SQL join hjælp til venneliste

Brug:

SELECT f.username,
       up.*
  FROM USERS f
  JOIN USER_PROFILES up ON up.user_id = f.id
  JOIN FRIENDS fr ON fr.userb_id = f.id
  JOIN USERS u ON u.id = fr.usera_id
 WHERE u.username = ?

...forudsat userb_id er ven-id.