[solved] Making a parentlist of id

Solution found

PHP Code:

function getCategoriesByParentId($fid) {
        $category_data = array();

        $category_query = $this->db->query("SELECT * FROM forum WHERE fid = '" . (int)$fid . "'");

        foreach ($category_query->result() as $category) {
            
            $category_data[] = array(
                'pid' => $category->pid,
            );

            $children = $this->getCategoriesByParentId($category->pid);

            if ($children) {
                $category_data = array_merge($children, $category_data);
            }           
        }

        return $category_data;
    } 


And

PHP Code:

      $all_categories = $this->getCategoriesByParentId(36);

        $arr = array();

        foreach ($all_categories as $category) {
            $arr[] = $category['pid'];
        }

        echo implode(',', $arr); 


There's only one rule - please don't tell anyone to go and read the manual.  Sometimes the manual just SUCKS!