Code First Approach in MVC With Entity Framework With Primary and Foreign Key Creation

In my previous article I explained what Code First Approach in MVC with Entity Framework is. Now in this article I will show how to create a Primary Key and Foreign Key using the code first approach in MVC with Entity Framework.

Here I will create 2 tables, Students and Course. Both tables will have a Primary Key and the Student table will reference the course table with CourseID as the Foreign Key.

Now open Visual Studio 2012 and select New Project.

mvc 4 web application

internet application

Now right-click on the project in the Solution Explorer then click on Manage NuGet Packages.

Now here in this project I will create 2 tables, one is the Student table and the second one is the Course table. Both tables will have a Primary Key and the Student and Course tables will have a Foreign Key, CourseID. So here I will create 2 clasess in the Model Folder.

Student.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Linq;
using System.Web;
namespace CodeFirstApproachWithPrimaryForeignKey.Models
{
public class Student
{
public Student()
{
}
[Key]
public int Id { get; set; }
public string Name { get; set; }
[DataType(DataType.Date),
DisplayFormat(DataFormatString = "{0:dd/MM/yy}",
ApplyFormatInEditMode = true)]
public DateTime? DateOfBirth { get; set; }
public string EmailId { get; set; }
public string Address { get; set; }
public string City { get; set; }
public int CourseId { get; set; }
public Course Course { get; set; } // Navigation Property
[NotMapped]
public string CourseName { get; set; }
}
}

Here CourseName will not be a field because I set it as NotMapped.

Now Course.cs

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
namespace CodeFirstApproachWithPrimaryForeignKey.Models
{
public class Course
{
public Course()
{
}
[Key]
public int CourseId { get; set; }
public string CourseName { get; set; }
public List<Student> Students { get; set; } // Navigation property
}
}

Now again right-click on the Model folder and add the new class StudentDBContext.cs.

using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
using System.Linq;
using System.Web;
namespace CodeFirstApproachWithPrimaryForeignKey.Models
{
public class StudentDBContext : DbContext
{
public StudentDBContext()
: base("StudentDbContext")
{
}
public DbSet<Student> Students { get; set; }
public DbSet<Course> Courses { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Course>().HasKey(p => p.CourseId);
modelBuilder.Entity<Course>().Property(c => c.CourseId)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
modelBuilder.Entity<Student>().HasKey(b => b.Id);
modelBuilder.Entity<Student>().Property(b => b.Id)
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
modelBuilder.Entity<Student>().HasRequired(p => p.Course)
.WithMany(b => b.Students).HasForeignKey(b => b.CourseId);
base.OnModelCreating(modelBuilder);
}
}
}

Here In this StudentDBContext.cs you can see I am using OnModelCreating. Here I define what will be the Primary Key and what will be the Foreign Key.

Now right-click on Controller then select Add -> Controller -> Student.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using CodeFirstApproachWithPrimaryForeignKey.Models;
namespace CodeFirstApproachWithPrimaryForeignKey.Controllers
{
public class StudentController : Controller
{
//
// GET: /Student/
StudentDBContext objContext;
public StudentController()
{
objContext = new StudentDBContext();
}
#region List and Details student
public ActionResult Index()
{
var students = (from p in objContext.Students
join f in objContext.Courses
on p.CourseId equals f.CourseId
select new
{
Id = p.Id,
Name = p.Name,
DateOfBirth = p.DateOfBirth,
EmailId = p.EmailId,
Address = p.Address,
City = p.City,
CourseName = f.CourseName
}).ToList()
.Select(x => new Student()
{
Id = x.Id,
Name = x.Name,
DateOfBirth = x.DateOfBirth,
EmailId = x.EmailId,
Address = x.Address,
City = x.City,
CourseName = x.CourseName
});
return View(students.ToList());
}
public ViewResult Details(int id)
{
//Student student = objContext.Students.Where(x => x.Id == id).SingleOrDefault();
var student = (from p in objContext.Students
join f in objContext.Courses
on p.CourseId equals f.CourseId
where (p.Id==id)
select new
{
Id = p.Id,
Name = p.Name,
DateOfBirth = p.DateOfBirth,
EmailId = p.EmailId,
Address = p.Address,
City = p.City,
CourseName = f.CourseName
}).ToList()
.Select(x => new Student()
{
Id = x.Id,
Name = x.Name,
DateOfBirth = x.DateOfBirth,
EmailId = x.EmailId,
Address = x.Address,
City = x.City,
CourseName = x.CourseName
}).SingleOrDefault();
return View(student);
}
#endregion
#region Create student
public ActionResult Create()
{
var data = from p in objContext.Courses
select new
{
CourseID = p.CourseId,
CourseName = p.CourseName
};
SelectList list = new SelectList(data, "CourseID", "CourseName");
ViewBag.Roles = list;
return View(new Student());
}
[HttpPost]
public ActionResult Create(Student student)
{
objContext.Students.Add(student);
objContext.SaveChanges();
return RedirectToAction("Index");
}
#endregion
#region Edit student
public ActionResult Edit(int id)
{
var data = from p in objContext.Courses
select new
{
CourseID = p.CourseId,
CourseName = p.CourseName
};
SelectList list = new SelectList(data, "CourseID", "CourseName");
ViewBag.Roles = list;
Student student = objContext.Students.Where(x => x.Id == id).SingleOrDefault();
return View(student);
}
[HttpPost]
public ActionResult Edit(Student model)
{
Student student = objContext.Students.Where(x => x.Id == model.Id).SingleOrDefault();
if (student != null)
{
objContext.Entry(student).CurrentValues.SetValues(model);
objContext.SaveChanges();
return RedirectToAction("Index");
}
return View(model);
}
#endregion
#region Delete student
public ActionResult Delete(int id)
{
Student student = objContext.Students.Find(id);
return View(student);
}
[HttpPost]
public ActionResult Delete(int id, Student model)
{
var student = objContext.Students.Where(x => x.Id == id).SingleOrDefault();
if (student != null)
{
objContext.Students.Remove(student);
objContext.SaveChanges();
}
return RedirectToAction("Index");
}
#endregion
}
}

