Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, bool given in

hai semua saya ada masalah ni mengenai login di php, saat saya berhasil login muncul error seperti ini :

1. Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, bool given in C:\xampp_7.4.7\htdocs\Aset\login.php on line 82

2. Warning: mysqli_fetch_array() expects parameter 1 to be mysqli_result, bool given in C:\xampp_7.4.7\htdocs\Aset\login.php on line 83

coding phpnya

include ('koneksi.php');

            if (isset($_POST['login'])) {

              $user=$_POST['username'];

              $pass=$_POST['password'];

              $level=$_POST['level'];

              $query=mysqli_query($connect, "SELECT * from user WHERE username='$user' AND password='$pass' AND level='$level'");

              $hasil=mysqli_num_rows($query);   // errornya disini 81

              $data=mysqli_fetch_array($query);  // errornya disini 82

              if ($hasil) {

                session_start();

                $_SESSION['username']=$data['nama'];

                $_SESSION['id']=$data['id_user'];

                $_SESSION['level']=$data['level'];

                header("location:index.php");

              }

              else

                echo "<script>alert('Periksa data dengan Benar')</script>";

                }

            ?>