PHP注销和更新数据库

Question

I am creating a simple web app using PHP/MySQL and I would like to display to the users something like the following;

`Last Login Time: Friday 4th of March at 2:25pm' 

My users database has the following structure;

+---------+-----------+-------------------+---------------------+
| user_id | user_name | user_email        | lastLogin           |
+---------+-----------+-------------------+---------------------+
| 1       | Joe       | [e-mail] | 0000-00-00 00:00:00 |
+---------+-----------+-------------------+---------------------+

What is the best way to approach this? Presumably I update the lastLogin column on logout? Then on the users next login, I select this column data and display it?

My code so far is as follows;

(The logout() function works perfectly fine if I remove the two $stmt lines.)

class.user.php

class USER {

    public function logout() {
        $stmt = $this->db->prepare("UPDATE users SET lastLogin = now()");
        $stmt->execute();
        session_destroy();
        unset($_SESSION['user_session']);
        return true;
    }

    public function lastLogin() {
        $stmt = $this->db->prepare("SELECT lastLogin FROM users WHERE user_name=:user_name");
        $stmt->bindparam(":user_name", $_SESSION['user_name']);
        $stmt->execute();

        while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
            $date = date('jS M Y h:i', strtotime($row['lastLogin']));
        }
        return $date;
    }

}

logout.php

require_once('session.php');
require_once('class.user.php');
$user_logout = new USER();

if($user_logout->is_loggedin()!="")
{
    $user_logout->redirect('index.php');
}
if(isset($_GET['logout']) && $_GET['logout']=="true")
{      
    $user_logout->logout();
    $user_logout->redirect('index.php');
}

index.php

<?php  echo '<p>Last Login ' .$USER->lastLogin();'</p>' ?>

Any help appreciated.

Answer 1

What is the best way to approach this? Presumably I update the lastLogin column on logout?

You can't force a user to logout so this approach wont work.

Instead of setting the lastLogin when logging out, consider setting it on logging in. You can keep a 2nd column actualLastLogin so avoid overwriting the value immediately.

On login, do:

UPDATE users
    SET lastLogin = NOW(),
    actualLastLogin = lastLogin
..

Then read the value of actualLastLogin.

It's possible users don't have a clear login moment because you might have a system that persist a session (such as a "remember me on this computer"). In that case you need to define what you think is a session. If you're inactive for 1 hour does that mark the end of your session? It's up to you.

---

Alternatively you could keep a log of logins and return the last one.