Author: Ayushi Yadav
Django
Django is a trendy web development framework that assists in building web applications. Django helps eliminate repetitive tasks making the development process an easy and time-saving experience.
Snowflake
Snowflake is a cloud-based data warehousing platform that allows you to store your data, process it and enable analytical solutions in a quick, efficient, and flexible way.
Prerequisite:
A system with any OS installed (Example: Windows, Mac, etc.)
Python installed (Recommended version: 3.7 and above)
IDE installed (Example: PyCharm, VSCode, etc)
Basic understanding of the frameworks (Django and the IDE you’re using)
Install Python
Django is a python based web framework and thus requires Python to be installed in your system.
Go to this website https://www.python.org/downloads/ and download Python based on the compatibility of your OS.
You can download the latest version of Python.
Here, I’m downloading the latest version of Python.
Click the “Download Python 3.10.5” button, and the download will start automatically.
At the bottom, you will see that the .exe file has been downloaded.
Once the .exe file is downloaded, open it, and a window will pop up.
Check all the boxes and click on “Install now.”
Installing specific release
In case you want to download a specific version of Python, you can download that as well.
Go to https://www.python.org/downloads/ and scroll down.
Find your specific version release compatible with your OS and click on it.
For example, I have downloaded python version 3.9.13.
Open the .exe file downloaded and click on Next and then install.
Python is installed successfully!
Install IDE
An IDE (Integrated Development Environment) understands your code much better than a text editor. It usually provides features such as build automation, code linting, testing, and debugging.
To run Django, you can install any IDE ( like PyCharm, VScode, etc.) based on your choice.
PyCharm is preferable as it is one of the best Django IDEs for any project that uses Python language.
It is a cross platform IDE created by Jet Brains, and it includes a smart code editor which allows you to write high-quality Python code.
Steps to install PyCharm:
Go to https://www.jetbrains.com/pycharm/download/ → Select the OS you are using → Choose the desired edition → Download.
Once downloaded, open the .exe file. A window will appear.
Click on Next → Choose the location you want to install Pycharm → Next → Install
Launch PyCharm
Windows search → Pycharm File → Click to launch (or) You can launch via the shortcut created on desktop
Create a Project Folder with a Virtual environment:
File → New project → Specify the name of your project → Select the Base interpreter.
(Note: As I have installed two versions of Python, I can choose any of the versions to create the virtual environment)
Click on ‘Create’
A virtual environment is being created.
And your PyCharm setup is ready!
Before you begin with installation of Django, Check if pip is installed
Note: pip is already included with python versions greater than 3.4
Verify if pip is working properly by running the following command:
pip –version
Great! You’re good to go with the installation of Django!
What to do if pip is not working?
If your pip command is not returning the version of pip that is installed in your system, it means it is not installed or configured properly.
The most common reason why pip does not work is that it is not properly configured.
To resolve this, Check if the PATH variable is set for your project folder. If it is not set, add the location of the project folder to the PATH variable.
How to find the location?
Locate the folder where you created the project → venv → Scripts
Copy the path
In my case, it is: C:\Users\DELL\PycharmProjects\Project\venv\Scripts
Paste the path in the environment variable PATH.
Follow the steps:
Start → Search →Edit the Environment variables → Environment variables → User variables → PATH → Edit → New → Paste the Path
Once the path is set properly, you are ready to install Django!
Install Django
Open the terminal window of PyCharm
Run this command:
pip install django (To install the latest version of Django)
OR
pip install django==3.2.1 (To install a specific version of Django, replace 3.2.1 with your required version)
Verify your Django installation by running either of the following commands in the terminal:
django-admin --version
OR
python -m django --version
After the successful installation of Django, you are now ready to create your web application!
Start your Django project
Run this command in the terminal:
django-admin startproject myapp (Specify your app name instead of myapp).
The project will be created as shown:
Install Snowflake connector for Python
To connect our Django project with the Snowflake database, we will use the snowflake-connector-python package.
