Opencart - add related to products without related

catalog.php

public function demo(){
        $this->load->model('catalog/product');
        $this->load->model('catalog/category');

	    $empty = $this->model_catalog_product->setRelated();

        foreach($empty as $item){
            $product_id = $item['product_id'];

            $product_categories = $this->model_catalog_product->getCategories($product_id);
            $related_products = array();



            foreach ($product_categories as $category_id) {
                $category_id = $category_id["category_id"];
                $category_products = $this->model_catalog_product->getProducts(array(
                    'filter_category_id' => $category_id
                ));

                $related_products = array_merge($category_products);
            }

            $related_products = array_filter($related_products, function ($item) use ($product_id) {
                return !(intval($item['product_id']) == intval($product_id));
            });

            shuffle($related_products);
            $related_products = array_slice($related_products, 0, 10);

            foreach ($related_products as $related_product) {
                $related_id = $related_product['product_id'];
                $this->db->query("DELETE FROM " . DB_PREFIX . "product_related WHERE product_id = '" . (int)$product_id . "' AND related_id = '" . (int)$related_id . "'");
                $this->db->query("INSERT INTO " . DB_PREFIX . "product_related SET product_id = '" . (int)$product_id . "', related_id = '" . (int)$related_id . "'");
                $this->db->query("DELETE FROM " . DB_PREFIX . "product_related WHERE product_id = '" . (int)$related_id . "' AND related_id = '" . (int)$product_id . "'");
                $this->db->query("INSERT INTO " . DB_PREFIX . "product_related SET product_id = '" . (int)$related_id . "', related_id = '" . (int)$product_id . "'");
            }

        }



    }

model.php

public function setRelated(){
    $query = $this->db->query("SELECT DISTINCT oc_product.product_id, oc_product_description.name, CONCAT('http://demo.ru/product/?product_id=', oc_product_description.product_id) AS url FROM oc_product  
      INNER JOIN oc_product_description ON oc_product.product_id = oc_product_description.product_id 
      WHERE oc_product.product_id NOT IN (SELECT product_id FROM oc_product_related) AND oc_product.manufacturer_id = 0 OR oc_product.manufacturer_id = 11;
    ");
    foreach ($query->rows as $result) {
        $product_data[] = array(
            'product_id' => $result['product_id'],
            'name' => $result['name'],
            'url' => $result['url']
        );
    }

    return $product_data;
}