[solved] Making a parentlist of id

I have a forum table.

I need to make a parent list of all my pids.

Lets say if I need to make parentlist for fid 36 As shown in image below Then then it should return PID numbers only 35, 34, 1 not to return 0 if pid is 0






Example

I have tried

PHP Code:

public function make_parent_list() {

$this->db->where('fid', '36');
               
$query = $this->db->get('forum');
        
$pid_list = array();

$pid_list[] = $query->row()->fid;
        
foreach ($query->result() as $category) {
        
$this->db->where('pid', $category->pid);
            
$query = $this->db->get('forum');

if ($query->num_rows() > 0) {

$pid_list[] = $query->row()->pid;

}

}

return $pid_list;

} 


Question How can I get it to properly make the parentlist. Can not seem to return 35, 34, 1  if fid 36

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