Benim sorgudan aşağıda aşağıdaki hata alıyorum, ve ben bu sorunu çözebilirsiniz nasıl merak ediyorum?

Duplicate column name 'user_id'

İşte MySQL sorgu.

"SELECT COUNT(users_friends.user_id) FROM ((SELECT *
FROM users_friends
INNER JOIN users ON users_friends.user_id = users.user_id
WHERE users_friends.user_id = '" . $user_id . "' 
AND users_friends.friendship_status = '1')
UNION
(SELECT *
FROM users_friends
INNER JOIN users ON users_friends.friend_id = users.user_id
WHERE users_friends.friend_id = '" . $user_id . "'
AND users_friends.friendship_status = '1')) as friends"

İşte benim yeni sorgu.

SELECT COUNT(user_id) FROM ((SELECT users_friends.user_id
FROM users_friends
INNER JOIN users ON users_friends.user_id = users.user_id
WHERE users_friends.user_id = '" . $user_id . "' 
AND users_friends.friendship_status = '1')
UNION
(SELECT users_friends.user_id
FROM users_friends
INNER JOIN users ON users_friends.friend_id = users.user_id
WHERE users_friends.friend_id = '" . $user_id . "'
AND users_friends.friendship_status = '1')) as friends