[5分]该字段可以参考sql语句中的多个表

在单价前加表名或表的别名。

比如：

Select a.货物ID,sum(a.数量) as 收料数量,sum(a.单价*a.数量)/sum(a.数量) as 收料单价,Last(b.数量) as 库存数量,Last(b.单价) as 库存单价

From 收料表 as a inner join 库存表 as b On a.货物ID=b.货物ID

Where a.日期>=#2015/1/1# and a.日期<=#2015/1/31#

Group By a.货物ID;