MySQL query display problem - php

Question

How can I display the users friends correctly on the users and friends side using my MySQL tables? My current code screws this up.
Users Friends Table
CREATE TABLE users_friends (
id INT UNSIGNED NOT NULL AUTO_INCREMENT,
user_id INT UNSIGNED UNSIGNED NOT NULL,
friend_id INT UNSIGNED NOT NULL,
friendship_status TINYINT(1) UNSIGNED NOT NULL DEFAULT 0,
date_created DATETIME NOT NULL,
PRIMARY KEY (id),
KEY user_id (user_id),
KEY friend_id (friend_id)
);
Users Table
CREATE TABLE users (
user_id INT UNSIGNED NOT NULL AUTO_INCREMENT,
username VARCHAR(255) NULL,
avatar VARCHAR(255) NULL,
password CHAR(128) NOT NULL,
PRIMARY KEY (user_id),
UNIQUE KEY (username)
);
My Current MySQL Code
SELECT users.*, users_friends.*
FROM users
INNER JOIN users_friends ON users.user_id = users_friends.friend_id
WHERE (users_friends.user_id = '" . $user_id . "'
OR users_friends.friend_id = '" . $user_id . "')
AND users_friends.friendship_status = 1
GROUP BY users_friends.date_created

Answer 1

Try this query. This should give you all friends for a particular user based on your database relationship.
SELECT A.user_id, A.friend_id, B.username, B.avatar
FROM users_friends AS A
INNER JOIN users AS B
ON A.friend_id = B.user_id
AND A.user_id = #userToBeSearched
UNION
SELECT A.friend_id, A.user_id, B.username, B.avatar
FROM users_friends AS A
INNER JOIN users AS B
ON B.user_id = A.user_id
AND A.friend_id = #userToBeSearched
Note : I have removed the Group By clause for now because
I am afraid i do not quite understand your schema enough to make sense of why you would be grouping rows only by date_created
Adding the grouping clause will involve making another nested table as you will not be able to select columns not in the Group Clause.
Data used to test:-
Table : user
user_id |username| avatar | password
1 A AAAA
2 B BBBB
3 C CCCCC
4 D DDDDD
Table : user_friends
id | user_id | friend_id | friendship_status | date_created
1 1 2 1 Friday, October 22, 2010 3:09:44 PM
2 2 3 1 Friday, October 22, 2010 3:43:18 PM
3 2 4 1 Friday, October 22, 2010 3:43:26 PM