Views Are for Create/Read/Details/Edit/Delete

Index.cshtml

<h2>Showing All Students</h2>
<p>
@Html.ActionLink("Create New", "Create")
</p>
<table style="width:100%;">
<tr>
<th >
@Html.DisplayNameFor(model => model.Name)
</th>
<th style="width:20%;">
@Html.DisplayNameFor(model => model.DateOfBirth)
</th>
<th style="width:20%;">
@Html.DisplayNameFor(model => model.EmailId)
</th>
<th>
@Html.DisplayNameFor(model => model.Address)
</th>
<th>
@Html.DisplayNameFor(model => model.City)
</th>
<th>
@Html.DisplayNameFor(model => model.CourseName)
</th>
<th></th>
</tr>
@foreach (var item in Model) {
<tr>
<td>
@Html.DisplayFor(modelItem => item.Name)
</td>
<td>
@Html.DisplayFor(modelItem => item.DateOfBirth)
</td>
<td>
@Html.DisplayFor(modelItem => item.EmailId)
</td>
<td>
@Html.DisplayFor(modelItem => item.Address)
</td>
<td>
@Html.DisplayFor(modelItem => item.City)
</td>
<td>
@Html.DisplayFor(modelItem => item.CourseName)
</td>
<td>
@Html.ActionLink("Edit", "Edit", new { id=item.Id }) |
@Html.ActionLink("Details", "Details", new { id=item.Id }) |
@Html.ActionLink("Delete", "Delete", new { id=item.Id })
</td>
</tr>
}
</table>

Create.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Student
@{
ViewBag.Title = "Create";
}
<h2>Create</h2>
@using (Html.BeginForm())
{
@Html.ValidationSummary(true)
<fieldset>
<legend>Student</legend>
<div class="editor-label">
@Html.LabelFor(model => model.Name)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Name)
@Html.ValidationMessageFor(model => model.Name)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.DateOfBirth)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.DateOfBirth)
@Html.ValidationMessageFor(model => model.DateOfBirth)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.EmailId)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.EmailId)
@Html.ValidationMessageFor(model => model.EmailId)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.Address)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Address)
@Html.ValidationMessageFor(model => model.Address)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.City)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.City)
@Html.ValidationMessageFor(model => model.City)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.CourseId)
</div>
<div class="editor-field">
@Html.DropDownListFor(m=>m.CourseId, ViewBag.Roles as SelectList, "Select ...", new { @class = "myClass", style = "width: 250px;" })
@* @Html.EditorFor(model => model.CourseId)*@
@Html.ValidationMessageFor(model => model.CourseId)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}

Delete.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Student
@{
ViewBag.Title = "Delete";
}
<h2>Delete</h2>
<h3>Are you sure you want to delete this?</h3>
<table>
<tr>
<td>@Html.DisplayNameFor(model => model.Name)</td>
<td>@Html.DisplayFor(model => model.Name)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.DateOfBirth)</td>
<td>@Html.DisplayFor(model => model.DateOfBirth)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.EmailId)</td>
<td>@Html.DisplayFor(model => model.EmailId)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.Address)</td>
<td>@Html.DisplayFor(model => model.Address)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.City)</td>
<td>@Html.DisplayFor(model => model.City)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.CourseName)</td>
<td>@Html.DisplayFor(model => model.CourseName)</td>
</tr>
<tr style="background-color: orange; padding: 25px;">
<td></td>
<td>@Html.ActionLink("Edit", "Edit", new { id = Model.Id }) |
@Html.ActionLink("Back to List", "Index")</td>
</tr>
</table>
@using (Html.BeginForm())
{
<table>
<tr style="background-color: orange; padding: 25px;">
<td></td>
<td>
<input type="submit" value="Delete" />
@Html.ActionLink("Back to List", "Index")
</td>
</tr>
</table>
}

