text: -- @testpoint: opengauss关键字null(保留)，作为同义词对象名,部分测试点合理报错
  
  
  --前置条件
  drop table if exists null_test;
  create table null_test(id int,name varchar(10));
  
  --关键字不带引号-失败
  drop synonym if exists null;
  create synonym null for null_test;
  
  
  --关键字带双引号-成功
  drop synonym if exists "null";
  create synonym "null" for null_test;
  insert into "null" values (1,'ada'),(2, 'bob');
  update "null" set "null".name='cici' where "null".id=2;
  select * from "null";
  
  --清理环境
  drop synonym "null";
  
  --关键字带单引号-合理报错
  drop synonym if exists 'null';
  create synonym 'null' for null_test;
  insert into 'null' values (1,'ada'),(2, 'bob');
  update 'null' set 'null'.name='cici' where 'null'.id=2;
  select * from 'null';
  
  --关键字带反引号-合理报错
  drop synonym if exists `null`;
  create synonym `null` for null_test;
  insert into `null` values (1,'ada'),(2, 'bob');
  update `null` set `null`.name='cici' where `null`.id=2;
  select * from `null`;
  --清理环境
  drop table if exists null_test cascade;