问一个奇怪的问题,关于select

[leojay1]

select distinct bdqyxx_id from GQBDWXX where XMXX_ID = '20060924000091070'
运行过后的结果是:20060924000091071

select * from bdqyxx qy where qy.bdqyxx_id in('20060924000091071')
这句话也有数据

但是我把两句结合起来就出问题了
select * from bdqyxx qy where qy.bdqyxx_id in(select distinct bdqyxx_id from GQBDWXX where XMXX_ID = '20060924000091070')
居然没有数据~~~~
麻烦帮一下忙,急!

[wiler]

请确定表GQBDWXX的列bdqyxx_id没有空值(null)

[Eric_1999]

select * from bdqyxx qy where qy.bdqyxx_id =(select distinct bdqyxx_id from GQBDWXX where XMXX_ID = '20060924000091070')

select * from bdqyxx qy where qy.bdqyxx_id exist(select 1 from GQBDWXX where XMXX_ID = '20060924000091070')

楼主，这两句有数据吗？

[wiler]

SQL> create table GQBDWXX (
2 XMXX_ID varchar2(50),
3 bdqyxx_id varchar2(50)
4 );

Table created

SQL> create table bdqyxx (
2 bdqyxx_id varchar2(50)
3 );

Table created

SQL> insert into GQBDWXX values('20060924000091070','20060924000091071');

1 row inserted

SQL> insert into bdqyxx values('20060924000091071');

1 row inserted

SQL> commit;

Commit complete

SQL> select * from bdqyxx qy
2 where qy.bdqyxx_id in(
3 select distinct bdqyxx_id
4 from GQBDWXX where XMXX_ID = '20060924000091070'
5 );

BDQYXX_ID
--------------------------------------------------
20060924000091071

-----------------------------------------
我的测试是通过的
楼主可换成这样的脚本，肯定能出数据：
select * from bdqyxx qy
where exists (
select b.bdqyxx_id from GQBDWXX b
where b.XMXX_ID = '20060924000091070' and qy.bdqyxx_id =b.bdqyxx_id
)