datatables.net列对另一列进行排序

Question

I'm still in deep trouble with that issue. I use datatable.net to display some data from my database (mySql).

I do exactely what the API notice me to do in order to sort columns by name ASC (toggle DESC). https://datatables.net/manual/server-side

order[i][column] integer Column to which ordering should be applied. This is an index reference to the columns array of information that is also submitted to the server.

order[i][dir] string Ordering direction for this column. It will be asc or desc to indicate ascending ordering or descending ordering, respectively.

So my code is like this:

AJAX call:

var dataTable = $('#tableau').DataTable({
        "processing":true,
        "serverSide":true,
        "order":[],
        "orderFixed": [],
        "ordering":true,
        "ajax":{
            url:"/charbon/clae-listes/actions/appel.php", 
            type:"POST"
        },

        "columnDefs":[
            {
                "targets":[ 2, 3], 
                "orderable":false,
            },
        ],
    });

And my appel.php script

...    
if(isset($_POST["order"]))
    {
    $query .= 'ORDER BY '.$_POST['order'][0]['column'].' '.$_POST['order'][0]['dir'].' ';
    }
    else
    {
        $query .= 'ORDER BY id DESC ';
    }
...

That's where trouble begins:

when I click my 1st column I receive that error message on localhost :

DataTables warning: table id=tableau - Invalid JSON response. For more information about this error, please see http://datatables.net/tn/1

And when I click my 2nd column to sort it that sorts the previous column. It's like datatables picks directly the column number from my database, and offset of 1 because my database doesn't have a column 0

how to attribute the right column to the right sorting?

output JSON response

1st column

<b>Fatal error</b>:  Uncaught PDOException: SQLSTATE[42S22]: Column not found: 1054 Unknown column '0' in 'order clause' in /Users/.../appel.php:45

2nd column

{"draw":9,"recordsTotal":10,"recordsFiltered":11,"data":[["type","Client","client".........

My headers

draw:9
columns[0][data]:0
columns[0][name]:
columns[0][searchable]:true
columns[0][orderable]:true
columns[0][search][value]:
columns[0][search][regex]:false
columns[1][data]:1
columns[1][name]:
columns[1][searchable]:true
columns[1][orderable]:true
columns[1][search][value]:
columns[1][search][regex]:false
columns[2][data]:2
columns[2][name]:
columns[2][searchable]:true
columns[2][orderable]:true
columns[2][search][value]:
columns[2][search][regex]:false
columns[3][data]:3
columns[3][name]:
columns[3][searchable]:true
columns[3][orderable]:false
columns[3][search][value]:
columns[3][search][regex]:false
order[0][column]:1
order[0][dir]:asc
start:0
length:10
search[value]:
search[regex]:false

Answer 1

Use header('Content-Type: application/json'); in order to send JSON data to the browser without having to parse it.

$output_data = /** your array with the data **/;
header('Content-Type: application/json');
echo json_encode($output_data);