Your startup project doesn't reference Microsoft.EntityFrameworkCore.Design

Question

I have 2 projects in my solution, I have a project with Entity Framework Core installed:

And in the other ASP.NET Web API project I have these packages:

Answer 1

If you want to do migrations without adding EF references in your services, your library with data access needs a way to construct an instance of your DbContext. You can do this by implementing IDesignTimeDbContextFactory, example:

public class MyContextFactory : IDesignTimeDbContextFactory
{
    public MyContext CreateDbContext(string[] args)
    {
        var optionsBuilder = new DbContextOptionsBuilder();
        optionsBuilder.UseSqlServer("Data Source=MyDatabase");

        return new MyContext(optionsBuilder.Options);
    }
}