Hi Gabriel, Ah, you're hitting the first bump in learning to think non-relationally. Rather than creating 3 models, what about creating a List of categories for each Podcast and just storing that on the podcast? The tradeoff is that it won't be easy to rename a podcast category, but that shouldn't be something that happens frequently.
When designing for the datastore, aim for designing for a key-value store when possible, and don't think in terms of joins. -- Ikai Lan Developer Programs Engineer, Google App Engine plus.ikailan.com | twitter.com/ikai On Mon, Oct 3, 2011 at 2:30 AM, gabriel munteanu <jajali...@gmail.com>wrote: > Hi, > > I have the following model [pseudo code]: > > db.Model("podcast", { > name: StringProperty, > description: TextProperty, > homePageURL: StringProperty, > addedDate: DateProperty > }); > > db.Model("category", { > name: StringProperty, > podcastsNumber: IntegerProperty > }); > > db.Model("podcastcategory", { > category: ReferenceProperty({referenceClass: Category}), > podcast: ReferenceProperty({referenceClass: Podcast}) > }); > > I am trying to query the datastore to show in the web page the latest > 5 podcasts in a certain category. > > Problem is my approach seems very costly: > > I do a query against podcastcategory and get al lentities there > filtered by my category property. > and i get all podcasts. > then I would have to sort them in my app by addedDate. > > I feel that something is wrong, maybe my query or my data modelling. I > would appreciate any advice or links to set me to the right direction. > > cheers, > Gabi > > -- > 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 > google-appengine-java@googlegroups.com. > To unsubscribe from this group, send email to > google-appengine-java+unsubscr...@googlegroups.com. > For more options, visit this group at > http://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 google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.