---try select a.货名,a.入数量-b.出数量 as 数量,a.进货日期 from (select 货名,sum(数量) as 入数量,max(进货日期) as 进货日期 from 进货表) a,(select 货名,sum(数量) as 出数量 from 出货表) b where a.货名=b.货名
发表于:2007-03-23 08:36:293楼 得分:0
select a.货名,a.入数量-b.出数量 as 数量,a.进货日期 from (select 货名,sum(数量) as 入数量,max(进货日期) as 进货日期 from 进货表 group by 货名) a,(select 货名,sum(数量) as 出数量 from 出货表 group by 货名) b where a.货名=b.货名