There is a corner case when the first column order_columns set to be ""

[Ryan Fan]

when the first column orderable flag set to be false, and the first ajax request will sent order[0][column] = 0, which could cause the datatable error.

[Ryan Fan]

def ordering(self, qs):
      if order:
            order = filter(lambda s:s not in ["-", ""], order) # add this line would help
            return qs.order_by(*order)

[Erik Telepovský]

Your solution works, but order triangle icon still shows up next to the column title in table header.

[Maciej Wisniowski]

If I understand this issue correctly the problem appears when in JavaScript code there is a column that is not orderable while it is still used for initial ordering, like:

var dt_table = $('.datatable').dataTable( {
        "language": dt_language,
        "order": [[ 0, "desc" ]],
        "lengthMenu": [[25, 50, 100, 200], [25, 50, 100, 200]],
        "columnDefs": [
            { "orderable": false, "searchable": true, "className": "center", "targets": [ 0 ] },
            { "orderable": true, "searchable": true, "className": "center", "targets": [ 1 ] }
        ],
        "searching": true,
        "processing": true,
        "serverSide": true,
        "stateSave": false,
        "ajax": USERS_LIST_JSON_URL
    } );

Above will cause exception if the server side code doesn't define first column name in order_columns:

class UsersList110Json(BaseDatatableView):
    model = User
    columns = ['username', 'email']
    order_columns = ['', 'email']

Such configuration of datatables doesn't make sense to me. If column is not orderable then it should not be set as default one. Also, even if there is a use case for this then server side code seems to be supposed to sort on that column, so there should be a definition for the first orderable column like:

order_columns = ['username', 'email']