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

How many cities are in Australia?
SELECT COUNT(*) FROM city AS T1 JOIN country AS T2 ON T1.country_id = T2.country_id WHERE T2.country = 'Australia'
SELECT COUNT(*) FROM "city" AS "T1" JOIN "country" AS "T2" ON "T1"."country_id" = "T2"."country_id" AND "T2"."country" = 'Australia'