Addamodel.md

The tutorial below is based on "Get started with ASP.NET Core Razor Pages in Visual Studio Code" from docs.microsoft.com.

Prerequisites

• .NET Core SDK 2.2
• Visual Studio Code
• Tutorial 1- Create a Razor Page application

Add a data model

In this section, we are adding classes to manage movies in a database.

• Add a folder named Models
• Add a class to Models folder named Movie.cs

Add the code below to Movie.cs

using System;

namespace RazorPagesMovie.Models
{
    public class Movie
    {
        public int ID { get; set; }
        public string Title { get; set; }
        public DateTime ReleaseDate { get; set; }
        public string Genre { get; set; }
        public decimal Price { get; set; }
    }
}

Add a database context class

Create a new class named MovieContext.cs in the Models folder. The database context, or DbContext, is a class provided by Entity Framework to facilitate database interactions.

using Microsoft.EntityFrameworkCore;

namespace RazorPagesMovie.Models
{
    public class MovieContext : DbContext
    {
        public MovieContext(DbContextOptions<MovieContext> options)
                : base(options)
        {
        }

        public DbSet<Movie> Movie { get; set; }
    }
}

The code above creates a DbSet property for the entity set. An entity set typically corresponds to a database table, and an entity corresponds to a row in the table.

Add a connection string

Open the appsettings.json file and add the MovieContext connection string as shown below.

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "ConnectionStrings": {
    "MovieContext": "Data Source=MvcMovie.db"
  }
}

Register the database context

Open Startup.cs file and add the code below to the ConfigureServices method.

public void ConfigureServices(IServiceCollection services)
{
    services.Configure<CookiePolicyOptions>(options =>
    {
        // This lambda determines whether user consent for non-essential cookies is needed for a given request.
        options.CheckConsentNeeded = context => true;
        options.MinimumSameSitePolicy = SameSiteMode.None;
    });

    services.AddDbContext<MovieContext>(options => options.UseSqlite(Configuration.GetConnectionString("MovieContext")));
    services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}

Add the following using statements: using RazorPagesMovie.Models and using Microsoft.EntityFrameworkCore.

Add scaffold tooling and perform initial migration

In the command line run the following commands

dotnet add package Microsoft.VisualStudio.Web.CodeGeneration.Design
dotnet add package Microsoft.EntityFrameworkCore.Sqlite
dotnet restore
dotnet ef migrations add InitialCreate
dotnet ef database update

Commands Explained

Command	Description
add package	installs the tools needed
ef migrations add InitialCreate	generates code to create the initial database schema based on the model specified in 'MovieContext.cs'. InitialCreate is the name of the migrations.
ef database update	creates the database

Scaffold the movie model

Install the aspnet-codegenerator global tool by running the following command:

dotnet tool install --global dotnet-aspnet-codegenerator --version 2.1.1

Note: You will need to close and reopen the console window to be able to use this tool.

Run the commands below

On Windows

dotnet aspnet-codegenerator razorpage -m Movie -dc MovieContext -udl -outDir Pages\Movies --referenceScriptLibraries

On Mac and Linux

dotnet aspnet-codegenerator razorpage -m Movie -dc MovieContext -udl -outDir Pages/Movies --referenceScriptLibraries

Test your app

1. Run the app dotnet run
2. Launch a browser and go to http://localhost:5000/movies

1. Create a new entry

• It works!

• Test Edit, Details and Delete links

Extra light read 7 minutes: If you want to read more on pages we just created click here for more information.

NEXT TUTORIAL :Modifying generated pages