text: -- create class,insert three record for this class,select data from this class,update this class by a query,select data from this class for looking, drop class
  create class xoo ( id int auto_increment , title varchar(100));
  
  insert into xoo(title) values ('aaa');
  insert into xoo(title) values ('bbb');
  insert into xoo(title) values ('ccc');
  
  select * from xoo order by 1;
  
  update xoo set title = 'ddd' where title = (select title from xoo where id = 3);
  
  select * from xoo order by 1;
  
  drop class xoo;
  