django: Demo app created

This PR updates the testing infrastructure to have the underlying tables
be a bit more flexibly named for the ORM, along with adding the example
code for Django.

Makefile

@@ -42,3 +42,4 @@ deps:
 	$(MAKE) deps -C ./python/sqlalchemy
 	$(MAKE) deps -C ./ruby/activerecord
 	$(MAKE) deps -C ./ruby/ar4
+	$(MAKE) deps -C ./python/django

python/django/Makefile

@@ -0,0 +1,8 @@
+.PHONY: start
+start:
+	./manage.py migrate cockroach_example && ./manage.py runserver 6543
+
+deps:
+	git clone https://github.com/cockroachlabs/cockroach-django || true
+	cd cockroach-django && pip install .
+	python -m pip install "django<2"

python/django/cockroach_example/migrations/0001_initial.py

@@ -0,0 +1,45 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.25 on 2019-10-14 18:21
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+import django.db.models.deletion
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Customers',
+            fields=[
+                ('id', models.AutoField(primary_key=True, serialize=False)),
+                ('name', models.CharField(max_length=250)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Orders',
+            fields=[
+                ('id', models.AutoField(primary_key=True, serialize=False)),
+                ('subtotal', models.DecimalField(decimal_places=2, max_digits=18)),
+                ('customer', models.ForeignKey(null=True, on_delete=django.db.models.deletion.CASCADE, to='cockroach_example.Customers')),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Products',
+            fields=[
+                ('id', models.AutoField(primary_key=True, serialize=False)),
+                ('name', models.CharField(max_length=250)),
+                ('price', models.DecimalField(decimal_places=2, max_digits=18)),
+            ],
+        ),
+        migrations.AddField(
+            model_name='orders',
+            name='product',
+            field=models.ManyToManyField(to='cockroach_example.Products'),
+        ),
+    ]

python/django/cockroach_example/models.py

@@ -0,0 +1,17 @@
+from django.db import models
+
+class Customers(models.Model):
+    id = models.AutoField(primary_key=True)
+    name = models.CharField(max_length=250)
+
+class Products(models.Model):
+    id = models.AutoField(primary_key=True)
+    name = models.CharField(max_length=250)
+    price = models.DecimalField(max_digits=18, decimal_places=2)
+
+class Orders(models.Model):
+    id = models.AutoField(primary_key=True)
+    subtotal = models.DecimalField(max_digits=18, decimal_places=2)
+    customer = models.ForeignKey(Customers, on_delete=models.CASCADE, null=True)
+    product = models.ManyToManyField(Products)
+

python/django/cockroach_example/settings.py

@@ -0,0 +1,134 @@
+"""
+Django settings for cockroach_example project.
+
+Generated by 'django-admin startproject' using Django 2.2.6.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/2.2/topics/settings/
+
+For the full list of settings and their values, see
+https://docs.djangoproject.com/en/2.2/ref/settings/
+"""
+
+import os
+
+
+from urlparse import urlparse
+
+# Build paths inside the project like this: os.path.join(BASE_DIR, ...)
+BASE_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+
+# Quick-start development settings - unsuitable for production
+# See https://docs.djangoproject.com/en/2.2/howto/deployment/checklist/
+
+# SECURITY WARNING: keep the secret key used in production secret!
+SECRET_KEY = '0pld^66i)iv4df8km5vc%1^sskuqjf16jk&z=c^rk--oh6i0i^'
+
+# SECURITY WARNING: don't run with debug turned on in production!
+DEBUG = True
+
+ALLOWED_HOSTS = []
+
+
+# Application definition
+
+INSTALLED_APPS = [
+    'django.contrib.admin',
+    'django.contrib.auth',
+    'django.contrib.contenttypes',
+    'django.contrib.sessions',
+    'django.contrib.messages',
+    'django.contrib.staticfiles',
+    'cockroach_example',
+]
+
+MIDDLEWARE = [
+    'django.middleware.security.SecurityMiddleware',
+    'django.contrib.sessions.middleware.SessionMiddleware',
+    'django.middleware.common.CommonMiddleware',
+    'django.middleware.csrf.CsrfViewMiddleware',
+    'django.contrib.auth.middleware.AuthenticationMiddleware',
+    'django.contrib.messages.middleware.MessageMiddleware',
+    'django.middleware.clickjacking.XFrameOptionsMiddleware',
+]
+
+ROOT_URLCONF = 'cockroach_example.urls'
+
+TEMPLATES = [
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'DIRS': [],
+        'APP_DIRS': True,
+        'OPTIONS': {
+            'context_processors': [
+                'django.template.context_processors.debug',
+                'django.template.context_processors.request',
+                'django.contrib.auth.context_processors.auth',
+                'django.contrib.messages.context_processors.messages',
+            ],
+        },
+    },
+]
+
+WSGI_APPLICATION = 'cockroach_example.wsgi.application'
+
+
+# Database
+# https://docs.djangoproject.com/en/2.2/ref/settings/#databases
+
+port = 26257
+addr = os.getenv('ADDR')
+if addr is not None:
+    url = urlparse(addr)
+    port = url.port
+
+DATABASES = {
+    'default': {
+        'ENGINE' : 'cockroach.django',
+        'NAME' : 'company_django',
+        'USER' : 'root',
+        'PASSWORD': '',
+        'HOST' : 'localhost',
+        'PORT' : port,
+    }
+}
+
+
+# Password validation
+# https://docs.djangoproject.com/en/2.2/ref/settings/#auth-password-validators
+
+AUTH_PASSWORD_VALIDATORS = [
+    {
+        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
+    },
+    {
+        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
+    },
+]
+
+
+# Internationalization
+# https://docs.djangoproject.com/en/2.2/topics/i18n/
+
+LANGUAGE_CODE = 'en-us'
+
+TIME_ZONE = 'UTC'
+
+USE_I18N = True
+
+USE_L10N = True
+
+USE_TZ = True
+
+
+# Static files (CSS, JavaScript, Images)
+# https://docs.djangoproject.com/en/2.2/howto/static-files/
+
+STATIC_URL = '/static/'

