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

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.