AspNetCore.Docs/aspnetcore/tutorials/first-mvc-app-xplat/adding-model.md

title	author	description	keywords	ms.author	manager	ms.date	ms.topic	ms.assetid	ms.technology	ms.prod	uid
Adding a model | Microsoft Docs	rick-anderson	Add a model to a simple ASP.NET Core app.	ASP.NET Core,	riande	wpickett	03/30/2017	get-started-article	8dc28498-eeee-4666-b903-b593059e9f39	aspnet	asp.net-core	tutorials/first-mvc-app-xplat/adding-model

[!INCLUDEadding-model1]

• Add a folder named Models.
• Add a class to the Models folder named Movie.cs.
• Add the following code to the Models/Movie.cs file:

[!code-csharpMain]

The ID field is required by the database for the primary key.

Build the app to verify you don't have any errors, and you've finally added a Model to your MVC app.

Prepare the project for scaffolding

• Add the following highlighted NuGet packages to the MvcMovie.csproj file:

  [!code-csharpMain]

• Save the file and select Restore to the Info message "There are unresolved dependencies".

• Create a Models/MvcMovieContext.cs file and add the following MvcMovieContext class:

  [!code-csharpMain]

• Open the Startup.cs file and add two usings:

  [!code-csharpMain]

• Add the database context to the Startup.cs file:

  [!code-csharpMain]

  This tells Entity Framework which model classes are included in the data model. You're defining one entity set of Movie objects, which will be represented in the database as a Movie table.

• Build the project to verify there are no errors.

Scaffold the MovieController

Open a terminal window in the project folder and run the following commands:

dotnet restore
dotnet aspnet-codegenerator controller -name MoviesController -m Movie -dc MvcMovieContext --relativeFolderPath Controllers --useDefaultLayout --referenceScriptLibraries 

[!NOTE] If you get an error when the scaffolding command runs, see issue 444 in the scaffolding repository for a workaround.

The scaffolding engine creates the following:

• A movies controller (Controllers/MoviesController.cs)
• Razor view files for Create, Delete, Details, Edit and Index pages (Views/Movies/*.cshtml)

The automatic creation of CRUD (create, read, update, and delete) action methods and views is known as scaffolding. You'll soon have a fully functional web application that lets you manage a movie database.

Create the database

You'll call the EnsureCreated method to cause EF Core to create the database if it doesn't exist.

This is a method you typically use only in a development environment. It creates a database to match your data model when you run the app for the first time. When you change your data model, you drop the database. The next time the app runs, EF Core creates a new database to match your new data model.

This approach doesn't work well in production, because you have data you don't want to lose by dropping the database. EF Core includes a Migrations feature that lets you preserve data when you make data model changes, but you won't be using Migrations in this tutorial. You'll learn more about data model changes in the Add a field tutorial.

Create a Models\DBinitialize.cs file and add the following code:

using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using System;

namespace MvcMovie.Models
{
    public static class DBinitialize
    {
        public static void EnsureCreated(IServiceProvider serviceProvider)
        {
            var context = new MvcMovieContext(
                serviceProvider.GetRequiredService<DbContextOptions<MvcMovieContext>>());
            context.Database.EnsureCreated();
        }
    }
}

Call the EnsureCreated method from the Configure method in the Startup.cs file. Add the call to the end of the method:

    app.UseMvc(routes =>
    {
        routes.MapRoute(
            name: "default",
            template: "{controller=Home}/{action=Index}/{id?}");
    });

    DBinitialize.EnsureCreated(app.ApplicationServices);
}

[!INCLUDEadding-model]

You now have a database and pages to display, edit, update and delete data. In the next tutorial, we'll work with the database.

Additional resources

• Tag Helpers
• Globalization and localization

[!div class="step-by-step"] Previous - Add a view Next - Working with SQLite