C# – ASP.NET Core MVC Application with Basic Database Access using Entity Framework – Video

The title somehow looks like random words, picked from a hat at one of those college games we are not supposed to talk about. Anyway, at the second reading it hopefully becomes a bit clearer. And it is simply the “magic” of creating 2 C# classes in visual studio and transferring them to tables in a database with the magic of Entity Framework. Then, with ASP, being able to access the database with the 2 tables and making simple CRUD (Create, Read, Update, Delete) actions. This is how the R in CRUD looks like:

As mentioned, there are 2 main classes in the application – Blog.cs and Post.cs and these have a relation 1-to-many between each other:

As far as the code is mainly generated from the scaffold features of Visual Studio, I will show only the PostController.cs and the \Posts\Details.cshtml here. The rest is in GitHub and in the video.

PostController.cs

using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Rendering;
using Microsoft.EntityFrameworkCore;
using EFGetStarted.Models;

namespace EFGetStarted.Controllers
{
    public class PostsController : Controller
    {
        private readonly BloggingContext _context;

        public PostsController(BloggingContext context)
        {
            _context = context;
        }

        // GET: Posts
        public async Task Index()
        {
            var bloggingContext = _context.Posts.Include(p => p.Blog);
            return View(await bloggingContext.ToListAsync());
        }

        // GET: Posts/Details/5
        public async Task Details(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var post = await _context.Posts
                .Include(p => p.Blog)
                .FirstOrDefaultAsync(m => m.PostId == id);
            if (post == null)
            {
                return NotFound();
            }

            return View(post);
        }

        // GET: Posts/Create
        public IActionResult Create()
        {
            ViewData["BlogId"] = new SelectList(_context.Blogs, "BlogId", "BlogId");
            return View();
        }

        // POST: Posts/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 async Task Create([Bind("PostId,Title,Content,BlogId")] Post post)
        {
            if (ModelState.IsValid)
            {
                _context.Add(post);
                await _context.SaveChangesAsync();
                return RedirectToAction(nameof(Index));
            }
            ViewData["BlogId"] = new SelectList(_context.Blogs, "BlogId", "BlogId", post.BlogId);
            return View(post);
        }

        // GET: Posts/Edit/5
        public async Task Edit(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var post = await _context.Posts.FindAsync(id);
            if (post == null)
            {
                return NotFound();
            }
            ViewData["BlogId"] = new SelectList(_context.Blogs, "BlogId", "BlogId", post.BlogId);
            return View(post);
        }

        // POST: Posts/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 async Task Edit(int id, [Bind("PostId,Title,Content,BlogId")] Post post)
        {
            if (id != post.PostId)
            {
                return NotFound();
            }

            if (ModelState.IsValid)
            {
                try
                {
                    _context.Update(post);
                    await _context.SaveChangesAsync();
                }
                catch (DbUpdateConcurrencyException)
                {
                    if (!PostExists(post.PostId))
                    {
                        return NotFound();
                    }
                    else
                    {
                        throw;
                    }
                }
                return RedirectToAction(nameof(Index));
            }
            ViewData["BlogId"] = new SelectList(_context.Blogs, "BlogId", "BlogId", post.BlogId);
            return View(post);
        }

        // GET: Posts/Delete/5
        public async Task Delete(int? id)
        {
            if (id == null)
            {
                return NotFound();
            }

            var post = await _context.Posts
                .Include(p => p.Blog)
                .FirstOrDefaultAsync(m => m.PostId == id);
            if (post == null)
            {
                return NotFound();
            }

            return View(post);
        }

        // POST: Posts/Delete/5
        [HttpPost, ActionName("Delete")]
        [ValidateAntiForgeryToken]
        public async Task DeleteConfirmed(int id)
        {
            var post = await _context.Posts.FindAsync(id);
            _context.Posts.Remove(post);
            await _context.SaveChangesAsync();
            return RedirectToAction(nameof(Index));
        }

        private bool PostExists(int id)
        {
            return _context.Posts.Any(e => e.PostId == id);
        }
    }
}

\Posts\Details.cshtml

@model EFGetStarted.Models.Post

@{
    ViewData["Title"] = "Details";
}

<h2>Details</h2>

<div>
    <h4>Post</h4>
    <hr>
    <dl class="dl-horizontal">
        <dt>
            @Html.DisplayNameFor(model => model.Title)
        </dt>
        <dd>
            @Html.DisplayFor(model => model.Title)
        </dd>
        <dt>
            @Html.DisplayNameFor(model => model.Content)
        </dt>
        <dd>
            @Html.DisplayFor(model => model.Content)
        </dd>
        <dt>
            @Html.DisplayNameFor(model => model.Blog)
        </dt>
        <dd>
            @Html.DisplayFor(model => model.Blog.BlogId)
        </dd>
    </dl>
</div>
<div>
    <a asp-action="Edit" asp-route-id="@Model.PostId">Edit</a> |
    <a asp-action="Index">Back to List</a>
</div>

The video:

The GitHub code:

https://github.com/Vitosh/ASP/tree/master/EFGetStarted

The Original Microsoft.com tutorial:

https://docs.microsoft.com/en-us/ef/core/get-started/aspnetcore/new-db?tabs=visual-studio