Share via


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

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 to DataSet

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.

Technical Articles

Introducing LINQ to Relational Data

Learn more about using LINQ against a relational database with LINQ to SQL and LINQ to Entities. What are the key scenarios for which each of these technologies was designed?


Entity Framework for Database Administrators (Level 200)

The Entity Framework is a new data technology from Microsoft that may particularly interest database administrators (DBAs). Join this webcast to see how this technology can radically change the development of applications from a DBA perspective, and also change access patterns on servers. We discuss these changes and their impact on DBAs and data developers.

Framework Masterclass: LINQ to SQL (Level 200)

Microsoft .NET Language Integrated Query (LINQ) provides a common way to work with data in your applications. In this session, we dive into how LINQ provides methods to work with Structured Query Language (SQL) databases, including how to query, insert, and manage data using the LINQ framework.

Introducing LINQ to DataSet (Level 200)

Join this session as we explore how new technologies within Microsoft Visual Studio code name "Orcas" make working with data a better experience. One such technology is Microsoft .NET Language Integrated Query (LINQ), code name for a set of extensions to the Microsoft .NET Framework that encompass language-integrated data query, set, and transform operations. We explore how LINQ to DataSet enables you to take advantage of the power of LINQ in your DataSet-based applications. We also demonstrate how using LINQ to DataSet can help you improve the performance and reliability of your existing code and use this exciting new functionality.

Introduction to Microsoft .NET Language Integrated Query, Code-Named the "LINQ" Project (Level 200)

The Microsoft .NET Language Integrated Query, code-named the "LINQ" project, is a set of extensions to the Microsoft .NET Framework that encompass language-integrated query, set, and transform operations. LINQ extends Microsoft Visual C# and Visual Basic with native language syntax for queries and provides class libraries to take advantage of these capabilities. In this session, we cover some of the basics of LINQ and explore the key LINQ-related components, such as:

  • BLINQ—A tool for generating Microsoft ASP.NET Web sites for displaying, creating, and manipulating data based on database schema
  • LINQ to SQL (formerly DLINQ)—A specialized API for accessing Structured Query Language (SQL) relational databases
  • LINQ to XML (formerly XLINQ)—A lightweight, rational, and simple API for manipulating XML.
Live From Redmond: VB9: LINQ to SQL & O/R Designer Deep Dive

This web cast extends the SQL and LINQ web cast by showing you how to use the new OR designer to build applications that take advantage of LINQ to SQL.

MSDN geekSpeak: LINQ to SQL with .NET Framework Developer and MVP Bill Jones (Level 200)

This geekSpeak features Microsoft .NET Framework expert and Microsoft Most Valuable Professional (MVP) Bill Jones. Bill takes on your toughest questions about implementing LINQ to SQL in the real world.

The .NET Language Integrated Query (LINQ) Framework (Level 300)

Simulcast from Microsoft Tech·Ed 2007. Do you build Microsoft .NET applications? In this session, learn how to use the .NET Framework to build better end-to-end solutions using the DinnerNow.NET sample application. From a Windows Presentation Foundation client to a Windows Modern, applications operate on data in several different forms: relational tables, XML documents, and in-memory objects. Each of these domains can have profound differences in semantics, data types, and capabilities, and much of the complexity in today's applications is the result of these mismatches. Luca Bolognese, LINQ Lead Program Manager, explains how the next release of Microsoft Visual Studio, code name "Orcas," aims to unify the programming models through LINQ capabilities in Microsoft Visual C# and Visual Basic, a strongly typed data access framework, and an innovative application programming interface (API) for manipulating and querying XML.

Using LINQ with Relational Data (Level 100)

One of the most common forms of data used in applications today continues to be relational data that is stored in various database systems such as Microsoft SQL Server. In this session, learn about the flavors of LINQ that are designed to access relational data including LINQ to SQL, LINQ to Datasets, and LINQ to Entities.

Using the .NET Language Integrated Query (LINQ) Framework with Relational Data (Level 300)

Recorded at Microsoft Tech·Ed 2007 in Orlando, FL. Database-centric applications have traditionally had to rely on two distinct programming languages: one for the database and one for the application. In this talk, we introduce LINQ to SQL, a component of the LINQ project designed to help integrate relational data and queries with Microsoft Visual C# and Microsoft Visual Basic .NET. LINQ to SQL enables developers to express queries and updates in terms of their local programming language without sacrificing the server-side execution model of current high-performance SQL-based approaches. Using these advances, database queries that previously were stored as opaque strings now benefit from static type checking, CLR metadata, design-time type inference, and, of course, IntelliSense. LINQ to SQL also supports a rich update capability that lets you save changes to an object graph back to the database using optimistic concurrency or transactions.