Introduction to Language Integrated Query (LINQ)

Language‐Integrated Query (LINQ), which is built on .NET Frameworks 3.5, is a new technology released with Visual Studio.NET 2008 by Microsoft in 2008. This chapter discusses and analyzes the LINQ, which includes LINQ to Objects, LINQ to DataSet, LINQ to SQL, LINQ to Entities, and LINQ to XML. An introduction to LINQ general programming guide is provided. Some popular interfaces widely used in LINQ, such as IEnumerable, IEnumerable(Of T), IQueryable and IQueryable(Of T), and Standard Query Operators (SQO) including the deferred and non‐deferred SQO, are discussed. The chapter also provides an introduction to LINQ Query. This is followed by a detailed discussion and analysis about the LINQ queries that is implemented for different data sources is provided in detail. Special improvements on LINQ are made for Visual Basic.NET. The main components of these improvements include: Lambda Expressions, Extension Methods, Implicitly Typed Local Variables, and Query Expressions.