Php 数据表不能与show all一起使用

这是ajax的工作原理：

$params= $_REQUEST;$columns = array( 

0 => 'employee_name', 
1 => 'employee_salary',
2 => 'employee_position',
3 => 'employee_city',
4 => 'employee_extension',
5 => 'employee_joining_date',
6 => 'employee_age');
$sql = "SELECT employee_id";$sql.=" FROM employee";$query=mysqli_query($conn, $sql) or die("employee-grid-data.php: get employees");$totalData = mysqli_num_rows($query);$totalFiltered = $totalData;



$sql = "SELECT employee_name, employee_salary, employee_position, employee_city, employee_extension, DATE_FORMAT(employee_joining_date, '%Y-%m-%d') as employee_joining_date, employee_age ";$sql.=" FROM employee WHERE 1=1";

if( !empty($params['columns'][0]['search']['value']) ){
$sql.=" AND  employee_name LIKE '".$params['columns'][0]['search']['value']."%' ";    }
if( !empty($params['columns'][1]['search']['value']) ){
$sql.=" AND  employee_salary LIKE '".$params['columns'][1]['search']['value']."%' ";}

if( !empty($params['columns'][2]['search']['value']) ){
$sql.=" AND  employee_position LIKE '".$params['columns'][2]['search']['value']."%' ";}

if( !empty($params['columns'][3]['search']['value']) ){
$sql.=" AND  employee_city LIKE '".$params['columns'][3]['search']['value']."%' ";}
$query=mysqli_query($conn, $sql) or die("employee-grid-data.php: get employees");$totalFiltered = mysqli_num_rows($query);  $sql.=" ORDER BY ".$columns[$params['order'][0]['column']]."   ".$params['order'][0]['dir']." LIMIT ".$params['start']." ,".$params['length']."   ";$query=mysqli_query($conn, $sql) or die("employee-grid-data.php: get employees1");
$data = array();while( $row=mysqli_fetch_array($query) ) {  // preparing an array
$nestedData=array(); 

$nestedData[] = $row["employee_name"];
$nestedData[] = $row["employee_salary"];
$nestedData[] = $row["employee_position"];
$nestedData[] = $row["employee_city"];
$nestedData[] = $row["employee_extension"];
$nestedData[] = $row["employee_joining_date"];
$nestedData[] = $row["employee_age"];

$data[] = $nestedData;}


json_data = array(
        "draw"            => intval( $params['draw'] ),   // for every request/draw by clientside , they send a number as a parameter, when they recieve a response/data they first check the draw number, so we are sending same number in draw. 
        "recordsTotal"    => intval( $totalData ),  // total number of records
        "recordsFiltered" => intval( $totalFiltered ), // total number of records after searching, if there is no searching then totalFiltered = totalData
        "data"            => $data   // total data array
        );echo json_encode($json_data);

我知道有很多代码，但我有这个问题，我单击选项show all in show entries in datatables我得到了这个错误：

datatables警告：table id=employee grid-无效的JSON响应。有关此错误的详细信息，请参阅http://datatables.net/tn/1

我不知道为什么索引中有这样的代码：

var dataTable =  $('#employee-grid').DataTable({
                                "bStateSave": false,
                                "aLengthMenu": [[10, 50, 75, -1], [10, 50, 75, "All"]], //this is your new code
    "iDisplayLength": 10, //this is your new code for number of records on page

  dom: 'lBfrtip',
    buttons: [
        {
        extend: 'excelHtml5',
        title: 'DataTable',
         text:      '<i class="fa fa-file-excel-o"></i>'
    },
            {
            extend:    'pdfHtml5',
            text:      '<i class="fa fa-file-pdf-o"></i>',
            title: 'DataTable'
        },
    {
        extend: 'csvHtml5',
        title: 'Datatable',
        text:      '<i class="fa fa-file-excel-o"></i>'
    }
    ],
            processing: true,
            serverSide: true,
            ajax: "employee-grid-data.php", // json datasource


            })

var-dataTable=$（“#员工网格”）.dataTable({
“bStateSave”：false，
“aLengthMenu”：[[10,50,75，-1]，[10,50,75，“All”]]，//这是您的新代码
“iDisplayLength”：10，//这是页面上记录数的新代码
dom:'lBfrtip'，
按钮：[
{
扩展：“excelHtml5”，
标题：“数据表”，
文本：“”
},
{
扩展：“pdfHtml5”，
文本：“”，
标题：“数据表”
},
{
扩展：“csvHtml5”，
标题：“数据表”，
文本：“”
}
],
处理：对，
服务器端：是的，
ajax：“employee grid data.php”，//json数据源
})

这是我在单击all时从ajax中得到的：

employee-grid-data.php:get employees1

---

我不知道为什么当我选择all nothing works时，我知道它来自ajax调用，但我不知道它是什么，请帮助提前感谢你，并为大量代码感到抱歉

你能发布ajax请求返回的原始数据吗？done it@freytagReplace

json\u data=array（

with

$json\u data=array（