实体框架+知识库+单位或工作问题 [英] entity framework + repository + unit or work question

问题描述

我正在考虑使用EF 4开始一个新项目，并浏览了一些文章，我找到了一篇有关EF的文章，其中包含存储库模式和工作单元（ http：// blogs。 msdn.com/b/adonet/archive/2009/06/16/using-repository-and-unit-of-work-patterns-with-entity-framework-4-0.aspx ）

I'm thinking about starting a new project using EF 4 and going through some articles, I found an article about EF with repository pattern and unit of work (http://blogs.msdn.com/b/adonet/archive/2009/06/16/using-repository-and-unit-of-work-patterns-with-entity-framework-4-0.aspx)

看那篇文章，它使用ObjectContext作为UnitOfWork，并将其传递到存储库。

Looking at that article, it uses the ObjectContext as the UnitOfWork and it passes it to the Repository.

我的问题是，如果我有2个ObjectContext，这意味着我将有2个工作单元，但实际上我希望在这2个上下文中执行的所有操作都成为一个工作单位，这种情况可能吗？我不想在每个上下文上调用save，我希望它是事务性的....而不使用transactionscope ...

My question is what if I have 2 ObjectContext which mean I will have 2 unit of work, but I actually wants all the operation perform on those 2 context to be one single unit of work, is this scenario possible? I don't want to call save on each context, I'd like it to be transactional .... without using transactionscope ...

例如，我有一个用于管理操作日志的上下文，另一个用于管理订单的上下文。可以说在我的业务层中，有一个名为AddOrder（）的方法。 AddOrder（）将使用订单上下文创建新订单，但还将使用操作日志上下文创建新的操作日志条目。由于这些是2个上下文，因此我必须在两个上下文上都调用save以提交....也许唯一的选择是只具有一个单独的上下文...。

For example, I have a context that manages Operation Log and another context that manages Orders. Lets say In my business layer, I have a method called AddOrder(). AddOrder() will use the order context to create a new order, but it will also use the operation log context to create a new operation log entry. Since those are 2 context, I'll have to call save on both context to commit .... maybe the only option is to have only one single context ....

编辑：我的意思是2个不同类型的上下文，例如：OperationalLogContext和OrderContext。

I meant 2 context of different types for example: OperationalLogContext and OrderContext.

推荐答案

是的-我相信这是可能的。

Yep - i believe it's possible.

最重要的是如何处理您的存储库。

The kicker is how handle your Repositories.

例如，每个存储库都应使用Context ..因此只需创建一个上下文并将其传递到每个存储库即可。

For example, each Repository should take a Context .. so just create one context and pass it to each repository.

（请输入代码！）很高兴你问：）

(code please!) Glad u asked :)

public interface IOrderRepository
{
    IQueryable<Order> FindAll();
}

public interface IOperationLogRepository
{
    IQueryable<OperationLog> FindAll();
}

public interface IUnitOfWork
{
    void Commit();
}

。

public class SqlServerContext : ObjectContext, IUnitOfWork
{
    public void SqlServerContext(string connectionString) 
        : base(connectionString)
    {
    }

    public void Commit()
    {
        this.SaveChanges();
    }

    // Your other POCO's and stuff here ..etc..
}

。

public class OrderRepostiory : IOrderRepository
{
    private readonly SqlServerContext _sqlServerContext;
    public void OrderRepostiory(SqlServerContext sqlServerContext)
    {
        _sqlServerContext = sqlServerContext;
    }

    public IQueryable<Order> FindAll()
    {
        _sqlServerContext.Orders;
    }
}

..最后是实例化。造成您的好男孩/女孩/彩虹独角兽，您将使用依赖注入..

.. and finally, instantiation. Cause your a good boy/girl/rainbow unicorn, you would be using Dependency Injection ..

public class SqlServerRegistry : Registry
{
    public SqlServerRegistry(string connectionString)
    {
        For<SqlServerContext>()
            .HybridHttpOrThreadLocalScoped()
            .Use<SqlServerContext>()
            .Ctor<string>("connectionString")
                .Is(connectionString);

        For<IOrderRepository>().Use<OrderRepository>();
        For<IOperationLogRepository>().Use<OperationLogRepository>();
    }
}

，由于SqlServerContext被定义为HttpOrThreadLocal，它将可以一次实例化并在多个存储库中 reused 。

and because the SqlServerContext is defined as HttpOrThreadLocal, it will be instantied ONCE and reused in multiple Repositories.

不知道或不了解DI / IoC吗？

Don't know or understand DI/IoC ?

然后这也将起作用。...

then this would also work....

private SqlServerContext _sqlServerContext;
private IOrderRepository _orderRepository;
private IOperationLogRepository _operationLogRepository;

[TestInitialize]
public void TestInitialise()
{
    _sqlServerContext = new SqlServerContext(
             ConfigurationManager.AppSettings["connectionString"]);
    _orderRepository = new OrderRepository(_sqlServerContext);
    _operationLogRepository= new OperationLogRepository(_sqlServerContext);
}

[TestMethod]
public void SomeTest()
{
    // Arrange.
    const int count = 10;

    // Act.
    var orders = _orderRepository.FindAll().Take(10).ToArray();

    // Assert.
    Assert.IsNotNull(orders);
    CollectionAssert.AllItemsAreNotNull(orders);
    Assert.AreEqual(count, orders.Length);
}

一次，这就是我刚刚输入的所有未经测试的代码正在考虑回答这个问题。

once more, that's all untested code which i just typed up, as I was thinking about answering this question.

HTH。

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