CODEWITHSUNDEEP
pythondjangodjango-queryset
arianhf
arianhf

Reputation: 153

ordering queries based on most upvotes

I want to order my query based on the number of upvotes but I can't figure out how to do it. It seems way too complex! ( btw am I over-complicating things?)

so here is my models.py

class Activity(models.Model):
    FAVORITE = 'F'
    LIKE = 'L'
    UP_VOTE = 'U'
    DOWN_VOTE = 'D'
    FOLLOW = 'W'
    REPORT = 'R'
    ACTIVITY_TYPES = (
        (FAVORITE, 'Favorite'),
        (LIKE, 'Like'),
        (UP_VOTE, 'Up Vote'),
        (DOWN_VOTE, 'Down Vote'),
        (FOLLOW, 'Follow'),
        (REPORT, 'Report')
    )

    user = models.ForeignKey(User)
    activity_type = models.CharField(max_length=1, choices=ACTIVITY_TYPES)
    date = models.DateTimeField(auto_now_add=True)

    # Below the mandatory fields for generic relation
    content_type = models.ForeignKey(ContentType, on_delete=models.CASCADE)
    object_id = models.PositiveIntegerField()
    content_object = GenericForeignKey()


class Entry(models.Model):
    text = models.TextField(default='')
    time_created = models.DateTimeField(auto_now=False, auto_now_add=True)
    time_updated = models.DateTimeField(auto_now=True, auto_now_add=False)
    created_by = models.ForeignKey(User, on_delete=models.CASCADE)

    class Meta:
        abstract = True

class QuestionManager(models.Manager):
    def by_topic(self, topic):
        ...
    def by_recent(self):
        ...
    def by_upvote_count(self):
        return self.all().order_by('-upvotes')[:5]\
        .select_related('created_by','created_by__userprofile')\
        .prefetch_related('question_comments','question_comments__reply',)


class Question(Entry):

    objects = models.Manager()
    get = QuestionManager()

    activities = GenericRelation(Activity, related_query_name='questions')

    def calculate_votes(self, type):
        return self.activities.filter(activity_type=type).count()

    up_votes = property(calculate_votes, 'U')
    down_votes = property(calculate_votes, 'D')

so, what I'm trying to do is to get by_upvote_count to return the top 5 upvoted items.

I found the Count() method of the django.db.models but could get it to work with my set up, I want to do something like this:

Question.objects.all().annotate(q = Count(activities__activity_type='U')).order_by('-q')

but obviously this doesn't work.

Upvotes: 0

Views: 45

Answers (2)

arianhf
arianhf

Reputation: 153

Ok, so after reading a bunch of articles and some questions in stackoverflow, I finally found a working answer, here it goes:

from django.db.models import Case,When
Question.objects.all()\
.annotate(upvotes=Count(
    Case(
        When(activities__activity_type='U', then=1)
    ), distinct=True
)).order_by('-upvotes')[:5]

Using Case, and When you can do conditionals in your queries.

Upvotes: 1

Exprator
Exprator

Reputation: 27523

you can do something like this 

Model.objects.filter(activity_type='U').annotate(q_count=Count('activity_type')).order_by('-q_count')[:5]

Upvotes: 1

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