如何指定任意嵌套的Django模型(如目录结构)？

from django.db import models

class Category(models.Model):
    name = models.CharField(max_length=100)
    parent = models.ForeignKey('self', null=True, blank=True, on_delete=models.CASCADE)

python manage.py makemigrations
python manage.py migrate

# 创建根目录
root_category = Category.objects.create(name='Root')

# 创建子目录
sub_category1 = Category.objects.create(name='Subcategory 1', parent=root_category)
sub_category2 = Category.objects.create(name='Subcategory 2', parent=root_category)

# 创建子目录的子目录
sub_sub_category = Category.objects.create(name='Sub-subcategory', parent=sub_category1)

# 获取根目录下的所有子目录
subcategories = Category.objects.filter(parent=root_category)

# 获取某个子目录的子目录
sub_subcategories = Category.objects.filter(parent=sub_category1)