在我的应用中,用户可以关注其他用户,并在他们关注的人员执行活动时获得更新.
我以这种方式存储以下关系:
class User(db.Model):
''' User details '''
username = db.StringProperty()
class Contacts(db.Model):
'''Store users contacts
parent= User (follower)
key_name= Users username (follower)
contacts = A list of keys of Users that a User follows '''
contacts = db.ListProperty(db.Key)
last_updated = db.DateTimeProperty(auto_now=True)
获取关注者和用户关注的用户(关注者和关注者):
'''Get Users that my_user follows'''
my_user = User().all().fetch(1)
contacts = Contacts.get_by_key_name(my_user.username).contacts
''' get my_user followers - copied from an answer here on stackoverflow '''
follower_index = models.Contacts.all(keys_only=True).filter('contacts =',my_user)
follower_keys = [f.parent() for f in follower_index]
followers = …在我的appengine python应用程序中,我有分片计数器,用于计算照片的favs数量和视图数量.
我有照片和计数器型号.要按受欢迎程度(最喜欢的数量)订购照片,我应该在我的照片实体(Photo.all().order('num_favs'))中存储最喜欢的#.由于我正在跟踪分片计数器中的fav的数量,我想知道用Counter模型中最新的#fores来更新我的Photo实体的最有效方法是什么？
这是我的模型的样子摘要:
class Photo(db.Model):
photo = db.BlobProperty()
favs = db.IntegerProperty() #num of favs
class Counter(db.Model):
#key_name = key to a model that's to be counted - Photo in this case
name = db.StringProperty() #counted entity key
count = db.IntegerProperty() #count
type = db.StringProperty() #type of model to count, "Photo" in this example
#Very unefficient way of updating my Photo entities with the latest count from Counter:
fav_counters = Counter.all().filter('type =', 'Photo')
for fav in fav_counters:
photo_fav = db.get(fav.name) …