CodeIgniter : display two query result with one return

Question

I am trying to display 'Category' database and this part is quite easy. The hard part is I need to count the subcategory from the 'Category' database and displaying them with one table.

Category | Sub Category
------------------------
Cat A    |      5
Cat B    |      7

here is my Model:

function category() {
$query = $this->db->get('category');
$result = $query->result_array();
foreach($query->row() as $q) {
 $this->db->where('subcat_id', $q['cat_id']);
 $query2 = $this->db->get('subcat');
 if($query2) {
  return true;
 } else {
  return false;
 }

here is my Controller:

function dispaly_category() {
$data['category'] = $this->mymodel->category();
$this->load->view('view', $data);
}

here is my View:

<table>
 <thead>
  <th>Category</th>
  <th>Subcategory</th>
 </thead>
 <tbody>
  <?php foreach($category as $c) : ?>
  <tr>
   <td><?php echo $c->category_name; ?></td>
   <td><?php echo (count subcat for the above category); ?></td>
  </tr>
  <?php endforeach; ?>
 </tbody>
</table>

Answer 1

i just post an answer with the assumption you've one Table only (you don't need a separate table for subcategories, but in case you really need your second table you should be able to derive this based on my answer)

Your Model

function category() 
{
    $query = $this->db
        ->select("c.*, count(cc.id) AS countSubCategories")
        ->from("category c")
        ->join("category cc", "cc.parent_id = c.cat_id","left")
        ->group_by("c.id")
        ->get();

    return $query->result();
}

Your Controller

function display_category() 
{

    $arrViewData = array(
        'category' => $this->mymodel->category()
    );
    $this->load->view('view', $arrViewData);
}

your view

<table>
 <thead>
    <th>Category</th>
    <th>Subcategory</th>
 </thead>
 <tbody>
    <?php foreach($category as $c) : ?>
    <tr>
        <td><?php echo $c->category_name; ?></td>
        <td><?php echo $c->countSubCategories; ?></td>
    </tr>
    <?php endforeach; ?>
 </tbody>
</table>