strprfcrm/app/Models/ProductSKU.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Database\Eloquent\SoftDeletes;

class ProductSKU extends Model
{
    use SoftDeletes;

    const DEFAULT_SORT_BY = 'created_at';
    protected $fillable = [
        'product_id',
        'order_id',
        'status',
        'rfid',
        'factory_number',
        'manufacture_date',
        'service_life',
        'certificate_number',
        'certificate_date',
        'certificate_issuer',
        'certificate_type',
    ];
    public $table = 'products_sku';

    /**
     * @return BelongsTo
     */
    public function product(): BelongsTo
    {
        return $this->belongsTo(Product::class, 'product_id', 'id');
    }

    public function order(): BelongsTo
    {
        return $this->belongsTo(Order::class, 'order_id', 'id');
    }
}