Question

我使用asp.net表单，我有一个select查询并插入查询但是如果我得到select错误消息; ＆＃34;条形码无效＆＃34 ;;它仍然插入数据库。我不确定如何合并一切;当用户收到错误消息时;不应该插入它，但如果成功则会给它们一个成功的消息。

if (barcode.StartsWith("B"))
        {
            string Data = " select boxLocation from Box where boxNo= " + barcode.TrimStart('B') + "";
            cmd = new SqlCommand(Data, conn);
            dr = cmd.ExecuteReader();

            if (dr.Read())
            {

            lblResult.Text = dr[0].ToString();

        }
        else
        {
            lblError.Text = barcode + " does not exist!!";

        }
    }
if (barcode.StartsWith("B"))
    {
        command.CommandText = "insert into Crate_Box (crate_box_no,Current_Location,Previous_Location, Username,Date,status,codeType)values (@crate_box_no,@Current_Location,@Previous_Location, @Username,@Date,@status,@codeType) ";

        command.Parameters.Add("@crate_box_no", SqlDbType.NVarChar).Value = barcode.TrimStart('B');
        command.Parameters.Add("@Current_Location", SqlDbType.NVarChar).Value = location;
        command.Parameters.Add("@Previous_Location", SqlDbType.NVarChar).Value = lblResult.Text;
        command.Parameters.Add("@Username", SqlDbType.NVarChar).Value = user;
        command.Parameters.Add("@Date", SqlDbType.NVarChar).Value = date;
        command.Parameters.Add("@status", SqlDbType.NVarChar).Value = actType;
        command.Parameters.Add("@codeType", SqlDbType.NVarChar).Value = "Box";
    }

Answer 1

尝试以下结构：

    if (barcode.StartsWith("B"))
    {
        try
        {
            // SELECT operation
            // INSERT operation
        }
        catch
        {
            lblError.Text = barcode + " does not exist!!";
        }
        finally
        {
            // Close DB connections and readers
        }
    }

选择并插入查询asp.net

1 个答案: