generate no antrian @oning

AntrianController.php

public function saveReservasi(Request $request)
{
    $rekmed = new Rekmed;
    /**
    * another field here
    *
    **/
    $rekmed->no_antrian = $this->genNoAntrian($request->tanggal);
    $rekmed->save();
}

private function genNoAntrian($tanggal)
{
    //hitung antrian by $tanggal + 1
    $cek = Rekmed::where('tanggal_booking', $tanggal)->count();
    return $cek+1;
}