How to Nested Categories in django admin - django

Question

I want to create muti category in my ecommerce website where sub category will be dependent on main category.
Please help me with this
class MainCategory(models.Model):
# name = models.CharField(max_length=50)
# date_created = models.DateTimeField(auto_now_add=True)
# def __str__(self):
# return self.name
# class SubCategory(models.Model):
# perentcategory = models.OneToOneField(MainCategory, on_delete=models.CASCADE, primary_key=True)
# name = models.CharField(max_length=50)
# date_created = models.DateTimeField(auto_now_add=True)
# def __str__(self):
# return self.name
# class Items(models.Model):
# main = models.ForeignKey(SubCategory, on_delete=models.CASCADE)
# name = models.CharField(max_length=255)
Posting this question 4th time

Answer 1

Change models.OneToOneField to models.ForeignKey so you can have multiple subcategories assigned to a main category:
class MainCategory(models.Model):
name = models.CharField(max_length=50)
date_created = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.name
class SubCategory(models.Model):
main_category = models.ForeignKey(MainCategory, on_delete=models.CASCADE, primary_key=True)
name = models.CharField(max_length=50)
date_created = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.name
class Items(models.Model):
main = models.ForeignKey(SubCategory, on_delete=models.CASCADE)
name = models.CharField(max_length=255)

Answer 2

You can use single model to accommodate both Category and Sub-categories. Something like this.
class Category(models.Model):
name = models.CharField(blank=False, max_length=200)
slug = models.SlugField(null=False)
parent = models.ForeignKey('self',blank=True, null=True ,related_name='children', on_delete=models.SET_NULL)
Then add following function to the above model
def get_categories(self):
if self.parent is None:
return self.name
else:
return self.parent.get_categories() + ' -> ' + self.name
def __str__(self):
return self.get_categories()
This will return structure similar to this image