weixin/app/Repositories/Models/Base/UserMessage.php

<?php

namespace App\Repositories\Models\Base;

use App\Repositories\Models\Model;

class UserMessage extends Model
{
    /**
     * @var string
     */
    protected $table = 'base_user_messages';

    protected $guarded = [];

    /**
     * The attributes excluded from the model's JSON form.
     *
     * @var array
     */
    protected $hidden = [];

    const IS_READ_OK = 1;
    const IS_READ_NO = 0;

    public function user()
    {
        return $this->morphTo('user')->select(['id', 'name']);
    }

    public function source()
    {
        return $this->morphTo('source');
    }

}