如何链接/或组合我的三个 Django 模型以更好地最大化关系和效率

Question

Im trying to model out my dB for my Django app.

I'm pretty content with that I have so far, only I have two questions regarding my models.

Here's a quick run-through of them.

UserBuckets contains every bucket a user has created.

TotalBuckets contains the total number of buckets a user has created.

Bucket Contains information for whats inside each user bucket.

class UserBuckets(models.Model):
    
    username = models.ForeignKey(UserModel.username)
    bucket_name = models.CharField()

    def get_all_buckets(self):
        all_buckets = UserBuckets.objects.all('bucket_name')
        return all_buckets

    def __str__(self):
        return self.bucket_name


class TotalBuckets(models.Model):

    username = models.ForeignKey(UserBuckets.username)
    total_buckets = models.IntegerField(blank=True, null=True)

    def total_buckets_calc(self):
        self.total_buckets = TotalBuckets.objects.aggregate(Sum('bucket_name', distinct=True))
        self.save()
    
    def __str__(self):
        return self.total_buckets

class Bucket(models.Model):

    owner = models.ManyToManyField(UserBuckets.username)
    bucket = models.ForeignKeyField(UserBuckets.bucket_name, on_delete=models.CASCADE)
    stocks = ArrayField(models.CharField(max_length=6),size=10) 
    stocks_in_bucket = models.IntegerField(blank=True, null=True)
    created = models.DateField(auto_now_add=True)
    slug = models.SlugField(unique=True, blank=True)

    def total_stocks_calc(self):
        self.stocks_in_bucket = Bucket.objects.aggregate(Sum('stocks_in_bucket', distinct=True))
        self.save()

    def get_absolute_url(self):
        return reverse("bucket:bucket-view", kwargs={"slug": self.slug})

    def __str__(self):
        return self.stocks

Here are my two questions:

1. I can see the argument of combining UserBuckets + TotalBuckets , however my only problem with that is the repeating the same datapoint for every new object that gets created. To keep things "clean", I separated them. Is this the "correct" procedure?

2. How can I properly reference that each bucket is an object based off of UserBuckets . I used a foreign key and a many-to-many key but doesn't that only cover the relationship basis?

Thank you for any help.

Answer 1

You only need the User-object and the Bucket-objects related to the user to find every bucket the user has created and the number of buckets the user has.

class User(models.Model):
    username = models.CharField()

class Bucket(models.Model):

    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name='buckets')
    stocks = ArrayField(models.CharField(max_length=6),size=10) 
    stocks_in_bucket = models.IntegerField(blank=True, null=True)
    created = models.DateField(auto_now_add=True)
    slug = models.SlugField(unique=True, blank=True)

    def total_stocks_calc(self):
        self.stocks_in_bucket = Bucket.objects.aggregate(Sum('stocks_in_bucket', distinct=True))
        self.save()

    def get_absolute_url(self):
        return reverse("bucket:bucket-view", kwargs={"slug": self.slug})

    def __str__(self):
        return self.stocks



EXAMPLE

user = User('Gabbeh')
b1 = Bucket(owner=user, ...)
b2 = Bucket(owner=user, ...)

all_buckets_owned_by_user = User.buckets()  # from related_name
all_buckets_owned_by_user = User.bucket_set()  # djangos naming wihtout setting related name
# or 
all_buckets_owned_by_user = Buckets.objects.filter(owner=user)

# To count just do .count() on the end of either query above.