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

title	author	description	keywords	ms.author	manager	ms.date	ms.topic	ms.assetid	ms.technology	ms.prod	uid
Adding a model to an ASP.NET MVC Core app	rick-anderson	Add a model to a simple ASP.NET Core app.	ASP.NET Core, MVC, scaffold, scaffolding	riande	wpickett	03/30/2017	get-started-article	8dc28498-eeee-1638-b903-b593059e9f39	aspnet	asp.net-core	tutorials/first-mvc-app-mac/adding-model

[!INCLUDEadding-model]

• In Solution Explorer, right-click the MvcMovie project, and then select Add > New Folder. Name the folder Models.

• Right-click the Models folder, and then select Add > New File.

• In the New File dialog:

  • Select General in the left pane.
  • Select Empty Class in the center pain.
  • Name the class Movie and select New.

Add the following properties to the Movie class:

[!code-csharpMain]

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

Build the project to verify you don't have any errors. You now have a Model in your MVC app.

Prepare the project for scaffolding

• Right click on the project file, and then select Tools > Edit File.

  

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

  [!code-csharpMain]

• Save the file.

• 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 

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.

Add the files to Visual Studio

• Add the MovieController.cs file to the Visual Studio project:

  • Right-click on the Controllers folder and select Add > Add Files.
  • Select the MovieController.cs file.

• Add the Movies folder and views:

  • Right-click on the Views folder and select Add > Add Existing Folder.
  • Navigate to the Views folder, select Views\Movies, and then select Open.
  • In the Select files to add from Movies dialog, select Include All, and then OK.

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);
}

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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 Adding a View Next Working with SQL