For background, let’s say I have two classes:

public class OrderType1 : ModelBase 
{
    public string Customer { get; set; }
}

public class OrderType2 : ModelBase 
{
    public string Customer { get; set; }
}

Then one class that can hold a reference to either of these types, based on a base class ModelBase which does not have the Customer field in it.

public class ScheduledOrder : ModelBase 
{
    public int ClientId { get; set; }

    [JsonIgnore]
    [ForeignKey(nameof(ClientId))]
    public virtual Client Client { get; set; }

    public int OrderType { get; set; }
    public int? TemplateId { get; set; }

    // This can be either OrderType1 or OrderType2
    [JsonIgnore]
    [ForeignKey(nameof(TemplateId))]
    public Virtual ModelBase Template { get; set; } 
}

I want to be able to include Template when I retrieve a ScheduledOrder from the database so that I can access the Customer field of either class, and maybe do specific things with each derived class.

When I attempt this I get errors in OnConfiguring of a completely different type and it looks unrelated.

My question is is something like this even possible? I want to avoid having to query the database again using an OrderType property or something.