Call to undefined method in Codeigniter 3 - php

Question

So i just want to make simple form to add, update, and delete some data(Name, id, and address). Add and delete works fine for me, but the update doesn't, codeigniter give me a error message :
A PHP Error was encountered
Severity: Error
Message: Call to undefined method Mahasiswa_model::getMahasiswa()
Filename: controllers/Mahasiswa.php
Line Number: 35
Backtrace:
And these is my code which i thought its related with the error.
This one file name is Mahasiswa.php
<?php
if (!defined('BASEPATH')) exit('no direcet script access allowed');
class Mahasiswa extends CI_Controller {
function __construct() {
parent::__construct();
$this->load->database();
$this->load->helper('url');
$this->load->helper('form');
$this->load->model('Mahasiswa_model');
}
public function index() {
$data['mhs'] = $this->Mahasiswa_model->retrieve();
$this->load->view('Mahasiswa_view', $data);
}
public function form_tambah() {
$this->load->view('Tambah_view');
}
public function submit() {
$this->Mahasiswa_model->add($this->input->post('var'));
$data['submitted'] = TRUE;
$this->load->view('Tambah_view', $data);
}
function delete() {
$this->Mahasiswa_model->delete($this->uri->rsegment(3));
$this->index();
}
function form_update() {
$data['mhs'] = $this->Mahasiswa_model->getMahasiswa($this->uri->rsegment(3));
$this->load->view('update_view', $data);
}
function update() {
$this->Mahasiswa_model->update($this->input->post('old_nim'),
$this->input->post('var'));
$this->index();
}
}
?>
And this one is Mahasiswa_model.php
<?php
class Mahasiswa_model extends CI_Model {
function retrieve() {
$query = $this->db->get('mhs');
if($query->result()) {
foreach ($query->result() as $content) {
$data[] = array(
$content->nim,
$content->nama,
$content->alamat
);
}
return $data;
} else {
return FALSE;
}
}
function add($arg) {
$data = array (
'nim' => $arg[0],
'nama'=> $arg[1],
'alamat' => $arg[2],
);
$this->db->insert('mhs', $data);
}
function delete($id) {
$this->db->where('nim', $id);
$this->db->delete('mhs');
}
function update($id, $form) {
$data = array(
'nim' => $form[0],
'nama' =>$form[1],
'alamat' => $form[2],
);
}
}
?>
Maybe someone can help me find where mistake i made? Line 35 not clear enough for me

Answer 1

This line in your controller is the problem:
$this->Mahasiswa_model->getMahasiswa($this->uri->rsegment(3));
You're calling the getMahasiswa method that should be available in your model, but (assuming the code you posted for your model is complete) it's not. Your model only has the retrieve, add, delete and update methods declared.
you either need to create the getMahasiswa method in your model, or you need to call a different method from your controller.
if you want to call a function from same controller then simply write.
$data = $this->getMahasiswa($parameter1);
IMP : function must be present there in the same controller.