How to Create Migration in Django: Step-by-Step Guide

To create a migration in Django, use the python manage.py makemigrations command which generates migration files based on your model changes. Then apply these changes to the database with python manage.py migrate.

Syntax

The main commands to create and apply migrations in Django are:

• python manage.py makemigrations [app_label]: Creates migration files for model changes in the specified app or all apps if none specified.
• python manage.py migrate: Applies all pending migrations to the database.

bash

python manage.py makemigrations [app_label]
python manage.py migrate

Example

This example shows how to create a new model and generate a migration for it, then apply the migration to update the database.

bash

1. Define a new model in your Django app's <code>models.py</code> file:

from django.db import models

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.CharField(max_length=100)

2. Run the command to create migration files:

python manage.py makemigrations

3. Apply the migration to update the database:

python manage.py migrate

Output

Migrations for 'yourapp':
  yourapp/migrations/0001_initial.py
    - Create model Book

Operations to perform:
  Apply all migrations: yourapp
Running migrations:
  Applying yourapp.0001_initial... OK

Common Pitfalls

Common mistakes when creating migrations include:

• Not running makemigrations after changing models, so migrations are not created.
• Forgetting to run migrate to apply changes to the database.
• Manually editing migration files, which can cause errors.
• Not specifying the app label when working with multiple apps, leading to confusion.

Always let Django generate migration files automatically and apply them promptly.

bash

Wrong way:
# Change models.py but forget to run makemigrations

Right way:
python manage.py makemigrations
python manage.py migrate

Quick Reference

Command	Purpose
python manage.py makemigrations	Create migration files for model changes
python manage.py migrate	Apply migrations to update the database
python manage.py showmigrations	List all migrations and their status
python manage.py sqlmigrate	Show SQL for a migration

Key Takeaways

Always run makemigrations after changing your models to create migration files.

Use migrate to apply migrations and update your database schema.

Never manually edit migration files unless you know exactly what you are doing.

Specify the app label in commands when working with multiple apps to avoid confusion.

Check migration status with showmigrations to track applied changes.