Laravel 7 Product Stock Model

ProductStock.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class ProductStock extends Model
{
    protected $table = "product_stock";
    protected $fillable = [
        'id', 
        'category_detail_id', 
        'product_id', 
        'material_id', 
        'size_id', 
        'color_id', 
        'qty_stock', 
        'qty_sold', 
        'cost', 
        'price', 
        'discount',  
        'discount_expired',  
        'active',  
        'created_at', 
        'updated_at', 
        'deleted_at'
    ];
    protected $hidden = [];

    public function category_detail()
    {
        return $this->hasOne('App\ProductCategoryDetail', 'id', 'category_detail_id');
    }

    public function product()
    {
        return $this->hasOne('App\Product', 'id', 'product_id');
    }

    public function material()
    {
        return $this->hasOne('App\ProductMaterial', 'id', 'material_id');
    }

    public function size()
    {
        return $this->hasOne('App\ProductSize', 'id', 'size_id');
    }

    public function color()
    {
        return $this->hasOne('App\ProductColor', 'id', 'color_id');
    }
}