Laravel model 未在资源 api 中获取关系

Question

I have 2 tables that are related to each other by 3rd table (where only stores the ids) now seems i can't get my data out of third table in API resource file

Logic

1. Product model (has many barcode)
2. Barcode model (belongs to product and belongs to outlet)
3. Outlet model (has many barcodes)
4. outlet_products table (stores barcode_id and outlet_id )

Code

Barcode model

class Barcode extends Model
{
    public function product()
    {
        return $this->belongsTo(Product::class);
    }

    public function outlet()
    {
        return $this->belongsTo(Outlet::class, 'outlet_products', 'barcode_id', 'outlet_id');
    }
}

Outlet model

class Outlet extends Model
{
    public function barcodes()
    {
        return $this->hasMany(Barcode::class, 'outlet_products', 'outlet_id', 'barcode_id');
    }
}

BarcodeResource

class BarcodeResource extends JsonResource
{
    public function toArray($request)
    {
        $arrayData = [
            'id' => $this->id,
            'sku' => $this->sku,
            'serial_number' =>  $this->serial_number ? (Int) $this->serial_number : null,
            'price' => (Int) $this->price,
            'discount' => $this->discount ? (Int) $this->discount : null,
            'product' => new ProductsResource($this->whenLoaded('product')),
            'outlet' => new OutletsResource($this->whenLoaded('outlet')),
        ];
        return $arrayData;
    }
}

Now I am trying to get my product barcodes and name of each barcode outlet.

Controller

$products = ProductsResource::collection(Product::orderBy('id', 'desc')->with(['barcodes', 'barcodes.outlet'])->get());

and the result is:

Any idea why i can't get my barcodes outlet?

Answer 1

Based on your question and comment above:

• A Product has many Barcode and a Barcode belongs to a Product . They have a One To Many relationship.

• An Outlet has many barcode and a Barcode has many Outlet . They have a Many To Many relationship.

---

Here's how to set the One To Many relationship.

In your Product class:

class Product extends Model
{
    public function barcodes()
    {
        return $this->hasMany('App\Barcode');
    }
}

In your Barcode class, set the inverse relationship:

class Barcode extends Model
{
    public function product()
    {
        return $this->belongsTo('App\Product');
    }
}

---

Here's how to set the Many To Many relationship.

In your Outlet class:

class Outlet extends Model
{
    public function barcodes()
    {
        return $this->belongsToMany('App\Barcode');
    }
}

In your Barcode class:

class Barcode extends Model
{
    public function outlets()
    {
        return $this->belongsToMany('App\Outlet');
    }
}

With a Many to Many relationship, you also need to create an intermediate table.

In this case, your pivot table will be barcode_outlet .

Important: Per Laravel convention, the intermediate table name must be in singular form and alphabetical order of the related model names (barcode_outlet in your case).

The intermediate table must have barcode_id and outlet_id columns. I will let you modify your migrations accordingly.

---

After setting the relationships, you will be able to use Eloquent to retrieve your models.

Example:

$barcode->outlets;
// returns a Collection of outlets

$barecode->product;
// returns a Product

$product->barcodes;
// returns a Collection of barcodes

$outlet->barcodes;
// returns a Collection of barcodes