ASP.NET Web API CRUD Operations

namespace WebAPISample1.Models
{
    public class Employee
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Designation { get; set; }
        public string Address { get; set; }
    }
}

namespace WebAPISample1.Models
{
    public class EmployeeRepository : IEmployeeRepository
    {
        private List<Employee> _employee = new List<Employee>();
        private int _nextId = 1;

        public EmployeeRepository()
        {
            this.Add(new Employee() { Name = "Raj Beniwal", Designation = "Asst. Project Manager", Address= "Noida" });
            this.Add(new Employee() { Name = "Dev Malhotra", Designation = "Tech Lead", Address = "Banglore" });
            this.Add(new Employee() { Name = "Neelesh Arora", Designation = "System Analyst", Address= "Pune"});
            this.Add(new Employee() { Name = "Samy Verma", Designation = "Project Manager", Address = "Washingtom DC" });
            this.Add(new Employee() { Name = "Ravinder Malik", Designation = "Team Lead", Address = "Gurgaon" });
        }

        public IQueryable<Employee> GetAll()
        {
            return _employee.AsQueryable();
        }

        public Employee Get(int id)
        {
            return _employee.Find(c => c.Id == id);
        }

        public Employee Add(Employee employee)
        {
            employee.Id = _nextId++;
            _employee.Add(employee);
            return employee;
        }

        public void Remove(int id)
        {
            Employee employee = _employee.Find(c => c.Id == id);
            _employee.Remove(employee);
        }

        public bool Update(Employee employee)
        {
            int index = _employee.FindIndex(c => c.Id == employee.Id);
            if (index == -1)
            {
                return false;
            }
            _employee.RemoveAt(index);
            _employee.Add(employee);
            return true;
        }
    }
}

namespace WebAPISample1.Models
{
    public interface IEmployeeRepository
    {
        IQueryable<Employee> GetAll();
        Employee Get(int id);
        Employee Add(Employee item);
        void Remove(int id);
        bool Update(Employee item);
    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
using WebAPISample1.Models;

namespace WebAPISample1.Controllers
{
    public class EmployeeController : ApiController
    {
        static readonly IEmployeeRepository repository = new EmployeeRepository();

        public IEnumerable<Employee> GetAllEmployee()
        {
            return repository.GetAll();
        }

        public Employee GetEmployee(int id)
        {
            Employee item = repository.Get(id);
            if (item == null)
            {
                throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
            }
            return item;
        }

        public IEnumerable<Employee> GetEmployeeByName(string name)
        {
            return repository.GetAll().Where(
                p => string.Equals(p.Name, name, StringComparison.OrdinalIgnoreCase));
        }

        public HttpResponseMessage PostEmployee(Employee item)
        {
            item = repository.Add(item);
            var response = Request.CreateResponse<Employee>(HttpStatusCode.Created, item);
            string uri = Url.Link("DefaultApi", new { id = item.Id });
            response.Headers.Location = new Uri(uri);
            return response;
        }

        public void PutEmployee(int id, Employee employee)
        {
            employee.Id = id;
            if (!repository.Update(employee))
            {
                throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.NotFound));
            }
        }

        public HttpResponseMessage DeleteEmployee(int id)
        {
            repository.Remove(id);
            return new HttpResponseMessage(HttpStatusCode.NoContent);
        }
    }
}

@{
    ViewBag.Title = "Employee List";
}
@section scripts {
    <style type="text/css">
        table {
            border: 1px solid #000;
            border-collapse: collapse;
            color: #666666;
            min-width: 200px;
        }

        tr {
            border: 1px solid #000;
            line-height: 25px;
        }

        th {
            background-color: #B1C3CC;
            color: #000;
            font-size: 13px;
            text-align: left;
        }

        th,
        td {
            padding-left: 5px;
        }
    </style>
    <script src="@Url.Content("~/Scripts/jquery-1.6.2.js")" type="text/javascript"></script>
    <script src="@Url.Content("~/Scripts/knockout-2.0.0.debug.js")" type="text/javascript"></script>
    <script type="text/javascript">
        function clearStatus() {
            $('#status').html('');
        }

        var detailModel = function () {
            this.Name = ko.observable();
            this.Designation = ko.observable();
            this.Address = ko.observable();
        }

        var API_URL = "api/employee/";
        var viewModel = new detailModel();

        //This function used to insert new employee record
        function add() {
            clearStatus();
            var employee = ko.toJS(viewModel);
            var json = JSON.stringify(employee);

            $.ajax({
                url: API_URL,
                cache: false,
                type: 'POST',
                contentType: 'application/json; charset=utf-8',
                data: json,
                statusCode: {
                    201 /*Created*/: function (data) {
                        self.employees.push(data);
                    }
                }
            });
        }

        //This function used to find employee by id
        function find() {
            clearStatus();
            var id = $('#employeeId').val();
            $.getJSON(API_URL + id,
                function (data) {
                    viewModel.Name(data.Name);
                    viewModel.Designation(data.Designation);
                    viewModel.Address(data.Address);
                })
                .fail(
                    function (xhr, textStatus, err) {
                        $('#status').html('Error: ' + err);
                    });
        }

        //This function used to updated employee based on id
        function update() {
            clearStatus();
            var id = $('#employeeId').val();
            var employees = ko.toJS(viewModel);
            var json = JSON.stringify(employees);
            $.ajax({
                url: API_URL + id,
                cache: false,
                type: 'PUT',
                contentType: 'application/json; charset=utf-8',
                data: json,
                success: function () { $.getJSON(API_URL, self.employees.update); }
            })
                .fail(
                    function (xhr, textStatus, err) {
                        $('#status').html('Error: ' + err);
                    });
        }

        $(document).ready(function () {
            self.employees = ko.observableArray();
            self.employees.update = function (data) {
                var c = self.employees;
                c.removeAll();
                c.push.apply(c, data);
                // Sort by ID
                c.sort(
                    function (left, right) { return left.Id - right.Id }
                );
            };
            ko.applyBindings(self.employees, document.getElementById('employees'));
            ko.applyBindings(viewModel, document.getElementById('detail'));
            $.getJSON(API_URL, self.employees.update);
        });
    </script>
}
<p id="body">
    <section class="content-wrapper main-content">
        <h3>Employees</h3>
        <table id="employees">
            <thead>
                <tr>
                    <th>ID</th>
                    <th>Name</th>
                    <th>Designation</th>
                    <th>Address</th>
                </tr>
            </thead>
            <tbody data-bind="foreach: employees">
                <tr>
                    <td data-bind="text: Id"></td>
                    <td data-bind="text: Name"></td>
                    <td data-bind="text: Designation"></td>
                    <td data-bind="text: Address"></td>
                </tr>
            </tbody>
        </table>
    </section>
    <section id="detail" class="content-wrapper">
        <h3>View Employee</h3>
        <p>
            <label for="employeeId">ID</label>
            <input type="text" title="ID" id="employeeId" size="5" />
            <input type="button" value="Get" onclick="find();" />
        </p>
        <p>
            <label for="name">Name</label>
            <input data-bind="value: Name" type="text" title="Name" id="name" />
        </p>
        <p>
            <label for="designation">Designation</label>
            <input data-bind="value: Designation" type="text" title="Designation" id="designation" />
        </p>
        <p>
            <label for="address">Address</label>
            <input data-bind="value: Address" type="text" title="Address" id="address" />
        </p>
        <p>
            <input type="button" value="Update" onclick="update();" />
            <input type="button" value="Add New" onclick="add();" />
        </p>
        <p>
            <p id="status"></p>
        </p>
    </section>
</p>