php - Laravel Eloquent: Best Way to Calculate Total Price -

im building simple buy , sell application laravel 5.1. each buy model has many buydetail stores bought item quantity , buy_price. have implement relationship between table on model.

class buy extends model {   #eloquent relationships    public function supplier()   {     return $this->belongsto('app\supplier');   }    public function buydetails()   {     return $this->hasmany('app\buydetail');   } } 

i'd calculate total price each buy. best way calculate total price using eloquent orm?

for implement this:

@foreach($buys $key => $value)     <?php         $total = 0;     ?>     @foreach($value->buydetails $k => $bd)         <?php             $total += ($bd['buy_price']*$bd['qty']);     ?>     @endforeach     <tr>     <td>{{$value->ref_number}}</td>     <td>{{$value->suplier->name}}</td>     <td>{{$value->created_at}}</td>     <td>{{$value->buydetails->count()}}</td>     <td>{{$total}}</td>     <td>         <a href="" class="btn btn-default btn-sm" title="show">detail</a>         <a href="" class="btn btn-primary btn-sm" title="edit">edit</a>         <a href="" class="btn btn-danger btn-sm" title="delete">delete</a>     </td>   </tr> @endforeach 

this can done in (at least) 2 ways.

using pure eloquent model logic:

class buy extends model {   public function gettotalprice() {     return $this->buydetails->sum(function($buydetail) {       return $buydetail->quantity * $buydetail->price;     });   } } 

the issue here needs fetch buy details database need fetch anyway display details in view.

if wanted avoid fetching relation database build query manually:

class buy extends model {   public function gettotalprice() {     return $this->buydetails()->sum(db::raw('quantity * price'));   } }