Node.js — PostgreSQL

Installation

npm install pg

Connection

const { Client } = require('pg');

const client = new Client({
    host: 'localhost',
    port: 5432,
    user: 'postgres',
    password: 'password',
    database: 'mydb'
});

await client.connect();

Pool

const { Pool } = require('pg');

const pool = new Pool({
    host: 'localhost',
    user: 'postgres',
    password: 'password',
    database: 'mydb',
    max: 20
});

const result = await pool.query('SELECT * FROM users');

Querying

// Simple query
const result = await pool.query('SELECT * FROM users');

// Parameterized query
const result = await pool.query(
    'SELECT * FROM users WHERE id = $1',
    [userId]
);

// Insert
await pool.query(
    'INSERT INTO users (name, email) VALUES ($1, $2)',
    ['John', 'john@example.com']
);

CRUD Operations

// Read
const { rows } = await pool.query('SELECT * FROM users');

// Create
await pool.query(
    'INSERT INTO users (name, email) VALUES ($1, $2)',
    [name, email]
);

// Update
await pool.query(
    'UPDATE users SET name = $1 WHERE id = $2',
    [name, id]
);

// Delete
await pool.query('DELETE FROM users WHERE id = $1', [id]);

Mini Practice

1. Set up PostgreSQL connection
2. Use connection pooling
3. Perform parameterized queries
4. Implement CRUD operations

Up Next

Continue with Testing — writing tests in Node.js.