请高手帮忙看看这个SQL，谢谢！

chen_mh

select * from
(
select a5sh,a5zh,a5dwm,a5gskm,a5bz,a5sh||a5zh,count(*) as count,sum(a5ye) as ye
from whrept.aa5fhz
where (substr(a5gskm,1,3) in ('202','205','251')
or substr(a5gskm,1,3) in ('201','221'))  '2'))
and a5bzh='01'
group by a5sh,a5zh,a5dwm,a5gskm,a5bz
) t1,
(
select a8sh,a8zh,a8sh||a8zh,a8jd,sum(a8fse) as fse from aaalszb
where  (substr(a8kmh,1,3) in ('202','205','251')
or substr(a8kmh,1,3) in ('201','221') )
and a8bzh='01'
group by a8sh,a8zh,a8jd
) t2
where t1.a5sh||a5zh(+)=t2.a8sh||a8zh
and substr(t1.a5bz,6,1)<>;'2';

t1.a5sh||a5zh中的内容包含t2.a8sh||a8zh 的内容，我想将t1表和t2表
中t1.a5sh||a5zh=t2.a8sh||a8zh的记录找出来，然后t1表中不符合条件的记录的t2表中的字段的付空值．整个查询的结果的记录数为t1表中的记录
数．
请问如何修改我的SQL语句．谢谢！！