Create Charts with AWS Redshift

This example shows you how to create a graph based on AWS Redshift.

This could be useful if you want to avoid making graphs directly from your production database.

This tutorial is based on this database sample.

We’ll create 2 charts:

1. Number of users (single value chart)
2. Top 5 buyers (leaderboard chart)

Connect to a Redshift Database

Install the NodeJS package for your Forest project

node install node-redshift --save

Create the database client and set up the credentials variables cf. package documentation: https://www.npmjs.com/package/node-redshift.

var Redshift = require('node-redshift');

var clientCredentials = {
  host: process.env.REDSHIFT_HOST,
  port: process.env.REDSHIFT_PORT,
  database: process.env.REDSHIFT_DATABASE,
  user: process.env.REDSHIFT_DB_USER,
  password: process.env.REDSHIFT_DB_PASSWORD,
};

const redshiftClient = new Redshift(clientCredentials);

Configure your database credentials in your env variables

Create the Single Value Chart

Step 1 - Create a Single Value Smart Chart in the Forest Project Dashboard.

Learn more about Smart Chart

Step 2 - Create the route to handle the Smart Chart

const express = require('express');
const router = express.Router();
const Liana = require('forest-express');

...

router.post('/stats/nb-users', Liana.ensureAuthenticated, async (request, response) => {

  const query = `
    SELECT count(*) as nb
    FROM users
  `;

  const data = await redshiftClient.query(query);

  let json = new Liana.StatSerializer({
    value: data.rows[0].nb
  }).perform();

  response.send(json);

});

Create the Leaderboard Chart

Step 1 - Create a Leaderboard Smart Chart in the Forest Project Dashboard.

Learn more about Smart charts

Step 2 - Create the route to handle the Smart Chart

const express = require('express');
const router = express.Router();
const Liana = require('forest-express');

...

router.post('/stats/top-5-buyers', Liana.ensureAuthenticated, async (request, response) => {

  const query = `
    SELECT firstname || ' ' || lastname AS key, total_quantity AS value
    FROM   (SELECT buyerid, sum(qtysold) total_quantity
            FROM  sales
            GROUP BY buyerid
            ORDER BY total_quantity desc limit 5) Q, users
    WHERE Q.buyerid = userid
    ORDER BY Q.total_quantity desc
  `;

  const data = await redshiftClient.query(query);

  let leaderboard = data.rows;
  let json = new Liana.StatSerializer({
    value: leaderboard
  }).perform();

  response.send(json);

});

Result