打开新页面时会话变量重置

Question

I wrote a whole new script to store my sessions in the database and everything seems to be working. For some reason whenever I open a page the session variables are gone.

I'm assuming this has something to do with me using session_start(); at the top of the page while I use session_start($session_id); on my script to start the session. Does this reset the session_id?

This is the main php script that sets the variables/sessions

<?php 
    session_start();
    include($_SERVER['DOCUMENT_ROOT']. '/../db_connect.php');
    if (!Isset($_SESSION['crecketgaming_usergroup'])){
        $_SESSION['crecketgaming_usergroup'] = "Guest";
    }
    try {
        $conn = new PDO("mysql:host=$servername:3307;dbname=$dbname", $username, $password);
    }catch(PDOException $e){
        echo "Connection failed: " . $e->getMessage();
    }

    onLoad($conn);
    function onLoad($conn){
        $session_id = "";
        if(isset($_COOKIE['Crecketgaming_sessionid'])){
            $time = time();
            $session_id = $_COOKIE['Crecketgaming_sessionid'];
            $addrip = $_SERVER['REMOTE_ADDR'];
            $sql = "SELECT * FROM sessions WHERE session_id = :sessionid AND ip = :addrip"; 
            $sth = $conn->prepare($sql);
            $sth->bindParam(':sessionid', $session_id, PDO::PARAM_STR);
            $sth->bindParam(':addrip', $addrip, PDO::PARAM_STR);
            if($sth->execute()){
            }else{
                echo "error";
            }
            $rowcount = $sth->rowCount();
            $row = $sth->fetch();   
            $userid = $row['user_id'];  
            //echo $row['user_id'];
            if ($rowcount > 0) {
            } else {
                $session_id = storeUID($conn);
            }
        } else {
            $session_id = storeUID($conn);
        }
        if($session_id !== "") {
            if($userid === NULL){
            }else{
                //echo $userid;
                setSessionDetails($conn, $userid);
            }
        }
    }

    function storeUID($conn){

        $addrip = $_SERVER['REMOTE_ADDR'];
        $session_id = createUID(100);
        $time = time();
        if(setcookie("Crecketgaming_sessionid", $session_id, mktime(). time()+60*60*24*30)){
            $agent = $_SERVER['HTTP_USER_AGENT']; 
            $ip = $ip = $_SERVER['REMOTE_ADDR'];
            $sql = "INSERT INTO sessions (session_id, ip, time) VALUES (:sessionid, :addrip, :time)";
            $sth = $conn->prepare($sql);
            $sth->bindParam(':sessionid', $session_id, PDO::PARAM_STR);
            $sth->bindParam(':addrip', $addrip, PDO::PARAM_STR);
            $sth->bindParam(':time', $time, PDO::PARAM_INT);
            $sth->execute();
        }
        return $session_id;
        session_start($session_id);
    }

    function createUID($length) {
        $chars = "abcdefghijkmnopqrstuvwxyz0123456789"; 
        srand((double)microtime()*1000000); 
        $i = 0; 
        $pass = '' ;
        while ($i < $length) { 
            $num = rand() % 33; 
            $tmp = substr($chars, $num, 1); 
            $pass = $pass . $tmp; 
            $i++; 
        }
        return $pass;
    }

    function setSessionDetails($conn, $userid) {
        session_start($session_id);
        session_id($session_id);
        $sql = "SELECT * FROM users WHERE user_ID = :user_ID";
        $sth = $conn->prepare($sql);
        $sth->bindParam(':user_ID', $userid);
        $sth->execute();
        $row = $sth->fetch();   
        $_SESSION['crecketgaming_usergroup'] = $row['Usergroup'];

        $_SESSION['crecketgaming_username'] = $row['Username'];

        $_SESSION['crecketgaming_userid'] = $row['user_ID'];

    }   
?>

And at the top of my index page for instance this is my only php code:

<?php
    session_start();
    include($_SERVER['DOCUMENT_ROOT']. '/../db_connect.php');
    include($_SERVER['DOCUMENT_ROOT']. '/includes/page_load.php');
    include($_SERVER['DOCUMENT_ROOT']. '/includes/check_session.php');
?>

This is called at the top of the page. db_connect contains my connection details to the server, page_load counts the amount of times a ip address refreshes the page and check_session is the file that was shown above.

I checked and if I put

echo $_SESSION['crecketgaming_userid']; //outputs "1"
echo $_SESSION['crecketgaming_usename '];  //outputs "crecket"
exit;

At the bottom of check_session.php it shows id 1 for example. But on the index page or any page for that matter they are all empty as if no one is logged in.

So my question is does session_start(); remove previous sessions the way I do it. I read that it starts or resumes a session but I never saw anything about session ids.

I'm kind of new to php so if anyone sees something to improve upon anywhere please tell me.

Answer 1

I set the session_id() after I already started one. All I had to do was swap these two:

session_id($session_id);
session_start();