.net EF 事物 订单流水号的生成 (一)

首先需要 添加 System.Transactions 程序集

数据表：

create table SalesOrder
(
ID int identity(1,1) primary key not null,
OrderNo nvarchar(50) not null,
OrderDate datetime not null,
UserName nvarchar(50) not null
)

create table FlowNo
(
ID int identity(1,1) primary key not null,
OrderNo nvarchar(50) not null,
OrderType nvarchar(50) not null,
Remark nvarchar(50) not null
)
insert FlowNo values ('SM160309-00001','SM','销售订单')

控制台测试程序。

测试的时候 ，可以 输入 userName ，最大字符为50，可以测试 输入50个字符以上的用户名，会发现

  var tempModel = db.SalesOrder.FirstOrDefault();
                            if (tempModel != null)
                                tempModel.UserName = tempModel.UserName + orderNo.ToString().PadLeft(5, '0');
                            db.SaveChanges();
这段代码 没有 效果了。虽然是后面的代码报错，第一行的数据不会发生改变。

using System;
using System.Linq;
using System.Transactions;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                using (var tran = new TransactionScope())
                {
                    using (var db = new pengbgDBEntities())
                    {
                        var flowNo = db.FlowNo.FirstOrDefault(x => x.OrderType == "SM");
                        if (flowNo != null)
                        {
                            var orderNo = int.Parse(flowNo.OrderNo.Split('-')[]) + ;
                            string newOrderNo;
                            if (flowNo.OrderNo.Split('-')[] != "SM" + DateTime.Now.ToString("yyMMdd"))
                            {
                                newOrderNo = "SM" + DateTime.Now.ToString("yyMMdd-") + .ToString().PadLeft(, '');
                            }
                            else
                            {
                                newOrderNo = "SM" + DateTime.Now.ToString("yyMMdd-") +
                                             orderNo.ToString().PadLeft(, '');
                            }
                            var userName = Console.ReadLine();
                            var tempModel = db.SalesOrder.FirstOrDefault();
                            if (tempModel != null)
                                tempModel.UserName = tempModel.UserName + orderNo.ToString().PadLeft(, '');
                            db.SaveChanges();
                            db.SalesOrder.Add(new SalesOrder
                            {
                                OrderDate = DateTime.Now,
                                OrderNo = newOrderNo,
                                UserName = userName
                            });
                            db.SaveChanges();

                            flowNo.OrderNo = newOrderNo;
                            db.SaveChanges();
                        }
                    }
                    tran.Complete();
                    Console.WriteLine("操作成功");
                }
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception.Message);
            }
            finally
            {
                Console.WriteLine("按任意键继续");
                Console.ReadKey();
            }

        }
    }
}