Django REST framework - Yugabyte Db

This document describes how to use Django REST framework, an ORM library in Python, with YugabyteDB.

Prerequisites

To use Django with YugabyteDB, you need the following:

YugabyteDB version 2.7 or later; see Quick Start.
Python3.
Django backend for YugabyteDB.
Django REST framework by executing the following command:
sh
```
pip3 install djangorestframework
```
psycopg2 by executing the following command:
sh
```
pip3 install psycopg2
```

Use Django REST framework

You can start using Django REST framework with YugabyteDB as follows:

Create a new Django project using the following command:
python
```
django-admin startproject yugabyteTest && cd yugabyteTest/
```
Set up a new Django application using the following command:
python
```
python manage.py startapp testdb
```

Create a model by adding the following code in testdb/models.py:

python

from django.db import models

class Users(models.Model):
    userId = models.AutoField(db_column='user_id', primary_key=True, serialize=False)
    firstName = models.CharField(max_length=50, db_column='first_name')
    lastName = models.CharField(max_length=50, db_column='last_name')
    email = models.CharField(max_length=100, db_column='user_email')

    class Meta:
        db_table = "users"

    def __str__(self):
        return '%d %s %s %s' % (self.userId, self.firstName, self.lastName, self.email)

Create a Serializer in testdb\serializers.py which manages serialization and deserialization from JSON and add the following code to it:

python

from rest_framework import serializers, status
from testdb.models import Users
from django.core.exceptions import ValidationError

class UserSerializer(serializers.ModelSerializer):
    class Meta:
        model = Users
        fields = ('userId', 'firstName', 'lastName', 'email')

Create a ViewSet in testdb/views.py and add the following code:

python

from django.shortcuts import render
from testdb.models import Users
from rest_framework import viewsets
from testdb.serializers import UserSerializer

class UserViewSet(viewsets.ModelViewSet):
    queryset = Users.objects.all()
    serializer_class = UserSerializer

Configure the application

The application now has all the elements and is ready to be configured.

Map the URLs in yugabyteTest/urls.py by adding the following code:

python

from django.urls import include, re_path
from rest_framework import routers
from testdb.views import UserViewSet

router = routers.SimpleRouter(trailing_slash=False)
router.register(r'users', UserViewSet)
urlpatterns = [
    re_path(r'^', include(router.urls))
]

For Django versions earlier than 4.0, add the following code in urls.py instead, as you can import the URLs using django.conf.urls:

python

from django.urls import path, include
from django.conf.urls import url, include
from rest_framework import routers
from testdb.views import UserViewSet

router = routers.SimpleRouter(trailing_slash=False)
router.register(r'users', UserViewSet)

urlpatterns = [
    url(r'^', include(router.urls))
]

Configure yugabyteTest/settings.py to use YugabyteDB by updating the value of DATABASES field.

python

DATABASES = {
    'default': {
        'ENGINE': 'yb_backend',
        'NAME': 'yugabyte',
        'HOST': 'localhost',
        'PORT': 5433,
        'USER': 'yugabyte',
        'PASSWORD': 'yugabyte',
        'CONN_MAX_AGE': None
    }
}

For better performance with YugabyteDB, use persistent connections (setting CONN_MAX_AGE).

You also need the application and rest framework in the INSTALLED_APPS field. Replace the existing code with the following:

python

INSTALLED_APPS = [
    'rest_framework',
    'testdb.apps.TestdbConfig',
    'django.contrib.contenttypes',
    'django.contrib.auth',
]

REST_FRAMEWORK = {
    'DEFAULT_AUTHENTICATION_CLASSES': [],
    'DEFAULT_PERMISSION_CLASSES': [],
    'UNAUTHENTICATED_USER': None,
}

Create the migrations using the following command:

python

python3 manage.py makemigrations

Migrate the changes to the database using the following command:

python

python3 manage.py migrate

A users table should be created in your database. Use the ysqlsh client shell to verify that the users table has been created in your database.

Run the application

Run the Django project using the following command:

python

python3 manage.py runserver 8080

Insert a row using the following command:

$ curl --data '{ "firstName" : "John", "lastName" : "Smith", "email" : "[email protected]" }' \
    -v -X POST -H 'Content-Type:application/json' http://localhost:8080/users

Verify that the new row is inserted by executing the following command:

$ curl http://localhost:8080/users

output

[{"userId":1,"firstName":"John","lastName":"Smith","email":"[email protected]"}]

Alternatively, you can verify using the ysqlsh client shell.