Entity Framework EF Model First Discover How to Use Model First

What is Entity Framework Model First?

Model First allows you to create a new model using the Entity Framework Designer and then generate a database schema from the model.

• The model is stored in an EDMX file (.edmx extension) and can be viewed and edited in the Entity Framework Designer.
• The classes that you interact with in your application are automatically generated from the EDMX file.

Create Model

Let's create a new empty project and add the EntityFramework NuGet package which is explained in the Code First approach.

We will use of Entity Framework Designer, which is included as part of Visual Studio, to create our model.

Right click on the project in Solution Explorer and choose Add > New Item... option.

Select Data from the left menu and then ADO.NET Entity Data Model.

Enter BookStore as the name and click Add. This launches the Entity Data Model Wizard. Select Empty FF Designer model and click Finish.

The Entity Framework Designer is opened with a blank model. Now we can start adding entities, properties, and associations to the model.

Right-click on the design surface and select Add New > Entity...

Enter Book as the entity name and BlogId as the key name and click OK.

Right-click on the new entity on the design surface and select Add New > Scalar Property, enter Title as the name of the property.

Similarly, add an Author entity with an AuthorId key and FirstName and LastName properties using the above-mentioned steps.

Right-click on the design surface and select Add New > Association...

Make one end of the relationship point to Author with a multiplicity of One and the other endpoint to Books with a multiplicity of Many.

It means that an Author has many Books and a Book belongs to one Author. Make sure to check the Add foreign key properties to 'Book' Entity box is checked and click OK.

We now have a simple model that we can generate a database from and use to read and write data.

Generate Database

Entity Framework can calculate a database schema that will allow us to store and retrieve data using the above model.

Right-click on the design surface and select Generate Database from Model.... Click New Connection... and specify the Server and database name and click OK.

You will be asked if you want to create a new database, select Yes.

Select *Next and the Entity Framework Designer will calculate a script to create the database schema.

Once the script is displayed, click Finish and the script will be added to your project and opened.

Right-click on the script and select Execute, you will be prompted to specify the database to connect to.

Access Data

Now that we have a model it's time to use it to access some data. The classes we are going to use to access data are being automatically generated for you based on the EDMX file.

using (var db = new BookStoreContainer())
{
    db.Books.Add(new Book { Title = "Introduction to Programming" });
    db.SaveChanges();

    foreach (var book in db.Books)
    {
        Console.WriteLine(book.Title);
    }
}

Related links

For further details please see the following links.

• https://www.tutorialspoint.com/entity_framework/entity_model_first_approach.htm
• https://www.entityframeworktutorial.net/model-first-with-entity-framework.aspx