两种办法:
1、 快速做一个和原表一样的备份表
create table new_table as (select * from old_table)
2、update aa p
set aa_code=(
select c.aa_code
from "bb" r, cc c
where p.bb_code = r.bb_code
and r.name = c.name
)
where exists (
select c.aa_code
from "bb" r, cc c
where p.bb_code = r.bb_code
and r.name = c.name
)