Django AutoField with primary_key vs default pk

Question

I am curious about Django database model pk.

Is there any difference this

class Category(models.Model):
    category_id = models.AutoField(primary_key=True)
    category_name = models.CharField(max_length=50)

between this?

class Category(models.Model):
   category_name = models.CharField(max_length=50)

Are the same things AutoField with primary_key and default pk?

Answer 1

Yes, the difference is, the column name in the database for the primary key is category_id and in the second case is id.

One way you can make the second example emulate the first one is:

class Category(models.Model):
   category_name = models.CharField(max_length=50)

   @property
   def category_id(self):
       return self.id

From the documentation,

AutoField

An IntegerField that automatically increments according to available IDs. You usually won’t need to use this directly; a primary key field will automatically be added to your model if you don’t specify otherwise