2.country_id HAVING COUNT(*) >= 3
SELECT "T2"."country" FROM "city" AS "T1" JOIN "country" AS "T2" ON "T1"."country_id" = "T2"."country_id" GROUP BY "T2"."country_id" HAVING COUNT(*) >= 3