text: --  @testpoint:opengauss关键字mode(非保留)，作为角色名
  
  
  --关键字不带引号-成功
  drop role if exists mode;
  create role mode with password 'gauss@123' valid until '2020-12-31';
  drop role mode;
  
  --关键字带双引号-成功
  drop role if exists "mode";
  create role "mode" with password 'gauss@123' valid until '2020-12-31';
  drop role "mode";
  
  --关键字带单引号-合理报错
  drop role if exists 'mode';
  create role 'mode' with password 'gauss@123' valid until '2020-12-31';
  
  --关键字带反引号-合理报错
  drop role if exists `mode`;
  create role `mode` with password 'gauss@123' valid until '2020-12-31';
  