Using PGvector with your Django App

Pgvector is an extention foor postgres which is useful to build vectorfield to store embedding etc.

How will we implement in our django application ?

• Install pgvector
• Create a empty migration file and add the pgvector-extension to the postgres and migrate it
• Finally add the field in any of your model

---

Let's get started -

1. Install pgvector

pip install pgvector

Official Repo : https://github.com/pgvector/pgvector

2. Create an empty migration file

I am assuming you have already created the app,where the vector field will be used in its models.

python manage.py makemigrations <your-app-name> --name enable_pgvector --empty

Now, when you go to your app directory you can see 0001_enable_pgvector.py newly created file inside migration folder of your app.

.
├── manage.py
├── pdf_store                      <<< MY APP
│   ├── admin.py
│   ├── apps.py
│   ├── __init__.py
│   ├── migrations
│   │   ├── 0001_enable_pgvector.py  <<< HERE
│   │   ├── 0002_initial.py
│   │   └──__init__.py
│   ├── models.py
│   ├── templates
│   ├── tests.py
│   └── views.py
├── pdf_chat_project              <<< MY PROJECT
│   ├── asgi.py
│   ├── __init__.py
│   ├── settings.py
│   ├── urls.py
│   └── wsgi.py
├── README.md
└── requirements.txt

Add the following code into it

from django.db import migrations
from pgvector.django import VectorExtension

class Migration(migrations.Migration):

    dependencies = [
        # Add your app's previous migration here if any
        # For now if you are doing it first-time without previous migration then no need to worry !
        # Just keep it blank
    ]

    operations = [
        VectorExtension(),
    ]

Then do migration :

python3 manage.py makemigrations

and

python3 manage.py migrate

3. Import and Add model to your models.py

Here is my code

from django.db import models
from pgvector.django import VectorField

class PDFDocument(models.Model):
    title     = models.CharField(max_length=255)
    pdf_file  = models.FileField(upload_to='pdfs/')
    embedding = VectorField(dimensions=1536)  # Adjust dimensions based on your model

    def __str__(self):
        return self.title

Then do the migration ++

Ta Da !!!