CREATE TABLE stadium (id VARCHAR2)
CREATE TABLE game (stadium_id VARCHAR2)

How many games has each stadium held?
SELECT T1.id, COUNT(*) FROM stadium AS T1 JOIN game AS T2 ON T1.id = T2.stadium_id GROUP BY T1.id
SELECT "T1"."id", COUNT(*) FROM "stadium" "T1" JOIN "game" "T2" ON "T1"."id" = "T2"."stadium_id" GROUP BY "T1"."id"