Question

我希望以ddmmyyyy / 0000格式生成salesID。

之后的数字

/应始终从0001开始新的一天。

示例

12072016/0001
12072016/0002
12072016/0003
13072016/0001
13072016/0002
13072016/0003
14072016/0001
14072016/0002

我尝试阅读如果在某个日期进行了销售，如果没有，那么我就开始了首次销售与当天的日期并添加0001，如果已经进行了销售，则增加它。

  myConnection.Open()
    Dim sel As SqlCommand = New SqlCommand("select Code as Code  from sales where saledate ='" & Format(Today, "yyyy-MM-dd") & "'", myConnection)
    Dim dr As SqlDataReader = sel.ExecuteReader
    If dr.HasRows Then


        While dr.Read

            dmyConnection.Open()
            Dim seld As SqlCommand = New SqlCommand("select max(Code) as Code from sales where saledate='" & Format(Today, "yyyy-MM-dd") & "'", dmyConnection)
            Dim r As SqlDataReader = seld.ExecuteReader
            code = Format((r("Code") + 1), "0000")
            Sales_ID = (Format(Today, "ddMMyyyy")) & "/" & code
            SalesID.Text = Sales_ID

            dmyConnection.Close()
        End While
        dr.Close()
        myConnection.Close()

    Else


        dr.Close()
        code = "0001"
        Sales_ID = (Format(Today, "ddMMyyyy")) & "/" & code
        SalesID.Text = Sales_ID
        myConnection.Close()
    End If

但是我收到了错误

无效读取无数据的尝试

我做错了什么？请帮忙。

生成唯一的salesID

0 个答案: