blocks|key|195948|text|DbContext是ObjectContext类的轻量级版本，它几乎就放在ObjectContext之上(甚至有一种方法可以仅从DbContext访问ObjectContext+)。它也更容易使用，IMO，并且使CRUD操作变得非常简单。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|195949|对于更好的信息，有谁比Julie+Lerman更好地了解更多关于差异的信息，就像EF+4.1中引入的那样。|offset|length|195950|entityMap|0|LINK|mutability|MUTABLE|url|http://thedatafarm.com/data-access/accessing-objectcontext-features-from-ef-4-1-dbcontext/^0|0|B|C|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@$D|P|E|Q|1|R]]|A|$]]|$1|F|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|G|$H|$5|I|J|K|A|$L|M]]]]

DbContext is a lightweight version of the ObjectContext class, which is laid almost right on top of ObjectContext (there is even a way to get to the ObjectContext from just the DbContext). It's also a lot easier to use, IMO, and makes CRUD operations a sinch.

For better information, who better to look to than <a href="http://thedatafarm.com/data-access/accessing-objectcontext-features-from-ef-4-1-dbcontext/">Julie Lerman</a> for more info on the differences, as was brought into EF 4.1.

blocks|key|197803|text|DbContext是一个较小的应用程序接口，它公开了ObjectContext最常用的功能。在某些情况下，这些功能会被镜像到DbContext应用编程接口中。在其他情况下，实体框架团队通过为我们提供像Find这样的方法或像DbSet.Local这样的属性，简化了更复杂的编码。但是有一个很大的API潜伏在下面，你可能仍然需要访问它。例如，您可能希望直接使用MetadataWorkspace针对类编写泛型代码，因为该API可以比反射更有效地读取模型。此外，MetadataWorkspace能够提供有关元数据的更多信息，而不是使用反射发现的信息，例如关键属性。或者，您可能希望利用通过实体SQL公开的特定于数据库的函数，而不能从LINQ访问实体。或者，您可能已经有一个使用ObjectContext编写的应用程序，并且希望在将来的更新中利用DbContext，而不替换所有的ObjectContext代码。(参考DbContext编程)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|197804|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

the DbContext is a smaller API exposing the most commonly used
features of the ObjectContext. In some cases, those features are mirrored in the DbContext
API. In other cases, the Entity Framework team has simplified more complex coding
by providing us with methods like Find or properties like DbSet.Local. But there’s
a big API lurking underneath that you may still need access to. For example, you might
want to work directly with the MetadataWorkspace to write generic code against classes
because that API can read the model more efficiently than reflection. Additionally, the
MetadataWorkspace is able to provide more information about the metadata than you
can discover with reflection, for example, for Key properties. Or you might want to
take advantage of a database-specific function that is exposed through Entity SQL,
which you can’t access from LINQ to Entities.
Or you may already have an application
written using the ObjectContext and you want to leverage the DbContext in future updates
without replacing all of the ObjectContext code.(Reference from Programming DbContext)

blocks|key|2826582|text|对象上下文：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2826583|1.支持编译查询2.支持实体自跟踪3.适用于实体框架4.0及以下版本4.它不是线程安全的。5.数据库优先和模型优先的方法是最好的。|2826584|数据库上下文：|2826585|1.不支持编译查询2.支持实体不自跟踪3.适用于实体框架4.1及以上版本4.对静态和共享成员(Public)是线程安全的5.数据库优先、模型优先和代码优先的方法是最好的。|2826586|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

<h2>Object Context:</h2>

1.It support compiled query
2.It support self tracking of entities
3.It available for entity frame work 4.0 and below version
4.It is not thread safe.
5.It is best for DB first and model first approach.

<h2>Database Context:</h2>

1.It does not support compiled query
2.It support not self tracking of entities
3.It available for entity frame work 4.1 and above version
4.It is thread safe for static and share member(public).
5.It is best for DB first and model first approach and code first approach.

From <code>MSDN</code>:

<blockquote>
 Represents a combination of the Unit-Of-Work and Repository patterns and enables you to query a database and group together changes that will then be written back to the store as a unit. <code>DbContext</code> is conceptually similar to <code>ObjectContext</code>.
</blockquote>

I though <code>DbContext</code> only handle the connection to the DB and the number of threads working against the DB. 

Now I understand it contains the tracking mechanism? I thought this was in the <code>ObjectContext</code>.

So what is (in plain English) the difference between them?

What's the difference between DbContext and ObjectContext

数据库

来自MSDN表示工作单元模式和存储库模式的组合，使您能够查询数据库并将更改组合在一起，然后将这些更改作为一个单元写回存储。DbContext在概念上类似于ObjectContext。我认为DbContext只处理到数据库的连接和针对数据库工作的线程数量。现在我知道它有追踪机制了？我以为这是在ObjectContext里...

问DbContext和ObjectContext有什么不同
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