未定義指數：上登錄（PHP）

Question

我收到此錯誤

Notice: Undefined index: username in C:\xampp\htdocs\login.php on line 24 

Notice: Undefined index: password in C:\xampp\htdocs\login.php on line 25 

這個代碼

<?php 

session_start(); 

$username = $_POST['username']; 
$password = $_POST['password']; 

if ($username&&$password) 
{ 

$connect = mysql_connect("localhost","root","") or die ("couldn't connect"); 
mysql_select_db("test") or die ("couldn't find DB"); 

$query = mysql_query("select * FROM users WHERE username='$username'"); 

$numrows = mysql_num_rows($query); 

if($numrows!=0) 
{ 
//login goahead 

while ($row = mysql_fetch_assoc($query)) 
{ 
    $dbusername = $row['username']; 
    $dbpassword = $row['password']; 

if($username==$dbusername&&$password==$dbpassword) 

{ 
    echo "You're in! <a href='member.php'>click here to continue</a>"; 
    $_SESSION['username']=$username; 

} 
else 
    echo"Incorrect Password"; 

} 
} 
else 
die("That user does not exist!"); 



} 
else 
die("please enter a username and password"); 

?> 

我已經試過周圍改變其中的if語句來檢查數據庫的用戶名和傳遞是並試圖重新定義電話，但它不會工作。任何幫助都會很棒。

Answer 1

你的問題似乎是在這裏：

$dbusername = $row['username']; 
$dbpassword = $row['password']; 

你的SQL查詢似乎表明，它沒有返回與行索引的用戶名或密碼的任何結果。

即。 $ row ['username']不存在等..