Why should you care?

Swapping SQL Server for PostgreSQL later only changes Infrastructure — Domain stays untouched.

See it live — copy this example

Create a Web API project (dotnet new webapi), paste the code, then run dotnet run.

public class UserDbContext : DbContext
{
    public UserDbContext(DbContextOptions<UserDbContext> o) : base(o) { }
    public DbSet<UserProfile> Users => Set<UserProfile>();
}

public class UserRepository : IUserRepository
{
    private readonly UserDbContext _db;
    public UserRepository(UserDbContext db) => _db = db;
    public Task AddAsync(UserProfile user, CancellationToken ct = default)
    {
        _db.Users.Add(user);
        return _db.SaveChangesAsync(ct);
    }
}

Run Example »

Edit the code and click Run — like W3Schools Try it Yourself.

What happened?

• EF configuration for Email value object conversion can live in OnModelCreating.
• Migrations live in Infrastructure project.

Try it yourself

1. Add Microsoft.EntityFrameworkCore.SqlServer package.
2. build UserRepository.
3. dotnet ef migrations add Initial -p Infrastructure -s Api
4. Change a string or route in the example and save — watch Swagger or the RabbitMQ Management UI update.
5. Break the code on purpose (remove a semicolon), read the error message, then fix it.

Remember

Infrastructure = EF + repository impl. One DbContext per service. Migrations version schema.