สอบถามการรับค่าจากฐานข้อมูลแบบ json โดยใช้ jquery รับค่า แล้วไม่แสดงผล

<script type="text/javascript">
               $(document).ready(function(){
                    $("#amount").keyup(function(){
 
                          var amount = $("#amount").val();
                          var type = $("#type").val();

                          $.ajax({
                              type:"post",
                              url:"data.php",
                              //dataType: "json",
                              data:"action=getdata&amount="+amount+"&type="+type,
                              beforeSend: function(){
                                  $('#data').html('<img src="image/fbloader.gif"></img> กำลังโหลด...');
                              },
                              success:function(data){
                                //alert(data);
                                setTimeout(function(){
                                    //$("#data").html(data);
                                    var obj = jQuery.parseJSON(data);
                                      $("#data").append(obj.name + '<br />');
                                      $("#alert-data").append(obj.id + '<br />');
                                },1000);
                                 
                              },
                              error: function(){
                                    $('#data').html('เกิดข้อผิดพลาด!!');
                              }
 
                          });
 
                    });
               });
  </script>

<?php
	include 'connect.php';

	$status = 'Y';
	$amount = htmlspecialchars($_POST['amount']);
	$type = htmlspecialchars($_POST['type']);

	try {
		if (isset($_POST['action']) && $_POST['action'] == 'getdata') {
			$data = $db->prepare('SELECT list,status,machine_id FROM tbl_machine WHERE status = :status AND type = :type LIMIT :amount');
			$data->bindParam(':status',$status, PDO::PARAM_STR);
			$data->bindParam(':type',$type, PDO::PARAM_STR);
			$data->bindParam(':amount',$amount, PDO::PARAM_INT);
			$data->execute();

			while ($fetch = $data->fetch(PDO::FETCH_ASSOC)) {
				//echo "<li>".$fetch['list']."</li>";

				$json =array("id"=>$fetch['machine_id'],"name"=>$fetch['list']);
				//header('Content-type: application/json');
				echo json_encode($json);
			}
				
    			
		}
		else {
			echo "ไม่มีเครื่องว่าง";
		}
	} 
	catch(PDOException $e) {
 			echo 'ERROR: ' . $e->getMessage();
	}
	
	
?>