Create Backups for All Models

July 22, 2024, 4:20 p.m.

Regular backups are essential to safeguard your data. In this guide, we'll walk through a simple Django management command to back up all models in your application. This script saves all model data to JSON files within a specified directory. Adapt this as you need for your project.

Step-by-Step Implementation

Create the Management Command

First, create a new management command in your Django application. You can do this by creating a directory structure like this:

your_app/
    management/
        __init__.py
        commands/
            __init__.py
            backup_all_models.py

Write the Backup Command

In backup_all_models.py, add the following code:

import os
from django.core.management.base import BaseCommand, call_command
from django.apps import apps

class Command(BaseCommand):
    help = "Create a backup of all models."

    def handle(self, *args, **options):
        backup_dir = "backup/"

        os.makedirs(backup_dir, exist_ok=True)

        app_models = apps.get_models()
        for model in app_models:
            related_objects = model.objects.all()

            if related_objects.exists():
                pks = list(related_objects.values_list("pk", flat=True))
                filename = os.path.join(backup_dir, f"{model._meta.app_label.lower()}_{model.__name__.lower()}.json")
                self.stdout.write(f"Backing up {model.__name__}")

                call_command(
                    "dumpdata",
                    f"{model._meta.app_label.lower()}.{model.__name__.lower()}",
                    "--pks",
                    ",".join(map(str, pks)),
                    output=filename,
                )
                self.stdout.write(self.style.SUCCESS(f"Successfully backed up {model.__name__} to {filename}."))

        self.stdout.write(self.style.SUCCESS(f"Backup completed successfully for all models in {backup_dir}."))

How It Works

• Directory Setup: The script first ensures that the backup/ directory exists.
• Iterate Through Models: It retrieves all models in the project and iterates through them.
• Data Extraction: For each model, it extracts all objects and their primary keys.
• Backup to JSON: It then uses Django's dumpdata command to serialize the data to a JSON file named after the model.

To execute the backup command, simply run:

python manage.py backup_all_models

This will generate JSON files for each model in the backup/ directory, ensuring all your data is safely stored.