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(EF) là của Microsoft Object Relational Mapping (ORM), giải pháp và lần đầu tiên được phát hành với NET 3.5SP1 Entity Framework nhận được nhiều lời chỉ trích khi nó được phát hành đầu tiên và đội bóng của Microsoft đã được cứng tại nơi làm việc đến địa chỉ một số trong những phê phán trong phiên bản mới nhất. | CHAPTER 8 Entity Framework Entity Framework EF is Microsoft s Object Relational Mapping ORM solution and was first released with .NET 3.5SP1. Entity Framework received much criticism when it was first released and the team at Microsoft has been hard at work to address some of these criticisms in the latest version. WARNING This chapter is written using a preview version of EF4 so final functionality may differ. It is also worth noting that EF is likely to have releases out of band. For the examples in this chapter you will need to install the EF CTP 2. EF and LINQ to SQL Some developers are understandably confused by the overlap between EF and LINQ to SQL. EF and LINQ to SQL were developed by two different teams hence the overlap. LINQ to sQl is a great piece of technology and very suitable as a simple light-weight wrapper to SQL. It is pretty clear however that Microsoft is pushing developers to use EF. This is a sensible although no doubt irritating move as LINQ to SQL is fundamentally flawed as a generic ORM solution in that It only works with SQL Server. Generated classes must have a 1 to 1 relationship with database objects. EF provides an abstraction above the database layer and a number of enhancements that make it superior to LINQ to SQL. Is LINQ to SQL Dead Er probably not. In October 2008 Microsoft s Tim Mallalieu Program Manager LINQ to SQL and LINQ to Entities stated We re making significant investments in the Entity Framework such that as of .NET 4.0 the Entity Framework will be our recommended data access solution for LINQ to relational scenarios. http blogs.msdn.com adonet archive 2008 10 29 update-on-linq-to-sql-and-linq-to-entities-roadmap.aspx 175 CHAPTER 8 ENTITY FRAMEWORK However after feedback from a large number of LINQ to SQL customers Microsoft seemed to back off on this a bit when Tim said We will continue make some investments in LINQ to SQL based on customer feedback. This post was about making our intentions for future innovation clear .