Design a generic model for multiple entities with Entity Framework - entity-framework

Question

How can I model this scenario with Entity Framewrok Code First:
Cats:
| Id | Name |
|----|-------|
| 1| Cat1|
| 2| Cat2|
| 3| Cat3|
Dogs:
| Id | Name |
|----|-------|
| 1 | Dog1|
| 2 | Dog2|
| 3 | Dog3|
Owner:
| Id | Name |TableName |EntityId|
|----|-------|--------------------
| 1 | John| Dog | 1|
| 2 | Pete| Cat | 1|
| 3 |Jessica| Cat | 2|
This is just an example of what I want to accomplish. I need that Owner Table can store any Animal, I meant, I have no control over the animal tables, so plus cats and dogs, there may be mouses, lions, etc.
Entity Framework support this? Can I model this with navigation properties?
I have read about Table Per Hierarchy but don't think that should follow this approach. Also, I want to navigate from Owner table to any animal entity.

Answer 1

I offer to you this solution, that completely compatible with your tables and also if you will add another table with new animal, it is not needed to make any changes at Owner class, that is why it is generic approach as you desired.
MODELS:
public class Animal
{
public int Id { get; set; }
[StringLength(64)]
public string Name { get; set; }
}
public class Dog : Animal
{
}
public class Cat : Animal
{
}
public class Owner
{
public int Id { get; set; }
[StringLength(64)]
public string Name { get; set; }
[StringLength(64)]
public string TableName { get; private set; }
public int? EntityId { get; private set; }
[NotMapped]
public Animal animal {
get {
if (EntityId == null || string.IsNullOrEmpty(TableName))
return null;
using (var context = new Context())
{
var type = typeof(Animal).Assembly.GetTypes().Where(x => x.Name.Contains(TableName)).First();
return (Animal)context.Set(type).Find(EntityId);
}
}
set {
//I assume that animal has already existed on this moment i.e. Id field is valid.
EntityId = value.Id;
TableName = value.GetType().Name;
}
}
}
IMPLEMENTATION:
var cat = context.Cats.Add(new Cat { Name = "Cat1" });
context.SaveChanges();
var owner = context.Owners.Add(new Owner { Name = "Owner", animal = cat });
context.SaveChanges();
var animal = owner.animal;