PHP无法识别现有会话，因此开始新的会话

Question

I have a website with a php log in. Everytime a page is visited, I call on session_start() .

I've been having this unusual problem where 1 in 5 times (or so), my session_start will fail to recognize the existing PHPSESSID cookie and instead creates a new one, so that I have 2 of them, and stops using all of the data stored in the first session.

It goes as such: I log in successfully, and am successfully redirected to the same page I was on but now logged in, and I am assigned a session id cookie, and the session successfully stores its data (all checked and confirmed)

Then I click any link on the page (even the link that takes me to the same page I'm on) and instead of continuing the session, it creates a new session, giving me a second session cookie and effectively logging me out.

This only happens 1 in 5 times, and only when I first visit the website. On successful trials, when I log in, navigating to another page leaves me with 1 session id cookie instead of 2.

I've been banging my head on the wall with this problem, and would love any help!

Answer 1

Call: echo session_id(); . What is returned?

This is your session ID. If it changes during the flow of your script, you will lose your $_SESSION data.

Answer 2

You may be destroying and recreating the session. Make sure that the session doesn't exist before you create it.

if(!$_SESSION)
   session_start();

Answer 3

obviously you will have sorted this, but for others who struggle with the same thing, i used this method in my logout.php file. the session_regenerate_id() resets the session variable used. hope this helps others

<?php   
session_start(); //to ensure you are using same session
session_unset($_SESSION['currentUser']);
session_destroy(); //destroy the session
$_SESSION = array();
session_regenerate_id(TRUE);
header("location:/final/index.html"); //to redirect back to "index.php" after logging out
exit();
?>