PHP-致命错误：未捕获错误：尝试在 null 上分配属性以及读取属性的警告
我用 PHP 编写代码，遇到了一些错误，它也跳过了我的 else 语句
<?php
// put your code here
// $select_query = "Select * from `user_table` where username='$user_username'";
// $result = mysqli_query($con, $select_query);
$sql = "Select * from `user_table` where username= ? "; // SQL with parameters
$stmt = $con->prepare($sql);
$stmt->bind_param("s", $user_username);
$stmt->execute();
$result = $stmt->get_result();
$row_count = mysqli_num_rows($result);
$row_data = mysqli_fetch_assoc($result);
$user_ip = getIPAddress();
if ($_SESSION['attempt'] == 5) {
$_SESSION['error'] = 'Attempt limit reach';
} else {
if ($row_count > 0) {
$_SESSION['username'] = $user_username;
$row = mysqli_fetch_object($result);
if (password_verify($user_password, $row_data['user_password'])) {
// if ($row_count == 1 and $row_count_cart == 0) {
//
// echo"<script>alert('Login Successfully')</script>";
// echo"<script>window.open('profile.php','_self')</script>";
// } else {
// $_SESSION['username'] = $user_username;
// echo"<script>alert('Login Successfully')</script>";
// echo"<script>window.open('payment.php','_self')</script>";
// }
if ($row->is_tfa_enabled)
{
$row->is_verified = false;
$_SESSION["username"] = $row;
$pin = rand(0, 9) . rand(0, 9) . rand(0, 9) . rand(0, 9) . rand(0, 9) . rand(0, 9);
$sql = "UPDATE user_table SET pin = '$pin' WHERE user_id = '" . $row->user_id . "'";
mysqli_query($con, $sql);
header("Location: enter_pin.php");
} else {
$row->is_verified = true;
$_SESSION["username"] = $row;
header("Location: profile.php");
}
} else {
echo"<script>alert('Invalid Credentials(Password Incorrect) " .$number ." attempt left ') </script>";
$_SESSION['error'] = 'Password incorrect ';
//this is where we put our 3 attempt limit
$_SESSION['attempt'] += 1;
//set the time to allow login if third attempt is reach
if ($_SESSION['attempt'] == 5) {
$_SESSION['attempt_again'] = time() + (1 * 60);
//note 5*60 = 5mins, 60*60 = 1hr, to set to 2hrs change it to 2*60*60
}
}
} else {
echo"<script>alert('Invalid Credentials')</script>";
}
}
}
?>
所以当我运行代码时它显示 2 个错误，即
1)警告：尝试在第 148 行的 C:xampphtdocsFinalYearProjectUsersuser_login.php 中读取 null 属性“is_tfa_enabled”
2）致命错误：未捕获错误：尝试在 C:xampphtdocsFinalYearProjectUsersuser_login.php:170 中的 null 上分配属性“is_verified”：170 堆栈跟踪：#0 {main} 抛出在 C: xampphtdocsFinalYearProjectUsersuser_login.php 第 170 行
当我将第 148 行更改为 $row_data['is_tfa_enabled'] 时，错误 1 将解决
