二表数据合并到同一个表：
select * from T1 select * from T2 select a.*,b.OutQty,c.InQty from ( select [DATE] from t1 union select [DATE] from t2 ) a left join t1 b on a.[DATE] =b.[DATE] left join t2 c on a.[DATE] =c.[DATE]
原文：http://www.cnblogs.com/ycdx2001/p/3522436.html