Laravel datatable sort not working how to use on join

I am using Laravel Datatable, Sorting is not working, Can someone help me.

controller

Table::select(array( DB::raw('table2.con_title'), DB::raw('........ Datatables::of(----)->make();

View

.dataTable({ "bProcessing": true, "bServerSide": true, "sAjaxSource": ajaxurl,

"aoColumnDefs": [ { mData:'table2.con_title' , aTargets: [0]},.......

error DataTables warning (table id = '-----'): Requested unknown parameter 'table2.con_title' from the data source for row 0

via fernandus