How to reference .NET framework from ASP.NET Core

Question

I have a ASP.NET MVC 5 / .NET 4.7 project that I want to upgrade to ASP.NET Core.

The MVC frontend references a service layer project (SL) which in its that uses a datal

Answer 1

If you want to switch to .NETCore and still be able to use older libraries you should tagret .NETFramework.
So when creating new project select:

ASP.NET Core Web Application (.NET Framework)

In addition this month(actually yesterday) .NETCore 2.0 along with EFCore 2.0 is released. Both frameworks have much more features, so I suggest migrating to 2.0 project.
Also EFCore 2.0 should now have most features that were needed so I would go with that as well.