Google App Engine + relationale Datenbank - erhalten ID

Question

Ich habe eine Frage meine db Modell wie folgt aussieht:

class UserAnswer (db.Model): 
user = db.UserProperty() 
name = db.StringProperty() 
email = db.StringProperty() 
occupation = db.IntegerProperty() 
howreach = db.IntegerProperty() 
rating = db.IntegerProperty() 
comment = db.StringProperty(multiline=True) 

class Involves(db.Model): 
shortName = db.StringProperty() 
fullName = db.StringProperty() 

class UserInvolves(db.Model): 
userAnswer = db.ReferenceProperty(UserAnswer) 
involve = db.ReferenceProperty(Involves) 

Wie kann ich einen wählen etwas tun:

def getInvolves(user): 
results = db.GqlQuery("Select * from UserInvolves as ui where ui.userAnswer.ID='"+user.ID+"'") 

meine ich, wie ich kann diesen ID-Schlüssel erhalten? Wie wenn ich versuche, wie oben ich einen Fehler recive:

Traceback (most recent call last): 
File "C:\Program Files\Google\google_appengine\google\appengine\ext\webapp\__init__.py", line 517, in __call__ 
handler.post(*groups) 
File "C:\Program Files\Google\google_appengine\demos\b00213576\main.py", line 217, in post 
involves = getInvolves(answer) 
File "C:\Program Files\Google\google_appengine\demos\b00213576\main.py", line 128, in getInvolves 
results = db.GqlQuery("Select * from UserInvolves as ui where ui.userAnswer.ID='"+user.ID+"'") 
AttributeError: 'UserAnswer' object has no attribute 'ID' 

Und ich weiß nicht, wie zu GAE konvertieren:/

Answer 1

user_answer = UserAnswer.get_by_id(user.ID) 
for user_involve in user_answer.userinvolves_set: 
    # these are your UserInvolves items