We have created the Database, yet it’s still completely empty. In order to test it against our existing application, it will be useful to find an easy way of adding some sample data programmatically.

In the most recent Entity Framework versions, up to and including EF6, it was possible to do that using the DbMigrationsConfiguration.Seed() method. Unfortunately, though, migrations configuration doesn’t exist in EF Core; this seems to be more of an implementation choice than a lack of features, since the seeding task can now be performed directly within the Startup.cs file.

Although this is definitely true, there is still some controversy going on between the EF Core developers community regarding that specific aspect. The absence of a high-level API and/or a consolidated pattern to run seeding after applying migrations is indeed something that should be addressed somehow, as executing such a delicate task during application run creates a number of issues, and it doesn’t seem to be a viable solution in most scenarios.