主题：关于网络编号的问题

Dim dr As DataRow = DataTables("单号定义").Find( "表名 ='" & CurrentTable.Name & "'")

If dr IsNot Nothing Then

    Static Index As Integer = 99999

    e.DataRow("系统单号") = dr("单号定义") & Format(Date.Today(),"yyyyMMdd") & Index

    Index = Index - 1

End If

Dim dr As DataRow = e.DataRow

Dim pf As String

If dr.IsNull("开单日期") Then '如果没有输入开单日期

    e.Cancel = True '取消保存此行

    MessageBox.Show("必须输入开单日期!","提示",MessageBoxButtons.OK,MessageBoxIcon.Information)

    Return

Else

    pf = Format(dr("开单日期"),"yyyyMMdd") '否则获得系统单号的前缀,两位年,两位月

End If

Dim cmd1 As New SQLCommand

Dim cmd2 As New SQLCommand

Dim Key As Integer

cmd1.C

cmd2.C

cmd1.commandText = "Select Count(*) From [编号] Where [前缀] = '" & pf & "'"

If cmd1.ExecuteScalar = 0 Then '如果系统单号表不存在前缀的行,那么增加一行

    cmd1.commandtext = "Insert Into 编号 (前缀, 顺序号) Values('" & pf & "',1)"

    cmd1.ExecuteNonQuery

End If

cmd1.commandText = "Select [顺序号] From [编号] Where [前缀] = '" & pf & "'"

Do

    Key = cmd1.ExecuteScalar() '从后台获得顺序号

    cmd2.commandText = "Update [编号] Set [顺序号] = " & (Key + 1) & " Where [顺序号] = " & Key & " And [前缀] = '" & pf & "'"

    If cmd2.ExecuteNonQuery() > 0 Then '更新顺序号

        Exit Do '更新成功则退出循环

    End If

Loop

Dim dr1 As DataRow = DataTables("单号定义").Find( "表名 ='" & CurrentTable.Name & "'")

If dr1 IsNot Nothing Then

    e.DataRow("系统单号") = dr1("单号定义")  & pf & Format(Key,"0000")

End If