Most of the time, the errors you get from your model properties will happen when you're saving data. For instance, if you try saving a string as an IntegerProperty, that will result in an error. The one exception (no pun intended) is ReferenceProperty. If you have lots of references and you're not completely careful about leaving in bad...
Given a Polymodel in Google App Engine, likeso: from google.appengine.ext import db from google.appengine.ext.db import polymodel class Base(polymodel.PolyModel): def add_to_referer(self): Referer(target=self).put() class Referer(db.Model): target = db.ReferenceProperty() @classmethod def who_referred(cls): for ...
The default choice field display of a reference property in appengine returns the choices as the string representation of the entire object. What is the best method to override this behaviour? I tried to override str() in the referenced class. But it does not work. ...
hi, i am filling up a big table with text items from different countries. My question is: Should i use a referencePropery to link to languages in another table?. Thats the way i would do it in a normal mysql relational database. or just go redundant and specify the language for each text in the table? Whats better? redundancy & incre...
I have a model User which appears as a ReferenceProperty in another model, Group. When I create a form for Group, using Meta, the form's values contain lots of generated strings. I'd like to stop this, and use the username field of User instead. I already define a key_name. However, str(user.key()) still gives a generated string. I cou...
Hi to all, I have the following problem: I'd like to retrieve all products of a category class Category(emodel): name = db.StringProperty() class Channel(emodel): name = db.StringProperty() category = db.ReferenceProperty(Category,collection_name="cat_set") class Product(emodel): name = db.StringProperty() ...
If I have two types of models that each reference each other, whichever one I try to define first says it does not recognize the referenced other type (because it is defined further down in the file). For example: class Author(db.Model): most_recent_book = db.ReferenceProperty(Book) class Book(db.Model): author = db.ReferencePr...
I am using google-app-engine webapp, part of the code is : class Post(db.Model): title = db.StringProperty(required=True) def categories(self): return (x.category for x in self.postcategory_set) class Category(db.Model): name = db.StringProperty() class PostCategory(db.Model): post = db.ReferenceProperty(Post)...
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...
Say I have two classes: class A(db.Model): class B(db.Model): a_reference = ReferenceProperty(A) I can now do the following: a = A() a.put() b = B(); b.a_reference = a.key() b.put() The documentation states the following two things: The ReferenceProperty value can be used as if it were a model instance, and the datastore...