CREATE TABLE MEDIATYPE (MediaTypeId VARCHAR2, Name VARCHAR2)
CREATE TABLE TRACK (MediaTypeId VARCHAR2)

How many tracks are in the AAC audio file media type?
SELECT COUNT(*) FROM MEDIATYPE AS T1 JOIN TRACK AS T2 ON T1.MediaTypeId = T2.MediaTypeId WHERE T1.Name = "AAC audio file"
SELECT COUNT(*) FROM "MEDIATYPE" "T1" JOIN "TRACK" "T2" ON "T1"."MediaTypeId" = "T2"."MediaTypeId" WHERE "AAC audio file" = "T1"."Name"