三个表如何做关联

三个表怎么做关联？
条件：

表A的number=表B的number=表C的number

表A的time=表C的time=20120312

表A的level=2

我现在是这样写的:

SQL code

select 表C.Value from 表A,表B,表C where 表A.number=表B.number and 表B.number=表C.number and 表A.level = 2 and 表A.time=to_date('20120311','yyyy/mm/dd') and 表C.time=to_date('20120311','yyyy/mm/dd')

SQL code

select C.Value from A,B,C where A.number=B.number and       A.number=C.number and       A.level = 2 and       A.time=C.time and                  A.time=to_date('20120311','yyyy/mm/dd')
[解决办法]
SQL code
select C.Value from A,B,C where A.number=B.number and       A.number=C.number and       A.level = 2 and       A.time=C.time and                  to_char(A.time,'yyyy/mm/dd')='20120311'