Mysql GROUP_CONCAT return only one value - mysql

Question

I try to return how many friends a user have through GROUP_CONCAT But i only get Lance and not also Bob and it seems if i remove the WHERE condition. It works fine, but i would like to keep it. Since i want get all rows which are connected to member
CREATE TABLE users(
id INT PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(255)
);
INSERT INTO users (name)
VALUES ("Gregor"),
("Liza"),
("Matt"),
("Tim"),
("Lance"),
("Bob");
CREATE TABLE committee(
id INT PRIMARY KEY AUTO_INCREMENT,
user_id INT,
friend_id INT,
member_id INT,
FOREIGN KEY (`user_id`) REFERENCES `users` (`id`),
FOREIGN KEY (`friend_id`) REFERENCES `users` (`id`),
FOREIGN KEY (`member_id`) REFERENCES `users` (`id`)
);
INSERT INTO committee (user_id, friend_id, member_id)
VALUES (3, 5, 1),
(4, 5, 1),
(3, 6, 2),
(4, 6, 2);
Here is the query:
SELECT u.name,
GROUP_CONCAT(f.name) AS friends
FROM committee c
INNER JOIN users u ON (u.id = c.user_id)
INNER JOIN users AS f ON (f.id = c.friend_id)
WHERE (c.member_id = 1)
GROUP BY u.id;
What i get now:
name friends
Matt Lance
Tim Lance
What i expect:
name friends
Matt Lance,Bob
Tim Lance,Bob

Answer 1

You need another join with committee to find all the other committees that Matt and Tim are on, so you can find their friends from those committees.
SELECT u.name,
GROUP_CONCAT(f.name) AS friends
FROM committee c
INNER JOIN users u ON (u.id = c.user_id)
INNER JOIN committee c2 ON c2.user_id = c.user_id
INNER JOIN users AS f ON (f.id = c2.friend_id)
WHERE (c.member_id = 1)
GROUP BY u.id;
DEMO