复制票号

Question

我的项目在创建新票证时生成连续的票号。 然而，在极少数情况下，这个数字重复。我已经分析了表格，发现当票证生成1到2分钟时会发生这种情况。

以下代码用于读取和填充文本框的票号;我使用Sql阅读器：

 Sub loadTicketNumber()


        Dim connetionString As String
        Dim sqlCnn As SqlClient.SqlConnection
        Dim sqlCmd As SqlClient.SqlCommand
        Dim sql As String

        connetionString = My.Settings.DBServer
        sql = "Select TicketNo FROM tbl_TicketNumber WHERE PC= '" & Soft_Parameters.QS_ClientPC & "'"

        sqlCnn = New SqlClient.SqlConnection(connetionString)
        Try
            sqlCnn.Open()
            sqlCmd = New SqlClient.SqlCommand(sql, sqlCnn)
            Dim sqlReader As SqlClient.SqlDataReader = sqlCmd.ExecuteReader()
            Dim x As Integer
            While sqlReader.Read()
                x = sqlReader.Item("TicketNo")

            End While
            sqlReader.Close()
            sqlCmd.Dispose()
            sqlCnn.Close()
            txtTicket.Text = x + 1
            txt_ReTicketNo.Text = x
        Catch ex As Exception
            MsgBox("Can not open connection ! ")
        End Try

    End Sub

但是当我保存我的SQL代码时会搜索Edit或New ticket;如果是新票，它会将新票号保存在另一个表中。

我会解释更多故障单编号将生成如果它的新票证，如果这个编辑的票证不会生成，这就是为什么编辑和添加新的是相同的子。

这是我的代码：

' these strings will dynamically generate at runtime i can add fields to form SQL statements 
    ' EditString is variable for edit SQL strin

    ' AddString is a variable for Insert into statement that holds data table columns
    ' AddStringVal uses that holds above Column value

    Try

        con.Open()
        Dim cm As New SqlClient.SqlCommand
        cm.Connection = con
        cm.CommandText = " DECLARE @tbl_ID TABLE (nID int) UPDATE tbl_Tickets " & _
        " SET  Ticket_Type = @Ticket_Type, VehicleNo= @VehicleNo," & _
        " Customer=@Customer, Job_Code=@Job_Code, Material=@Material, " & _
        " First_Weight=@First_Weight, Second_Weight=@Second_Weight, Net_Weight=@Net_Weight, " & _
        " Add_Charges=@Add_Charges, Deduction=@Deduction, Ticket_Amount=@Ticket_Amount, " & _
        " Source=@Source, Destination=@Destination, Operator=@Operator, Out_Time=@Out_Time, PC=@PC, Unit_Price=@Unit_Price" & _
        EditString & _
        " OUTPUT INSERTED.QS_Code INTO @tbl_ID (nID)  WHERE (VehicleNo=@VehicleNo) AND (Second_Weight IS NULL) AND  (Ticket_Type <>'DELETED') " & _
       " IF @@ROWCOUNT=0  " & _
        " BEGIN " & _
            " INSERT INTO tbl_Tickets (Ticket_Type, TicketNo, VehicleNo, nDate, Customer,Job_Code,Material, " & _
            " First_Weight, Second_Weight, Net_Weight, Unit_Price, Add_Charges, Deduction, Ticket_Amount,Source, " & _
            " Destination, Operator, In_Time, PC " & _
            AddString & " ) VALUES (@Ticket_Type, @TicketNo, @VehicleNo, @nDate, @Customer,@Job_Code,@Material, " & _
            " @First_Weight, @Second_Weight, @Net_Weight, @Unit_Price, @Add_Charges, @Deduction, @Ticket_Amount,@Source, " & _
            " @Destination, @Operator, @In_Time, @PC  " & _
            AddStringVal & " ) SELECT IDENT_CURRENT('tbl_Tickets') FROM tbl_Tickets " & _
            " UPDATE tbl_TicketNumber " & _
            " SET TicketNo = @TTicket, PC= @TPC, nDate= @TnDate" & _
            " WHERE (PC=@TPC) " & _
                " IF @@ROWCOUNT=0 " & _
                " BEGIN " & _
                " INSERT INTO tbl_TicketNumber (TicketNo, PC, nDate) VALUES (@TTicket,@TPC,@TnDate) END  " & _
        " END SELECT * From @tbl_ID"

