Difference between SingleOrDefault() n FirstOrDefault()

Whenever you use SingleOrDefault, you clearly state that the query should result in at most a single result. On the other hand, when FirstOrDefault is used, the query can return any amount of results but you state that you only want the first one.

I personally find the semantics very different and using the appropriate one, depending on the expected results, improves readability.

AngularJS ASP.NET MVC Editable Grid

Model-------------

public class Employee

    {

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public string Country { get; set;

   }

View......

<link href="../../style/bootstrap.min.css" rel="stylesheet" type="text/css" />

<script src="../../script/angular.js" type="text/javascript"></script>

<script type="text/javascript">

    var app = angular.module('myApp', []);

    app.controller('HomeCtrl', ['$scope', '$http', function ($scope, $http) {

        $http({

            method: 'POST',

            url: 'Home/GetEmployees'

        })

        .then(function (response) {

            console.log(response);

            $scope.employees = response.data.employees;

            angular.forEach($scope.employees, function (obj) {

                obj["showEdit"] = true;

            });

        }, function (error) {

            console.log(error);

        });

        $scope.toggleEdit = function (emp) {

            emp.showEdit = emp.showEdit ? false : true;

        }

    } ]);

</script>

<div ng-app="myApp" ng-controller="HomeCtrl" class="container">

    <div class="row">

        <div class="bs-example marginTop50" data-example-id="table-within-panel">

            <div class="panel panel-default">

                <div class="panel-heading">

                    <h3>Code Handbook</h3></div>

                <div class="panel-body">

                    <p>

                        AngularJS ASP.NET MVC Editable Grid Demo</p>

                </div>

                <table class="table">

                    <thead>

                        <tr>

                            <th>

                                #

                            </th>

                            <th>

                                First Name

                            </th>

                            <th>

                                Last Name

                            </th>

                            <th>

                                Country

                            </th>

                            <th>

                            </th>

                        </tr>

                    </thead>

                    <tbody>

                        <tr ng-repeat="emp in employees">

                            <th scope="row">

                                {{$index+1}}

                            </th>

                            <td>

                                <span ng-show="emp.showEdit">{{emp.FirstName}}</span>

                                <input ng-show="!emp.showEdit" type="text" ng-model="emp.FirstName" class="form-control" >

                            </td>

                            <td>

                                 <span ng-show="emp.showEdit">{{emp.LastName}}</span>

                                 <input ng-show="!emp.showEdit" type="text" ng-model="emp.LastName" class="form-control" >

                            </td>

                            <td> <span ng-show="emp.showEdit">{{emp.Country}}</span>

                                <input ng-show="!emp.showEdit" type="text" ng-model="emp.Country" class="form-control" >

                            </td>

                            <td>

                                <span ng-show="emp.showEdit" ng-click="toggleEdit(emp)" class="glyphicon glyphicon-pencil"></span>

                                <span ng-show="!emp.showEdit" ng-click="toggleEdit(emp)" class="glyphicon glyphicon-ok"></span>

                            </td>

                        </tr>

                    </tbody>

                </table>

            </div>

        </div>

    </div>

</div>

Controller----

public JsonResult GetEmployees()

        {

            List<Employee> empList = new List<Employee>();

            Employee emp = new Employee { FirstName = "James", LastName = "Bond", Country = "Germany" };

            empList.Add(emp);

            emp = new Employee { FirstName = "Roy", LastName = "Agasthyan", Country = "United States" };

            empList.Add(emp);

            return Json(new { employees = empList });

        }