NodeJS drivers

• PostgreSQL node-postgres Driver

node-postgres is a collection of node.js modules for interfacing with your PostgreSQL database. It has support for callbacks, promises, async/await, connection pooling, prepared statements, cursors, streaming results, C/C++ bindings, rich type parsing, and more. YugabyteDB has full support for node-postgres.

CRUD operations with node-postgres driver

Learn how to establish a connection to YugabyteDB database and begin basic CRUD operations using the steps in Build an Application in the Quick Start section.

The following sections break down the quick start example to demonstrate how to perform common tasks required for Node.js application development using the PostgreSQL node-postgres driver.

Step 1: Download the driver dependency

Download and install the node-postgres driver using the following command (you need to have Node.JS installed on your system):

npm install pg

After this, you can start using the driver in your code.

Step 2: Connect to your cluster

Before connecting to the YugabyteDB cluster, first import the pg package.

  const pg = require('pg');

Create a client to connect to the cluster using a connection string.

const connectionString = "postgresql://user:[email protected]:port/database"
const client = new Client(connectionString);
client.connect()

Use SSL

The following is an example connection string for connecting to a YugabyteDB cluster with SSL enabled.

const connectionString = "postgresql://user:[email protected]:port/database?ssl=true&sslmode=verify-full&sslrootcert=~/.postgresql/root.crt"
const client = new Client(connectionString);
client.connect()

For other ways to provide connection and SSL-related details, refer to the node-postgres documentation.

If you have created a cluster on YugabyteDB Managed, follow the steps to obtain the cluster connection parameters and SSL Root certificate.

Step 3: Query the YugabyteDB cluster from your application

Create a new JavaScript file called QuickStartApp.js in your project directory. Copy the following sample code, which sets up tables and queries the table contents. Replace the connection string yburl parameters with the cluster credentials and SSL certificate if required.

const pg = require('pg');

function createConnection(){
    const yburl = "postgresql://yugabyte:[email protected]:5433/yugabyte";
    const client = new pg.Client(yburl);
    client.connect();
    return client;
}

async function createTableAndInsertData(client){
    console.log("Connected to the YugabyteDB Cluster successfully.")
    await client.query("DROP TABLE IF EXISTS employee").catch((err)=>{
        console.log(err.stack);
    })
    await client.query("CREATE TABLE IF NOT EXISTS employee" +
                "  (id int primary key, name varchar, age int, language text)").then(() => {
                    console.log("Created table employee");
                }).catch((err) => {
                    console.log(err.stack);
                })
    
    var insert_emp1 = "INSERT INTO employee VALUES (1, 'John', 35, 'Java')"
    await client.query(insert_emp1).then(() => {
        console.log("Inserted Employee 1");
    }).catch((err)=>{
        console.log(err.stack);
    })
    var insert_emp2 = "INSERT INTO employee VALUES (2, 'Sam', 37, 'JavaScript')"
    await client.query(insert_emp2).then(() => {
        console.log("Inserted Employee 2");
    }).catch((err)=>{
        console.log(err.stack);
    })
}

async function fetchData(client){
    try {
        const res = await client.query("select * from employee")
        console.log("Employees Information:")
        for (let i = 0; i<res.rows.length; i++) {
          console.log(`${i+1}. name = ${res.rows[i].name}, age = ${res.rows[i].age}, language = ${res.rows[i].language}`)
        }
      } catch (err) {
        console.log(err.stack)
      }
}

(async () => {
    const client = createConnection();
    if(client){
        await createTableAndInsertData(client);
        await fetchData(client);
    }
})();

When you run the application using the command node QuickStartApp.js, you should see output similar to the following:

Connected to the YugabyteDB Cluster successfully.
Created table employee
Inserted Employee 1
Inserted Employee 2
Employees Information:
1. name = John, age = 35, language = Java
2. name = Sam, age = 37, language = JavaScript

If there is no output or you get an error, verify the parameters included in the connection string.

After completing these steps, you should have a working Node.JS app that uses the PostgreSQL node.js driver to connect to your cluster, set up tables, run queries, and print out results.

Next steps

• Learn how to build Node.js applications using Sequelize ORM.