using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        List<Parent> parents = new List<Parent>() { new Child1(), new Child2()};

        Database<Parent> db = new Database<Parent>();

        foreach (Parent parent in parents)

            db.Add(parent, Guid.NewGuid());

        foreach (Parent parent in db.storage.Values)

            Console.WriteLine(parent.GetType());

    }

}

​

public class Database<T>

        {

            public Dictionary<Guid,T> storage = new Dictionary<Guid, T>();

​

            public void Add(T obj, Guid id) { storage[id] = obj; }

​

            public void Remove(Guid id) { storage.Remove(id); }

        }

​

public class Parent

{

​

}

​

public class Child1 : Parent

{

​

}

​

public class Child2 : Parent

{

​

}