Number Rows返回null

Question

我正在处理使用分页脚本的成员列表，它给我以下错误

  

mysqli_num_rows（）期望参数1为mysqli_result，给定为null

$stmt = $db->prepare("SELECT * FROM users");
$stmt->execute();
$result = $stmt->get_result();   
$count = mysqli_num_rows($result);

if ($count < 1) {        
    echo "<h1 class='text-center'>No Users</h1>";
} else {        
    $count = ceil($count / $per_page);