无法在登录系统中写入PHP Cookie或会话

我尝试在登录过程后访问该页面，但无法访问，因为会话写入命令不起作用。在搜索了这个网站后，我仍然找不到解决方案。 我尝试了所有可能的解决方案，但没有一个对我有效，因为我要求解决会话问题

include 'config.php';
$cdate = date("d.m.Y");
$cdate = date("d.m.Y");

if($_POST['kontrol'] == 'register'){
    $un = $_POST['nick'];
    $email = $_POST['email'];
    $password = $_POST['password'];
    $kontrol = $db-query("SELECT * FROM user WHERE username = '{$un}'")->fetch(PDO::FETCH_ASSOC);
    $kontrol2 = $db->query("SELECT * FROM user WHERE email = '{$email}'")->fetch(PDO::FETCH_ASSOC);
    if($kontrol['username'] == $un){
        echo "<font color='red'> The username is already being used !";
    }else{if($kontrol2['email'] == $email){echo "<font color='red'> The Email adress is already being used !";}
            else{
            $query = $db->prepare("INSERT INTO user SET
            username = ?,
            pass = ?,
            fullname = ?,       
            email = ?,      
            cdate = ?,      
            status = ?,     
            lastlogin = ?,      
            bday = ?,       
            pnum = ?        

            ");
            $insert = $query->execute(array(
                $_POST['nick'], md5($_POST['pass1']), $_POST['fullname'], $_POST['email'], $cdate, "0", $cdate, $_POST['bday'], $_POST['pnum']

            ));
            if ( $insert ){
        print "<font color='red'>Your registration has been successfully completed";
            }else{
        echo "<font color='red'>Your registration has failed";

                 }
              }
         }

//-------登录---------

}else if($_POST['kontrol1'] == 'login'){

    $username = $_POST['nick1'];
    $password = md5($_POST['pass']);

    if (!$username || !$password ){
        echo "Enter your user name and password";
    }else{

        $query = $db->query("SELECT * FROM user WHERE username = '$username' && pass = '$password'")->fetch(PDO::FETCH_ASSOC);

        if ($query){
            session_start();
                $_SESSION['login'] = true;
                $_SESSION['id'] = $query["id"];
                $_SESSION['status'] = $query["status"];
                $_SESSION['username'] = $query["username"];
                $_SESSION['password'] = $query["password"];

    } else{
    echo "<font color='red'> The username or password you entered is incorrect </font>";

        }
          }

                }

---

您需要在每个页面的顶部添加session_start。

您的问题是..？现在登录非常流行，似乎有50%的PHP+HTML主题都是关于这个主题的，似乎每个人都想登录，但没有人想注销。注销更重要。我在我的帖子中做了必要的调整。在运行我的帖子之后，我注意到它没有很好的组织。