ASP数据库存查询的问题!

select tz_a.*,tz_b.*,tz_c.* from tz_a,tz_b,tz_c where tz_a.pc_id=070101 and tz_b.pc_id=070101 and tz_c.pc_id=070101
或者
(select * from tz_a where pc_id=070101)
union all
(select * from tz_b where pc_id=070101)
union all