php - success not being called jQuery AJAX -

the success not being called on completion of ajax request. response request 200 have no idea why won't return anything. if inspect in chromes developer tools says 'this request has no response data available'. have made query know fact succeed.

my request:

$.ajax({                 url: 'search.php',                 datatype: 'json',                 data: {                     l_id: <?php echo $_get['l_id']; ?>                 },                 success: function(data) {                     alert(data);                     console.log(data);                     $("#datatable td:nth-child(2)").each(function () {                         $(this).html(data);                     });                 }             }); 

my search.php:

<?php  require_once '../dbconni.php';  $list_id = $_get['l_id'];  $matches = $db->query("select l_name wfp_lists l_id={$list_id}");  while($match = $matches->fetch_object()) {     $data[] = $matches->l_name; }  json_encode($data); 

i don't understand how status code of 200 can returned , success not called.. thought success called on return of http status code 200