How to insert looping radio button value into db - php

Question

I'm really newbie at a code and these things, I try to make absent from, but I don't know how to take value from looping radio button, I don't know how to write it in the controller
this is my view
<tr>
<th>No</th>
<th>Nim</th>
<th>Nama Mahasiswa</th>
<th>Absen</th>
</tr>
</thead>
<tbody>
<?php $i=1; foreach ($absensi1 as $data) { ?>
<tr>
<th><?php echo $i; ?></th>
<th><?php echo $data->nim; ?></th>
<th><?php echo $data->nama; ?></th>
<th>
<label>
<input type="radio" name="kehadiran<?= $i ?>" <?php echo($data->absen == 'Hadir')?'checked':'' ?> value="1" >Hadir
<input type="radio" name="kehadiran<?= $i ?>" <?php echo($data->absen == 'Tidak Hadir')?'checked':'' ?> value="2" >
Tidak Hadir
<input type="radio" name="kehadiran<?= $i ?>" <?php echo($data->absen == 'Izin')?'checked':'' ?> value="3" >
Izin
</label>
</th>
</tr>
<?php $i++; } ?>
</tbody>
</table>
</div>
<a href="<?php echo base_url('absen/simpan') ?>" class="btn btn-primary pull-right" >Simpan</a>
</div>
and this is my controller, and it doesn't work actually, so how to write the controller for when I clicked simpan button it will be saved into my db
public function simpan()
{
$role = $this->session->userdata('role_id');
$absen = $this->input->post('kehadiran');
$nim = $this->input->post('nim');
$data =
[
'absen' =>$absen,
// 'setuju' => '1'
];
$this->db->set('mahasiswa',$data);
$this->db->update('mahasiswa');
redirect('Absen');
}

Answer 1

Why you are using different names ?
$_POST['Name_Of_Radio_Buttons'] gives value of radio button selected
You can Insert the value to db or If you want to change content make simple if statement
if($_POST['Name_Of_Radio_Buttons'] == 1 ){
$ToUpload = 'TestOne';
}else if($_POST['Name_Of_Radio_Buttons'] == 2){
$ToUpload = 'TestTwo';
}
and Upload $ToUpload to Db