LINQ, Language INtegrated Query, is a new extension to the Visual Basic and C# programming languages designed to simplify data queries and database interaction. It addreses O/R mapping issues by making query operations like SQL statements part of the programming language. Adding to its power, LINQ is extensible and can be used to query various data sources. It offers built-in support for querying in-memory collections like arrays or lists, XML, DataSets, and relational databases. LINQ in Action is a fast-paced, comprehensive tutorial for professional developers who want to use LINQ. This book explores what can be done with LINQ, shows you how it works in an application, and addresses the emerging best practices.