Connecting with Python

This guide explains how to connect a Python application to a Hydra database using the  psycopg2-binary package. It covers environment setup, configuration, and execution of a simple query to test connectivity. 
 Variables 
 To connect to a Hydra database, you only need one environment variable — the connection URI. 
 
 
 
 
 Variable 
 
 
 Description 
 
 
 Purpose 
 
 
 
 
 
 
 HYDRA_URI 
 
 
 Full Hydra (PostgreSQL-compatible) connection string from the Elestio service overview 
 
 
 Provides all credentials and connection details in a single URI 
 
 
 
 
 A typical URI format looks like: 
 postgresql://<USER>:<PASSWORD>@<HOST>:<PORT>/<DATABASE> 
 You can find the details needed in the URI from the  Elestio service overview  details. Copy and replace the variables carefully in the URI example provided above. 
 
 Prerequisites 
 Install Python 
 Check if Python is installed: 
 python --version 
 If not installed, download it from https://python.org . 
 Install  psycopg2-binary 
 Install the PostgreSQL driver for Python: 
 pip install psycopg2-binary 
 Code 
 Once all prerequisites are set up, create a new file named hydra.py and add the following code and replace the HYDRA_URI with actual link or in environment setup as you wish: 
 import psycopg2
import os

def get_db_version():
 try:
 # Use the Hydra URI from environment variable
 connection_uri = os.getenv('HYDRA_URI', 'POSTGRESQL_URI')
 db_connection = psycopg2.connect(connection_uri)
 db_cursor = db_connection.cursor()
 db_cursor.execute('SELECT VERSION()')
 db_version = db_cursor.fetchone()[0]
 return db_version

 except Exception as e:
 print(f"Database connection error: {e}")
 return None

 finally:
 if 'db_cursor' in locals():
 db_cursor.close()
 if 'db_connection' in locals():
 db_connection.close()

def display_version():
 version = get_db_version()
 if version:
 print(f"Connected to Hydra: {version}")

if __name__ == "__main__":
 display_version() 
 🔐 Tip: Save your URI in an .env file or set it in your terminal session like this: 
 export HYDRA_URI=postgresql://user:password@host:port/database 
 To execute the script, open the terminal or command prompt and navigate to the directory where  hydra.py . Once in the correct directory, run the script with the command 
 python hydra.py 
 If the connection is successful, you’ll see: 
 Connected to Hydra: PostgreSQL 14.13 (Debian 14.13-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit