text: -- [er] vclass is unupdatable if select using operation *
  
  create class c1 ( id int, id_key int, id_s string );
  
  insert into c1 values( 1, 1, 'test1');
  insert into c1 values( 2, 2, 'test2');
  insert into c1 values( 3, null, 'test3');
  insert into c1 values( 4, null, 'test4');
  insert into c1 values( 5, null, 'test5');
  
  insert into c1 values( 5, 5, 'test5');
  
  create vclass v1 as 
                     select id*1 from c1 where id between 3 and 5;
  
  SELECT * FROM v1;
  
  select v1 from v1;
  
  
  
  drop class c1;
  drop vclass v1;