Connect an application

• YSQL
• YCQL

• YugabyteDB node-postgres Smart Driver
• PostgreSQL node-postgres Driver

The YugabyteDB node-postgres smart driver is a Node.js driver for YSQL, built on the PostgreSQL node-postgres driver, with additional connection load balancing features.

CRUD operations

The following sections demonstrate how to perform common tasks required for Node.js application development using the YugabyteDB node-postgres smart driver.

To start building your application, make sure you have met the prerequisites.

Step 1: Download the driver dependency

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

npm install @yugabytedb/pg

You can start using the driver in your code.

Step 2: Set up the database connection

The following table describes the connection parameters required to connect, including smart driver parameters for uniform and topology load balancing.

Create a client to connect to the cluster using a connection string. The following is an example connection string for connecting to a YugabyteDB cluster with uniform and topology load balancing:

postgresql://yugabyte:yugabyte@128.0.0.1:5433/yugabyte?loadBalance=true? \
    ybServersRefreshInterval=240& \
    topologyKeys=cloud.region.zone1,cloud.region.zone2

After the driver establishes the initial connection, it fetches the list of available servers from the cluster, and load-balances subsequent connection requests across these servers.

Use SSL

The following table describes the connection parameters required to connect using TLS/SSL.

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

postgresql://yugabyte:yugabyte@128.0.0.1:5433/yugabyte?loadBalance=true&ssl=true& \
    sslmode=verify-full&sslrootcert=~/.postgresql/root.crt

Refer to Configure SSL/TLS for more information on default and supported SSL modes, and examples for setting up your connection strings when using SSL.

Use SSL with YugabyteDB Aeon

If you created a cluster on YugabyteDB Aeon, use the cluster credentials and download the SSL Root certificate.

With clusters in YugabyteDB Aeon, you can't use SSL mode verify-full; other SSL modes are supported. To use the equivalent of verify-full, don't set the sslmode or sslrootcert parameters in your connection string; instead, use the ssl object with the following parameters:

For example:

async function createConnection(i){
    const config = {
        connectionString: "postgresql://admin:yugabyte@us-west1.5afd2054-c213-4e53-9ec6-d15de0f2dcc5.aws.yugabyte.cloud:5433/yugabyte?loadBalance=true",
    ssl: {
        rejectUnauthorized: true,
            ca: fs.readFileSync('./root.crt').toString(),
            servername: 'us-west1.5afd2054-c213-4e53-9ec6-d15de0f2dcc5.aws.yugabyte.cloud',
        },
    }

Step 3: Write your application

Create a new JavaScript file called QuickStartApp.js in your project directory.

Copy the following sample code to set up tables and query the table contents. Replace the connection string yburl parameters with the cluster credentials and SSL certificate, if required.

const pg = require('@yugabytedb/pg');

function createConnection(){
    const yburl = "postgresql://yugabyte:yugabyte@localhost:5433/yugabyte?loadBalance=true";
    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);
    }
})();

Run the application

Run the application QuickStartApp.js using the following 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.

Learn more

YugabyteDB smart drivers for YSQL