Question

i have two tables
one for users which keeps the user info
another is for friends

users_table   :  id , username , avatar
friends_table :  id , u1_id , u2_id 

now i want to show each user friends in his profile

and i want to do it with one query

so in friends table my user could be in the u1_id or u2_id based on who has requested the friendship

and becuz i want to join each friend to the users_table and get his username and avatar i cant simply do

select * from friends_table where u1_id = $profile_id || u2_id = $profile_id

so i have to run two query

select f.u1_id , u.username , u.avatar from friends_table f join users_table u on f.u1_id = u.id
where f.u2_id = $profile_id 

select f.u2_id , u.username , u.avatar from friends_table f join users_table u on f.u2_id = u.id
where f.u1_id = $profile_id 

is there any way to do this with one query ?

or something like this

select f.u1_id ,  f.u2_id , u.username , u.avatar from friends_table where u1_id = $profile_id || u2_id = $profile_id

if( u1_id = $profile_id )
join users_table u on f.u2_id = u.id

if( u2_id = $profile_id )
join users_table u on f.u1_id = u.id

my problem is in the join part , i want to join the friends_table with usres_table on the friends id not current owner of profile id

Answer 1

select u.id,
    u.username,
    u.avatar
from friends_table f
join users_table u on f.u1_id = u.id || f.u2_id = u.id
where u.ID <> $profile_id
    and (f.u1_id = $profile_id || f.u2_id = $profile_id)