Get Username Matches ID - codeigniter

Question

I have tried many ways of getting the username in codeigniter models. that matches the row id. But can not seem to get my model to work.
I have looked at user guide many times all ways get errors.
It shows the row id / user id OK when echo it
But can not seem to make a model to be able to match username with row id and then echo it.
Any suggestion on suitable model function.
when I click on my edit button it shows up in url http://localhost/codeigniter/codeigniter-blog/admin/users/edit/1 which works.
Model
// Not return username that matches id.
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class Model_user extends CI_Model {
function getUsername() {
$this->db->select('username');
$this->db->where('user_id');
$query = $this->db->get('user');
return $query->row();
}
}
Controller function.
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
class Users extends CI_Controller {
public function __construct() {
parent::__construct();
$this->load->library('user');
if ($this->session->userdata('isLogged') == TRUE) {
return true;
} else {
redirect('/');
}
}
public function index() {
$data['title'] = "Users";
$data['base'] = config_item('HTTP_SERVER');
$data['isLogged'] = $this->user->isLogged();
$this->load->model('users/model_user');
$data['text_enabled'] = "Enabled";
$data['text_disabled'] = "Disabled";
$results = $this->model_user->getUsers();
foreach ($results as $result) {
$data['users'][] = array(
'user_id' => $result['user_id'],
'username' => $result['username'],
'edit' => site_url('users/edit/' . $result['user_id'])
);
}
$data['header'] = $this->load->view('template/common/header', $data, TRUE);
$data['footer'] = $this->load->view('template/common/footer', NULL, TRUE);
return $this->load->view('template/users/users_list', $data);
}
function edit($user_id = 0, $user_group_id = 0) {
$data['title'] = "Users";
$data['base'] = config_item('HTTP_SERVER');
$data['isLogged'] = $this->user->isLogged();
$this->load->model('users/model_user');
$data['user_id'] = "Current User ID" . " " . $user_id . ":";
$data['user_group_id'] = "Current User Group ID" . " " . $user_group_id . ":";
$data['username'] = "Current User Name:" . " " . $this->model_user->getUsername();
$data['header'] = $this->load->view('template/common/header', $data, TRUE);
$data['footer'] = $this->load->view('template/common/footer', NULL, TRUE);
return $this->load->view('template/users/users_form', $data);
}
}

Answer 1

'where' requires a second argument, which you would pass as an argument to your model function. so something like this in the model
class Model_user extends CI_Model {
function getUsername($id) {
$this->db->select('username');
$this->db->where('user_id', $id);
$query = $this->db->get('user');
return $query->row();
}
}
this corresponds to an sql query like
SELECT username FROM user WHERE user_id = ?
so in the controller just pass the user id in the argument to the model function
$data['username'] = "Current User Name:" . " " . $this->model_user->getUsername($user_id);

Answer 2

I have found best way to get my username to match user id
On My Model
function getUsername($user_id) {
if (empty($user_id)) {
return FALSE;
}
$this->db->select('username');
$this->db->where('user_id', $user_id);
$query = $this->db->get('user');
if ($query->num_rows() == 1) {
$result = $query->result_array();
return $result[0]['username'];
} else {
return FALSE;
}
}
on Controller function
$this->model_user->getUsername($user_id);