Retrieving data is probably the most important function of any development effort, and apart from many third party tools, Microsoft have released a couple of innovations related to representing and querying data with .NET 3.5 Service Pack 1.  The developer, now more than ever, has a myriad of ways to communicate with a database.  This post delves into these new technologies.

With the release of Visual Studio 2008 SP1 and the .NET Framework 3.5 SP1 many new data access features were added to ADO.NET 2.0 and there are now substantially more new data-related technologies and components than delivered by any .NET Framework and Visual Studio version since 1.0.

These changes have a common set of goals for the developer.  Foremost reducing the amount of code required to perform data related tasks and to reduce or eliminate what’s often called the impedance mismatch between the code for managing data, which usually involves Structured Query Language (SQL), and object- oriented (OO) programming.

What are these technologies, how do they relate to one another?

The first is the new Entity Data Model exposed as part of the ADO.NET Entity Framework.  The Entity Framework and its related designers, wizards and tools abstracts the relational (logical) schema of the data that is stored in a database and presents its conceptual schema which supports an upper layer of custom business objects, which can represent a domain model.

Furthermore a set of extensions were added to the .NET Framework for integrating queries into the programming language known as LINQ.  Language Integrated Query (LINQ) extensions were added to the Visual Basic 9.0 and C# 3.0 languages and compilers provide developers with a set of standard query operators to query a variety of data sources with a standard query language similar to SQL. LINQ extensions to VB and C# are said to implement the LINQ pattern.

ADO.NET Data Services Framework (formerly Project Astoria) enables developers to make data available as a simple Representational State Transfer (REST) Web service with Atom Publication (AtomPub or APP) format or JavaScript Object Notation (JSON) as the wire format.  EF is Astoria’s preferred data source; LINQ to SQL or other LINQ-enabled data sources create read-only Astoria services.

ASP.NET Dynamic Data (DD) is a framework for auto generating complete data-intensive Web sites from a LINQ to SQL or LINQ to Entities data source.  DD is a highly enhanced version of an earlier project named BLINQ.  DD can create an administrative Web site for a complex database in a few minutes by a process known as scaffolding.

What bodes for the future of Data Access?  Microsoft envisions an Entity Data Platform that enables customers to define a common Entity Data Model across data services and applications. The Entity Data Platform is a multi-release vision, with future versions of reporting tools, replication, data definition and security all being built around a common Entity Data Model.

With version 4.0 of the .NET Framework waiting in the wings it will be interesting to see how Microsoft moves towards its Data Access Strategy.