code: protected function getUserInfo($uid)
      {
          static $userinfo = array();
          if (!isset($userinfo[$uid])) {
              $userinfo[$uid] = \think\Db::name($this->_config['AUTH_USER'])->where(array('uid' => $uid))->find();
          }
          return $userinfo[$uid];
      }
docs: 获得用户资料,根据自己的情况读取数据库