Including derived child properties in Entity Framework Core 2.0

Question

Using Entity Framework Core 2.0, I am trying to construct a query to include related data for a polymorphic child entity.

For example, given the following types:

Answer 1

This functionality is not available in EFC 2.0.

It's been tracked as #3910 Query: Support Include/ThenInclude for navigation on derived type and according to the current EFC Roadmap, it's scheduled for EFC 2.1 release (Include for derived types item under Features we have committed to complete).