Most applications are currently written on top of relational databases. At some point, these applications will have to interact with the data represented in a relational form. Database schemas are not always ideal for building applications, and the conceptual models of applications differ from the logical models of databases. The Entity Data Model (EDM) is a conceptual data model that can be used to model the data of a particular domain so that applications can inthttp://www.cnblogs.com/Chinese-xu/archive/2007/09/21/900876.htmleract with data as entities or objects. For more information, see Entity Data Model.
许多应用程序经常基于一个关系型数据库来编写。在有些时候，这些应用程序将不得不和以关系方式提供的数据相比配。在编写应用程序时，数据架构通常不是一下子就很理想的，并且应用程序的概念模型和数据库的逻辑逻辑模型是不一致的。实体数据模型(EDM)是一种概念数据模型，能被用来对特定的领域进行数据建模。因此应用程序能和作为实体或对向的数据相匹配。更多信息请参考实体数据模型。
Through the EDM, ADO.NET exposes entities as objects in the .NET environment. This makes the object layer an ideal target for Language-Integrated Query (LINQ) support. Therefore, LINQ to ADO.NET includes LINQ to Entities. LINQ to Entities enables developers to write queries against the database from the same language used to build the business logic. The following diagram shows the relationship between LINQ to Entities and the Entity Framework, ADO.NET 2.0, and the data store.
通过使用EDM，ADO.NET在 .net 环境中以对象的方式公开实体。这使得对象层成为集成语言查询(LINQ)的一个理想的操作目标。因此，ADO.net-LINQ 包括了实体LINQ。实体LINQ支持开发人员使用和编写业务逻辑相同的语言来编写基于数据库的查询。下图展示了实体LINQ、实体框架、ADO.NET 2.0以及数据库之间的关系
For LINQ to Entities sample applications, see Data Access and Storage. For information about late breaking changes in the ADO.NET Entity Framework and LINQ to Entities, see the ADO.NET team blog.