mysql join 2 tables filtering results

I have 2 tables users and referral.

here is the structure of 2 tables.

referral table

|    Column    |
----------------
| ref_id       |
| from_user_id |
| to_user_id   | 
| ref_name     |    
| ref_phone    |    
| ref_email    |        
| ref_note     |

users table

|    Column    |
----------------
| user_id         |
| user_name       |
| user_first_name |
| user_last_name  |
| user_email      |
| user_phone      |

i have 2 sections where a user can see received and sent referrals.

in received referral section how do i get the first_name and last_name from users table joining the from_user_id in referral table.

so far i came up with this query for received referral which gets me the intended result set. but how can get the users table firstname and lastname from referral table from_user_id

SELECT users.user_id, users.user_name, users.user_firstname, users.user_lastname, referral.ref_name, referral.ref_phone, referral.ref_email, referral.ref_note
FROM referral JOIN users 
ON referral.to_user_id = users.user_id 
WHERE referral.to_user_id = (logged in user id)

similarly in the sent referral section how do i get the user firstname and lastname joining users and referral table from_user_id key

SELECT users.user_id, users.user_name, users.user_firstname, users.user_lastname
            FROM referral JOIN users 
            ON referral.from_user_id = users.user_id
            WHERE referral.from_user_id = (logged in user id)

any help would be greatly appreciated.

Answer

I think you want two joins on the users table:

select r.ref_name, r.ref_phone, r.ref_email, r.ref_note,
    uf.user_id as from_user_id, uf.user_name as from_user_name, uf.user_firstname as from_user_firstname, uf.user_lastname as from_user_lastname, 
    ut.user_id as to_user_id,   ut.user_name as to_user_name,   ut.user_firstname as to_user_firstname,   ut.user_lastname as to_user_lastname
from referral r
inner join users ut on r.to_user_id   = ut.user_id 
inner join users uf on r.from_user_id = uf.user_id
where r.to_user_id = ?