caiping/app/admin/model/Admin.php

<?php
/**
 * @copyright Copyright (c) 2021 勾股工作室
 * @license https://opensource.org/licenses/Apache-2.0
 * @link https://www.gougucms.com
 */

namespace app\admin\model;

use think\Model;

class Admin extends Model{

    protected $table = 'cp_admin';

    public function department(){
        return $this->hasone('Department', 'id', 'unit_name')
            ->bind(['department_title' => 'title']);
    }

}