使用$ _SESSIONS檢查用戶登錄

Question

下面是以下腳本，第一個腳本是checklogin.php。這匹配存儲在MYSQL數據庫中的用戶名和密碼。一旦檢查到這些信息，他們將通過使用重定向功能發送到他們的個人頁面。

最底層的php腳本是user1的登錄頁面。我想在那裏確認此人已正確登錄並無權查看此頁面。

此刻，當我以user1身份登錄時，顯示頁面3.php，即它說我沒有正確登錄。我知道我需要設置一個會話，如： $ _SESSION [logged in'] =='y'; ，我認爲這應該去的地方密碼正在比較存儲在數據庫中。目前，我無法輸入我的登錄信息，最後直接輸入正確的文件。任何幫助都感激不盡。

<?php 

session_start(); 
$username = mysql_real_escape_string($_POST['username']); 
$password = mysql_real_escape_string($_POST['password']); 

mysql_connect("localhost", "root", "root") or die(mysql_error()); //Connect to server 
mysql_select_db("first_db") or die("Cannot connect to database"); //Connect to database 
$query = mysql_query("SELECT * from users WHERE username='$username'"); //Query the users table if there are matching rows equal to $username 
$exists = mysql_num_rows($query); //Checks if username exists 
$table_users = ""; 
$table_password = ""; 

if ($exists > 0) { 
    //IF there are no returning rows or no existing username 

    //$_SESSION['logged in'] == 'y'; 

    while ($row = mysql_fetch_assoc($query)) { 
     //display all rows from query 
     $table_users = $row['username']; // the first username row is passed on to $table_users, and so on until the query is finished 
     $table_password = $row['password']; // the first password row is passed on to $table_users, and so on until the query is finished 
     $table_id = $row['id']; 
     $page_id = $row['page']; 
    } 

    if (($username == $table_users) && ($password == $table_password)) { 
     // checks if there are any matching fields 

     if ($password == $table_password) { 
      $_SESSION['user'] = $username; //set the username in a session. This serves as a global variable 
      $_SESSION['logged_in'] = 'y'; 
      //echo $table_id; 
      //echo $page_id; 

      redirect($page_id); //take the user to the page specified in the users table 
     } else { 
      echo "Login Failed"; 
     } 
    } else { 
     print '<script>alert("1. Incorrect Password!");</script>'; //Prompts the user 
     print '<script>window.location.assign("login.php");</script>'; // redirects to login.php 
    } 
} else { 
    print '<script>alert("Incorrect Username!");</script>'; //Prompts the user 
    print '<script>window.location.assign("login.php");</script>'; // redirects to login.php 
} 

function redirect($page_id) 
{ 
    /* Redirect browser */ 
    header('Location: '.$page_id); 
    /* Make sure that code below does not get executed when we redirect.   */ 
    exit; 
} 

?> 

和着陸頁

<?php 

session_start(); 
//user logged in?? 

if ($_session['logged in'] != 'Y') { 
    //No- jump to log in page. 
    header("location: 3.php"); 
    exit(); 
} 
else 
{ 
    echo 'this works'; 
} 

?> 

Answer 1

你定義諸如會話：

$_SESSION['logged in'] == 'y'; 

這應該是：

$_SESSION['logged in'] = 'y'; 

但你檢查，如：

if ($_session['logged in'] != 'Y') { 

它應該是：

if ($_SESSION['logged in'] != 'y') { 

你檢查，如果它是一個大寫Ÿ，同時它擁有一個小寫ÿ。所以它永遠不會成功。

而且$_SESSION是superglobal這意味着：

超級全局變量 - 超全局是內置的，它們總是 適用於所有範圍

和變量是大小寫敏感的變量。