从CodeIgniter中的数据库获取下拉列表

Question

I am new to CodeIgniter and I have been trying to populate the drop down list on the view page with data from the database with no success. I tried using the recomendations from this question but the drop down is still empty (display data from database to dropdown CodeIgniter)

Here is my view:

<label>City</label>
<select class="form-control>
    <option value="">All</option>
    <?php
    foreach($groups as $city)
    {
        echo '<option value="'.$city['cityidd'].'">'.$city['city'].'</option>';
    }
    ?>  
</select> <br/>

Here is my controller:

<?php 
class Main_controller extends CI_Controller 
{
    function __construct() 
    { 
         parent::__construct(); 
         $this->load->helper('url'); 
         $this->load->database(); 
    } 

      public function index() 
    { 
         $this->load->helper('form'); 
         $this->load->view('supplier_add'); 
    } 
}

Here is my model:

class Site_model extends CI_Model
{
    public function __construct() 
    {
        /* Call the Model constructor */
        parent::__construct();
    }
    function getAllGroups()
    {
        $query = $this->db->query('SELECT city FROM citys');

        return $query->result();
    }
}

The table name is "citys" then the corresponding column heads are "cityidd" and "city"

Answer 1

There are several issue found there. Make changes as below

 function __construct(){ 
    parent::__construct(); 
    $this->load->helper('url');
    $this->load_model('Site_model');
    $this->load->database(); 
} 
public function index(){ 
  $this->load->helper('form');
  $data['groups'] = $this->site_model->getAllGroups();
  $this->load->view('supplier_add',$data); 
} 

Finally model

function getAllGroups(){
    $query = $this->db->query('SELECT cityidd,city FROM citys');
    return $query->result_array();
}

and now test