text: --  @testpoint:opengauss关键字nothing(非保留)，作为角色名
  
  
  --关键字不带引号-成功
  drop role if exists nothing;
  create role nothing with password 'gauss@123' valid until '2020-12-31';
  drop role nothing;
  
  --关键字带双引号-成功
  drop role if exists "nothing";
  create role "nothing" with password 'gauss@123' valid until '2020-12-31';
  drop role "nothing";
  
  --关键字带单引号-合理报错
  drop role if exists 'nothing';
  create role 'nothing' with password 'gauss@123' valid until '2020-12-31';
  
  --关键字带反引号-合理报错
  drop role if exists `nothing`;
  create role `nothing` with password 'gauss@123' valid until '2020-12-31';
  