getting errror like Call to a member function getQuery() on array

$claimfiles = DB::select(
    DB::raw("SELECT id,received_time,GROUP_CONCAT(eraid SEPARATOR ', ') as EraID,GROUP_CONCAT(pdf SEPARATOR ', ') as PDF FROM claimmd_era  where pdf !='' GROUP BY received_time")
);

return Datatables::of($claimfiles)->make(true);

via Chebli Mohamed