Have you read the "Many to Many" section of this article: http://code.google.com/appengine/articles/modeling.html
<http://code.google.com/appengine/articles/modeling.html> On Wed, Dec 22, 2010 at 11:06 PM, Kevin J <[email protected]> wrote: > I have this code: > > ----- > > class Group(db.Model): > leader = db.UserProperty() > description = db.StringProperty(multiline=False) > name = db.StringProperty(multiline=False) > > class Person(db.Model): > email = db.UserProperty() > groups = db.ListProperty(db.ReferenceProperty(Group)) > > class Message(db.Model): > content = db.StringProperty(multiline=True) > group = db.ReferenceProperty(Group) > writer = db.ReferenceProperty(Person) > date = db.DateTimeProperty(auto_now=True) > > ---- > > and this line is giving me an error: > > groups = db.ListProperty(db.ReferenceProperty(Group)) > > Here is my call stack: > > ---- > > Traceback (most recent call last): > File "C:\Program Files\Google\google_appengine\google\appengine\tools > \dev_appserver.py", line 3245, in _HandleRequest > self._Dispatch(dispatcher, self.rfile, outfile, env_dict) > File "C:\Program Files\Google\google_appengine\google\appengine\tools > \dev_appserver.py", line 3186, in _Dispatch > base_env_dict=env_dict) > File "C:\Program Files\Google\google_appengine\google\appengine\tools > \dev_appserver.py", line 531, in Dispatch > base_env_dict=base_env_dict) > File "C:\Program Files\Google\google_appengine\google\appengine\tools > \dev_appserver.py", line 2410, in Dispatch > self._module_dict) > File "C:\Program Files\Google\google_appengine\google\appengine\tools > \dev_appserver.py", line 2320, in ExecuteCGI > reset_modules = exec_script(handler_path, cgi_path, hook) > File "C:\Program Files\Google\google_appengine\google\appengine\tools > \dev_appserver.py", line 2216, in ExecuteOrImportScript > exec module_code in script_module.__dict__ > File "C:\Documents and Settings\robodoggy\My Documents\coolkevapp > \MainPage.py", line 31, in <module> > class Person(db.Model): > File "C:\Documents and Settings\robodoggy\My Documents\coolkevapp > \MainPage.py", line 33, in Person > groups = db.ListProperty(db.ReferenceProperty(Group)) > File "C:\Program Files\Google\google_appengine\google\appengine\ext > \db\__init__.py", line 2971, in __init__ > raise TypeError('Item type should be a type object') > TypeError: Item type should be a type object > > ----- > > What I'm trying to do is to create a list of groups that each person > belongs to. As you can see, it dislikes me having a list of Groups. > > Does anyone know an alternative way to do this? > > ----- > > Sorry if I wasn't clear with something. Ask and I'll answer. > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To post to this group, send email to [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-appengine%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-appengine?hl=en. > > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-appengine?hl=en.
