update

<?php
        if(isset($_POST['nis'])){
           for ($i = 0; $i < count($_POST['nis']); $i++){
            $nis = $_POST['nis'][$i];
            $kd_mapel = $_POST['kd_mapel'][$i];
            $kkm = $_POST['kkm'][$i];
            $NA = $_POST['NA'][$i];
            $ket = $_POST['ket'][$i];
            $semester =$_POST['semester'][$i];

             $kelas = $_POST['kelas'][$i];
            $desk = $_POST['desk'][$i];

            $sql="INSERT INTO rapot (nis,kd_mapel,nilai,kkm,keterangan,deskripsi,semester,id_kelas)
                        values('$nis','$kd_mapel','$NA','$kkm','$ket','$desk','$semester','$kelas')";



                $query = mysqli_query($link, $sql);
           echo $sql;


      }
      print_r($_POST);


    ?>

    <?php
}