設定那些欄位可以被更新
在Models裡面增加檔案
在terminal下指令php artisan make:model CartItem
自動新增顯示

裡面的程式碼:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class CartItem extends Model
{
    use HasFactory;
}

下指令讓新增檔案可以快速被讀取composer dump-autoload
下指令php artisan tinker

撈出全部資料 下指令CartItem::all()顯示

設定那些欄位可以更新’’表示都可以更新protected $guarded = [''];

設定那些欄位不顯示 protected $hidden =['updated_at'];

數量*10

設定其他關聯php artisan make:model Product

再設定 php artisan make:model Cart

設定CartItem 一對多的關係

修改後的程式碼:

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class CartItem extends Model
{
   use HasFactory;

   protected $guarded = [''];   
   protected $appends = ['current_price'];

   public function getCurrentPriceAttribute()
   {
       return $this->quantity * 10;
   }
   public function product()
   {
       return $this->belongsTo(Product::class);
   }
   public function cart()
   {
       return $this->belongsTo(Cart::class);
   }

}
```

--------------

Cart裡面去設定雙向功能
原來:
![https://ithelp.ithome.com.tw/upload/images/20250818/20119035kkomoIpuUu.png](https://ithelp.ithome.com.tw/upload/images/20250818/20119035kkomoIpuUu.png)
修改後:
![https://ithelp.ithome.com.tw/upload/images/20250818/20119035nuV7IwharX.png](https://ithelp.ithome.com.tw/upload/images/20250818/20119035nuV7IwharX.png)



<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Cart extends Model
{
   use HasFactory;

   public function cartItems()
   {
       return $this->hasMany(CartItem::class);
   }

}


------------
Product裡面去設定雙向功能

原來:
![https://ithelp.ithome.com.tw/upload/images/20250818/20119035E3vqP4hdTm.png](https://ithelp.ithome.com.tw/upload/images/20250818/20119035E3vqP4hdTm.png)
修改後:
![https://ithelp.ithome.com.tw/upload/images/20250818/20119035euV9nuvs0v.png](https://ithelp.ithome.com.tw/upload/images/20250818/20119035euV9nuvs0v.png)

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
   use HasFactory;
   public function cartItems()
   {
       return $this->hasMany(CartItem::class);
   }
}



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我們明天見~