LINQ

 

LINQ(Language Integrated Query)

• LINQ is a uniform programming model for any kind of data access. LINQ enables you to query and manipulate the data independently of data sources.
• Its like a query language which can query any data source and any transform. LINQ also provide full type safety and compile time checking.
• LINQ can serve as a good entity for middle tier. So it will sit in between the UI and the data access layer.

• LINQ uses an SQL-like syntax to make query expressions well beyond the capabilities of embedded SQL as implemented in programming languages. 
• LINQ (Language Integrated Query) is a Microsoft programming model and methodology that essentially adds formal query capabilities into Microsoft .NET-based programming languages.

Simple example of LINQ:

using System;
using System.Linq;
using System.Collections.Generic;

class appnew {
    static void Main() {
        string[] names = { "Tom", "harry", "Frank", "David", "John" };
        IEnumerable<string> query = from s in names 
                                    where s.Length == 5
                                    orderby s
                                    select s.ToUpper();
       foreach (string item in query)
       Console.WriteLine(item);
                      }

              }

compile and run this program, the output is shown as:

harry
Frank
David