需要帮助理解Nhibernate事务和如何不重复代码（如果可能） [英] Need help understanding Nhibernate Transactions and how not to duplicate code (if possible)

问题描述

我了解您应该始终使用交易。我也看到NHibernate.ITransaction实现Dispose，所以我需要包装我的ITransaction对象在using语句。所以，这是否意味着对于每个非只读存储库方法（即更新，编辑...）我必须声明：

I understand that you should always use transactions. I also see that NHibernate.ITransaction implement a Dispose, so I need to wrap my ITransaction object in a using statement. So, does that mean that for every non-readonly repository method (i.e. update, edit...) I have to declare:

using (ITransaction _transaction = _session.BeginTransaction(//isolationlevel)) {
  //procedure code here
}

有一种方式，我可以包装这（我不看到我可以）。

Is there a way that I can wrap this (I am not seeing that I can).

此外，

using (_transaction = _session.BeginTransaction(IsolationLevel.ReadCommitted) {
  try {
    _session.SaveOrUpdate(entity);
      try {
        _transaction.Commit();
      catch (//some exception ex) {
        _transaction.RollBack();
      }
  }
  catch (//some exception ex) {
    //log ex
  }
}

还是有一个更好的方法，如在会话和事务方法相同的尝试/捕获？

Or is there a better way such as having both session and transaction methods in the same try/catch?

感谢，

推荐答案

当使用ISession直接是这样的：（你应该使用一个事务，即使是读取）

The recommended practice when using the ISession directly is this: (you should use a transaction even for reads)

using(var session = factory.OpenSession())
using(var tx = session.BeginTransaction())
{
    // all the code that uses the session goes here
    // use session to load and/or save entity
}

这基本上是创建一个工作单元。

This is basically creating an unit of work.

根据您的操作上下文（Web请求，wcf请求），您可能希望将所有操作都包含在单个工作单元内。有关网络请求，请参阅此 WCF操作。 this 。

Depending on your operation context ( web request, wcf request ) you might want to have all the operation inside a single unit of work. For web request see this for WCF operation see this.

还有Sixto Saez说调用SaveOrUpdate是一种气味。在大多数情况下，您有以下两种情况之一：

Also as Sixto Saez said calling SaveOrUpdate is a smell. In most of the cases you have one of these two cases:

1您创建一个新实体并调用session.Save（entity）;

1 You create a new entity and call session.Save(entity);

或

2从会话中获取一个或多个实体（使用Get / Load或通过查询），修改实体和更改将被nhibernate保存在会话处理上。 （除非你改变了会话刷新模式，但这不是重点）。

2 You get an entity or more from the session ( with Get/Load or by query ), modify the entity and the changes will be saved by nhibernate on session disposal. ( unless you change the session flush mode but that is not the point ).

这篇关于需要帮助理解Nhibernate事务和如何不重复代码（如果可能）的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！