password_hash无法正常工作

Question

我正在使用我在其他网页上使用的代码，这在其他网页上运行正常，但在新网页上却没有。用于登录的MySQLi表也设置完全相同。我不认为这是登录脚本，因为我将来自其他站点的密码哈希插入数据库进行测试，我可以用它登录。

这是注册码：

include('sql.php');
$username = $_POST['username'];
$password = $_POST['password'];
$confirm = $_POST['confirm'];

if($username == '' || $password = '') {
    header('Location:/register.php');
}
if($password != $confirm) {
    header('Location:/register.php');
}
$sql = "INSERT INTO login (username, password) VALUES ('" . $username . "', '" . password_hash($password, PASSWORD_DEFAULT) . "')";
if(mysqli_query($mysqli, $sql)) {
    header('Location: /dashboard.php');
} else {
    echo $mysqli->error;
}
mysqli_close($mysqli);

登录：

session_start();
$error = '';

if(isset($_POST['submit'])) {
    if(empty($_POST['username']) || empty($_POST['password'])) {
        header("Location: /admin.php?error=invalid");
    } else {
        include('sql.php');
        $username = mysqli_real_escape_string($mysqli, stripslashes($_POST['username']));
        $password = mysqli_real_escape_string($mysqli, stripslashes($_POST['password']));
        $sql = "SELECT * FROM login WHERE username='" . $username . "'";
        $result = $mysqli->query($sql);
        if($result->num_rows == 1) {
            while($row = $result->fetch_assoc()) {
                $verify = password_verify($password, $row['password']);
                if($verify == false) {
                    header("Location: /admin.php?error=mismatch");
                } else {
                    $_SESSION['login_user'] = $username;
                    $_SESSION['login_pass'] = $password;
                    if($_POST['stay'] == 'stay') {
                        setcookie('username', $username, time() + 31536000, '/');
                        setcookie('password', $password, time() + 31536000, '/');
                    }
                    header("location: /dashboard.php");
                }
            }
        } else {
            header("Location: /admin.php?error=mismatch");
        }
        mysqli_close($mysqli);
    }
}