Django nonrel Requête de confusion

Question

Je crée un projet de pratique django-nonrel hébergé sur Google AppEngine pour me familiariser avec Django et la plate-forme AppEngine, mais je suis confronté à un problème de requête complexe. Voici mon models.py:

class Character(models.Model): 
     name = models.CharField(max_length=200) 
     url_name = models.CharField(max_length=200) 

     def save(self, *args, **kwargs): 
      self.url_name = self.name.replace(" ", "-").lower() 
      super(Character, self).save(*args, **kwargs) # Call the "real" save() method. 


    def __unicode__(self): 
     return '%s' %(self.name) 

class Season(models.Model): 
    season_number = models.IntegerField() 

    def __unicode__(self): 
     return u'Season %d' % (self.season_number) 

class Episode(models.Model): 
    season = models.ForeignKey(Season) 
    episode_name = models.CharField(max_length=200) 
    episode_number= models.IntegerField() 

    def __unicode__(self): 
     return u'Season %d, Episode %d "%s"' %(self.season.season_number, self.episode_number, self.episode_name) 

class Quote(models.Model): 
    author = models.ForeignKey(Character) 
    episode = models.ForeignKey(Episode) 
    quote_text = models.TextField() 

    def __unicode__(self): 
     return u'"%s" (%s)' % (self.quote_text, self.episode) 

Maintenant, voici où la confusion est:. Pourquoi Quote.objects.all() Travaux de order_by ('épisode'), tandis que Quote.objects.filter (author__name = "Michael Scott") .order_by ('episode') ne fonctionne pas? Comme en témoigne le dernier filtre, le problème n'est pas avec l'appel author__name, car cet index a été enregistré en utilisant dbindexer. Le problème est avec la partie order_by ('episode'), mais je ne comprends pas pourquoi cela fonctionnerait sur un QuerySet mais pas sur un autre.

>>> from QuotesCMS.models import Character, Season, Episode, Quote 
>>> Quote.objects.all().order_by('episode') 
[<Quote: "My proudest moment here wasn't when I increased profits by 17 percent, or cut expenditure without losing a single member of staff. No no no. It was a young Guatemalan guy, first job in the country, barely spoke a word of English, but he came to me and said, 'Mr. Scott, will you be the godf 
ather to my child?' Wow... wow. Didn't work out in the end. We had to let him go. He sucked." (Season 1, Episode 1 "Pilot")>, <Quote: " Abraham Lincoln once said, 'If you are a racist, I will attack you with the North,' and those are the principles I carry with me into the workplace." (Season 1, Epi 
sode 2 "Diversity Day")>, <Quote: "I love inside jokes... I'd love to be a part of one someday." (Season 3, Episode 2 "The Convention")>, <Quote: "I declare...bankruptcy!!!" (Season 4, Episode 4 "Money")>, <Quote: "When I'm at home at night in my own house in my sweats, drinking red wine, watching m 
y mystery stories the last thing in the whole godforsaken world I want to hear is the voice of Michael Scott." (Season 4, Episode 4 "Money")>, <Quote: "As of this morning, we are completely wireless here on Schrute Farms. So as soon as I find out where Mose hid all the wires, we can have power back 
on. " (Season 4, Episode 4 "Money")>, <Quote: "I just realized that this is Pam's and my first night away together. I used to play it over in my head, and it was just a little bit different. Maybe a nice hotel, or a romantic dinner, wine, but wine that wasn't made out of beets. Didn't think Dwight w 
ould be involved at all. And I always imagined less manure. I mean, some manure, just less." (Season 4, Episode 4 "Money")>] 

-

>>> Quote.objects.filter(author__name="Michael Scott").order_by('episode') 
Traceback (most recent call last): 
    File "<console>", line 1, in <module> 
    File "C:\OfficeQuotes\django\db\models\query.py", line 93, in __repr__ 
    data = list(self[:REPR_OUTPUT_SIZE + 1]) 
    File "C:\OfficeQuotes\django\db\models\query.py", line 108, in __len__ 
    self._result_cache.extend(self._iter) 
    File "C:\OfficeQuotes\django\db\models\query.py", line 317, in iterator 
    for row in compiler.results_iter(): 
    File "C:\OfficeQuotes\djangotoolbox\db\basecompiler.py", line 411, in results_iter 
    for entity in results: 
    File "C:\OfficeQuotes\djangoappengine\db\compiler.py", line 138, in fetch 
    for entity in results: 
    File "C:\Program Files (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py", line 3317, in next 
    next_batch = self.__batcher.next_batch(Batcher.AT_LEAST_OFFSET) 
    File "C:\Program Files (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py", line 3203, in next_batch 
    batch = self.__next_batch.get_result() 
    File "C:\Program Files (x86)\Google\google_appengine\google\appengine\api\apiproxy_stub_map.py", line 613, in get_result 
    return self.__get_result_hook(self) 
    File "C:\Program Files (x86)\Google\google_appengine\google\appengine\datastore\datastore_query.py", line 2917, in __query_result_hook 
    yaml_index=yaml, xml_index=xml) 
NeedIndexError: no matching index found. 
The suggested index for this query is: 
- kind: QuotesCMS_quote 
    properties: 
    - name: author_id 
    - name: episode_id 

-

>>> Quote.objects.filter(author__name="Michael Scott") 
    [<Quote: "I declare...bankruptcy!!!" (Season 4, Episode 4 "Money")>, <Quote: " Abraham Lincoln once said, 'If you are a racist, I will attack you with the North,' and those are the principles I carry with me into the workplace." (Season 1, Episode 2 "Diversity Day")>, <Quote: "My proudest moment her 
    e wasn't when I increased profits by 17 percent, or cut expenditure without losing a single member of staff. No no no. It was a young Guatemalan guy, first job in the country, barely spoke a word of English, but he came to me and said, 'Mr. Scott, will you be the godfather to my child?' Wow... wow. 
    Didn't work out in the end. We had to let him go. He sucked." (Season 1, Episode 1 "Pilot")>, <Quote: "I love inside jokes... I'd love to be a part of one someday." (Season 3, Episode 2 "The Convention")>] 

espère que les citations sont un peu divertissant, et merci d'avance pour toute aide.

Answer 1

Vous devez gérer et mettre à jour les index pour les requêtes de votre application.

Cochez (au moins) la section Index configuration de Datastore Indexes. Le message d'erreur que vous avez également inclut les informations sur l'index dont vous aurez probablement besoin pour la requête particulière que vous avez effectuée.

Notez également que la configuration de l'index ne devient pas effective immédiatement après le téléchargement, cela peut prendre un certain temps pour générer des index nouvellement ajoutés. J'ai seulement vu des retards de quelques minutes, mais mon DB est également assez petit. YMMV.