orderable in datatable code example

Example 1: datatables sorting order

// 3 is the column index, starting from 0 at the leftmost
$('#table').DataTable( {
   order: [[ 3, "desc" ]] // or "asc" for ascending
} );

// to sort on multiple rows
$('#example').DataTable( {
	order: [[ 3, 'desc' ], [ 0, 'asc' ]]
} );

// if using legacy datatables (initialization with lowercase dataTable)
aaSorting: [[3, "desc"]]

Example 2: orderable false in datatable

$('#example').DataTable( {
  columnDefs: [
    { orderable: false, targets: 0 }
  ]
} );

reference: 
https://datatables.net/reference/option/columns.orderable