datatables 的 class.php 出现如下错误

错误：

An SQL error occurred: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'ORDER BY request_id ASC↵ LIMIT 0, 10' at line 4

我的服务器端代码如下，名为 request-list.php

    <?php
   $inc_files = array("ph_utils");
   require_once ('autoload.php');
   $db = new db();
   $table = 'wallet_load_request';
  $primaryKey = 'request_id';
  $columns = array(
   array('db' => 'request_id', 'dt' => 0),
   array('db' => 'request_date', 'dt' => 1),
   array('db' => 'trans_mode', 'dt' => 2),
   array('db' => 'trans_amt', 'dt' => 3),
   array('db' => 'request_status', 'dt' => 4),
   array('db' => 'org_id', 'dt' => 5)
  );
  $sql_details = array(
   'user' => PH_DB_USER,
   'pass' => PH_DB_PSWD,
   'db' => PH_DB,
   'host' => PH_DB_HOST
   );
require_once('ssp.class.php');
$filterByStaus = isset($_REQUEST['filter_by_status']) ? 
$_REQUEST['filter_by_status'] : "PENDING";

switch ($filterByStaus) {
case 'REJECTED':
$fixedFilter .= " AND request_status = 'REJECTED'";
break;
case 'APPROVED':
$fixedFilter .= " AND request_status = 'APPROVED'";
break;
default:
break;
}
$output = SSP::simple($_GET, $sql_details, $table, $primaryKey, $columns, 
$fixedFilter);
foreach ($output['data'] as $i => $d) {
$request_id = $output['data'][$i][0];
$trans_amt = $output['data'][$i][3];
$request_status = $output['data'][$i][4];
$org_id = $output['data'][$i][5];
$output['data'][$i][0] = '<div class="text-center"><h4><span class="label label-success"> #'. $request_id .'</span></h4></div>';

if ($request_status == 'APPROVED') {
$output['data'][$i][4] = '<div class="text-center"><span class="label label-success"> APPROVED </span></div>';
$output['data'][$i][5] = '<div class="text-center"><button id="accept" type="button" class="text-center btn btn-success accept disabled" data-request_id=\'' . $request_id . '\' data-org_id=\'' . $org_id . '\' data-trans_amt=\'' . $trans_amt . '\'><i class="fa fa-ban"></i> ACCEPT</button></div>';
$output['data'][$i][6] = '<div class="text-center"><button id="reject" type="button" class="text-center btn btn-danger reject disabled" data-request_id=\'' . $request_id . '\'><i class="fa fa-ban"></i> REJECT</button></div>';
} else if ($request_status == 'REJECTED') {
$output['data'][$i][4] = '<div class="text-center"><span class="label label-danger"> REJECTED </span></div>';
$output['data'][$i][5] = '<div class="text-center"><button type="button" id="accept"  class="text-center btn btn-success accept disabled" data-request_id=\'' . $request_id . '\' data-org_id=\'' . $org_id . '\' data-trans_amt=\'' . $trans_amt . '\'><i class="fa fa-ban"></i> ACCEPT</button></div>';
$output['data'][$i][6] = '<div class="text-center"><button type="button" id="reject" class="text-center btn btn-danger reject disabled" data-request_id=\'' . $request_id . '\'><i class="fa fa-ban"></i> REJECT</button></div>';
} else {
$output['data'][$i][4] = '<div class="text-center"><span class="label label-warning"> PENDING </span></div>';
$output['data'][$i][5] = '<div class="text-center"><button type="button" id="accept" class="text-center btn btn-success accept" data-request_id=\'' . $request_id . '\' data-org_id=\'' . $org_id . '\' data-trans_amt=\'' . $trans_amt . '\'><i class="fa fa-ban"></i> ACCEPT</button></div>';
$output['data'][$i][6] = '<div class="text-center"><button type="button" id="reject" class="text-center btn btn-danger reject" data-request_id=\'' . $request_id . '\'><i class="fa fa-ban"></i> REJECT</button></div>';
 }

}     
SSP::sendJson($output);

我的 jquery 代码如下 request-list.js

var requestList = {
  oTable: {},
  init: function () {

   requestList.oTable = $('#req_list').dataTable({
    "processing": true,
    "serverSide": true,
    "columnDefs": [{className: "data_middle ", "targets": [0, 1, 2, 3, 4, 5, 6]}],
    "columns": [null, null, null, {"orderable": false}, {"orderable": false}, {"orderable": false}, {"orderable": false}],
   "ajax": {
   "url": "web/request-list",
   "data": function (d) {
     return $.extend({}, d, {
     "filter_by_status": $('#status').val(),

     });
   }
 }
});
}
}

我的前端代码是 list.html

    <br>


    <div class="row">
     <div class="col-md-10 col-md-offset-1">
      <table class="table table-bordered table-striped table-hover" id="req_list">
       <thead>
        <tr>
         <th>Request ID</th>
         <th>DATE</th>
         <th>Mode</th>
         <th class="text-center">AMOUNT</th>
         <th class="text-center">STATUS</th>
         <th class="text-center">ACCEPT</th>
         <th class="text-center">REJECT</th>
        </tr>
       </thead>
       <tbody>
       </tbody>
      </table>
     </div>
    </div>

运行代码后，页面显示警告，如下所示 DataTables 警告：table id=req_list - 发生 SQL 错误：SQLSTATE[42000]：语法错误或访问违规：1064 您的 SQL 语法有错误；检查与您的 MySQL 服务器版本相对应的手册，了解第 4 行“ORDER BY request_id ASC LIMIT 0, 10”附近用户的正确语法

在控制台中我收到错误

jquery.dataTables.min.js:39 Uncaught TypeError: Cannot read property 'length' of undefined

自定义 ssp 代码如下，位于以下链接中

https://drive.google.com/open?id=0B-e2dOqifK3QOFFnRjhTYjhPQmM