Connect a JavaScript/Node.js application to Neon Postgres

Learn how to run SQL queries in Neon from JavaScript using pg, postgres.js, or the Neon serverless driver

This guide describes how to create a Neon project and connect to it from a Node.js application using popular Postgres clients:

node-postgres (pg): The most widely-used and robust driver for Node.js.
Postgres.js: A modern, high-performance driver with a focus on a great developer experience.
@neondatabase/serverless: The Neon serverless driver, which connects over HTTP and is optimized for serverless and edge environments.

You'll learn how to connect to your Neon database from a JavaScript application and perform basic Create, Read, Update, and Delete (CRUD) operations.

Connect from the Server-Side Only

Your database connection string contains sensitive credentials and must never be exposed in client-side javascript code (e.g., in a browser). All database operations should be handled in a secure, server-side environment like a Node.js backend or a serverless function.

Prerequisites

A Neon account. If you do not have one, see Sign up.
Node.js v18 or later.

Create a Neon project
If you do not have one already, create a Neon project.
1. Navigate to the Projects page in the Neon Console.
2. Click New Project.
3. Specify your project settings and click Create Project.
Your project is created with a ready-to-use database named neondb. In the following steps, you will connect to this database from your JavaScript application.
Create a Node.js project
For your Node.js project, create a project directory, initialize it with npm, and install the required libraries.
1. Create a project directory and change into it.
```
mkdir neon-nodejs-quickstart
cd neon-nodejs-quickstart
```
  Open the directory in your preferred code editor (e.g., VS Code).
2. Initialize a new Node.js project. The -y flag accepts all the default settings.
```
npm init -y
```
3. Install the required libraries using npm.
  node-postgres (pg)
  Neon serverless driver
  postgres.js
  npm install pg dotenv
4. Open your package.json file and add the following line into it:
```
{
  // other properties
  "type": "module"
}
```
  This allows you to use ES module syntax (import) in your JavaScript files.
Store your Neon connection string
Create a file named .env in your project's root directory. This file will securely store your database connection string, keeping your credentials separate from your source code.
1. In the Neon Console, select your project on the Dashboard.
2. Click Connect on your Project Dashboard to open the Connect to your database modal.
3. Select Node.js from the connection string dropdown and copy the full connection string.
4. Add the connection string to your .env file as shown below.
```
DATABASE_URL="postgresql://[user]:[password]@[neon_hostname]/[dbname]?sslmode=require&channel_binding=require"
```
  Replace [user], [password], [neon_hostname], and [dbname] with your actual database credentials.

Examples

This section provides example JavaScript scripts that demonstrate how to connect to your Neon database and perform basic operations such as creating a table, reading data, updating data, and deleting data.

Create a table and insert data

In your project directory, create a file named create_table.js and add the code for your preferred library. This script connects to your Neon database, creates a table named books, and inserts some sample data into it.

node-postgres (pg)

Neon serverless driver

postgres.js

import 'dotenv/config';
import { Pool } from 'pg';

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
  ssl: {
    require: true,
  },
});

async function setup() {
  const client = await pool.connect();
  try {
    console.log('Connection established');

    // Drop the table if it already exists
    await client.query('DROP TABLE IF EXISTS books;');
    console.log('Finished dropping table (if it existed).');

    // Create a new table
    await client.query(`
      CREATE TABLE books (
          id SERIAL PRIMARY KEY,
          title VARCHAR(255) NOT NULL,
          author VARCHAR(255),
          publication_year INT,
          in_stock BOOLEAN DEFAULT TRUE
      );
    `);
    console.log('Finished creating table.');

    // Insert a single book record
    await client.query(
      'INSERT INTO books (title, author, publication_year, in_stock) VALUES ($1, $2, $3, $4);',
      ['The Catcher in the Rye', 'J.D. Salinger', 1951, true]
    );
    console.log('Inserted a single book.');

    // Data to be inserted
    const booksToInsert = [
      { title: 'The Hobbit', author: 'J.R.R. Tolkien', year: 1937, in_stock: true },
      { title: '1984', author: 'George Orwell', year: 1949, in_stock: true },
      { title: 'Dune', author: 'Frank Herbert', year: 1965, in_stock: false },
    ];

    // Insert multiple books
    for (const book of booksToInsert) {
      await client.query(
        'INSERT INTO books (title, author, publication_year, in_stock) VALUES ($1, $2, $3, $4);',
        [book.title, book.author, book.year, book.in_stock]
      );
    }
    console.log('Inserted 3 rows of data.');
  } catch (err) {
    console.error('Connection failed.', err.stack);
  } finally {
    client.release();
    pool.end();
  }
}

setup();

The above code does the following:

Loads the connection string from the .env file.
Connects to the Neon database.
Drops the books table if it already exists to ensure a clean slate.
Creates a table named books with columns for id, title, author, publication_year, and in_stock.
Inserts a single book record and then multiple book records.

Run the script using the command for your runtime:

node create_table.js

When the code runs successfully, it produces the following output:

Connection established
Finished dropping table (if it existed).
Finished creating table.
Inserted a single book.
Inserted 3 rows of data.