        'this will pass parameters to update tbl_TicketNumber that stores my last ticket number
        cm.Parameters.AddWithValue("@TTicket", Val(txtTicket.Text))
        cm.Parameters.AddWithValue("@TPC", Soft_Parameters.QS_ClientPC)
        cm.Parameters.AddWithValue("@TnDate", Now)


        'this will pass parameters to update tbl_Tickets that stores all my ticket details
        cm.Parameters.AddWithValue("@Ticket_Type", cboTicketType.Text)
        cm.Parameters.AddWithValue("@TicketNo", Val(txtTicket.Text))
        cm.Parameters.AddWithValue("@VehicleNo", cboV_Code.Text)
        cm.Parameters.AddWithValue("@nDate", dtpDate.Value)
        cm.Parameters.AddWithValue("@Customer", Val(cboCustomer.SelectedValue))
        cm.Parameters.AddWithValue("@Job_Code", Val(cboJobCode.SelectedValue))
        cm.Parameters.AddWithValue("@Material", Val(cboMaterial.SelectedValue))
        cm.Parameters.AddWithValue("@First_Weight", Val(txtFWeight.Text))
        If Val(txtSWeight.Text) > 0 Then cm.Parameters.AddWithValue("@Second_Weight", Val(txtSWeight.Text)) Else cm.Parameters.AddWithValue("@Second_Weight", DBNull.Value)
        If Val(txtNetWeight.Text) > 0 Then cm.Parameters.AddWithValue("@Net_Weight", Val(txtNetWeight.Text)) Else cm.Parameters.AddWithValue("@Net_Weight", DBNull.Value)
        If txtUnitPrice.Visible = True Then cm.Parameters.AddWithValue("@Unit_Price", Val(txtUnitPrice.Text)) Else cm.Parameters.AddWithValue("@Unit_Price", DBNull.Value)
        If txtAddition.Visible = True Then cm.Parameters.AddWithValue("@Add_Charges", Val(txtAddition.Text)) Else cm.Parameters.AddWithValue("@Add_Charges", DBNull.Value)
        If txtDeduction.Visible = True Then cm.Parameters.AddWithValue("@Deduction", Val(txtDeduction.Text)) Else cm.Parameters.AddWithValue("@Deduction", DBNull.Value)
        If txtTktPrice.Visible = True Then cm.Parameters.AddWithValue("@Ticket_Amount", Val(txtTktPrice.Text)) Else cm.Parameters.AddWithValue("@Ticket_Amount", DBNull.Value)
        If cboSource.Visible = True Then cm.Parameters.AddWithValue("@Source", cboSource.Text) Else cm.Parameters.AddWithValue("@Source", DBNull.Value)
        If cboDestination.Visible = True Then cm.Parameters.AddWithValue("@Destination", cboDestination.Text) Else cm.Parameters.AddWithValue("@Destination", DBNull.Value)
        cm.Parameters.AddWithValue("@Operator", txtOperator.Text)
        cm.Parameters.AddWithValue("@Out_Time", Now)
        cm.Parameters.AddWithValue("@In_Time", Now)
        cm.Parameters.AddWithValue("@PC", Soft_Parameters.QS_ClientPC)


        lblQS_Code.Text = Convert.ToInt32(cm.ExecuteScalar.ToString())

    Catch ex As Exception
            txtError.Text = ex.Message
    Finally
        If Not con.State = ConnectionState.Closed Then con.Close()
             con.Close()
        'if this save is not firstweight edit then it will save new ticket no and generate new ticket
        If TicketFirstweightEdit = False Then
            '  SaveTicketNumber()
            loadTicketNumber()
        Else
            TicketFirstweightEdit = False
        End If

        'after saving this will clear fields automatically
        MsgBox("Data has been Updated Successfully!", MsgBoxStyle.OkOnly, "Data Updated!!")

