為什麼$username用var_dump()輸出的一直是空字串

Question

if(!isset($_POST['submit'])){  

    exit('非法存取!');

}  

$username=htmlspecialchars($_POST["使用者名稱"]);

var_dump($username);

$password=MD5 ( $_POST["密碼"]);

$con=mysqli_connect('localhost','root','greg1997714','ky');

if(mysqli_errno($con ) )

{

echo 'mysqli_error($con)';

exit;

}

$sql1="select user_name ,user_password from users where user_name='$username' limit=1";

$sql2="select user_name,user_password from users where user_name='$username' and user_password='$password' users where user_name='$username' and user_password='$password' limit=1 " ;

$result = mysqli_num_rows(mysqli_query($con,$sql1));

echo $result;

if($result)

# {

echo"";

退出;

mysqli_close($con);

}

$result = mysqli_num_rows(mysqli_query($con,$sql2));

if($result)

{

echo" ; ”;

exit;

mysqli_close($con);

}

echo"登陸成功！";

mysqli_close($con);

?>

#

Answer 1

$_POST["username"] 有取得到值嗎,如果沒有 說明post請求本身就存在問題