SQL to get friends AND friends of friends of a user

Question

My MySQL tables structure is like this.

USER
int id
varchar username

FRIEND_LIST
int user_id
int friend_id

For each friend relationship I inse

Answer 1

SELECT f1.user_id, f1.friend_id FROM
friends_info f1
WHERE f1.user_id = 1 OR
f1.user_id IN
(
 select f2.friend_id
 from friends_info f2
 where f2.user_id = 1
)
 ORDER BY user_id