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