ADO.NET

ADO.NET provides consistent access to data sources such as Microsoft SQL Server and XML, as well
as to data sources exposed through OLE DB and ODBC. Learn more about the new and enhanced features available in ADO.NET 2.0.

A primary goal of the ADO.NET Entity Framework is to raise the level of abstraction available for data programming, thus simplifying the development of data aware applications and enabling developers to write less code. ADO.NET 3.5 will be released in two parts, both of which contain significant innovations. The first will release with Visual Studio Orcas and the second will release the ADO.NET Entity Framework in the first half of 2008.

Microsoft Language Integrated Query (LINQ) offers developers a new way to query data using strongly-typed queries and strongly-typed results, common across a number of disparate data types including relational databases, .NET objects, and XML. By using strongly-typed queries and results, LINQ improves developer productivity with the benefits of IntelliSense and compile-time error checking.

LINQ to SQL is an object-relational mapping (ORM) framework that allows the direct 1-1 mapping of a Microsoft SQL Server database to .NET classes, and query of the resulting objects using LINQ. More specifically, LINQ to SQL has been developed to target a rapid development scenario against Microsoft SQL Server where the database closely resembles the application object model and the primary concern is increased developer productivity.

LINQ to Entities is, specifically, a part of the ADO.NET Entity Framework which allows LINQ query capabilities. The Entity Framework is the evolution of ADO.NET that allows developers to program in terms of the standard ADO.NET abstraction or in terms of persistent objects (ORM) and is built upon the standard ADO.NET Provider model which allows access to third party databases. The Entity Framework introduces a new set of services around the Entity Data Model (EDM) (a medium for defining domain models for an application).

LINQ is a way to make queries and set based operations first class citizens in the .NET world. It allows queries to be written in the development language, and provides compile time type checking. In addition, LINQ allows for the full power of the framework to be utilized when writing queries. LINQ to DataSets brings this power to your DataSet based application.

The ADO.NET Data Services framework consists of a combination of patterns and libraries that enable the creation and consumption of data services for the web. The goal of the ADO.Net Data Services framework is to facilitate the creation of flexible data services that are naturally integrated with the web, using URIs to point to pieces of data and simple, well-known formats to represent that data, such as JSON and plain XML. This results in the data service being surfaced to the web as a REST-style resource collection that is addressable with URIs and that agents can interact with using the usual HTTP verbs such as GET, POST or DELETE.