Php 如何从codeigniter中的数据库中获取高达n级的子类别

我想获得类别->子类别->成功，最多n个数字，如flipkart提供的产品类别， 我已经写了以下代码，但我只得到了子类别， 请告诉我如何更改n个子类别的代码。 请告诉我至少3或4个级别

我的控制器

public function index()
{
    $data['detail']=$this->store_model->get_product();
    $data['xajax_js'] = $this->xajax->getJavascript(base_url());
    $cat['result']=$this->store_model->get_categories();
    $this->load->view('user/header');
    $this->load->view('user/banner');
    $this->load->view('user/categories',$cat);
    $this->load->view('user/index',$data);
    $this->load->view('user/footer');
}

模型是

function get_categories()
{

    $this->db->order_by('parentId');
    $categories=$this->db->get('categories')->result_array();
    $result = array();
    foreach($categories as $cat)
    {
        if($cat['parentId'] && array_key_exists($cat['parentId'], $result))
        {
            $result[$cat['parentId']]['sub_categories'][] = $cat;
        }
        else
        {
            $result[$cat['categoryId']] = $cat;
        }
    }
    return $result;
}

该视图用于打印数据

 <table border="1">
                              <?php foreach ($result as $cat):?>
                        <tr>
                             <td>&nbsp;&nbsp;&nbsp;&nbsp;<?=$cat['categoryName'];?></td>
                             <td>&nbsp;&nbsp;&nbsp;&nbsp;<?=$cat['categoryId'];?></td>
                             <td>&nbsp;&nbsp;&nbsp;&nbsp;<?=$cat['parentId'];?></td>

                        </tr>
                        <?php if(isset($cat['sub_categories'])):?>
                        <?php foreach($cat['sub_categories'] as $sub_category):?>
                         <tr>
                              <td>   <?=$sub_category['categoryName'];?></td>
                              <td>   <?=$sub_category['categoryId'];?></td>
                              <td>   <?=$sub_category['parentId'];?></td>

                        </tr>
                        <?php endforeach;?>
                        <?php endif;?>
                       <?php endforeach;?>
                    </table>

---

请告诉我答案。

您是在请求MySQL查询，还是子类别的CSS-HTML？请确认，stackoverflow是一个问答网站。您需要具体说明您面临的问题，而不是要求用户提供代码。@nightgaunt我问的是MySQL解决方案，我知道它应该如何以CSS和HTML打印。给我MySQL或Codeigniter的解决方案。

categoryId  categoryName                   parentId                 status  catSeq  

     1  Electronics                           0                Active         0
     2  Automobile                            0                Active         1
     3  Books                                 0                Active         2
     4  Mobiles & Accessories                 1                Active         0
     5  Cooking, Food & Wine                  5                Active         2
     6  Laptops                               1                Active         2
     9  Digital Device                        1                Active         1
    10  Tablet                                0                Active         2
    11  Laptop                                0                Active         0
    12  Mouse                                 9                Active         0
    13  Sony Viao                            11                Active         0
    14  Logitech                             12                Active         0
    15  Keyboard                              9                Active         0
    16  Motorcycles                           2                Active         0
    17  Literature & Fiction                  3                Active         0
    18  Keyboard                             19                Active         1
    19  Computer Accessories                  1                Active         3
    20  Cars                                  2                Active         2
    21  Scooters                              2                Active         1
    22  Children Picture Books                3                Active         2
    23  Headphone                            19                Active         0
    26  Biographies & Autobiographies         3                Active         1
    27  Cameras                               1                Active         1