ORACLE中 2张类似表进行数据对比，并把值放到另一张表里面进行显示

你要不嫌累：
insert into aaa_ALL_COMPARISON_ALL
select aa1.aaa,DATA1,DATA2,DATA3.......,DATA31 from
(select a1.aaa,(case when b1.aaa is null then 0 else 1 end) DATA1
from aaa_ALL a1 left join 20100301 b1 on a1.aaa=b1.aaa) aa1
inner join
(select a2.aaa,(case when b2.aaa is null then 0 else 1 end) DATA2
from aaa_ALL a2 left join 20100301 b2 on a2.aaa=b2.aaa) aa2
on aa1.aaa=aa2.aaa
inner join
.
.
.
.
inner join
(select a31.aaa,(case when b31.aaa is null then 0 else 1 end) DATA31
from aaa_ALL a31 left join 20100331 b31 on a31.aaa=b31.aaa) aa31
on aa1.aaa=aa31.aaa
如果aaa不是唯一，上述语句无效。

好像得用存储过程 了，

楼主需要在表C 形成30 条记录还是一条记录啊？

没错，用存储过程来实现。
不过你这表结构设计得实在是有点不理解。