看不懂你想做什么。
Dim d As Date = Today() '获取当前日期
Dim y As Integer = d.Year '获取当前日期的年份
Dim m As Integer = d.Month '获取当前日期的月份
Dim Days As Integer = Date.DaysInMonth(y,m) '获取当前月份的天数
Dim fd As Date = New Date(y,m,1) '获得当前月份的第一天
Dim ld As Date = New Date(y,m,Days) '获当前月份的最后一天
Dim bh As String = Format(d,"yyyyMM") & "-" '生成编号的前6位,4位年,2位月
For Each dr2 As Row In Tables("orderlist").Rows
Dim max As String
Dim idx As Integer
Dim flt As String
flt = "orderTime >= #" & fd & "# And orderTime <= #" & ld & "# And [_Identify] <> " & dr2("_Identify")
max = Tables("orderList").Compute("Max(orderNo)",flt) '取得该月的相同供应商的最大订单编号
If max > "" Then '如果存在最大编号
idx = CInt(max.Substring(max.Length - 2)) + 1 '获得最大订单号的后二位顺序号,并加1
Else
idx = 1 '否则顺序号等于1
End If
dr2("orderNo") = bh & Format(idx,"00")
Next