cssd-back/app/Item.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Item extends Model
{
    public $fillable = ['name', 'size', 'unique_id', 'specific', 'note', 'user_id'];
    public function packages()
    {
        return $this->belongsToMany('App\Package', 'item_package')->withPivot('count');
    }
    public function user()
    {
        return $this->belongsTo('App\User');
    }
}