This requires python version >= 3.7
Run this command in the terminal to install the package:
pip install snowflake-connector-python
In your views.py file of the Django project,
Import the snowflake connector using
import snowflake.connector
Now to setup the connection, configure it in the below format
ctx = snowflake.connector.connect(
user='<username>',
password='<password>',
account='<account>',
warehouse='<warehouse>',
database='<database>',
schema='<schema>',
role='<role>'
)
The query is specified like this:
cur = ctx.cursor()
sql = "write your query here"
cur.execute(sql)
Example:
To fetch the records, use function fetchall()
records = cur.fetchall();
Here is a demo of the connection between Django and Snowflake
Let us consider a Snowflake account with DEV_DB as the database and PLACES_DATA as the schema, which contains a table named ‘PLACES’
‘PLACES’ table consists of 14 rows.
Each row specifies the name of the place.
The data is shown below:
Now let us retrieve the data present in the Snowflake database for our Django project.
Specify the path in Urls.py file as shown in the image.
Views.py file
Import snowflake.connector in the Views.py file
Create a function and specify the following inside the function,
Set up the connection configuration
def index(request):
ctx = snowflake.connector.connect(
user='ayushiyadav805',
password='********',
account='su00845.ap-south-1',
warehouse='COMPUTE_WH',
database='DEV_DB',
schema='PLACES_DATA',
role='DEV_ENGINEER'
)
Specify the query that you want to run
cur = ctx.cursor()
sql = "select * from PLACES order by place_name"
cur.execute(sql)
records = cur.fetchall();
Return the template (home.html) along with the context dictionary ‘params’ (if you have any)
return render(request, "home.html", params)
So, the views.py file will contain the following code altogether:
import snowflake.connector
from django.shortcuts import render, redirect
def index(request):
ctx = snowflake.connector.connect(
user='ayushiyadav805',
password='********',
account='su00845.ap-south-1',
warehouse='COMPUTE_WH',
database='DEV_DB',
schema='PLACES_DATA',
role='DEV_ENGINEER'
)
cur = ctx.cursor()
sql = "select * from PLACES order by place_name"
cur.execute(sql)
records = cur.fetchall();
def convertTuple(tup):
str = ''
for item in tup:
str = str + item
return str
dbrecord = [];
for row in records:
str = convertTuple(row)
dbrecord.append(str)
print("Database record includes : \n", dbrecord)
params = {'places_data': dbrecord}
return render(request, "home.html", params)
Create a template
Home.html
The home.html is a file created inside the templates folder.
Django requires an efficient way to generate the HTML files dynamically and thus relies on templates.
A template consists of static HTML code along with a way to generate the dynamic content that needs to be inserted in the output.
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Demo</title>
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.0-beta1/dist/css/bootstrap.min.css" rel="stylesheet"
integrity="sha384-0evHe/X+R7YkIZDRvuzKMRqM+OrBnVFBL6DOitfPri4tjfHxaWutUpFmBp4vmVor" crossorigin="anonymous">
</head>
<body>
<div class="container pt-4">
<h1>Django integration with Snowflake Demo</h1>
<h5>We have connected our project to Snowflake database.</h5>
<h5>The results are being retrieved from the 'Places' table stored in our Snowflake database</h5>
<div class="container pt-3">
<table class="table table-striped">
<thead><tr><th scope="col">Name of the Place</th></tr></thead>
<tbody>
{% for i in places_data%}
<tr><td>{{i}}</td></tr>
{% endfor %}
</tbody>
</table>
</div>
</div>
</body>
</html>
Start the Django development server
Use the following command to run server python manage.py runserve.
Take a look at the output in the terminal window.
You can see the database records printed in the console.
Now, Click on the development server URL ( http://127.0.0.1:000/).
This will redirect you to the browser with your project running on the server.
Output:
The data from the snowflake database will be displayed on the website.
All the records present in the table are shown in our Django web application.
Conclusion
A successful connection between Snowflake and Django web app has been established.
We can define the query and perform the basic operations, including:
Creation of tables
Creation of schemas
Creation of databases
Insertion of data into tables
Creation of roles
Performing select operations on the data stored in the tables