This is an example of my view.
create view VIEWTEST as
select
'1' as TYPE,
TABLE1.KEYFIELD1 as KEYFIELD1,
'' as KEYFIELD2,
'' as KEYFIELD3,
TABLE1.FIELDX as FIELD1
from TABLE1
when TABLE1.FIELDS = TABLE2.FIELDS
union all SELECT
'2' as TYPE,
'' as KEYFIELD1,
TABLE2.KEYFIELD10 as KEYFIELD2...