EF Code First and linq extension methods - foreign keys, am i doing it wrong? - linq

Question

I have something like this: (pseudocode)
public class Author
{
int id;
public List<Thread> Threads;
public List<ThreadPoints> ThreadPointses;
}
public class Thread
{
int id;
public List<ThreadPoints> ThreadPointses;
}
public class ThreadPoints
{
int id;
int Points;
}
And i am not sure if above is correct, but now i would want to obtain number of points' that specified Author have in specified Thread.
I cannot directly call ThreadPoints.Thread_id, because it's not accessible, even if it physically is in the database.
So do i need to change my model, or am i unaware of some useful methods?
So basically, my model looks like that:
public class Account
{
[Key]
public Guid AccountId { get; set; }
public string UserName { get; set; }
public List<Post> Posts { get; set; }
public List<Post> ModifiedPosts { get; set; }
public List<Thread> Threads { get; set; }
public List<ThreadPoints> ThreadPointses { get; set; }
public List<Thread> LastReplied { get; set; }
public int Points { get; set; }
}
public class Thread
{
[Key]
public int Id { get; set; }
public List<ThreadPoints> ThreadPointses { get; set; }
public List<Post> Posts { get; set; }
public int CurrentValue { get; set; }
public int NumberOfPosts { get; set; }
public int TotalValue { get; set; }
public int Views { get; set; }
public string Title { get; set; }
public DateTime DateCreated { get; set; }
}
public class ThreadPoints
{
[Key]
public int Id { get; set; }
public int Points { get; set; }
}
And what i need, is, when user creates a thread, he gives some amount of points into it. In the next action, i want to take that amount of points (from database), and increase it. But i only have thread id as input information.
Your answer might be good, (as far i am trying to implement it), but anyways, i am not sure about this model. Maybe i should manually add foreign keys into my model? It surely would be simpler, but then i would have two foreign keys in my database...

Answer 1

Since you're not explicitly mapping your FK's, entity framework is generating them and hiding them away, so to get to the Id's of the properties, you'll need to follow the navigation collections.
I'm not sure about your question, but are you wanting the number of Points, inside of a specific Threadpoint for a given author? Your model doesn't seem to support this very well, but you could do something like this-
public int GetPoints(Author author, Thread thread)
{
int points = author.Threads.FirstOrDefault(t => t.id == thread.id).ThreadPointses.Sum(tp => tp.Points);
}
This would return the sum of all the points contained in the list of threadpoints, which are contained in the list of threads with the same id as the thread you passed in, for the specified author.
If this doesn't work for you - can you post your actual model?