Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in ครับ ช่วยหน่อยครับ

<?
 session_start();
 ?>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<?
 include "config.php";
 mysql_query("SET NAMES UTF8 ");
 mysql_select_db("bakery");
 $name = $_POST["name"];
 $province = $_POST["province"];
 $zip = $_POST["zip"];
 $email = $_POST["email"];
 $phone = $_POST["phone"];
 $address = $_POST["address"];
 $total = $_POST["total_order"];
 if ($name == ""){
 echo "<h3 align=center> error : กรุณากรอกชื่อ </h3>" ;
 exit();
 } else if ($address == ""){
 echo "<h3 align=center> error : กรุณากรอกที่อยู่ </h3>" ;
 exit();
 }
 $date_now = date("Y-m-d");
 $sql1= "insert into order values (null,
'$name', '$address','$province','$zip','$phone', '$email', '$date_now', '$total')";

 mysql_query($sql1, $conn);

 $sql2 = "select max(order_id) from order";
 $ex2 = mysql_db_query($dbname,$sql2);
 $row = mysql_fetch_row($ex2);
 for($i=0; $i<count($sess_id); $i++) {
 $sql3 = "insert into 1 values ('$row[0]' , '$sess_id[$i]',
'$sess_num[$i]', '$sess_price[$i]')" ;
 mysql_query($sql3, $conn);
 }
 session_unregister("sess_id");
 session_unregister("sess_name");
 session_unregister("sess_price");
 session_unregister("sess_num");
 echo "<h3 align=center> ทำการบันทึกใบสั่งซื้อเรียบร้อยแล้ว </h3>";
 echo "<h3 align=center><a href=index.php>กลับหน้าหลัก </a></h3>";
 mysql_close($conn);
?>