--把你所有可以關聯到的倏件關聯起來，取你要的列，就應是結果
create or replace view v_ac
as
select distinct A.*,C.*
from A,B,C,A_B,B_C
where A.crID=A_B.crID and B.IGID=A_B.IGID
    and B.IGID=B_C.IGID and C.ICID=B_C.ICID;