嵌套事务范围，必需 -> 禁止 -> 必需

Question

内部 TransactionScope 将哪个事务作为环境事务？

using ( var t1 = new TransactionScope( TransactionScopeOption.Required ) )
{
    //MyStuff

    using ( var t2 = new TransactionScope( TransactionScopeOption.Suppress) )
    {
        //MyStuff

        using ( var t3 = new TransactionScope( TransactionScopeOption.Required) )
        {
            //Mystuff

            t3.Complete();
        }

        t2.Complete();
    }

    t1.Complete();
}

Answer 1

t3。那里没有其他选择，因为 t2 的范围是抑制 t1，而不是创建它自己的环境。因此在最里面的范围内只有 t3 而没有别的。

如果 t2 是 RequireNew，那么最内层的作用域环境就是 t2，因为 t3 会加入 t2。

Answer 2

记住：被抑制的 TransactionScope 不需要“完成”

没有交易。

例如，您可以在此处执行此操作：

    static void TestMethod()
    {
        using (Model1 ctx = new Model1())
        {
            Console.WriteLine("Count = {0}", ctx.Test.Count());
            Console.WriteLine("Has Value 'Test1' = {0}", ctx.Test.Count(x => x.Value == "Test1"));
            Console.WriteLine("Has Value 'Test2' = {0}", ctx.Test.Count(x => x.Value == "Test2"));
        }

        using (Transactions.TransactionScope scope = new Transactions.TransactionScope())
        {
            using (Model1 ctx = new Model1())
            {
                ctx.Test.Add(new Test { Value = "Test1" });

                Console.WriteLine("Add 'Test1'");
                Console.WriteLine("SaveChanges = {0}", ctx.SaveChanges());
            }

            using (Transactions.TransactionScope scope2 = new Transactions.TransactionScope(Transactions.TransactionScopeOption.Suppress))
            {
                using (Model1 ctx = new Model1())
                {
                    ctx.Test.Add(new Test { Value = "Test2" });

                    Console.WriteLine("Add 'Test2'");
                    Console.WriteLine("SaveChanges = {0}", ctx.SaveChanges());
                }
            }
        }

        using (Model1 ctx = new Model1())
        {
            Console.WriteLine("Count = {0}", ctx.Test.Count());
            Console.WriteLine("Has Value 'Test1' = {0}", ctx.Test.Count(x => x.Value == "Test1"));
            Console.WriteLine("Has Value 'Test2' = {0}", ctx.Test.Count(x => x.Value == "Test2"));
        }
    }

输出：

• 计数 = 1
• 值 'Test1' = 0
• 值 'Test2' = 0
• 添加“Test1”
• SaveChanges = 1
• 添加“Test2”
• SaveChanges = 1
• 计数 = 1
• 值 'Test1' = 0
• 值 'Test2' = 1

这意味着抑制范围内的每个查询都不能通过仅处置范围来回滚。

但如果你这样做：

    static void TestMethod()
    {
        using (Model1 ctx = new Model1())
        {
            Console.WriteLine("Count = {0}", ctx.Test.Count());
            Console.WriteLine("Has Value 'Test1' = {0}", ctx.Test.Count(x => x.Value == "Test1"));
            Console.WriteLine("Has Value 'Test2' = {0}", ctx.Test.Count(x => x.Value == "Test2"));
            Console.WriteLine("Has Value 'Test3' = {0}", ctx.Test.Count(x => x.Value == "Test3"));
        }

        using (Transactions.TransactionScope scope = new Transactions.TransactionScope())
        {
            using (Model1 ctx = new Model1())
            {
                ctx.Test.Add(new Test { Value = "Test1" });

                Console.WriteLine("Add 'Test1'");
                Console.WriteLine("SaveChanges = {0}", ctx.SaveChanges());
            }

            using (Transactions.TransactionScope scope2 = new Transactions.TransactionScope(Transactions.TransactionScopeOption.Suppress))
            {
                using (Model1 ctx = new Model1())
                {
                    ctx.Test.Add(new Test { Value = "Test2" });

                    Console.WriteLine("Add 'Test2'");
                    Console.WriteLine("SaveChanges = {0}", ctx.SaveChanges());
                }

                using (Transactions.TransactionScope scope3 = new Transactions.TransactionScope())
                {
                    using (Model1 ctx = new Model1())
                    {
                        ctx.Test.Add(new Test { Value = "Test3" });

                        Console.WriteLine("Add 'Test3'");
                        Console.WriteLine("SaveChanges = {0}", ctx.SaveChanges());
                    }

                    scope3.Complete();
                }
            }
        }

        using (Model1 ctx = new Model1())
        {
            Console.WriteLine("Count = {0}", ctx.Test.Count());
            Console.WriteLine("Has Value 'Test1' = {0}", ctx.Test.Count(x => x.Value == "Test1"));
            Console.WriteLine("Has Value 'Test2' = {0}", ctx.Test.Count(x => x.Value == "Test2"));
            Console.WriteLine("Has Value 'Test3' = {0}", ctx.Test.Count(x => x.Value == "Test3"));
        }
    }

输出：

• 计数 = 0
• 值 'Test1' = 0
• 值 'Test2' = 0
• 值 'Test3' = 0
• 添加“Test1”
• SaveChanges = 1
• 添加“Test2”
• SaveChanges = 1
• 添加“Test3”
• SaveChanges = 1
• 计数 = 2
• 值 'Test1' = 0
• 值 'Test2' = 1
• 值 'Test3' = 1

你可以看到：“scope”和“scope3”之间没有关系，因为“scope3”提交了它的变化。

“scope2”也提交其更改，因为“scope2”是一个被抑制的范围。