I'm trying to use sum() get the sum of column value, but unfortunately it isn't working and I can't figure out where I am wrong.

$total = Invoice::where('status', 'Completed')
             ->sum('amount');

This returns error Call to a member function first() on string

invoices (Table)

I want to display the sum of invoices' amount in the view.

Blade View

CodePudding user response：

try this:

$total = Invoice::select(
DB::raw(SUM(amount) as total_amount)
)->where('status', 'Completed')->pluck('total_amount');

and foreach the value in the view file like:

@foreach(total as total_value)
<td>{{total_value}}</td>
@endforeach

CodePudding user response：

convert the `amount` attribute into Int before storing into database.for example 
$amount = $request->amount;
$invoice = new Invoice();
$invoice->amount = (int)$amount;
--
--
--
$invoice->save();

then you can use the above query for column sum