主题：[求助]按日期顺序编号，相同日期编号相同

参考

http://www.foxtable.com/bbs/dispbbs.asp?BoardID=2&ID=114407&skin=0

For Each dr As DataRow In DataTables("采购明细").Select("")
    Dim d As Date = dr("到货时间")
    Dim bh As String = Format(d,"yyyy") & "-" '生成编号的前缀
    Dim max As String
    Dim idx As Integer
    Dim flt As String
    flt = "到货时间 >= #" & d & "# And 到货时间 < #" & d.AddDays(1) & "# And [_Identify] <> " & dr("_Identify")
    max = dr.DataTable.Compute("Max(采购订单号)",flt)
    If max > "" Then '如果存在最大单据编号
        idx = CInt(max.Substring(bh.length,3))
    Else
        d = new Date(d.year, 1, 1)
        flt = "到货时间 >= #" & d & "# And 到货时间 < #" & d.Addyears(1) & "# And [_Identify] <> " & dr("_Identify")
        max = dr.DataTable.Compute("Max(采购订单号)",flt)
        If max > "" Then
            idx = CInt(max.Substring(bh.length,3)) + 1 '获得最大单据编号的后四位顺序号,并加1
        Else
            idx = 1 '否则顺序号等于1
        End If
    End If
    dr("采购订单号") = bh & Format(idx,"000")
Next