Unable to resolve NULL driver for [Maatwebsite\Excel\Transactions\TransactionManager]

Question

I am trying to download data from database to excel file. I have import the Maatwebsite\Excel from composer also. my code in my controller is:

function excel()
    {
$month = date('m');
DB::statement("CREATE OR REPLACE VIEW monthly_cost AS
select  user_name,  id, phone, sum(cost) as cost from (
        select users.name as user_name, users.roll as id,users.phone as phone, BC.individual_cost as cost
        from breakfast_orders BO, breakfast_costs BC,users
        WHERE (BO.date=BC.date) and (BO.user_id=users.id)and MONTH(BO.date)='$month'
        UNION ALL
        select users.name as user_name, users.roll as id,users.phone as phone, LC.individual_cost as cost
        from lunch_orders LO, lunch_costs LC,users
        WHERE (LO.date=LC.date) and (LO.user_id=users.id) and MONTH(LO.date)='$month'
        UNION ALL
        select users.name as user_name, users.roll as id,users.phone as phone, DC.individual_cost as cost
        from dinner_orders ddO, dinner_costs DC,users
        WHERE (ddO.date=DC.date) and (ddO.user_id=users.id) and MONTH(ddO.date)='$month'
            ) x group by id,user_name,phone");

     $customer_data=DB::table('monthly_cost')->get()->toArray();
     $customer_array[] = array('Name', 'ID', 'Phone', 'Cost', 'Month');
     foreach($customer_data as $customer)
     {
      $customer_array[] = array(
       'Name'  => $customer->user_name,
       'ID'   => $customer->id,
       'Phone'    => $customer->phone,
       'Cost'  => $customer->cost,
       'Month'   => $month
      );
     }
     Excel::create('Customer Data', function($excel) use ($customer_array){
      $excel->setTitle('Customer Data');
      $excel->sheet('Customer Data', function($sheet) use ($customer_array){
       $sheet->fromArray($customer_array, null, 'A1', false, false);
      });
     })->download('xlsx');
    }

what should I do now?

Answer 1

Just run php artisan config:clear or php artisan config:cache.