referenceproperty

This is my model, Players and Clubs. As a Club can have many players and a player can have many clubs (in its carrer), I used a many-to-many relationship: class Club(db.Model): name = db.StringProperty() link = db.StringProperty() class Player(db.Model): name = db.StringProperty() link = db.LinkProperty() class ClubHasPlayer(db.Model): club = db.ReferenceProperty(Club, required=True, collection_name='club_players') player = db.ReferenceProperty(Player, required=True, collection_name='player_clubs') number = IntegerProperty() Now, I have a search interface where one can search for all players,

I would like to know -an example is highly appreciated- How to model relationships in Google App Engine for Java? -One to Many -Many to Many I searched allover the web and I found nothing about Java all guides and tutorials are about Python. I understood from this article that in Python the relationships are modeled using ReferenceProperty . However, I found nothing about this class in the Javadoc reference. Furthermore, in this article they discussed the following: there's currently a shortage of tools for Java users, largely due to the relative newness of the Java platform for App Engine.

I am trying to get all parent/children from a one to many relationship. Traditionally, I could do this with a join, but doing so in the datastore is escaping me. I have found several partial examples to do this, but not one that is complete yet. I have: class Owner(db.Model): name = db.StringProperty() class Pet(db.Model): petname = db.StringProperty() owner = db.ReferenceProperty(Owner, collection_name='pets') #now I want to print all pets owned by scott scott = Owner(name="scott") scott.put() Pet(owner=scott,petname="rufus").put() pets = Pet.all().filter('owner =', "scott").fetch(100) print