DataTables display data from Mysql using columnDefs

When i try to display data from Mysql table using columnDefs all the data is displayed in a single column. How to display each data in its specific column?

Here is code:

$(document).ready(function() {
                    $('#panier_table').DataTable( {
                        "processing": true,
                        "serverSide": true,
                        "ajax": "",
                        columnDefs: [ {                        
                            data: "Piece",
                            data: "Order",                                                                                   
                            orderable: false,
                            className: 'select-checkbox',
                            targets:   0,
                        } ],
                        select: {
                            style:    'os',
                            selector: 'td:first-child'
                        },
                        order: [[ 1, 'asc' ]],  
                    } );
                } );