Connect Python to an Oracle DB with FastAPI and SQLAlchemy

Python is a popular programming language for developing web applications, and FastAPI is a modern web framework for building APIs with Python. If you need to connect your Python application to an Oracle database, SQLAlchemy is a powerful ORM that can help streamline the process.

In this article, we will walk you through the steps to connect Python to an Oracle database using FastAPI and SQLAlchemy.

Step 1: Install required libraries

First, make sure you have Python installed on your machine. You can install FastAPI and SQLAlchemy using pip:

pip install fastapi
pip install sqlalchemy
pip install cx_oracle

Step 2: Create a FastAPI application

Create a new Python file for your FastAPI application. Import the required libraries:

from fastapi import FastAPI
from sqlalchemy import create_engine

Create an instance of the FastAPI class:

app = FastAPI()

Step 3: Configure SQLAlchemy for Oracle

Create a SQLAlchemy engine with the Oracle database URL:

database_url = 'oracle+cx_oracle://username:password@host:port/service'
engine = create_engine(database_url)

Step 4: Define database models

Create your database models using SQLAlchemy’s ORM:

from sqlalchemy import Column, Integer, String, Text, Date, DateTime
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

Define your models:

class User(Base):
  __tablename__ = 'users'
  id = Column(Integer, primary_key=True)
  name = Column(String)

Step 5: Create database tables

Create the database tables using the metadata object:

Base.metadata.create_all(bind=engine)

Step 6: Run the FastAPI application

Add routes to your FastAPI application and run it using uvicorn:

if __name__ == '__main__':
  import uvicorn
  uvicorn.run("app:app", host="0.0.0.0", port=8000, reload=True)

With these steps, you should now be able to connect your Python application to an Oracle database using FastAPI and SQLAlchemy. Happy coding!