//menampilkan datanya di datatable

$data['mapelKelas'] = $this->m_admin->tampil_mapelKelas($idK);



//menampilkan di select

 $data['selectMapel'] = $this->m_admin->select_mapel($idK);

 $data['idKelas'] = $idK;

 $this->load->view('admin/v_daftarmapel', $data);

public function select_mapel($idK)

 {

 $this->db->from("tbmapel as a");

 //$this->db->join("tbmapel_kelas as b", "b.id_mp = a.id_mapel", 'left outer');

 // $this->db->where('b.id_kelas !=', $idKelas);

 $hasil = $this->db->get();

 return $hasil;

 }

<div class="col-lg-12">

 <div class="card-body font-weight-bold">

 <div class="alert alert-info col-md-12">

 INFORMASI:<br>Silahkan masukkan daftar mata pelajaran yang ingin didaftarkan di kelas.

 </div>

 <div class="col-md-12">

 <div id="alert" class="col-md-6">

 <small class="text-danger pl-3"> <?= $this->session->flashdata('mapel'); ?></small>

 </div>



 <form action="<?= base_url('admin/mapel/simpan_mapelkelas/') . $idKelas; ?>" method="post" class="form-inline">

 <div class="form-group mx-sm-3 mb-2">

 <label class="mr-3">Mata Pelajaran</label>

 <select name="mapel" class="form-control">

 <option value="">===</option>

 <?php

 foreach ($selectMapel->result_array() as $row) :

 $idMapel = $row['id_mapel'];

 $namaMapel = $row['mata_pelajaran'];

 ?>

 <option value="<?= $idMapel; ?>"><?= $namaMapel; ?></option>

 <?php endforeach; ?>

 </select>

 </div>



 <button type="submit" class="btn btn-primary mb-2">Tambahkan</button>

 </form>

 </div>

 </div>

 </div>

 <div class="card-body">

 <?= $this->session->flashdata('pesan'); ?>

 <div class="table-responsive">

 <table class="table table-striped table-bordered dt-responsive" id="tabelku" width="100%" cellspacing="0">

 <thead>

 <tr>

 <th class="text-center" style="width: 5%">No</th>

 <th class="text-center" style="width: 30%">Nama Mata Pelajaran</th>

 <th class="text-center" style="width: 5%">Guru</th>

 <th class="text-center" style="width: 20%">Action</th>

 </tr>

 </thead>

 <tbody>

 <?php

 $no = 1;

 foreach ($mapelKelas->result_array() as $row) :

 $idMapelKelas = $row['id_mapelkelas'];

 $namaMapel = $row['mata_pelajaran'];

 ?>

 <tr>

 <td class="text-center"><?= $no++; ?></td>

 <td class="text-center"><?= $namaMapel; ?></td>

 <td class="text-center"></td>

 <td class="text-center">

 <a id="btnMasuk" href="" class="btn btn-primary"><i class="fa fas-fw fa-plus" aria-hidden="true"></i></a>

 </td>

 </tr>

 <?php endforeach; ?>

 </tbody>

 </table>

 </div>

 </div>