Hi all. I've only been working with relational databases up to now, and have some problems with JDO.
I seem to have some trouble grasping the basic design patterns with POJO/JDO here. This is probably a very basic issue, but its hard when the mind is setup to think from an entirely different perspective :-). So, what I want to do here is to have child objects of the same type referenced from different parents. For example... Say we have a class Person, class CarRegister, class Car. A Car class with a Key. class Car { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Key key; ...other persistent objects... } In Person, I have a list of Car objects that the person owns. class Person { @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Long id; @Persistent private List<Car> ownedCars; } In CarRegister, I also have a list of all Car objects registered. class CarRegister{ @PrimaryKey @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) private Long id; @Persistent private List<Car> registeredCars; } Is this possible? The documentation seem to suggest that a key is made up of the entity parent id and some other stuff, which should mean that the above wouldn't work. (The key value includes the key of the entity group parent (if any) and either the app-assigned string ID or the system-generated numeric ID). I could of course save a list of keys/ids to Car objects instead, but that to me would kind of defeat the purpose of this kind of database. So I want a List of Car objects in both Person and CarRegister, and they must somehow share the same objects in the database. This must be one of the basic use cases, but I have been unable to find an optimal solution for it. Thanks in advance. BR, Andreas --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to google-appengine@googlegroups.com To unsubscribe from this group, send email to google-appengine+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en -~----------~----~----~----~------~----~------~--~---