CREATE TABLE GENRE (GenreId VARCHAR, Name VARCHAR)
CREATE TABLE TRACK (GenreId VARCHAR)

How many tracks belong to rock genre?
SELECT COUNT(*) FROM GENRE AS T1 JOIN TRACK AS T2 ON T1.GenreId = T2.GenreId WHERE T1.Name = "Rock"
SELECT COUNT(*) FROM "GENRE" AS "T1" JOIN "TRACK" AS "T2" ON "T1"."GenreId" = "T2"."GenreId" WHERE "Rock" = "T1"."Name"