Can't get the joined table value in codeigniter

I have two tables one is products another is categories. I save the category id to the post tables category field. I have joined both the table in Post_model and able to fetch the category name in listing page when I run foreach() but it is giving an error when I want to fetch it in details page(slug page). It says the undefined variable name in product details page.

Product_model

class Product_model extends CI_Model{
    public function __Construct(){
        $this->load->database();
    }


    public function get_products($slug = FALSE){
        if($slug === FALSE){
            $this->db->order_by('products.id', 'DESC');
            $this->db->join('categories','categories.id = products.category');
            $query= $this->db->get('products');
            return $query->result_array();

        }

        $query= $this->db->get_where('products', array('slug' => $slug));
        return $query->row_array();
    }



 In Controller

        public function index(){

               $data['subview']= 'pages/listing';
               $data['products'] = $this->Product_model->get_products();

               $this->load->view('layout_main',$data);
               print_r($data['products']);
        }

        public function view($slug= NULL){
              $data['post'] = $this->Product_model->get_products($slug);

                    if(empty($data['post'])){
                        show_404();
                    }

             $data['title'] = $data['post'] ['title'];


              $this->load->view('pages/product_view',$data);

        }

in View

               <?php foreach ($cv_products as $post) : ?> 
                <div class="col-4">
                 <a class="all-link--pro" href="<?php echo site_url("product_view/".$post['slug'])?>"> //pro slug link  
                    <img class="img-fluid img-size" src="<?php echo base_url("assets/img/".$post['main_img'])?>">//pro img
                    <p><?php echo $post['title'] ?></p>//pro title
                    <p><?php echo $post['name'] ?></p>//pro cat
                    <p>Rs. <?php echo $post['price']; ?></p>//pro price
                 </a>      
                </div> 
              <?php endforeach; ?>

It's working perfectly I get all product list and the respective category but after clicking the slug link or <a class="all-link--pro" href="<?php echo site_url("product_view/".$post['slug'])?>"> i get all except error on name field

<p><?php echo $post['title'] ?></p>
<p><?php echo $post['price'] ?></p>
<p><?php echo $post['name'] ?></p>

Just wanna get the categories.name from categories table where products.category is quals to categories id

Solution

forasmuch as you are using foreach you have to change $query to

    $query= $this->db->get_where('products', array('slug' => $slug));
    return $query->result_array();

if you want to get the subject name:

problem is in the model file.
if slug !== false no join will happen.

change get_products() after your if block to:

$this->db->join('categories','categories.id = products.category');
$this->db->where(array('slug' => $slug));
$query = $this->db->get("products")->row_array();
return $query;

UPDATE:

you get that error because you are trying to use foreach for an associative array.

in slug page, your result is like this:
['yourTitle',1000,'yourName']
when you use foreach, the output will be a string each time in the loop.

it's better to have a separate view for your slug page, but if you are not going to do that, change $query to:

$query = $this->db->get("products")->result_array();