    End Try

忘记我传递的字符串部分

DECLARE @tbl_ID TABLE (nID int) 
UPDATE tbl_Tickets 
        SET  Ticket_Type = @Ticket_Type, VehicleNo= @VehicleNo,
        Customer=@Customer, Job_Code=@Job_Code, Material=@Material,
        First_Weight=@First_Weight, Second_Weight=@Second_Weight, Net_Weight=@Net_Weight, 
        Add_Charges=@Add_Charges, Deduction=@Deduction, Ticket_Amount=@Ticket_Amount, 
        Source=@Source, Destination=@Destination, Operator=@Operator, Out_Time=@Out_Time, PC=@PC, Unit_Price=@Unit_Price

         OUTPUT INSERTED.QS_Code INTO @tbl_ID (nID)  WHERE (VehicleNo=@VehicleNo) AND (Second_Weight IS NULL) AND  (Ticket_Type <>'DELETED')

IF @@ROWCOUNT=0  
    BEGIN 
       INSERT INTO tbl_Tickets (Ticket_Type, TicketNo, VehicleNo, nDate, Customer,Job_Code,Material, 
          First_Weight, Second_Weight, Net_Weight, Unit_Price, Add_Charges, Deduction, Ticket_Amount,Source, 
          Destination, Operator, In_Time, PC) 
       VALUES (@Ticket_Type, @TicketNo, @VehicleNo, @nDate, @Customer,@Job_Code,@Material, 
          @First_Weight, @Second_Weight, @Net_Weight, @Unit_Price, @Add_Charges, @Deduction, @Ticket_Amount,@Source, 
          @Destination, @Operator, @In_Time, @PC)

       SELECT IDENT_CURRENT('tbl_Tickets') FROM tbl_Tickets 
       UPDATE tbl_TicketNumber 
             SET TicketNo = @TTicket, PC= @TPC, nDate= @TnDate
             WHERE (PC=@TPC) 
       IF @@ROWCOUNT=0 
           BEGIN 
              INSERT INTO tbl_TicketNumber (TicketNo, PC, nDate) VALUES (@TTicket,@TPC,@TnDate) 
           END  
    END 
SELECT * From @tbl_ID

Answer 1

将loadTicket sub更改为

Sub loadTicketNumber()

    Dim connetionString As String
    Dim sqlCnn As SqlClient.SqlConnection
    Dim sqlCmd As SqlClient.SqlCommand
    Dim sql As String

    connetionString = My.Settings.DBServer
    sql = String.Format("Select ISNULL(MAX(TicketNo), 0) TicketNo FROM tbl_TicketNumber WHERE PC= '{0}'", Soft_Parameters.QS_ClientPC)

    Using sqlCnn SqlClient.SqlConnection = New SqlClient.SqlConnection(connetionString)
        Try
            sqlCnn.Open()
            Using SqlClient.SqlCommand sqlCmd = New SqlClient.SqlCommand(sql, sqlCnn)
                Dim x As Integer
                x = Convert.ToInt32(sqlCmd.ExecuteScalar());
            End Using
            txtTicket.Text = x + 1
            txt_ReTicketNo.Text = x
        Catch ex As Exception
            MsgBox("Can not open connection ! ")
        End Try
    End Using
End Sub

这不仅运行得更快，而且还会正确处理对象，因为你的try中没有finally，如果有问题，你就不会丢弃connection或command。

但我无法看到为什么会创建重复的TicketNo。但代码很难阅读。我建议你更好地格式化它。 为什么在SELECT IDENT_CURRENT('tbl_Tickets') FROM tbl_Tickets之后运行Insert？因为它似乎没有任何用途？