Laravel 8 – Insert column of sums of child's columns and show it

I want to sum money column from payments table:

Then, append it to every Client in index method (I’m getting all user->clients).

>Solution :

Eloquent has aggregate methods for relationships to do this already:

$clients = Client::where(...)->withSum('payments as sum', 'payment_money')->get();

foreach ($clients as $client) {
    echo $client->sum;
}

Laravel 8.x Docs – Eloquent – Relationships – Other Aggregate Functions withSum