select B.* from A,B where A.cardid=B.cardid and A.cardid=?
union all
select C.* from A,C where A.cardid=C.cardid and A.cardid=?

------解决方案--------------------
select a.* from a right outer join b on a.cardid=b.cardid
right outer join c on a.cardid=c.cardid

------解决方案--------------------

create view vw_view   as   select cardid ,col2,col3 from man
union all
select cardid ,col2,col3 from car
union all
select cardid ,col2,col3 from card t  
where not exists(select 1 from man a where a.cardid=t.cardid)
and not  exists(select 1 from car a where a.cardid=t.cardid)

这样？