Context: CREATE TABLE club (club_id VARCHAR, club_name VARCHAR); CREATE TABLE coach (club_id VARCHAR)
Question: How many coaches does each club has? List the club id, name and the number of coaches.
Answer: SELECT T1.club_id, T1.club_name, COUNT(*) FROM club AS T1 JOIN coach AS T2 ON T1.club_id = T2.club_id GROUP BY T1.club_id