在多个 django 模型之间查询

Question

I have 3 models categories, badges, and reward. The users are awarded badges and are stored under reward. The user model is the default model provided by django.

class BadgeCategory(models.Model):
    name = models.CharField(max_length=30)

class Badge(models.Model):
    points = models.IntegerField(default=1)
    title = models.CharField(max_length=30)
    category = models.ForeignKey(BadgeCategory,on_delete=models.SET_NULL,null=True)


class Reward(models.Model):
    awarded_by = models.CharField(max_length=30)
    user = models.ForeignKey(User, on_delete=models.CASCADE)
    badges = models.ForeignKey(Badge, on_delete=models.CASCADE)

BadgeCategory refers to the category under which the badge falls, Badge refers to various badges. and reward contains all the various badges given to users. I am looking to find a query such that I get the following format of the output

Username	category 1	category 2
user 1	count(category 1)	count(category 2)
user 2	count(category 1)	count(category 2)

here count(category k) refers to the number of rewards that user has received having category k, If no reward is received it should be zero and username column should contain all the users. I have tried and reached to this query

Reward.objects.all().values('user__username','badges__category__name') \
        .order_by().annotate(Count('badges__category__name'))

This gives the output having the users that have received at least one reward and only the category of which the badge has been received and the corresponding count of badges with that category, Let's say my database has 2 users A, B and C, 2 categories cat1,cat2 A has 2 badges of cat 1 and 1 badge of cat 2 B has 1 badge of cat 1 C has no badge Then the above query gives

Username	Category	Count
A	cat 1	2
A	cat 2	2
B	cat 1	1

If the above format is not feasible I could work around with the format that I have received but including all the users.

Thanks and any kind of help is appreciated.