phpstock/app/model/AccountItem.php

<?php
declare (strict_types = 1);

namespace app\model;

use think\Model;

/**
 * @mixin \think\Model
 */
class AccountItem extends Model
{
    protected $connection='mysql_sys';
    public function GetUidByDepartId($departId){
        return $this->where(["itemid"=>$departId])->column("account_id");
    }
}