Details.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Student
@{
ViewBag.Title = "Details";
}
<h2>Details Of Student</h2>
<table>
<tr>
<td>@Html.DisplayNameFor(model => model.Name)</td>
<td>@Html.DisplayFor(model => model.Name)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.DateOfBirth)</td>
<td>@Html.DisplayFor(model => model.DateOfBirth)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.EmailId)</td>
<td>@Html.DisplayFor(model => model.EmailId)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.Address)</td>
<td>@Html.DisplayFor(model => model.Address)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.City)</td>
<td>@Html.DisplayFor(model => model.City)</td>
</tr>
<tr>
<td>@Html.DisplayNameFor(model => model.CourseName)</td>
<td>@Html.DisplayFor(model => model.CourseName)</td>
</tr>
<tr style="background-color: orange; padding: 25px;">
<td></td>
<td>@Html.ActionLink("Edit", "Edit", new { id = Model.Id }) |
@Html.ActionLink("Back to List", "Index")</td>
</tr>
</table>

Edit.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Student
@{
ViewBag.Title = "Edit";
}
<h2>Edit</h2>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Student</legend>
@Html.HiddenFor(model => model.Id)
<div class="editor-label">
@Html.LabelFor(model => model.Name)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Name)
@Html.ValidationMessageFor(model => model.Name)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.DateOfBirth)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.DateOfBirth)
@Html.ValidationMessageFor(model => model.DateOfBirth)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.EmailId)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.EmailId)
@Html.ValidationMessageFor(model => model.EmailId)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.Address)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.Address)
@Html.ValidationMessageFor(model => model.Address)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.City)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.City)
@Html.ValidationMessageFor(model => model.City)
</div>
<div class="editor-label">
@Html.LabelFor(model => model.CourseId)
</div>
<div class="editor-field">
@Html.DropDownListFor(m=>m.CourseId, ViewBag.Roles as SelectList, "Select ...", new { @class = "myClass", style = "width: 250px;" })
@* @Html.EditorFor(model => model.CourseId)*@
@Html.ValidationMessageFor(model => model.CourseId)
</div>
<p>
<input type="submit" value="Save" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}

Now again right-click on Controller then select Add-> Controller -> Course.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using CodeFirstApproachWithPrimaryForeignKey.Models;
namespace CodeFirstApproachWithPrimaryForeignKey.Controllers
{
public class CourseController : Controller
{
//
// GET: /Course/
StudentDBContext objContext;
public CourseController()
{
objContext = new StudentDBContext();
}
#region List and Details course
public ActionResult Index()
{
var courses = objContext.Courses.ToList();
return View(courses);
}
public ViewResult Details(int id)
{
Course course = objContext.Courses.Where(x => x.CourseId == id).SingleOrDefault();
return View(course);
}
#endregion
#region Create course
public ActionResult Create()
{
return View(new Course());
}
[HttpPost]
public ActionResult Create(Course course)
{
objContext.Courses.Add(course);
objContext.SaveChanges();
return RedirectToAction("Index");
}
#endregion
#region edit course
public ActionResult Edit(int id)
{
Course course = objContext.Courses.Where(x => x.CourseId == id).SingleOrDefault();
return View(course);
}
[HttpPost]
public ActionResult Edit(Course model)
{
Course course = objContext.Courses.Where(x => x.CourseId == model.CourseId).SingleOrDefault();
if (course != null)
{
objContext.Entry(course).CurrentValues.SetValues(model);
objContext.SaveChanges();
return RedirectToAction("Index");
}
return View(model);
}
#endregion
#region Delete course
public ActionResult Delete(int id)
{
Course course = objContext.Courses.Find(id);
return View(course);
}
[HttpPost]
public ActionResult Delete(int id, Course model)
{
var course = objContext.Courses.Where(x => x.CourseId == id).SingleOrDefault();
if (course != null)
{
objContext.Courses.Remove(course);
objContext.SaveChanges();
}
return RedirectToAction("Index");
}
#endregion
}
}

