yf_manage_shop_related_products admin module

    public function related_products($id = '')
    {
        $product_related_id = null;
        $product_related_data = [];
        $sql = 'SELECT * FROM ' . db('shop_product_related') . ' WHERE product_id = ' . $id;
        $product = db()->query($sql);
        $product_related_id = '';
        while ($A = db()->fetch_assoc($product)) {
            $product_related_id .= $A['related_id'] . ',';
        }
        $product_related_id = rtrim($product_related_id, ',');
        if ($product_related_id != '') {
            $sql = 'SELECT * FROM ' . db('shop_products') . " WHERE active='1'  AND id IN (" . $product_related_id . ')  ORDER BY name';
            $product = db()->query_fetch_all($sql);
            $products = [];
            foreach ((array) $product as $v) {
                $product_related_data[] = [
                    'related_id' => $v['id'],
                    'name' => $v['name'],
                ];
            }
        }
        return $product_related_data;
    }