insert delete update in wcf using entity framework

first create table

create table book
( ID int identity(1,1),
BooKName varchar(50)
)

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using System.Text;

namespace RestBookexample
{
    // NOTE: You can use the "Rename" command on the "Refactor" menu to change the interface name "IService1" in both code and config file together.
    [ServiceContract]
    public interface IService1
    {

        [OperationContract]
        List<Booki> GetBooksList();

        [OperationContract]
        List<Booki> GetBookById(string id);

        [OperationContract]
        void AddBook(string name);

        [OperationContract]
        void UpdateBook(string id, string name);

        [OperationContract]
        void DeleteBook(string id);

     
        // TODO: Add your service operations here
    }


    // Use a data contract as illustrated in the sample below to add composite types to service operations.
    [DataContract]
    public class Booki
    {

        int Id = 0;
        string bookName ="";

        [DataMember]
        public string BookName
        {
            get { return bookName; }
            set { bookName = value; }
        }
        [DataMember]
        public int ID
        {
            get { return Id; }
            set { Id = value; }
        }
     
    }
}

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using System;

using System.Collections.Generic;

using System.Linq;

using System.Runtime.Serialization;

using System.ServiceModel;

using System.ServiceModel.Web;

using System.Text;

namespace RestBookexample

{

    public class Service1 : IService1

    {

        public List<Booki> GetBooksList()

        {

            test_dbEntities entities = new test_dbEntities();

            Booki boo = null;

            List<Booki> booklist = new List<Booki>();

            for (int i = 0; i < entities.books.ToList().Count; i++)

            {

                 boo = new Booki();

                 boo.BookName = entities.books.ToList()[i].BooKName;

                 boo.ID = entities.books.ToList()[i].ID;

                 booklist.Add(boo);            

            }

            return booklist;      

            

        }

        public List<Booki> GetBookById(string id)

        {

            int bookId = Convert.ToInt32(id);

            List<Booki> booklist = new List<Booki>();

            try

            {                              

            

            test_dbEntities entities = new test_dbEntities();

            Booki boo = null;

            

            for (int i = 0; i < entities.books.ToList().Count; i++)

            {

                 boo = new Booki();

                 boo.BookName = entities.books.ToList()[i].BooKName;

                 boo.ID = entities.books.ToList()[i].ID;

                 booklist.Add(boo); 

            }         

               

            }

            catch

            {

                throw new FaultException("Something went wrong");

            }

            return booklist.Where(em => em.ID == bookId).ToList().Take(1).ToList();

        }

        public void AddBook(string name)

        {

            test_dbEntities entities = new test_dbEntities();

            book boo = new book();

            boo.BooKName = name;

            entities.AddTobooks(boo);

            entities.SaveChanges();

        }

        public void UpdateBook(string id, string name)

        {

            try

            {

                int bookId = Convert.ToInt32(id);

                using (test_dbEntities entities = new test_dbEntities())

                {

                    book book1 = entities.books.SingleOrDefault(b => b.ID == bookId);

                    book1.BooKName = name;

                    entities.SaveChanges();

                }

            }

            catch

            {

                throw new FaultException("Something went wrong");

            }

        }

        public void DeleteBook(string id)

        {

            try

            {

                int bookId = Convert.ToInt32(id);

                using (test_dbEntities entities = new test_dbEntities())

                {

                    book book1 = entities.books.SingleOrDefault(b => b.ID == bookId);

                    entities.DeleteObject(book1);

                    entities.SaveChanges();

                }

            }

            catch

            {

                throw new FaultException("Something went wrong");

            }

        }

    }

}