Sql for at få alle venners venner, som ikke er min ven

Her går du... simpelt tilmeld dig

SELECT F2.friend_id
FROM FRIENDSHIPS F
JOIN FRIENDSHIPS F2 ON F.friend_id = F2.user_id
WHERE F2.friend_id NOT IN (SELECT friend_ID FROM FRIENDSHIPS WHERE user_id = @user_id)
  AND F.user_id = @user_id