text: --  @testpoint:opengauss关键字cobol非保留)，作为序列名
  --关键字不带引号-成功
  drop sequence if exists cobol;
  create sequence cobol start 100 cache 50;
  
  --清理环境
  drop sequence cobol;
  
  --关键字带双引号-成功
  drop sequence if exists "cobol";
  create sequence "cobol" start 100 cache 50;
  
  --清理环境
  drop sequence "cobol";
  
  --关键字带单引号-合理报错
  drop sequence if exists 'cobol';
  
  --关键字带反引号-合理报错
  drop sequence if exists `cobol`;
  