how to loop through hidden courses and remove from database

Question

In my code i need to loop through hidden courses in jquery then remove it from employee course table in database sql in edit httppost under save button

see green font in place of my code i need

[HttpPost]
public ActionResult Edit(Cusomemp2 custom)
{
var result = db.Employees
.Where(p => p.Id == custom.Id)
.Include(c => c.EmployeeCourses)
.FirstOrDefault();
if (custom.empcourses.Any())
{
//here i need to loop through data and remove hidden courses
}
result.Name = custom.Name;
result.EmployeeCourses = custom.empcourses;
db.SaveChanges();
return View();
}

i use following model Cusomemp2 to represent data

public class Cusomemp2
{
public int Id { get; set; }
public List<EmployeeCourse> empcourses { get; set; }
}

in edit view model my code as following

@model StudentCourses.Models.Cusomemp2
@{
Layout = null;
}
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Edit</title>
<script src="~/scripts/jquery-1.10.2.js"></script>
<script>
$(function () {
var index = 0;
$("#CourseId").change(function () {
var id = $(this).val();
var txt = $("#CourseId option:selected").text();
$("#tb").append("<tr><td><input type = 'hidden' name='empcourses[" + index + "].CourseId' value='" + id + "'/></td><td>" + txt + "</td><td><input type='button' value='remove' class='r'</td></tr>")
index++;
});
$("#tb").on("click", ".r", function () {
$(this).parent().parent().hide();
$(this).parent().prev().prev().find("input").val("0");
});
$.ajax({
url: "/Employeedata/getcoursesbyempid",
data:{x:$("#hid").val()},
success: function (res) {
$.each(res, function (i, e) {
$("#tb").append("<tr><td><input type = 'hidden' name='empcourses[" + index + "].CourseId' value='" + e.Id + "'/></td><td>" + e.CourseName + "</td><td><input type='button' value='remove' class='r'</td></tr>")
index++;
});
}
})
});
</script>
</head>
<body>
<div>
@using (Html.BeginForm())
{
<div>
<input type="hidden" value="@ViewBag.hid" id="hid" />
Name: @Html.TextBoxFor(a => a.Name)
<br />
Courses:@Html.DropDownList("CourseId")
<br />
<table id="tb"></table>
<input type="submit" value="save" />
</div>
}
</div>
</body>
</html>

see image below it show what i need

ahmed salah · Answer

after remove c++ by jquery button remove then click save it give me null exception error as image below attached with my message

Pradeep Shet · Answer

hi I hope this answers your question public ActionResult Edit(Cusomemp2 custom) { var result = db.Employees .Where(p => p.Id == custom.Id) .Include(c => c.EmployeeCourses) .FirstOrDefault(); if (custom.empcourses.Any()) { foreach(var e in c ustom.empcourses ) { var course = db.EmployeeCourses.Where(x=>x.CourseId == e.CourseId).FirstOrDefault(); db. EmployeeCourses.Delete(course); } db.SaveChanges(); } result.Name = custom.Name; result.EmployeeCourses = custom.empcourses; db.SaveChanges(); return View(); }