Read data

In your project directory, create a file named read_data.js. This script connects to your Neon database and retrieves all rows from the books table.

node-postgres (pg)

Neon serverless driver

postgres.js

import 'dotenv/config';
import { Pool } from 'pg';

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
  ssl: {
    require: true,
  },
});

async function readData() {
  const client = await pool.connect();
  try {
    console.log('Connection established');

    // Fetch all rows from the books table
    const { rows } = await client.query('SELECT * FROM books ORDER BY publication_year;');

    console.log('\n--- Book Library ---');
    rows.forEach((row) => {
      console.log(
        `ID: ${row.id}, Title: ${row.title}, Author: ${row.author}, Year: ${row.publication_year}, In Stock: ${row.in_stock}`
      );
    });
    console.log('--------------------\n');
  } catch (err) {
    console.error('Connection failed.', err.stack);
  } finally {
    client.release();
    pool.end();
  }
}

readData();

Run the script using the command for your runtime:

node read_data.js

When the code runs successfully, it produces the following output:

Connection established

--- Book Library ---
ID: 2, Title: The Hobbit, Author: J.R.R. Tolkien, Year: 1937, In Stock: true
ID: 3, Title: 1984, Author: George Orwell, Year: 1949, In Stock: true
ID: 1, Title: The Catcher in the Rye, Author: J.D. Salinger, Year: 1951, In Stock: true
ID: 4, Title: Dune, Author: Frank Herbert, Year: 1965, In Stock: false
--------------------

Update data

In your project directory, create a file named update_data.js. This script connects to your Neon database and updates the stock status of the book 'Dune' to true.

node-postgres (pg)

Neon serverless driver

postgres.js

import 'dotenv/config';
import { Pool } from 'pg';

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
  ssl: {
    require: true,
  },
});

async function updateData() {
  const client = await pool.connect();
  try {
    console.log('Connection established');

    // Update a data row in the table
    await client.query('UPDATE books SET in_stock = $1 WHERE title = $2;', [true, 'Dune']);
    console.log("Updated stock status for 'Dune'.");
  } catch (err) {
    console.error('Connection failed.', err.stack);
  } finally {
    client.release();
    pool.end();
  }
}

updateData();

Run the script using the command for your runtime:

node update_data.js

After running this script, you can run read_data.js again to verify the change.

node read_data.js

When the code runs successfully, it produces the following output:

Connection established

--- Book Library ---
ID: 2, Title: The Hobbit, Author: J.R.R. Tolkien, Year: 1937, In Stock: true
ID: 3, Title: 1984, Author: George Orwell, Year: 1949, In Stock: true
ID: 1, Title: The Catcher in the Rye, Author: J.D. Salinger, Year: 1951, In Stock: true
ID: 4, Title: Dune, Author: Frank Herbert, Year: 1965, In Stock: true
--------------------

You can see that the stock status for 'Dune' has been updated to true.

Delete data

In your project directory, create a file named delete_data.js. This script connects to your Neon database and deletes the book '1984' from the books table.

node-postgres (pg)

Neon serverless driver

postgres.js

import 'dotenv/config';
import { Pool } from 'pg';

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
  ssl: {
    require: true,
  },
});

async function deleteData() {
  const client = await pool.connect();
  try {
    console.log('Connection established');

    // Delete a data row from the table
    await client.query('DELETE FROM books WHERE title = $1;', ['1984']);
    console.log("Deleted the book '1984' from the table.");
  } catch (err) {
    console.error('Connection failed.', err.stack);
  } finally {
    client.release();
    pool.end();
  }
}

deleteData();

Run the script using the command for your runtime:

node delete_data.js

After running this script, you can run read_data.js again to verify that the row has been deleted.

node read_data.js

When the code runs successfully, it produces the following output:

Connection established

--- Book Library ---
ID: 2, Title: The Hobbit, Author: J.R.R. Tolkien, Year: 1937, In Stock: true
ID: 1, Title: The Catcher in the Rye, Author: J.D. Salinger, Year: 1951, In Stock: true
ID: 4, Title: Dune, Author: Frank Herbert, Year: 1965, In Stock: true
--------------------

You can see that the book '1984' has been successfully deleted from the books table.

Next steps: Using an ORM or framework

While this guide demonstrates raw SQL queries, for more advanced and maintainable data interactions, consider using an Object-Relational Mapper (ORM) or query builder. ORMs let you work with your data as objects and manage schema changes through migrations, keeping your database structure in sync with your application models.

Explore these guides to integrate popular data tools with Neon:

Using Bun or Deno

If you are using Bun or Deno, you can also connect to Neon databases using the Neon serverless driver or other Postgres clients. Follow these guides for more information:

Source code

You can find the source code for the applications described in this guide on GitHub.

Resources

Need help?

Join our Discord Server to ask questions or see what others are doing with Neon. Users on paid plans can open a support ticket from the console. For more details, see Getting Support.

Connect a JavaScript/Node.js application to Neon Postgres

Connect from the Server-Side Only

Prerequisites

Create a Neon project

Create a Node.js project

Store your Neon connection string

Examples

Create a table and insert data

Read data

Update data

Delete data

Next steps: Using an ORM or framework

Using Bun or Deno

Source code

Get started with node-postgres (pg)

Get started with the Neon Serverless Driver

Get started with postgres.js

Resources

Need help?

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