NHibernate mapping message logic

I made some classes that represents my messages logic:

• Message - representation of THE message :)

• MessageBoxBase - base class for all 3 kind of messagebox

• MessageInbox - represe开发者_如何学JAVAnting inbox

• MessageOutbox - representing outbox
• MessageCustombox - user defined message box
• MessageBoxItem - message item in any messagebox with such data as IsReaded etc.
• MessageBoxCollection - Collection of messageboxes - Inbox, Outbox and List of CustomBoxes - only that 3 properties.

Finally in my agregate root User have MessageboxCollection, and I can use it somewhat like that:

myUser.MessageBoxes.Inbox.Add(...)
myUser.MessageBoxes.Outbox.Items....

I dont have any DB structure right now and I'm open on sugestion, but I was thinking about something like that:

• MessageInInbox - UserId,MessageId, IsReaded etc.
• MessageInOutBox - Same as in Inbox
• MessageInCustomBox - UserId,MessageId, CustomBoxId and so on
• CustomBox - BoxId, UserId, BoxName etc.
• Message - plain message row, subject, content, author etc.

One I'm sure is that I don't want to create in DB row for each Inbox/Outbox for each user like it is in CustomBox case (something like unnecessary dictionary for inboxes and outboxes per user).

And in that point I have a problem - how the hell to map that ? :)

Have any suggestions? Maybe my domain is crappy? I'm waiting for yours response :)

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There is a more simple solution that is that you only have two database tables called messages and boxes.

Messages - (Id, IsRead, Subject, Message, Sender, UserId, BoxId)

Boxes - (Id, Name, UserId)

This solution now allows a user to have several custom boxes and he should always have the defaults created for him. And the Object model can be User has a list of Boxes and each box has a list of messages.