在Linq to Sql中管理并发更新时的冲突（3）：使用记录的时间戳进行检测

那么，我们一直说出现了“并发更新冲突”，那么发生冲突后又会出现什么问题呢？我们来看一个略有些复杂的示例：

try
{
 LinqToSqlDemoDataContext dataContext = new LinqToSqlDemoDataContext();

    Order order1 = dataContext.Orders.Single(o => o.OrderID == 1);
    Order order2 = dataContext.Orders.Single(o => o.OrderID == 2);
    Order order3 = dataContext.Orders.Single(o => o.OrderID == 3);

    Console.WriteLine("Order 1:" + order1.Introduction);
    Console.WriteLine("Order 2:" + order2.Introduction);
    Console.WriteLine("Order 3:" + order3.Introduction);
    Console.WriteLine();

    order1.Introduction = "Order 1 modified.";
    order2.Introduction = "Order 2 modified.";
    order3.Introduction = "Order 3 modified.";

    dataContext.Log = Console.Out;
    // 在下面的语句上设置一个断点
    dataContext.SubmitChanges();
}
catch (ChangeConflictException e)
{
    Console.WriteLine("---------- ' + e.Message + ' ----------");
}

LinqToSqlDemoDataContext db = new LinqToSqlDemoDataContext();
Order o1 = db.Orders.Single(o => o.OrderID == 1);
Order o2 = db.Orders.Single(o => o.OrderID == 2);
Order o3 = db.Orders.Single(o => o.OrderID == 3);

Console.WriteLine("Order 1: " + o1.Introduction);
Console.WriteLine("Order 2:" + o2.Introduction);
Console.WriteLine("Order 3:" + o3.Introduction);

Console.ReadLine();

假设我们的数据表里有以下三条记录：