How about something like this?
class User {
Long id;
...
}
class Deck {
Long id;
Long userId;
...
}
class Card {
Long id;
Long deckId;
...
}
Then inserting a card into the deck is a simple insert and finding all
cards in a deck is a single query. The same for adding a deck to a
user.
This structure has its own trade-offs, of course.
On Mar 10, 4:15 pm, tempy <fay...@gmail.com> wrote:
> Exactly, CardList is potentially very large and I want to avoid having
> to load it just to add the cardreference.
>
> On Mar 10, 10:43 pm, WillSpecht <willspe...@gmail.com> wrote:
>
> > So if you have a reference to a new card and do
>
> > cardList.add(cardRefference)
>
> > all you are loading into memory is the card list and the new card.
>
> > Is this what you are trying to avoid?
>
> > On Mar 10, 4:06 pm, tempy <fay...@gmail.com> wrote:
>
> > > Actually cards can only be owned by one deck... so that's not a
> > > problem. Deck<--1...0toN-->card.
>
> > > The thing that I am looking for is a way to add new cards without
> > > loading a deck's entire card collection, and to add decks without
> > > loading a User's entire deck collection.
>
> > > On Mar 10, 9:15 pm, WillSpecht <willspe...@gmail.com> wrote:
>
> > > > The way I understand it, if an object can be owned by more than one
> > > > object it must be unowned. I would assume that cards can be in
> > > > multiple decks so they must be unowned. I would assume each deck
> > > > would belong to one user so decks could be owned. I don't know a good
> > > > way to store cards that can be queried in one query unless you have
> > > > each card store what decks they are in. This could be even more
> > > > difficult if cards appear more than once in a deck. If that is true I
> > > > would suggest a join table.
>
> > > > On Mar 10, 2:20 pm, tempy <fay...@gmail.com> wrote:
>
> > > > > I have the following datastructure:
>
> > > > > "Users" are the root entities, and each "user" can have one or more
> > > > > "decks", and each deck can have one or more "cards."
>
> > > > > When a user wants to add a deck, I would like to be able to add the
> > > > > deck to the user's collection of decks without first fetching all of
> > > > > the user's decks (potentially a large amount of data), then adding the
> > > > > new deck to that collection, and then persisting the user. Rather, I
> > > > > would like to simply instantiate the deck and append it to the user's
> > > > > collection of decks, without ever retrieving the entire collection.
>
> > > > > Similarly, if a user wants to add a new card to an existing deck, I
> > > > > would like to add the card to the deck without first retrieving the
> > > > > entire deck (that is, the deck with all of its cards).
>
> > > > > I would like to preserve the option of fetching a user with a
> > > > > populated collection of all their decks and to retrieve a deck with a
> > > > > populated collection of all its cards, which is possible with owned
> > > > > relationships. But to accomplish what I have mentioned above, would I
> > > > > be forced to use unowned relationships? (Collections of keys instead
> > > > > of collections of objects.)
>
> > > > > Thanks,
> > > > > Mike
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