LINQ :

Language Integrated Query (LINQ, pronounced "link") is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages.

Microsoft LINQ defines a set of method names (called standard query operators, or, more recently, standard sequencing operators[citation needed]), along with translation rules from so-called query expressions to expressions using these method names, lambda expressions and anonymous types. These can, for example, be used to project and filter data in arrays, enumerable classes, XML (XLINQ), relational database, and third party data sources. Other uses, which utilize query expressions as a general framework for readably composing arbitrary computations, include the construction of event handlers[1] or monadic parsers.[2]

Many of the concepts that LINQ has introduced were originally tested in Microsoft's Cω research project. LINQ was released as a part of .NET Framework 3.5 on November 19, 2007.

Example :

public void Linq102()

{

string[] categories = new string[]{

"Beverages",

"Condiments",

"Vegetables",

"Dairy Products",

"Seafood" };



List products = GetProductList();



var q =

from c in categories

join p in products on c equals p.Category

select new { Category = c, p.ProductName };



foreach (var v in q)

{

Console.WriteLine(v.ProductName + ": " + v.Category);

}

}

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