ADO.NET Entity Framework

作为下一代 ADO.NET 3.0 的开发框架，Entity Framework 让我们从复杂的关系数据模型中解脱出来，使用更加符合面向对象的实体数据模型(Entity Data Model)来完成业务设计和开发。
Entity Framework 很像 NHibernate，同样采取 XML 进行映射。不过借助于强大的可视化设计工具和向导，我们可以非常方便地完成这些头疼的工作。 Entity Framework  对 Linq 的直接支持 —— LINQ to Entities
Entity Framework Features:

1. Entity Designer

• Generate a model from a database (via wizard) and display it on the designer surface
• Edit conceptual model properties (namespace, alias, etc.)
• Control visual aspects of the design surface (layout) and persist changes
• Add, Delete, and Edit Entities; Scalar properties; Associations; and Inheritance
• Automatic set management
• Automatic Navigation property management
• Error reporting
• Validate model and mappings using Entity Framework Runtime

2. Entity Mapping

• View the mapping for a C-Side Entity or Association
• Rename or delete C-Side objects without worrying about mapping
• Map an EntityType to multiple tables
• Apply multiple conditions to a table mapping
• Map associations
• Automatic generation of conditions and referential constraints on associations
• TPH: Map an Entity hierarchy to a single table
• TPT: Map an Entity hierarchy to multiple tables

3. Entity Model Browser

• Understand and visualize the model in a tree hierarchy
• Visually relate shapes on the designer surface with hierarchy in model

4. Visual Studio Integration

• Support for C# and VB in multiple project types: ASP.NET Web site, ASP.NET Web Application Project, Console, WinForms, and Library
• Project system integration: item template for .edmx file, model generation wizard, EdmxDeploy.exe, and Entity Framework validation on build
• Support for multiple Visual Studio editions: Express, Standard, Pro, and VSTS.

ADO.NET team blog