Work with the database

The API keeps its data in a SQLite file called movie-reviews.db. With dotnet run it sits next to the app. In the container it’s at /app/data/movie-reviews.db, on the movie-reviews-data volume, so it survives a restart and a rebuild. Nothing to install, nothing to provision, nothing to forget the password for.

When the database is created

Every time the API starts, it applies any pending Entity Framework Core migrations. If Database:SeedSampleData is true and the database is empty, it also seeds the sample movies, authors and reviews. It’s on in appsettings.local.json and appsettings.docker.json, and off everywhere else, so a deployed copy never starts life full of fake reviews.

The sample data uses a fixed seed, so every machine gets the same 15 authors, the same movies and the same ids. That’s why the examples in these docs can name a movie id and expect it to exist on your laptop too.

Start again

Delete movie-reviews.db, or drop the volume:

docker compose down -v

The next start builds a fresh database and seeds it again.

Use a different connection string

Set ConnectionStrings__MovieReviews. To keep everything in memory, which is what the tests do:

docker run --rm -p 8080:8080 -e DOTNET_ENVIRONMENT=docker \
  -e ConnectionStrings__MovieReviews="Data Source=MovieReviews;Mode=Memory;Cache=Shared" \
  acme-movies:local

Add a migration

After you change the data model in src/Infrastructure:

dotnet tool install --global dotnet-ef
dotnet ef migrations add AddDirectors --project ./src/Infrastructure --output-dir Databases/MovieReviews/Migrations

The next start applies it.

The tests have their own copy

Every test class builds its own in-memory SQLite database from the same migrations and the same seed, so dotnet test never touches movie-reviews.db. You can run the tests while the API is running and neither will notice.

Swap SQLite for something real

Everything database-shaped lives in Infrastructure, and every class there is internal. To move to PostgreSQL, SQL Server or anything else, implement the repository interfaces from Application (IMoviesRepository, IAuthorsRepository and IReviewsRepository) against the new store and register them in Infrastructure/DependencyInjection.cs. Application and Presentation don’t need to know it happened. That’s the whole sales pitch of Clean Architecture in one paragraph.