Entity Framework - related ICollection getting materialized into HashSet

Question

I use EntityFramework POCO + proxies + lazy loading in my project. Today I was pretty surprized to see that the class Transaction has its related collection Rows materialized into HashSet (instead of EntityCollection). I need EntityCollection for tracking changes in the collection.

public class Transaction
{
    public virtual ICollection<TransactionRow> Rows { get; set; }
}

However other entity classes have their related collection materialized into EntityCollection.

I am loading the Transaction through ObjectQuery, so it should be in the context. The proxy for the object is also created.

Could anyone tell - how does Entity Framework decide what to use - HashSet or EntityCollection? Why some thing become HashSets?

Tactician

Answer 1

Change tracking proxy is created only when these two conditions are met:

• POCO class is public, non-sealed and non-abstract
• All persisted properties (with getter and setter) are marked as virtual

Juggle

Ouch, I just inspected the class once more and realized that the collection was not marked as virtual :) Thanks for the hint! – Tactician