How can I set value for extra field on Eloquent pivot table
pivot is available only in the context of a relation:
// won't work$model = Model::first();$model->pivot; // null// will work$anotherModel = AnotherModel::first();$relatedModel = $anotherModel->relation()->first();$relatedModel->pivot; // Pivot objectBut for what you are trying to do simply use additional param in the save method:
$product = Product::find($item->id);$order->product()->save($product, ['price' => 12.34]);For existing relation:
$product = $order->product()->find($productId);$product->pivot->price = 12.34;$product->pivot->save();// or$order->product()->updateExistingPivot($productId, ['price'=>12.34]);And I suggest you use products for that kind of relation in order to make it easier to read.