Overview

Django 1.7, released on September 2, 2014, is a major release that integrates a schema migration system directly into the framework. Until now, developers had to use the third-party library South to manage database evolution. Django 1.7 makes this tool built-in with the makemigrations and migrate commands.

Key Features

Built-in migrations

The migration system automatically detects changes made to models and generates migration files. These files are version-controllable and allow reproducing the schema evolution on any environment.

python 
# After modifying a model:
# python manage.py makemigrations
# Migrations for 'catalog':
#   catalog/migrations/0002_product_weight.py
#     - Add field weight to product

# Apply the migrations:
# python manage.py migrate

# Example of a generated migration file
from django.db import migrations, models

class Migration(migrations.Migration):
    dependencies = [
        ('catalog', '0001_initial'),
    ]

    operations = [
        migrations.AddField(
            model_name='product',
            name='weight',
            field=models.DecimalField(
                max_digits=6, decimal_places=2, null=True
            ),
        ),
    ]

Application registry

The new application registry (AppConfig) provides a clean entry point for configuring each Django application. It allows defining human-readable names, running initialization code at startup, and connecting signals reliably.

python 
# catalog/apps.py
from django.apps import AppConfig

class CatalogConfig(AppConfig):
    name = 'catalog'
    verbose_name = 'Product Catalog'

    def ready(self):
        """Code executed when the application starts."""
        import catalog.signals  # noqa: F401

# catalog/signals.py
from django.db.models.signals import post_save
from django.dispatch import receiver
from catalog.models import Product

@receiver(post_save, sender=Product)
def notify_new_product(sender, instance, created, **kwargs):
    if created:
        print(f"New product added: {instance.name}")

Sources