Invoice Model

Invoice.php

<?php
 
class Invoice extends Eloquent {
 
protected $table = 'invoice';
 
public function getInvoiceTickets()
{
return $this->hasMany('InvoiceTicket', 'invoice_id');
}
 
public function getInvoiceBalance() {
$ticketResult = $this->getInvoiceTickets()->with('getTicket')
->get( array(
DB::raw( 'SUM(cost) AS costs')
));
return $ticketResult[0]->costs;
}
}