baoshi-was/app/UserWorkgroup.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class UserWorkgroup extends Model
{
    protected $table="user_workgroups";
    protected $fillable=['name','warehouse_id'];

    public function users(){
        return $this->belongsToMany('App\User','user_workgroup_user','user_workgroup_id','user_id');
    }
    public  function wareHouse(){
        return $this->belongsTo('App\Warehouse','warehouse_id','id');
    }

}