Node.js with Postgres database connectivity

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

async function main() {
  // Connection configuration
  const config = {
    host: "localhost",
    user: "postgres", // Replace with your PostgreSQL username
    password: "mypassword", // Replace with your PostgreSQL password
    port: 5432, // Default PostgreSQL port
  };

  // Create a client to connect to the default "postgres" database
  const client = new Client({ ...config, database: "postgres" });

  try {
    // Connect to PostgreSQL
    await client.connect();
    console.log("Connected to PostgreSQL!");

    // Create database if it doesn't exist
    const dbName = "mydb";
    const createDbQuery = `SELECT 'CREATE DATABASE ${dbName}' WHERE NOT EXISTS (
        SELECT FROM pg_database WHERE datname = '${dbName}'
    );`;

    const createDbResult = await client.query(createDbQuery);
    if (createDbResult.rowCount > 0) {
      console.log(`Database '${dbName}' created successfully.`);
    } else {
      console.log(`Database '${dbName}' already exists.`);
    }

    // List all databases
    const listDbQuery = `SELECT datname FROM pg_database WHERE datistemplate = false;`;
    const dbListResult = await client.query(listDbQuery);
    console.log("Available databases:");
    dbListResult.rows.forEach((db) => console.log(JSON.stringify(db)));

  } catch (err) {
    console.error("Error:", err.message);
  } finally {
    // Disconnect the client
    await client.end();
    console.log("Disconnected from PostgreSQL.");
  }
}

// Run the main function
main();

PS D:\React_Project\NodeProject> node NodeJsDBConnectivityExample.js  
node:internal/modules/cjs/loader:1252
  throw err;
  ^

Error: Cannot find module 'pg'
Require stack:
- D:\React_Project\NodeProject\NodeJsDBConnectivityExample.js
    at Function._resolveFilename (node:internal/modules/cjs/loader:1249:15)
    at Function._load (node:internal/modules/cjs/loader:1075:27)
    at TracingChannel.traceSync (node:diagnostics_channel:315:14)
    at wrapModuleLoad (node:internal/modules/cjs/loader:218:24)
    at Module.require (node:internal/modules/cjs/loader:1340:12)
    at require (node:internal/modules/helpers:141:16)
    at require (node:internal/modules/helpers:141:16)
    at Object.<anonymous> (D:\React_Project\NodeProject\NodeJsDBConnectivityExample.js:1:20)
    at Object.<anonymous> (D:\React_Project\NodeProject\NodeJsDBConnectivityExample.js:1:20)
    at Module._compile (node:internal/modules/cjs/loader:1546:14)
    at Module._compile (node:internal/modules/cjs/loader:1546:14)
    at Object..js (node:internal/modules/cjs/loader:1689:10)
    at Object..js (node:internal/modules/cjs/loader:1689:10)
    at Module.load (node:internal/modules/cjs/loader:1318:32) {
    at Module.load (node:internal/modules/cjs/loader:1318:32) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [ 'D:\\React_Project\\NodeProject\\NodeJsDBConnectivityExample.js' ]
  code: 'MODULE_NOT_FOUND',
  requireStack: [ 'D:\\React_Project\\NodeProject\\NodeJsDBConnectivityExample.js' ]
}

Node.js v22.11.0
Node.js v22.11.0
PS D:\React_Project\NodeProject> npm install pg

PS D:\React_Project\NodeProject> npm install pg


added 13 packages, and audited 104 packages in 1s

15 packages are looking for funding
  run `npm fund` for details

found 0 vulnerabilities
PS D:\React_Project\NodeProject> node NodeJsDBConnectivityExample.js
Connected to PostgreSQL!
Database 'mydb' created successfully.
Available databases:
{"datname":"postgres"}
Disconnected from PostgreSQL.
PS D:\React_Project\NodeProject> node NodeJsDBConnectivityExample.js
Connected to PostgreSQL!
Database 'mydb' already exists.
Available databases:
{"datname":"postgres"}
{"datname":"mydb"}
Disconnected from PostgreSQL.
PS D:\React_Project\NodeProject>