create table lzmb
(
   id varchar2(64),
   name varchar2(128),
   description varchar2(256),
   other varchar2(128)
);

create table lzma
(
   id varchar2(64),
   name varchar2(128),
   description varchar2(256),
   other varchar2(128)
);

create table lzmc
(
   id varchar2(64),
   name varchar2(128),
   description varchar2(256),
   other varchar2(128)
);

create or replace view lzm_viewa as
select * from lzma union all
select * from lzmc;

select * from lzm_viewa

create or replace view lzm_viewb as
select a.id as id, a.name as name, a.description as description, '' as other from lzma a union all
select c.id as id, c.name as name, c.description as description, '' as other from lzmc c union all
select b.id as id, b.name as name, b.description as description, b.other as other from lzmb b;

select * from lzm_viewb