dsum（）究竟怎么用？

[southdoor]

"select 品牌,规格型号,花纹,dsum(数量,b?,操作类别='买') as 进货数量," & _
"dsum(进价金额,b?,操作类别='买') as 进价金额," & _
"dsum(数量,b?,操作类别='卖') as 销售数量" & _
"into a from b " & _
"group by 品牌,规格型号,花纹"
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
总是提示dsum参数错误

[southdoor]

我其实就是在access中用
能将上面的要求用dsum写出来吗?
谢谢

[southdoor]

或者说,在access中能实现吗

[OracleRoob]

因为dsum()不是聚合函数,所以不太好实现

[changechange]

"select 品牌,规格型号,花纹,dsum(""数量"",""b"",""操作类别='买'"") as 进货数量," & _
"dsum(""进价金额"",""b"",""操作类别='买'"") as 进价金额," & _
"dsum(""数量"",""b"",""操作类别='卖'"") as 销售数量" & _
"into a from b " & _
"group by 品牌,规格型号,花纹"

注意！对 DSUM 来说，它的参数永远是文字

[OracleRoob]

To:changechange

下面也可以啊，只是结果数据没什么用罢了!

select 品牌,
规格型号,
花纹,
dsum(数量,'b',操作类别='买') as 进货数量,
dsum(进价金额,'b',操作类别='买') as 进价金额2,
dsum(数量,'b',操作类别='卖') as 销售数量
from b

[OracleRoob]

应该这样用：
select 品牌,规格型号,花纹,
sum(iif(操作类别='买',数量,0)) AS 进货数量,
sum(iif(操作类别='买',进价金额,0)) AS 进货金额,
sum(iif(操作类别='卖',数量,0)) AS 销售数量
into a
from b
group by 品牌,规格型号,花纹

[southdoor]

谢谢
那请问dsum在什么情况下用,dsum能解决问题吗?

[OracleRoob]

一般不在SQL中用dsum()，在VBA代码中用，比如：求某一品牌1所有操作类型='买'的进货数量:
dsum("数量","B","操作类别 = '买' and 品牌 = 1")

[southdoor]

To:changechange
-----------------------------
非常高兴能过,但结果不是我想要的,因为,a表中进货数量,进价金额,销售数量对全部记录都是一样的.是先统计后分组赋值的.
并没有按分组后的结果进行统计求和.
怎么办?