Laravel 8中关联模型在API Resource中的数据返回问题及优化方案咨询

Let's break down what's causing your error and refactor your code into a cleaner, more Laravel-idiomatic solution:

Root Cause of the Error #

Your lastPrice relationship in the Products model is a hasMany—this returns a collection of ProductPrice models, not a single instance. But in your Products Resource, you used lastPrice::make($this->lastPrice) which is designed for individual models. When the Resource tried to access $this->id, it was trying to fetch that property from the collection itself (which doesn't have an id), hence the error.

Step 1: Fix the Products Resource #

Update your Products Resource to use the collection() method for the lastPrice relationship, since it returns multiple items:

public function toArray($request) {
    return [
        'id' => $this->id,
        'prices' => lastPrice::collection($this->lastPrice), // Use collection() instead of make()
        'status' => $this->status,
        'slug' => $this->slug,
        'title' => $this->title,
        'description' => $this->description,
        'txt' => $this->txt,
        'lang' => $this->lang,
        'created_at' => $this->created_at,
        'updated_at' => $this->updated_at,
    ];
}

Step 2: Clean Up the lastPrice Resource #

Instead of manual loops and direct database calls, leverage Laravel's relationship features and nested Resources. We'll also keep your caching logic but integrate it more cleanly:

First, (optional but recommended) rename your ProductPrice relationship to follow Laravel conventions for readability:

// ProductPrice model
public function publisher() { // Renamed from getPublisher
    return $this->belongsTo(ProductsPublisher::class, 'publisher_id');
}

Then update your lastPrice Resource:

public function toArray($request) {
    // Cache the publisher data directly using the relationship
    $publisher = Cache::remember(
        'publisher_' . $this->publisher_id,
        env('CACHE_TIME_LONG'),
        fn() => $this->publisher
    );

    return [
        'id' => $this->id,
        'main_price' => $this->main_price,
        'off_price' => $this->off_price,
        'created_at' => $this->created_at,
        'publisher' => SinglePublisher::make($publisher),
    ];
}

If you want to keep the original getPublisher relationship name, just replace $this->publisher with $this->getPublisher.

Step 3: Optimize with Eager Loading #

Prevent N+1 database queries by eager loading the lastPrice relationship and its associated publisher in your controller:

$products = Product::where('id', $id)
    ->where('slug', $slug)
    ->where('status', 'confirm')
    ->with(['lastPrice.publisher']) // Eager load related data upfront
    ->first();

Why This Is More Elegant #

• No manual iteration: Laravel Resources handle collection looping automatically when using collection().
• Encapsulated logic: Caching and relationship access are kept within the Resource where they belong.
• Better performance: Eager loading cuts down on unnecessary database calls.
• Readable code: Follows Laravel conventions, making it easier for other developers to understand.

内容的提问来源于stack exchange，提问作者Soroush Tayyebi