.NET中 关于脏读 不可重复读与幻读的代码示例

并发可能产生的三种问题

脏读

定义：A事务执行过程中B事务读取了A事务的修改，但是A事务并没有结束（提交），A事务后来可能成功也可能失败。

比喻：A修改了源代码并且并没有提交到源代码系统，A直接通过QQ将代码发给了B，A后来取消了修改。

代码示例
代码如下:
[TestMethod]
         public void 脏读_测试()
         {
             //前置条件
             using (var context = new TestEntities())
             {
                 Assert.AreEqual(1, context.Tables.Count());
             }

             var autoResetEvent = new AutoResetEvent(false);

             var transactionOptions1 = new TransactionOptions { IsolationLevel = IsolationLevel.ReadCommitted };
             var transactionOptions2 = new TransactionOptions { IsolationLevel = IsolationLevel.ReadUncommitted };

             using (var ts1 = new TransactionScope(TransactionScopeOption.Required, transactionOptions1))
             {
                 //添加数据
                 using (var context = new TestEntities())
                 {
                     context.Tables.Add(new Table() { Id = Guid.NewGuid(), Name = "段光伟" });
                     context.SaveChanges();
                 }

                 ThreadPool.QueueUserWorkItem(data =>
                 {
                     using (var ts2 = new TransactionScope(TransactionScopeOption.Required, transactionOptions2))
                     {