LINQ is a uniform programming

LINQ is a uniform programming model for any kind of data. LINQ enables you to query and manipulate data with a consistent model that is independent from data sources.

■ LINQ is just another tool for embedding SQL queries into code.
■ LINQ is yet another data abstraction layer.

All of these descriptions are somewhat correct, but they each focus on just a single aspect.LINQ can do a lot more than just embed SQL queries, it is much easier to use than a "uniformprogramming model," and it is far from being just another set of rules for modeling data.

LINQ is a methodology that simplifies and unifies the implementation of any kind of data access. LINQ does not force you to use a specific architecture; it facilitates the implementationof several existing architectures for accessing data. As with every tool, it can be used in both good and in bad ways. To get the most out of LINQ, you will have to master it.
Today, data managed by a program can belong to different data domains: an array, an object graph, an XML document, a database, a text file, a registry key, an e-mail message, Simple Object Access Protocol (SOAP) message content, a Microsoft Office Excel file…. The list is long. Each data domain has its own specific access model. When you have to query a database, you typically use SQL. You navigate XML data with Document Object Model (DOM) or XQuery.

You iterate an array and build algorithms to navigate an object graph. You use specific application programming interfaces (APIs) to access other data domains, such as an Office Excel file, an e-mail message, or the Microsoft Windows registry. In the end, you have different programming models to access different data sources.

The unification of data access techniques into a single comprehensive model has been tried in many ways. For example, there are Open Database Connectivity (ODBC) providers that allow