.NET数据访问策略：From "LINQ to SQL" to "LINQ to X"

ScottGu的LINQ to SQL系列blog让人耳目 一新。随然此.NET 3.5中的数据访问技术仅针对SQL Server，但显然是.NET数据访问技术的升级的序幕。

紧接着ASP.NET 3.5 Extension 中出现了Entity Framework，LINQ to Entities 来了，数据访问技术的升级将从SQL不断扩展到其他数据源平台。

.NET数据访问策略值得一看：
http://blogs.msdn.com/data/archive/2007/04/28/microsoft-s-data-access-strategy.aspx

LINQ will ship as part of the next version of Visual Studio and the .NET Framework, codenamed Orcas.  At the time that Orcas first ships, the .NET Framework will include support for LINQ over in-memory objects, LINQ over XML (XLINQ), LINQ over ADO.NET DataSets (LINQ to DataSet), and LINQ queries directly mapped to Microsoft SQL Server schemas (LINQ to SQL).

LINQ to SQL 与LINQ to Entities的区别？

LINQ to SQL supports rapid development of applications that query Microsoft SQL Server databases using objects that map directly to SQL Server schemas.  LINQ to Entities supports more flexible mapping of objects to Microsoft SQL Server and other relational databases through extended ADO.NET Data Providers.

If you are writing an application that requires any of the following features, you should use the ADO.NET Entity Framework:

·         The ability to define more flexible mapping to existing relational schema, for example:

o   Mapping a single class to multiple tables

o   Mapping to different types of inheritance

o   Directly Modeling Many to Many relationships

o   Mapping to an arbitrary query against the store

·         The ability to query relational stores other than the Microsoft SQL Server family of products.

·         The ability to share a model across Replication, Reporting Services, BI, Integration Services, etc.

·         A full textual query language

·         The ability to query a conceptual model without materializing results as objects