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 -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-j...@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
