Professional Visual Basic 2012 and .NET 4.5 Programming

Entity Framework Architecture

Figure 10.1 shows the architecture used within the Entity Framework. As you can see from the diagram, the Entity Framework is composed of a number of logical layers. The lowest layer is related to the actual data access, and involves the familiar ADO.NET data providers. The Entity Framework is not an entirely new method of retrieving data, but is an extension of your existing knowledge of ADO.NET. The additional layers are intended to make your development experience easier and more flexible. At the data layer, Entity Framework does not differ from ADO.NET or LINQ to SQL, as it deals with the tables directly.

Figure 10.1 Entity Framework Layer Diagram

Above the actual data access layer is the storage layer. This is basically a representation of the structure of the database, using XML syntax. It includes any of the tables you've added to your model, as well as the relationships between them.

Above the storage layer is the mapping layer. This serves as a means of translating between the storage layer below and the conceptual layer above. You can think of it as a relatively thin layer, responsible for mapping the fields of the database tables to the appropriate properties of the classes used by your application.Next is the conceptual layer. This is the layer that provides the entities of your model, providing you with the classes you will work with ...