CODEWITHSUNDEEP
google-app-enginegoogle-cloud-datastore
starter
starter

Reputation: 31

Filter by part of date

My model 

class BaseArticleModel(polymodel.PolyModel):
    title = db.StringProperty()
    created_at = db.DateProperty(auto_now_add=True)
    updated_at = db.DateProperty(auto_now=True)

class News(BaseArticleModel):
    body = db.TextProperty()

I need get rows by last month. I use interactive console. When to do filter like this

q = News.all().filter('created_at.month = ',datetime(2011,04,01).month)
print q[0].title

I get "IndexError: The query returned fewer than 1 results"

Upvotes: 0

Views: 1426

Answers (2)

Greg Haskins
Greg Haskins

Reputation: 6794

To query based on a month, I'd suggest adding an additional derived field to your model which is automatically updated when the object gets saved:

class BaseArticleModel(polymodel.PolyModel): 
    title = db.StringProperty() 
    created_at = db.DateProperty(auto_now_add=True)
    updated_at = db.DateProperty(auto_now=True)

    # will be auto-generated
    created_at_month = db.IntegerProperty()

    def put(self, *args, **kwargs):
        self.created_at_month = self.created_at.month
        super(BaseArticleModel, self).put(*args, **kwargs)

Edit: Re-reading your question, it looks like you're not really looking for all posts from a given month (e.g. October of any year), but rather just posts in a single month. If that's the case then you should be able to just revise your query to a simple comparison:

# get News posted in April, 2011
all_news = News.all()
all_news.filter('created_at >=', datetime(2011, 4, 1))
all_news.filter('created_at <', datetime(2011, 5, 1))

Edit #2: As noted by Nick below, overriding put() would be bad form, since it would only be effective when called as a bound method, and will NOT work with db.put() or other ways of saving to the datastore.

Upvotes: 1

starter
starter

Reputation: 31

I was get something like your solution in the Google App Engine group.

class BaseArticleModel(polymodel.PolyModel):
    title = db.StringProperty()
    created_at = db.DateProperty(auto_now_add=True)
    updated_at = db.DateProperty(auto_now=True)
    @db.ComputedProperty
    def CM(self):
        return self.created_at.month

Upvotes: 3

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