Question

我正在做一个关于appengine的博客。我想进行查询以获取按类别发布的数量。所以我需要通过appengine中的Reference属性进行过滤。看看我的实际代码。

这些是我的模特：

class Comment(db.Model) :
    user = db.ReferenceProperty(User)
    post = db.ReferenceProperty(Blog)
    subject = db.StringProperty(required = True)
    content = db.TextProperty(required = True)
    date = db.DateProperty(auto_now_add = True)
    last_modified = db.DateProperty()
    status = db.BooleanProperty(default = True)

class Category(db.Model):
    name = db.StringProperty()
    date = db.DateProperty(auto_now_add=True)

class Blog(db.Model) :
    subject = db.StringProperty(required = True)
    content = db.TextProperty(required = True)
    date = db.DateProperty(auto_now_add = True)
    category = db.ReferenceProperty(Category)
    user = db.ReferenceProperty(User)
    last_modified = db.DateProperty(auto_now = True)
    status = db.BooleanProperty()
    likes = db.IntegerProperty(default = 0)
    users_liked = db.ListProperty(db.Key, default = [])
    dislikes = db.IntegerProperty(default = 0)
    users_disliked = db.ListProperty(db.Key, default = [])

这是我的疑问：

def numcomments_all_category() :
    dic = {}
    category = get_category()
    for cat in category :
        dic[cat.key().id()] = Comment.all().filter("post.category =", cat.key()).ancestor(ancestor_key).count()
    return dic

但似乎过滤器（“post.category =”，cat.key（））不是正确的方法。

Answer 1

我暂时没有使用db，但我认为这样的事情会起作用：

count = 0
# Get all blogs of the desired category
blogs = Blog.all().filter("category =", cat.key())
for blog in blogs:
    # For each blog, count all the comments.
    count += Comment.all().filter("post =", blog.key()).count()

通过Appnengine中的引用属性进行筛选

1 个答案: