ASP.NET MVC Application with EF6 Code First Approach

In this ASP.NET MVC Tutorial, we are going to see a simple but practical implementation for Entity Framework Code First Approach. We have already given examples on Entity Framework Model First as well as traditional Database First approaches in other examples. You can follow other sample implementations at below given URLs.

• Entity Framework Database First Approach 
• Entity Framework Model First Approach

While using Code-First Approach, we start with creating classes in code first as per our domain requirements instead of doing database design(the traditional way). On the basis of our classes and provided configuration, Code-First APIs will create the database on the fly.

So, for the sake of this implementation, we will start by writing C# code (creating C# classes for domain as well as context classes). When the application will run, Code First APIs will create the new database (if it does not exist yet) and map classes with the database using default code-first conventions.

Entity Framework Code First Approach

Following are the steps we can follow for Entity Framework Code First Approach:

Create visual studio project “Entity_Framework_FAQ”.

On next screen choose template as MVC.

Click “OK”, Your application will be created and you get following welcome screen:

If you have not installed Entity Framework, please install it by using Nuget Package Console Command as follows:

Install-Package EntityFramework -Version 6.1.1

Or follow the link to Install Entity Framework in Visual Studio using step by step approach.

In Code-First approach, Instead of designing database tables first, classes are created first.

Create class “Category.cs” as shown below:

Add following code in “Category.cs” as shown below:

public class Category
{
    public int CategoryId { get; set; }
    public string CategoryName { get; set; }
    public ICollection<Product> Products { get; set; }
}

Similarly add product class and add following code to it:

public class Product
{
    public int ProductId { get; set; }
    public string ProductName { get; set; }
    public decimal Price { get; set; }
    public int CategoryId { get; set; }
    public virtual Category category { get; set; }
}

Add a data context class that will contain the category model and product model:

It will contain following code:

public class EF_FAQ_Entities : DbContext
{
    public DbSet<Category> Categories { get; set;}
    public DbSet<Product> Products { get; set; }
}

Add new Controller “Products” as shown in below steps:

After click on “Add” button, the scaffolding technique will put all the necessary code in the respective controller and related views.

Product Controller will contain following code:

public class ProductsController : Controller
    {
        private EF_FAQ_Entities db = new EF_FAQ_Entities();
        // GET: Products
        public ActionResult Index()
        {
            var products = db.Products.Include(p => p.category);
            return View(products.ToList());
        }

        // GET: Products/Details/5
        public ActionResult Details(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }

            Product product = db.Products.Find(id);
            if (product == null)
            {
                return HttpNotFound();
            }
            return View(product);
        }

        // GET: Products/Create
        public ActionResult Create()
        {
            ViewBag.CategoryId = new SelectList(db.Categories, "CategoryId", "CategoryName");
            return View();
        }

        // POST: Products/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "ProductId,ProductName,Price,CategoryId")] Product product)
        {
            if (ModelState.IsValid)
            {
                db.Products.Add(product);
                db.SaveChanges();

                return RedirectToAction("Index");
            }

            ViewBag.CategoryId = new SelectList(db.Categories, "CategoryId", "CategoryName", product.CategoryId);
            return View(product);
        }

        // GET: Products/Edit/5
        public ActionResult Edit(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }
 
           Product product = db.Products.Find(id);
            if (product == null)
            {
                return HttpNotFound();
            }

            ViewBag.CategoryId = new SelectList(db.Categories, "CategoryId", "CategoryName", product.CategoryId);
            return View(product);
        }

        // POST: Products/Edit/5
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit([Bind(Include = "ProductId,ProductName,Price,CategoryId")] Product product)
        {
            if (ModelState.IsValid)
            {
                db.Entry(product).State = EntityState.Modified;
                db.SaveChanges();

                return RedirectToAction("Index");
            }

            ViewBag.CategoryId = new SelectList(db.Categories, "CategoryId", "CategoryName", product.CategoryId);
            return View(product);
        }



        // GET: Products/Delete/5
        public ActionResult Delete(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }

            Product product = db.Products.Find(id);
            if (product == null)
            {
                return HttpNotFound();
            }

            return View(product);
        }

        // POST: Products/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public ActionResult DeleteConfirmed(int id)
        {
            Product product = db.Products.Find(id);
            db.Products.Remove(product);

            db.SaveChanges();
            return RedirectToAction("Index");
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                db.Dispose();
            }

            base.Dispose(disposing);
        }
    }

Similarly add “Categories” controller. Categories controller will contain following code:

public class CategoriesController : Controller
    {
        private EF_FAQ_Entities db = new EF_FAQ_Entities();

        // GET: Categories
        public ActionResult Index()
        {
            return View(db.Categories.ToList());
        }

        // GET: Categories/Details/5
        public ActionResult Details(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }

            Category category = db.Categories.Find(id);
            if (category == null)
            {
                return HttpNotFound();
            }

            return View(category);
        }

        // GET: Categories/Create
        public ActionResult Create()
        {
            return View();
        }

        // POST: Categories/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "CategoryId,CategoryName")] Category category)
        {
            if (ModelState.IsValid)
            {
                db.Categories.Add(category);
                db.SaveChanges();

                return RedirectToAction("Index");
            }

            return View(category);
        }

        // GET: Categories/Edit/5
        public ActionResult Edit(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }

            Category category = db.Categories.Find(id);
            if (category == null)
            {
                return HttpNotFound();
            }

            return View(category);
        }

        // POST: Categories/Edit/5
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Edit([Bind(Include = "CategoryId,CategoryName")] Category category)
        {
            if (ModelState.IsValid)
            {
                db.Entry(category).State = EntityState.Modified;
                db.SaveChanges();

                return RedirectToAction("Index");
            }

            return View(category);
        }

        // GET: Categories/Delete/5
        public ActionResult Delete(int? id)
        {
            if (id == null)
            {
                return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
            }

            Category category = db.Categories.Find(id);

            if (category == null)
            {
                return HttpNotFound();
            }

            return View(category);
        }

        // POST: Categories/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public ActionResult DeleteConfirmed(int id)
        {
            Category category = db.Categories.Find(id);
            db.Categories.Remove(category);

            db.SaveChanges();

            return RedirectToAction("Index");
        }

        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                db.Dispose();
            }

            base.Dispose(disposing);
        }
    }

Put connection string in web.config as:

<connectionStrings>
    <add name="EF_FAQ_Entities" connectionString="Data Source=YourSQLInstanceName;Initial Catalog=EF_FAQ;Integrated Security=True;" providerName="System.Data.SqlClient" />
</connectionStrings>

When you run the application and access “/categories”, it will automatically create the database same as the name of Context class i.e.

While accessing the url ”Categories”, following screen will appear:

Click on create new, to create new category.

After creation of categories, let’s create products.

Access “/Products”, following screen will appear,

Create new product,

This is very basic example for ASP.NET MVC Application with Code-First Approach using two related entities i.e. Category & Product. Hopefully, it will be helpful for understanding the approach in a more practical way.

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