Select Database ไม่เจอ แต่ Echo มาดูไปรันใน SQL เจอ เป็นเพราะอะไร

mysql_query($sqll) or die(mysql_error());

$id=130;
$sqll = " SELECT step_id	FROM factory 	WHERE req_id = '$id' ";
$sql_query = mysql_query($sqll) or die(mysql_error()); 
$number = mysql_num_rows($sql_query);

 $sql_max=" SELECT MAX(req_id) as max FROM fo_req_detail ";
$query=mysql_query($sql_max);
$rd=mysql_fetch_array($query);
$max_ticket=$rd['max'];      // ถ้าใส่ กำหนดให้เลย  $max_ticket=200;  จะได้ 


		echo 	$sql_sc="Select step_id,req_id,date_format(start_time,'%H:%i') AS t_start
				,date_format(finished_time,'%H:%i') AS t_finished,contents,charge 
				from fo_time_schedule 
				WHERE req_id = $max_ticket ";
				$obque = mysql_query($sql_sc)or die(mysql_error()); 
			
			echo     $nunrows=mysql_num_rows($obque);