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Abstract model vs concrete model in Python Django

python django
Table of Contents

Abstract Model

  • In Django, abstract base classes are useful when you want to put some common information into several other models.

  • You write your base class and put abstract=True in the Meta class.

  • This model will then not be used to create any database table.

  • Instead, when it is used as a base class for other models, its fields will be added to those of the child class.

  • An abstract base class and a child class.

from django.db import models

class CommonInfo(models.Model):
    name = models.CharField(max_length=100)
    age = models.PositiveIntegerField()

    class Meta:
        abstract = True

class Student(CommonInfo):
    home_group = models.CharField(max_length=5)

  • The Student model will have three fields: name, age and home_group.

  • The CommonInfo model cannot be used as a normal Django model.

Concrete Model

  • Concrete models are regular Django models that inherit directly from django.db.models.Model.

  • They result in a database table being created when you run migrations.

  • They can be queried directly, and you can create instances of them.

  • Example of a concrete model.

rom django.db import models

class Person(models.Model):
    first_name = models.CharField(max_length=50)
    last_name = models.CharField(max_length=50)

  • When you run python manage.py makemigrations and python manage.py migrate, a table for Person will be created in your database.

  • You can then use this model to create, read, update, and delete records in that table.

References