再帰的にクエリを実行するにはどうすればよいですか?

function foo($id) {  $res = array();  $rs = mysql_query("select * from aaa where user='$id'");  if($row = mysql_fetch_assoc($rs)) {    $res[] = $row;    $res = array_merge($res, foo($row['puser']));  }  return $res;}

$ids = array();function getuser($user){    global $ids;    $result=mysql_query("select * from `aaa` where user='".$user."'",$link);    $data=mysql_fetch_assoc($result);    if($data['puser']!=''){        $ids[] = $user;        getuser($data['puser']);    }}getuser(32);print_r($ids);