Querying 2 Entities With Objectify

Question

I have 2 diferent Entities:

• USER :

   @Entity public class UserMW { @Id private Long id; private String name; private Long score; ... } 

• USER_CHALLENGE

   @Entity public class UserChallengeMW { @Id private Long id; @Index private Ref<UserMW> user; @Index @Load private Ref<ChallengeMW> challenge; } 

I want to be able to get one ChallengeMW object and query all users which have done this ChallengeMW. So far it's pretty simple. I just need to query USER_CHALLENGE filtering by "Ref challenge". Something like this:

ofy().load().type(UserChallengeMW.class).filter("challenge", challengeRef).list();

The problem is , I want to order it according to the property " score " into USER entity. Any idea about what is the correct way to go?

Answer 1

Unfortunately, there are no joins in the datastore. Either denormalize the 'score' into the UserChallengeMW object or query for all the data and sort it in memory.