zOs/SQL/EXSERVER

with nmC1 as
(
select right(strip(current server), 4) dbSys
    from sysibm.sysDummy1
)
, nmC2 as
( select case when posStr(dbSys, 'V') > 0 then 'V'
              when dbSys = 'DBAF'         then 'A'
              when dbSys = 'DBTF'         then 'T'
                                          else 'P'
         end nmCn, dbSys
    from nmC1
)
, nmCn as
( select case when nmCn = 'V' then 'BUA' else 'OA1' || nmCn end cr
       , case when nmCn = 'V' then ''    else '99'          end cr99
       , nmCn, dbSys
    from nmC2
)
select * from nmCn