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.comwrote:
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.
