如何选择共同的朋友 - How to select mutual friends

How to select mutual friends

本文关键字：朋友选择何选择 | 更新日期: 2023-09-27

请我想选择一个用户的共同朋友，$my_id是$_SESSION['user']; 而$user_id是所选用户。这是代码：

    <?php
include 'connect.php';
include 'functions.php';
$my_frnds = mysqli_query{$con, "SELECT * FROM friends WHERE one='$my_id' OR two='$my_id'"};
while($my_friends = mysqli_fetch_array($my_frnds)){
    $one = $my_friends['one'];
    $two = $my_friends['two'];
    if($one == $my_id){
        $user == $two;
    } else
        $user == $one;
}
$user_frnds = mysqli_query{$con, "SELECT * FROM friends WHERE one='$user_id' OR two='$user_id'"};
while($user_friends = mysqli_fetch_array($user_frnds)){
    $user_one = $user_friends['one'];
    $user_two = $user_friends['two'];
    if($user_one == $my_id){
        $users == $user_two;
    } else
        $users == $user_one;
}
?>

假设我的朋友是（

1,2,3,4,5,6,7），用户朋友是（2,4,6,7,8,9,10），所以共同的朋友是（2,4,6,7）我的问题是我如何让共同的朋友出来并回显他们的ID？对不起，我弄错了，这是原始编码

如果一个是你的ID，两个是朋友ID：

select * from friends 
inner join (select * from friends where one = $user_id) as temp on temp.two = friends.two
where friends.one = $my_id

    SELECT * FROM friends AS f1
    INNER JOIN 
    (SELECT * FROM friends WHERE one = $user_id OR two = $user_id) AS f2 
    ON (f1.one = f2.one OR f1.one = f2.two) 
    WHERE f1.one = $my_id OR f1.two = $my_id

希望这有帮助。