Data Warehouse Setup (PostgreSQL + Python)

This project connects to a PostgreSQL database using Python and environment variables.
Real credentials are never stored in the code or in the Git repository; they are provided via a local .env file that is gitignored.

Requirements

• Python 3.10+
• PostgreSQL server installed locally on your machine
• pip for installing dependencies

Installation

1. Clone this repository:

   git clone https://github.com/your-username/your-repo.git
   cd your-repo

2. Install dependencies:

   pip install -r requirements.txt

   The requirements.txt file should include at least:

   psycopg2
   python-dotenv
   

Configure PostgreSQL (local)

PostgreSQL should be already installed and running locally on your machine (for example via the official installer or your OS package manager).

From there (run in 'psql'), create a database and user that this project will use. Example SQL:

CREATE DATABASE data_warehouse;
CREATE USER myapp_user WITH PASSWORD 'your_strong_password';
GRANT ALL PRIVILEGES ON DATABASE data_warehouse TO myapp_user;

You can change the database name, user, and password if you prefer; just keep the .env file in sync.

Environment Variables (.env)

This project reads database configuration from environment variables.
For local development, those variables come from a .env file in the project root (which is not committed to Git).

1. Create a new file called .env in the project root:

   DB_HOST=localhost
   DB_NAME=data_warehouse
   DB_USER=myapp_user
   DB_PASSWORD=your_strong_password
   DB_PORT=5432

2. Ensure .env is listed in .gitignore so your secrets are not pushed to Git.

3. In the code, python-dotenv loads these values:

   from dotenv import load_dotenv
   load_dotenv()  # loads .env into os.environ

   Then the script uses os.getenv("DB_HOST"), etc., to build the connection.

Running the Script

With PostgreSQL running locally and .env configured:

python data_warehouse_setup.py

The script will:

• Load environment variables from .env
• Use them to create a PostgreSQL connection via psycopg2
• Run whatever logic is implemented to set up the data warehouse (e.g. creating tables, inserting seed data)