在产品页面上获取类别父ID-opencart

Question

Is there a way to get the category parent_id of a product, in the product page of Opencart v1.5.4.1. What am trying to change the button href based on the category parent_id.. If parent_id = 20 then the button should have href1 else href2.

So far, i've done this but its not working.

Added before " $this->load->model('tool/image'); "

$product_cat = $this->model_catalog_product->getCategories($product_id);      
$product_cat_parent = $this->model_catalog_category->getCategory($product_cat[0]['category_id']);
            if ($product_cat_parent['parent_id'] == '20') {
                $this->data['sizeguide'] = $this->url->link('faq/faq/info', 'fpath=12');
            } else {
                $this->data['sizeguide'] = $this->url->link('faq/faq/info', 'fpath=13');
            }

in template file:

<a class="button2 sizeguidebox" href="<?php echo $sizeguide; ?>"><?php echo $text_sizeguide; ?></a>

Answer 1

This looks more complicated but it actually simpler and more efficient as a fool proof method of checking. It will pick all of the categories related to the current product, find all their category info, and filter the categories with the parent_id of 20. If the query has any results (ie one of the categories is a subcategory of the category with ID 20) then it will set the faq info accordingly

$product_cat = $this->model_catalog_product->getCategories($product_id);
$result = $this->db->query("
SELECT
    `c`.`parent_id`
FROM
    `" . DB_PREFIX . "category` `c`
LEFT JOIN
    `" . DB_PREFIX . "product_to_category` `p2c`
ON
    `c`.`category_id` = `p2c`.`category_id`
WHERE
    `c`.`parent_id` = '20'
AND
    `p2c`.`product_id` = '" . (int) $product_id . "'
");

if($result->num_rows > 0) {
    $this->data['sizeguide'] = $this->url->link('faq/faq/info', 'fpath=12');
} else {
    $this->data['sizeguide'] = $this->url->link('faq/faq/info', 'fpath=13');
}

Note that this hasn't been tested but should work in theory