LINQ

Basically LINQ address the current database development model in the context of Object Oriented Programming Model. If some one wants to develop database application on .Net platform the very simple approach he uses ADO.Net. ADO.Net is serving as middle ware in application and provides complete object oriented wrapper around the database SQL. Developing application in C# and VB.Net so developer must have good knowledge of object oriented concept as well as SQL, so it means developer must be familiar with both technologies to develop an application. If here I can say SQL statements are become part of the C# and VB.Net code so it’s not mistaken in form of LINQ. According to Anders Hejlsberg the chief architect of C#.

“Microsoft original motivation behind LINQ was to address the impedance mismatch between programming languages and database.”

LINQ has a great power of querying on any source of data, data source could be the collections of objects, database or XML files. We can easily retrieve data from any object that implements the IEnumerableO-tag(T)C-tag interface. Microsoft basically divides LINQ into three areas and that are give below.

LINQ to Object {Queries performed against the in-memory data}
LINQ to ADO.Net
LINQ to SQL (formerly DLinq) {Queries performed against the relation database only Microsoft SQL Server Supported}
LINQ to DataSet {Supports queries by using ADO.NET data sets and data tables}
LINQ to Entities {Microsoft ORM solution}
LINQ to XML (formerly XLinq) { Queries performed against the XML source}