Question

因此，在'index.php'中，用戶將他們的用戶名和密碼輸入到HTML輸入中，並將它們保存爲'$ username'和'$ password'。那麼PHP說：

<?php 
$loginquery = mysqli_query($connection,"SELECT * FROM users WHERE username = '$username' AND password = '$password'"); 
$user = mysqli_fetch_array($loginquery); 
session_start(); 
$_SESSION['username'] = $user['username']; 
echo $_SESSION['username']; 
?> 

它呼應的出「$ _SESSION [」用戶名「]」好了，但如果我然後去「home.php」它沒有實際保存的變量，它說「注意：未定義的變量：_SESSION在/Applications/XAMPP/xamppfiles/htdocs/tobyscott/home.php上線24'

這實在是煩我！謝謝:)

Answer 1

你有一個在session_start（）;聲明在你的home.php中 - 或者它在那裏失蹤？

Answer 2

聽起來像你使用提交給自己的腳本。

添加一個條件，以確保表單處理邏輯只能運行GET/POST提交：

if(!empty($_POST[ 'varname' ])) 
{ 
    // Logic 
    $loginquery = mysqli_query($connection,"SELECT * FROM users WHERE username = '$username' AND password = '$password'"); 
    $user = mysqli_fetch_array($loginquery); 
    session_start(); 
    $_SESSION['username'] = $user['username']; 
    echo $_SESSION['username']; 
} 

OR：

if(!empty($_GET[ 'varname' ])) 
{ 
    // Logic 
    $loginquery = mysqli_query($connection,"SELECT * FROM users WHERE username = '$username' AND password = '$password'"); 
    $user = mysqli_fetch_array($loginquery); 
    session_start(); 
    $_SESSION['username'] = $user['username']; 
    echo $_SESSION['username']; 
}