Schema Migrations with Django

Django has built-in support for schema migrations. Below, we’ll walk through the process of setting up a Django project with Nile and running your first migration.

1. Install Django

   If you don’t already have Django installed, you can install it using pip:

   pip install django
   
2. Create a new Django project

   django-admin startproject myproject
   

   This will create a new Django project in the myproject directory.

3. Create a new app

   cd myproject
   python manage.py startapp myapp
   

   This will create a new Django app in the myproject directory.

   If all went well, the myproject directory should now have the following structure:

   myproject/
       manage.py
       myproject/
           __init__.py
           settings.py
           urls.py
           wsgi.py
       myapp/
           __init__.py
           admin.py
           apps.py
           migrations/
               __init__.py
           models.py
           tests.py
           views.py
   
4. Setting up Nile Database

   Edit the myproject/settings.py file to include the Nile database URL:

   DATABASES = {
       "default": {
           "ENGINE": "django.db.backends.postgresql",
           "NAME": "mydb",
           "USER": "myuser",
           "PASSWORD": "mypassword",
           "HOST": "us-west-2.db.thenile.dev",
           "PORT": "5432",
       }
   }
   

   You can find your database credentials in the Nile dashboard.

5. Run the migrations built-in migrations

   Django has several default modules that need database tables created. To create these tables, run the following command:

   python manage.py migrate
   

   This will create the tables in the database.

6. Create a new model

   In myapp/models.py, create a new model:

   from django.db import models
   
   class MyModel(models.Model):
       name = models.CharField(max_length=255)
   

   And update the installed apps in myproject/settings.py to include your app:

   INSTALLED_APPS = [
       'myapp.apps.MyappConfig',
       'django.contrib.admin',
       'django.contrib.auth',
       'django.contrib.contenttypes',
       'django.contrib.sessions',
       'django.contrib.messages',
       'django.contrib.staticfiles',
   ]
   
7. Create a new migration

   To create a new migration, run the following command:

   python manage.py makemigrations myapp
   

   This will create a new migration file in the myapp/migrations directory.

8. Run the migration

   To run the migration, run the following command:

   python manage.py migrate
   

   This will apply the migration to the database.

   Connect to your database and see a new table created, called myapp_mymodel.