Hi,
I'm not understanding how to implement a simple unowned relationship.
I have two classes like:
class Farm {
List<Key> mHorses;
}
class Horse {
@PrimaryKey
Key mKey;
}
so a Farm can have some horses. I'd like to create a new horse, then
put it on a farm, in one transaction. But how do I know the key of the
horse during the transaction?:
Farm farm = loadFarm(...);
Horse horse = new Horse();
horse.setName("Roger");
try {
tx = pm.currentTransaction();
tx.begin();
pm.makePersistent(horse); // is the key available now?
farm.mHorses.add(horse.mKey);
pm.makePersistent(farm);
tx.commit();
}
when is the Horse.mKey value actually set and ready for use? Or do I
have to do this as two separate atomic operations:
1) Save the horse which generates its mKey value.
2) If that worked, add it to the farm, persist the farm again.
3) If that worked, all good, if not, have to delete the horse cause
now it's in limbo?
Thanks
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