How to use entity framework in ASP.Net Core MVC

In this article we will discuss How to use entity framework in ASP.Net Core MVC.

Here we will explain how to configure Entity Framework and connect to SQL Server database and  displayed in View in ASP.Net Core MVC..

Before start this article, please visit our previous article Populating DropDownList inside Razor Pages in ASP.Net Core MVC

Database

	CREATE TABLE [dbo].[States](
	[stateAbbrev] [nchar](10) NULL,
	[stateName] [nchar](20) NULL,
	[stateID] [smallint] NOT NULL
	) ON [PRIMARY]
	GO

view raw States.sql hosted with ❤ by GitHub

Downloading Entity Framework Core

You will need to install the Microsoft.EntityFrameworkCore.SqlServer package using the following command.

Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 2.1.1

Model

Let's create a class in Models folder like below.

	public class States
	{
	[Key]
	public Int16 stateID { get; set; }
	public string stateName { get; set; }
	public string stateAbbrev { get; set; }
	}

view raw States.cs hosted with ❤ by GitHub

Database Context

Now you will need to add a new class to your project by right clicking the Solution Explorer and then click on Add and then New Item option of the Context Menu.

Inside the class, first inherit the EntityFrameworkCore namespace and then inherit the DbContext class.

Then using Dependency Injection, a Constructor is created DbContextOptions are passed as parameter and also the Constructor of base class i.e. DbContext class is inherited.

Finally, a DbSet Collection property of Customer Model class is created, which will be later used for holding the Data fetched from SQL Server Database Table.

	public class DBContextEF : DbContext
	{
	public DBContextEF(DbContextOptions<DBContextEF> options) : base(options)
	{
	}
	public DbSet<States> States { get; set; }
	}

view raw DBContextEF.cs hosted with ❤ by GitHub

Adding the Connection String inside AppSettings.json

The following Connection String setting has been added in the AppSettings.json file.

	{
	"Logging": {
	"LogLevel": {
	"Default": "Information",
	"Microsoft": "Warning",
	"Microsoft.Hosting.Lifetime": "Information"
	}
	},
	"AllowedHosts": "*",
	"ConnectionStrings": {
	"DBConnection": "Data Source=MSCNUR1888004;Initial Catalog=DentalJobs;Integrated security=true"
	}
	}

view raw appsettings.json hosted with ❤ by GitHub

Configuring Database Context in Startup class

Inside the Startup class, the IConfiguration is injected in the Startup class and assigned to the private property Configuration.

Then the Connection String is read from the AppSettings.json file and is used to add the DbContext service.

	public void ConfigureServices(IServiceCollection services)
	{
	services.AddControllersWithViews();
	string conStr = this.Configuration.GetConnectionString("DBConnection");
	services.AddDbContext<DBContextEF>(options => options.UseSqlServer(conStr));
	}

view raw startup.cs hosted with ❤ by GitHub

Controller

Inside the Index Action method, the Top 10 records are fetched from the States Table.

	public class HomeController : Controller
	{
	private readonly ILogger<HomeController> _logger;
	private DBContextEF Context { get; }
	public HomeController(ILogger<HomeController> logger, DBContextEF _context)
	{
	_logger = logger;
	this.Context = _context;
	}
	public IActionResult Index()
	{
	List<States> states = Context.States.Take(10).ToList();
	return View(states);
	}
	}

view raw HomeController.cs hosted with ❤ by GitHub

View

Inside the View, in the very first line the State Entity is declared as IEnumerable which specifies that it will be available as a Collection.

For displaying the records, an HTML Table is used. A loop will be executed over the Model which will generate the HTML Table rows with the State records.

	@using MVCCore.EF.Models
	@model IEnumerable<States>
	@{
	ViewData["Title"] = "Home Page";
	}
	<div class="text-center">
	<h4>State List</h4>
	<hr />
	<table class="table table-bordered">
	<tr>
	<th>State ID</th>
	<th>State Name</th>
	<th>State Abbreviation</th>
	</tr>
	@foreach (States state in Model)
	{
	<tr>
	<td>@state.stateID</td>
	<td>@state.stateName</td>
	<td>@state.stateAbbrev</td>
	</tr>
	}
	</table>
	</div>

view raw Index.cshtml hosted with ❤ by GitHub

Output

When run the application we can see the output like below.

</> Find the Source Code in Github

  Summary

In this tutorial we discussed about How to use entity framework in ASP.Net Core MVC. If have any question related to this topic then give your feedback.