View for Course

Index.cshtml

@model IEnumerable<CodeFirstApproachWithPrimaryForeignKey.Models.Course>
@{
ViewBag.Title = "Index";
}
<h2>Index</h2>
<p>
@Html.ActionLink("Create New", "Create")
</p>
<table>
<tr>
<th>
@Html.DisplayNameFor(model => model.CourseName)
</th>
<th></th>
</tr>
@foreach (var item in Model) {
<tr>
<td>
@Html.DisplayFor(modelItem => item.CourseName)
</td>
<td>
@Html.ActionLink("Edit", "Edit", new { id=item.CourseId }) |
@Html.ActionLink("Details", "Details", new { id=item.CourseId }) |
@Html.ActionLink("Delete", "Delete", new { id=item.CourseId })
</td>
</tr>
}
</table>

Create.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Course
@{
ViewBag.Title = "Create";
}
<h2>Create</h2>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Course</legend>
<div class="editor-label">
@Html.LabelFor(model => model.CourseName)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.CourseName)
@Html.ValidationMessageFor(model => model.CourseName)
</div>
<p>
<input type="submit" value="Create" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}

Delete.cshtml

model CodeFirstApproachWithPrimaryForeignKey.Models.Course
@{
ViewBag.Title = "Delete";
}
<h2>Delete</h2>
<h3>Are you sure you want to delete this?</h3>
<fieldset>
<legend>Course</legend>
<div class="display-label">
@Html.DisplayNameFor(model => model.CourseName)
</div>
<div class="display-field">
@Html.DisplayFor(model => model.CourseName)
</div>
</fieldset>
@using (Html.BeginForm()) {
<p>
<input type="submit" value="Delete" /> |
@Html.ActionLink("Back to List", "Index")
</p>
}

Details.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Course
@{
ViewBag.Title = "Details";
}
<h2>Details</h2>
<fieldset>
<legend>Course</legend>
<div class="display-label">
@Html.DisplayNameFor(model => model.CourseName)
</div>
<div class="display-field">
@Html.DisplayFor(model => model.CourseName)
</div>
</fieldset>
<p>
@Html.ActionLink("Edit", "Edit", new { id=Model.CourseId }) |
@Html.ActionLink("Back to List", "Index")
</p>

Edit.cshtml

@model CodeFirstApproachWithPrimaryForeignKey.Models.Course
@{
ViewBag.Title = "Edit";
}
<h2>Edit</h2>
@using (Html.BeginForm()) {
@Html.ValidationSummary(true)
<fieldset>
<legend>Course</legend>
@Html.HiddenFor(model => model.CourseId)
<div class="editor-label">
@Html.LabelFor(model => model.CourseName)
</div>
<div class="editor-field">
@Html.EditorFor(model => model.CourseName)
@Html.ValidationMessageFor(model => model.CourseName)
</div>
<p>
<input type="submit" value="Save" />
</p>
</fieldset>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
@section Scripts {
@Scripts.Render("~/bundles/jqueryval")
}

Run the Application

create

Now see your database:

Click on Course then select Create New.

Showing All Course List:

Click on Edit Course:

Details of a course:

course detail

Delete an existing Course:

delete course

Now click on Student-> Create New.

student create new

List of all students.

student list

Edit any student record:

edit student

Details of any student:

student detail

Delete any student record:

delete student

Now see your database. See the records in both tables and see the Primary Key and Foreign Key existence:

check database

If you want to run this application in your machine then just change the connection string in the web.config file.

15 Comments

Join the conversation! Your thoughts help the community grow.

Rahul Patil7y ago
<a target="_blank" class="LinkNormalBlue" href="https://www.c-sharpcorner.com/members/rahul-saxena8">Rahul Saxena</a> can I create a database first or Database Automatically create a model In code first approach??
Zain Nabi8y ago
How do I insert into a foreign key using a textbox instead of drop down list
Rahul Kumar Saxena11y ago
Thank u Shridhar Sharma
Shridhar Sharma11y ago
very useful..Good to see this article listing on "Articles Of The Day".
Rahul Kumar Saxena11y ago
Thanks Syed Shanu Bro..
Syed Shanu11y ago
Contrats Rahul for Article of the Day :)
Rahul Kumar Saxena11y ago
Thanks Karthik Muthu Karuppan...
Karthik Muthu Karuppan11y ago
Good one
Rahul Kumar Saxena11y ago
Thanks Manoj Bhoir...
Manoj Bhoir11y ago
Good One. Keep It Up.
Rahul Kumar Saxena11y ago
Thanks Nitin Tyagi...
Rahul Kumar Saxena11y ago
Thanks Santhakumar Munuswamy...
Nitin11y ago
very well explained.
Santhakumar Munuswamy11y ago
Thanks for sharing
Santhakumar Munuswamy11y ago
Good Work