Question

我正在设计一个系统，允许用户在预先配置的有序对象集中选择多个对象（比如5）（计数> 5）。基本上，用户必须选择一组9中的前5个对象。我必须保存这些条目并找出具有最大投票（最大选择）的对象和基于最右边条目的获胜者。

我的模特：

class User(AbstractUser):
    '''Info about user '''

class Contest(models.Model):
    name = models.CharField(max_length=255)
    created = models.DateField(auto_now_add=True)


class ObjectsForContest(models.Model):
    name = models.CharField(max_length=255)
    contest = models.ManyToManyField('Contest', through='OrderedObjectsForContest')

class OrderedObjectsForContest(models.Model):
    choice = models.ForeignKey(ObjectsForContest)
    contest = models.ForeignKey(Contest, related_name='ordered_options')
    order = models.PositiveIntegerField()

    class Meta:
        ordering = ['order']

class UserEntriesForContest(models.Model):
    user = models.ForeignKey(User, related_name="entries_for_contest")
    contest = models.ForeignKey(Contest, related_name='participating_users')
    objects_selected = models.ManyToManyField(ObjectsForContest, through='OrderedChoicesByUser', null=True, blank=True)

    def __unicode__(self):
        return self.user.unique_id

class OrderedChoicesByUser(models.Model):
    choice = models.ForeignKey(ObjectsForContest)
    contest = models.ForeignKey(UserEntriesForContest)
    order = models.PositiveIntegerField()

    class Meta:
        ordering = ['order']

我的序列化器非常简单。串行器：

class ContestObjectsSerializer(serializers.ModelSerializer):
    class Meta:
        model = ObjectsForContest
        exclude = ("contests", )


class ContestObjectsThroughSerializer(serializers.ModelSerializer):
    choice = ContestObjectsSerializer()

    class Meta:
        model = OrderedObjectsForContest
        exclude = ("id", )


class Contest(serializers.ModelSerializer):
    winner = SimpleUserProfileSerializer()  #this serializes the user and not included here.
    choices = ContestObjectsThroughSerializer(many=True)

    class Meta:
        model = Contest


class UserEntriesForContestSerializer(serializers.ModelSerializer):
    choices_made = ContestObjectsSerializer(many=True)

    class Meta:
        model = UserEntriesForContest

如何找到最大用户根据订单选择的选项？

实施例。根据比赛的对象:(名称，顺序）

(Apple, 1), (Orange, 2), (Grapes, 3), (Mango, 4), (Apricot, 5), (Cherry, 6), (Guava, 7), (Jackfruit, 8), (Lime, 9)

我们假设有5个用户选择：

#User 1:
(Apple, 1), (Lime, 2), (Grapes, 3), (Mango, 4), (Apricot, 5)
#User 2:
(Apple, 1), (Orange, 2), (Lime, 3), (Mango, 4), (Apricot, 5)
#User 3:
(Apple, 1), (Orange, 2), (Grapes, 3), (Cherry, 4), (Apricot, 5)
#User 4:
(Apple, 1), (Orange, 2), (Lime, 3), (Cherry, 4), (Apricot, 5)
#User 5:
(Apple, 1), (Lime, 2), (Grapes, 3), (Cherry, 4), (Apricot, 5)

获奖名单应为：

(Apple, 1), (Orange, 2), (Grapes, 3), (Cherry, 3), (Apricot, 5)

我需要知道如何根据我的模型获得此列表。

Answer 1

可以通过DRF中的SerializerMethodField完成多对多订单

students_listss = serializers.SerializerMethodField('get_students_list')

def get_students_list(self, instance):
    return Student.objects\
        .filter()\
        .order_by('name')\
        .values_list('name', flat=True)

您可以像往常一样在order_by（）

中应用订单条件

Answer 2

使用tastypie REST框架来获取详细信息。通过使用tatsypie，您可以使用http://django-tastypie.readthedocs.org/en/latest/fields.html#tomanyfield

访问文件

Django多对多，使用REST进行排序和序列化

2 个答案: