Hi, It is not in JDO and if lowlevelAPI is used, it might be possible.
Please examine [com.google.appengine.api.datastore.Entity#getParent] http://code.google.com/intl/en/appengine/docs/java/javadoc/com/google/appengine/api/datastore/Entity.html#getParent() thanks. Hope some of this helps. > Hi, > I’m a beginner in JDO. So I read the google > tutorialhttp://code.google.com/intl/de/appengine/docs/java/datastore/relation... > Well, I understand how to make a owned relationship. > Bur I didn’t understand how I should make a unowned relation. > So here’s the google example for unowned one-to-one relationship: > > @PersistenceCapable > public class Person { > @PrimaryKey > @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) > private Key key; > > @Persistent > private Key favoriteFood; > > // ... > > } > > @PersistenceCapable > public class Food { > @PrimaryKey > @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) > private Key key; > > // ... > > } > > So a Person can have a favored Food. But a Food is not linked to only > one Person, but can be the favored Food of more than one Person. > > Ok, I understand that we don’t have a Food-Object in the class Person, > but instead we have the Key to the food. > > Ok, now I want to get the favored Food Object of a Person. How do I > get now the Food Object? > > Is the only way to get it by calling the getObjectById() or to make a > query like “SELECT FROM Food WHERE key = person.getFavoredFoodKey()” > > Is there another fully automatically way to get the Food-Object? > > -- > 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 [email protected]. > To unsubscribe from this group, send email to > [email protected]. > For more options, visit this group > athttp://groups.google.com/group/google-appengine-java?hl=en. -- 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 [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
