LINQ in Asp.Net

             
                                           

                          Simple SELECT,  

                DELETE Using LINQ to SQL

Language integrated query (LINQ) is a Microsoft .NET framework programming model, which adds query capabilities to the .NET programming languages. These extensions provide shorter and expressive syntax to manipulate data. A number of features have been added to C# and Visual Basic to support LINQ. It envelops powerful querying on objects, XML files, and databases.

LINQ encapsulates heavy generics. Distinguishing features include extension methods, lambda expressions, an object initializer, query syntax, and anonymous types. These are language extensions to enhance syntactic performance to queries.

LINQ Operations:

Step 1: Create a COURSE Table in the database

          CREATE TABLE book

          { 

                bookid    varchar(20),pk

                bkname  varchar(30),

                author     varchar(20),

                price       varchar(10)

          }

The SELECT Operation

private void GetBook()
{
      //create DataContext object
      OperationDataContext OdContext = new OperationDataContext();
      var BookTable = from Book in OdContext.GetTable<Book>() select  Book;
      grdBook.DataSource = BookTable;
      grdBook.DataBind();
}



The DELETE Operation

private void DeleteBook()
{
      OperationDataContext OdContext = new OperationDataContext();
      //Get Single Book which need to Delete
      BOOK  objBook= OdContext.BOOK.Single(Book => Book.Book_name == "java");
      //Puts an entity from this table into a pending delete state and parameter is the entity which to be deleted.
      OdContext.BOOK.DeleteOnSubmit(objBook);
      // executes the appropriate commands to implement the changes to the database
      OdContext.SubmitChanges();
}