Getting Started

All the examples in this workshop are based on Autobarn, a fictional website for listing used cars for sale. Autobarn is an ASP.NET web application that uses an in-memory data store, so you can download and run the Autobarn code without any external dependencies.

Prerequisites

To complete the exercises in the workshop, you’ll need the Autobarn source code and a .NET runtime. The Autobarn repository is hosted on GitHub. Get started by cloning the Autobarn repo to your local machine:

git clone git@github.com:ursatile/autobarn.git
cd autobarn
cd dotnet
dotnet build
dotnet test
dotnet run --project Autobarn.Website**

Sqlite and in-memory databases

Autobarn uses Entity Framework (EF) Core, but it’s configured to use the Sqlite DB provider with an in-memory database

SQLite is a C-language library that implements a small, fast, self-contained, high-reliability, full-featured, SQL database engine. SQLite is the most used database engine in the world. SQLite is built into all mobile phones and most computers and comes bundled inside countless other applications that people use every day.

from https://sqlite.org/

In other words, SQLite is a tiny database engine that doesn’t use a server: it runs in the same process as our application code, which makes it perfect for development and testing scenarios where we need to connect a database but we don’t really care what happens to the data.

If you take a look in Program.cs you’ll see these lines:

SqliteConnection sqliteConnection = new($"Data Source=:memory:");
sqliteConnection.Open();
builder.Services.AddDbContext<AutobarnDbContext>(options => options.UseSqlite(sqliteConnection));

and

using var scope = app.Services.CreateScope();
await using var db = scope.ServiceProvider.GetRequiredService<AutobarnDbContext>();
db.Database.EnsureCreated();

The in-memory provider for Sqlite (initialised by the "Data Source=:memory" connection string) will create a temporary database that persists for as long as there’s at least one open connection, so we explicitly open a connection that stays open for the lifetime of the application, and then we use EF Core’s Database.EnsureCreated() method to scaffold the data schema and populate it with sample data.

The data itself is held in a set of CSV files in the Autobarn.Data.Sample folder/namespace, and is inserted using the .HasData() method called from the AutobarnDbContext class.