请教这种交叉组合统计该怎么做 - 专家坐堂 - Foxtable(狐表) - 新一代数据库软件，完美融合Access、Foxpro、Excel、vb.net之优势，人人都能掌握的快速软件开发工具!

Dim dt1,dt2 As fxDataSource

Dim dts As fxDataSource() ={dt1,dt2}

Dim v1 As String() = {"入库","出库"}

Dim jb As SQLJoinTableBuilder

Dim s1,s2 As String

Dim n1 As Integer

For Each s1 In v1

jb =new SQLJoinTableBuilder("查询",s1 & "表")

jb.AddExp("日期", s1 & "日期")

jb.AddExp(s1 & "单号", s1 & "单号")

jb.AddExp(s1 & "数量", "数量")

if n1= v1.length-1 then jb.AddExp("结余", "0.0")

dts(n1) = jb.BuildDataSource()

n1+=1

s2 = "日期"

dts(0).Combine(s2,dts(1),s2)

dts(0).show("查询")

Dim t1 As Table =Tables("查询")

t1.StopRedraw

t1.sort = s2

For Each r As Row In t1.Rows

If r.Index= 0 Then

r("结余") = r("入库数量")-r("出库数量")

Else

r("结余") =t1(r.Index-1,"结余")+ r("入库数量")-r("出库数量")

End If

t1.ResumeRedraw

如考虑一日内有多笔出入库(同日出入单号相同),这样可能更好些:

Dim dt1,dt2 As fxDataSource

Dim dts As fxDataSource() ={dt1,dt2}

Dim v1 As String() = {"入库","出库"}

Dim g As GroupTableBuilder

Dim s1,s2 As String

Dim n1 As Integer

For Each s1 In v1

g =new GroupTableBuilder("查询",DataTables(s1 & "表"))

g.Groups.AddDef(s1 & "日期",DateGroupEnum.None,"日期") '添加客户列用于分组

g.Groups.AddDef(s1 & "单号") '添加产品列用于分组

g.Totals.AddDef("数量",s1 & "数量") '添加数量列用于统计

If n1= v1.length-1 Then g.Totals.AddDef("数量","结余")

dts(n1) = g.BuildDataSource()