Query SQL สำหรับ ดึง Tree ใน งาน MLM เข้าทำไง ครับ

$r = mysql_query("SELECT Upline FROM Member WHERE MemberId = 'A5'");
$upline = mysql_result($r,0);
$dept = 0;
$a5_to_a3 = null;
while($upline != NULL){
  $dept++;
  $r = mysql_query("SELECT Upline FROM Member WHERE MemberId = '$upline'");
  $upline = mysql_result($r,0);
  if ($upline == 'A3'){
    $a5_to_a3 = $dept;
  }
}
if (is_null($a5_to_a3){
 echo 'a5 ไม่อยู่ในสายของ a3';
} else {
 echo "a5 อยู่ในชั้นที่ {$a5_to_a3} ของสายงาน a3';
}

DELIMITER $$

CREATE DEFINER=`root`@`localhost` FUNCTION `between_deep`(ancestor INT,descendant INT) RETURNS INT(11)
    DETERMINISTIC
BEGIN    
    DECLARE  has_record,dept, maxdept, d_to_a INT(11) DEFAULT 0;    
    DECLARE p_id INT(11) DEFAULT 0;
    SET p_id = 0;    
    SET has_record = 0;    
    SET dept = 0;
    SET maxdept = 50;    
    SET d_to_a = -1;
    SELECT `Upline`,1 INTO p_id,has_record FROM `Member` WHERE `MemberId` = descendant;
    WHILE (has_record<>0 AND d_to_a = -1) DO      
      SET dept = dept + 1;
      IF (p_id = ancestor) THEN
         SET d_to_a = dept;         
      END IF;
      SELECT `Upline`,1 INTO p_id,has_record FROM `Member` WHERE `MemberId` = p_id LIMIT 1;
      IF dept > maxdept THEN #ป้องกันการวนซ้ำไม่รู้จบ        
        SET has_record = 0;
        SET d_to_a = -2;
      END IF; 
    END WHILE;
    RETURN d_to_a;
 END$$

DELIMITER ;