PHP和Mysql-如何使我的登录系统与数据库一起使用？

Question

I've been coding for a short while now, and I am currently creating a website in PHP, html and with a mysql database. I got a table in my database for users, and my registration code works well : it registers the user, with the email adress, name, nickname and password he chose ; and an account with an already existing mail or nickname cannot be created.

My login code works... Almost.

<?php
session_start();
[...]
$query_users = "SELECT `name`, `password`, `id_user` FROM `users`";
$result_users = mysqli_query($link, $query_users);
while ($row = mysqli_fetch_assoc($result_users))
{
    if (($row['name'] == $_POST['nickname']) && ($row['password'] == $_POST['password']))
    {
        $_SESSION['id'] = $row['id_user'];
        $_SESSION['name'] = $row['name'];
        header('Location: /Myblog/?action=login_success');
    }
}
?>

You can't login if your username/password doesn't match with something in the database. But it seems that my $_SESSION aren't remembered by the server as soon as I change my page : check ?action=login_success

<?php
$user = $_SESSION['name'];
echo 'Welcome, $user.';
?>

And it only displays "Welcome, ." Does anyone know why it doesn't work ? Do I have to change all the way my code is built or is it just a little something that I forgot ?

Answer 1

You forgot to put session_start() in your second file. This function must be put in every file where you want to use sessions in

Answer 2

Also you forgot to double quote the welcome message, like that:

echo "Welcome, $user";

Single quotes don't parse variables.