NHibernate-内存中的关联未更新

Question

I have the following problem model:

class Item
{
    public virtual int Id { get; set; }

    public virtual Category Category { get; set;}

    // Bi-directional mapping to simplify object traversal.
    public virtual Storage Storage { get; set; }
}

class Category
{
    public virtual int Id { get; set; }

    // Bi-directional mapping to simplify object traversal.
    public virtual IList<Item> Items { get; set; }
}

class Storage
{
    public virtual int Id { get; set; }

    public virtual IList<Item> Items { get; set;}
}

The problem is that whenever I delete a Storage object containing some Item instances as follows :

Category category = ...; // This instance already exists in the database. 
Storage storage = ...; // This instance already exists in the database.

Item item = new Item();
item.Category = category; // Inverse is used on HasMany association
category.Items.add(item);
item.Storage = storage; // Inverse is used on HasMany association
storage.Items.add(item);
session.Save(storage);
session.Flush();

// HasMany association on Storage cascades delete to Item
session.Delete(Storage);
session.Flush();

the Item still remains in Category.Items . Is this behavior expected? Or is it necessary to explicitly remove the deleted Item instances from the parent Category ?

Answer 1

I am no more able to find a reference for following statement, but I believe NHibernate considers that removing a deleted entity from loaded one-to-many collections is not its responsibility.

If you have some remaining work to do on your already loaded category, you should then remove explicitly the deleted items, or Refresh (see end of 9.2§) the category.

If you have some remaining work to do with the currently opened session, without having anymore knowledge of which Category are hold in its first level cache with their Items loaded and containing some deleted ones, and requiring any Category yielded by this session to have its Items up to date, you may then Clear the session before going on. (This will evict all loaded entities.)

But it would be better to simply finish the unit of work at your Flush. (Close the session.) Category loaded from (or attached into) a newly opened session would have their Items up to date.