Laravel Sum of relation

Question

I want to return the sum of \"amount\" from my payments table. There can be many payments for one invoice. The below \"->sum(\'amount\') does not work, it returns:

Call

Answer 1

First decide which Invoice (for example id 1)

$invoice = Invoices::find(1);

Then eager load all the corresponding payments

$eagerload = $invoice->payments;

Finally assuming you have the amount field in your Invoice model you can simply find the sum using the method below:

$totalsum = $eagerload->sum('amount');