主题：这个问题能不能帮我解决

不用累加，直接：

Dim Sum As Double
Sum = Tables("订单").Compute("Sum(数量)")

你既然各产品都算出来了，算完之后，进销存表生成汇总模式就行了，做个按钮，代码为：

DataTables("进销存").DataCols("代码").RaiseDataColChanged()

Dim t As Table = Tables("进销存")
Dim g As Subtotalgroup
t.SubtotalGroups.Clear()
t.GroupAboveData = False
t.TreeVisible = False
t.SpillNode = True

g = New Subtotalgroup
g.Aggregate = AggregateEnum.Sum
g.GroupOn = "*"
g.TotalOn = "期初数量,入库数量,出库数量,结存数量,期初金额,入库金额,出库金额,结存金额"
g.Caption = "总计"
t.SubtotalGroups.Add(g)

t.Subtotal()

DataTables("进销存").DataCols("代码").RaiseDataColChanged()

Dim t As Table = Tables("进销存")
Dim g As Subtotalgroup
t.SubtotalGroups.Clear()
t.GroupAboveData = False
t.TreeVisible = False
t.SpillNode = True

g = New Subtotalgroup
g.Aggregate = AggregateEnum.Sum
g.GroupOn = "*"
g.TotalOn = "期初数量,入库数量,出库数量,结存数量,期初金额,入库金额,出库金额,结存金额"
g.Caption = "总计"
t.SubtotalGroups.Add(g)

t.Subtotal()

Dim r As Row = t.Rows(t.Rows.Count(True) - 1, True)
r("结存数量") = r("期初数量") + r("入库数量") - r("出库数量")
r("结存金额") = r("期初金额") + r("入库金额") - r("出库金额")

参考：

http://help.foxtable.com/topics/1911.htm

http://help.foxtable.com/topics/1964.htm