Learning Backend – Part 1: Setting Up Your Backend Environment

Prerequisites

Choose a Code Editor:
It is recommended to use Visual Studio Code (VS Code) for its powerful features, extensive extensions, and excellent support for JavaScript and Node.js.
Alternatives include Sublime Text, Atom, or any other code editor of your choice.

1. Installing Node.js

Download & Install:
Download Node.js from the official website and install the LTS version for stability.
Verification:
Confirm the installation by running:
```
node -v
npm -v
```
Both commands should return valid version numbers.

2. Setting Up PostgreSQL

Installation:
Download and install PostgreSQL from postgresql.org/download.
Configuration:
Set a password for the postgres superuser during installation.
Verification:
Verify the installation by running:
```
psql -U postgres
```
Enter your password to confirm access.
If you encounter an error (e.g., “could not connect to server” or “password authentication failed”), ensure that the PostgreSQL service is running and that your credentials are correct. Check your system’s service status (using `sudo service postgresql status` on Linux or `brew services list` on macOS) and review your `pg_hba.conf` configuration if necessary.

Database & User Setup:
Create a database and a dedicated user (if not done already):

CREATE DATABASE my_test_db;
CREATE USER my_app_user WITH PASSWORD 'mypassword';
GRANT ALL PRIVILEGES ON DATABASE my_test_db TO my_app_user;

Additional Resources:
For a detailed guide on setting up PostgreSQL with PGAdmin, check out
How to Set Up a PostgreSQL Database in PGAdmin: A Step-by-Step Guide.

3. Setting Up the Project Directory

Initialize Project Directory:

mkdir my-backend-project
cd my-backend-project
npm init -y

Project structure after this step:

my-backend-project/
└── package.json

Install Required Dependencies:
```
npm install pg dotenv
```
Why these packages?
- pg: PostgreSQL client to connect and interact with the PostgreSQL database.
- dotenv: Securely manages sensitive information through environment variables.
Project structure after installing dependencies:
```
my-backend-project/
├── node_modules/
├── package-lock.json
└── package.json
```

4. Configuring Environment Variables

Create .env file:
Add database credentials securely to .env:

DB_HOST=localhost
DB_PORT=5432
DB_USER=my_app_user
DB_PASSWORD=mypassword
DB_NAME=my_test_db

Updated project structure after adding .env:

my-backend-project/
├── .env
├── node_modules/
├── package-lock.json
└── package.json

5. Writing Database Connection Script

Create index.js:
Add a connection test script in index.js:

require('dotenv').config();

const { Pool } = require('pg');
const pool = new Pool({
  host: process.env.DB_HOST,
  port: process.env.DB_PORT,
  user: process.env.DB_USER,
  password: process.env.DB_PASSWORD,
  database: process.env.DB_NAME
});

async function testConnection() {
  try {
    const result = await pool.query('SELECT NOW()');
    console.log('Connection successful:', result.rows[0]);
  } catch (error) {
    console.error('Connection error:', error);
  } finally {
    await pool.end();
  }
}

testConnection();

Updated project structure after creating index.js:

my-backend-project/
├── .env
├── index.js
├── node_modules/
├── package-lock.json
└── package.json

6. Testing the Database Connection

Run your script:
```
node index.js
```
The output will be displayed in your terminal (console). You should see output similar to:
```
Connection successful: { now: '2025-03-22T10:15:00.000Z' }
```

7. Common Debugging Steps

Issue: Connection refused or could not connect to server

Cause: PostgreSQL service isn’t running.

Solution: Start PostgreSQL:

# Linux:
sudo service postgresql start

# macOS (Homebrew):
brew services start postgresql

# Windows:
# Use Windows Services tool to start PostgreSQL.

Issue: password authentication failed
- Cause: Incorrect username/password.
- Solution: Verify or reset credentials:
```
ALTER USER my_app_user WITH PASSWORD 'mypassword';
```
Issue: relation "table_name" does not exist
- Cause: Querying a non-existent table.
- Solution: Create the table first:
```
CREATE TABLE test_table (
  id SERIAL PRIMARY KEY,
  name VARCHAR(255) NOT NULL
);
```
General Debugging Tips:
- Read the full error messages carefully.
- Check database host, port, and credentials.
- Ensure the PostgreSQL service is active.

High-Level Interaction Diagram

The diagram below illustrates the interactions among Node.js, PostgreSQL, and the environment configuration:

Explanation:

Node.js: Loads sensitive configurations from .env and establishes a connection with PostgreSQL using the pg module.
.env: Contains sensitive information like database host, port, user, password, and name.
PostgreSQL: Handles the database queries and returns results to Node.js.

Next Steps

Create basic REST API endpoints using frameworks like Express.js.
Handle CRUD operations with PostgreSQL.
Implement better error handling, logging, and additional security features.

Further Parts in the “Learning Backend” Series

Part 2: Building a REST API with Express.js
Part 3: Implementing Database CRUD Operations
Part 4: Authentication, Authorization, and Security

Join the Conversation

Share your experiences and insights with other learners and developers:

What resources or techniques helped you the most?
What challenges did you face?
Do you have recommendations to share?

Happy coding! 🚀

Learning Backend – Part 1: Setting Up Your Backend Environment