python/django/cockroach_example/urls.py

@@ -0,0 +1,35 @@
+"""cockroach_example URL Configuration
+
+The `urlpatterns` list routes URLs to views. For more information please see:
+    https://docs.djangoproject.com/en/2.2/topics/http/urls/
+Examples:
+Function views
+    1. Add an import:  from my_app import views
+    2. Add a URL to urlpatterns:  path('', views.home, name='home')
+Class-based views
+    1. Add an import:  from other_app.views import Home
+    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
+Including another URLconf
+    1. Import the include() function: from django.urls import include, path
+    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
+"""
+from django.contrib import admin
+from django.conf.urls import url
+
+from .views import CustomersView, OrdersView, PingView, ProductView
+
+urlpatterns = [
+    url('admin/', admin.site.urls),
+
+    url('ping/', PingView.as_view()),
+
+    # Endpoints for customers URL.
+    url('customer/', CustomersView.as_view(), name='customers'),
+    url('customer/<int:id>/', CustomersView.as_view(), name='customers'),
+
+    # Endpoints for customers URL.
+    url('product/', ProductView.as_view(), name='product'),
+    url('product/<int:id>/', ProductView.as_view(), name='product'),
+
+    url('order/', OrdersView.as_view(), name='order'),
+]

python/django/cockroach_example/views.py

@@ -0,0 +1,77 @@
+from django.http import JsonResponse, HttpResponse
+from django.utils.decorators import method_decorator
+from django.views.generic import View
+from django.views.decorators.csrf import csrf_exempt
+
+import json
+import sys
+
+from .models import *
+
+class PingView(View):
+    def get(self, request, *args, **kwargs):
+        return HttpResponse("python/django", status=200)
+
+@method_decorator(csrf_exempt, name='dispatch')
+class CustomersView(View):
+    def get(self, request, id=None, *args, **kwargs):
+        if id is None:
+            customers = list(Customers.objects.values())
+        else:
+            customers = list(Customers.objects.filter(id=id).values())
+        return JsonResponse(customers, safe=False)
+
+    def post(self, request, *args, **kwargs):
+        form_data = json.loads(request.body.decode())
+        name = form_data['name']
+        c = Customers(name=name)
+        c.save()
+        return HttpResponse(status=200)
+
+    def delete(self, request, id=None, *args, **kwargs):
+        if id is None:
+            return HttpResponse(status=404)
+        Customers.objects.filter(id=id).delete()
+        return HttpResponse(status=200)
+
+    # The PUT method is shadowed by the POST method, so there doesn't seem
+    # to be a reason to include it.
+
+@method_decorator(csrf_exempt, name='dispatch')
+class ProductView(View):
+    def get(self, request, id=None, *args, **kwargs):
+        if id is None:
+            products = list(Products.objects.values())
+        else:
+            products = list(Products.objects.filter(id=id).values())
+        return JsonResponse(products, safe=False)
+
+    def post(self, request, *args, **kwargs):
+        form_data = json.loads(request.body.decode())
+        name, price = form_data['name'], form_data['price']
+        p = Products(name=name, price=price)
+        p.save()
+        return HttpResponse(status=200)
+
+    # The REST API outlined in the github does not say that /product/ needs
+    # a PUT and DELETE method
+
+@method_decorator(csrf_exempt, name='dispatch')
+class OrdersView(View):
+    def get(self, request, id=None, *args, **kwargs):
+        if id is None:
+            orders = list(Orders.objects.values())
+        else:
+            orders = list(Orders.objects.filter(id=id).values())
+        return JsonResponse(orders, safe=False)
+
+    def post(self, request, *args, **kwargs):
+        form_data = json.loads(request.body.decode())
+        c = Customers.objects.get(id=form_data['customer']['id'])
+        o = Orders(subtotal=form_data['subtotal'], customer=c)
+        o.save()
+        for p in form_data['products']:
+            p = Products.objects.get(id=p['id'])
+            o.product.add(p)
+        o.save()
+        return HttpResponse(status=200)

python/django/cockroach_example/wsgi.py

@@ -0,0 +1,16 @@
+"""
+WSGI config for cockroach_example project.
+
+It exposes the WSGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/2.2/howto/deployment/wsgi/
+"""
+
+import os
+
+from django.core.wsgi import get_wsgi_application
+
+os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'cockroach_example.settings')
+
+application = get_wsgi_application()

python/django/manage.py

@@ -0,0 +1,21 @@
+#!/usr/bin/env python
+"""Django's command-line utility for administrative tasks."""
+import os
+import sys
+
+
+def main():
+    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'cockroach_example.settings')
+    try:
+        from django.core.management import execute_from_command_line
+    except ImportError as exc:
+        raise ImportError(
+            "Couldn't import Django. Are you sure it's installed and "
+            "available on your PYTHONPATH environment variable? Did you "
+            "forget to activate a virtual environment?"
+        ) 
+    execute_from_command_line(sys.argv)
+
+
+if __name__ == '__main__':
+    main()