Laravel刀片嵌套属于关系访问

Question

I have a nested BelongsTo relationship in eloquent Laravel, when I try to access it one level its success, but when I try to access it two level. its getting error "Trying to get property of non-object"

Here's my structure models

OrderProduct.php

public function product()
{
    return $this->belongsTo('App\Models\Product');
}

Product.php

public function domain()
{
    return $this->belongsTo('App\Models\Domain');
}

What I want to do is getting domain information from order_product eloquent, and I did this on blade, but getting error "Trying to get property of non-object"

$order_product = OrderProduct::first();
$domain_name = $order_product->product->domain->name;

But when I have product eloquent and try to access the domain name, its success

$product = Product::first();
$domain_name = $product->domain->name;

What should I do to access domain relationship from order_product through product->domain relationship?

Thanks

Answer 1

The problem occures when you are fetching domain from product which doesn't have domain. You can use laravel optional function:

$orderProduct = OrderProduct::with('product.domain')->first();
$domain_name = optional($orderProduct->product->domain)->name;

Note: I also use eager load to reduce queries.