Build a Node.js application

Prerequisites

This tutorial assumes that you have installed:

Clone the orm-examples repository

$ git clone https://github.com/yugabyte/orm-examples.git

This repository has a Node.js example that implements a REST API server. The scenario is that of an e-commerce application. Database access in this application is managed through the Sequelize ORM. It consists of the following:

  • The users table contains the users of the e-commerce site.
  • The products table contains a list of products the e-commerce site sells.
  • Orders placed by the users are populated in the orders table. An order can consist of multiple line items, each of these are inserted in the orderline table.

The application source is in the repository. You can customize a number of options using the properties file located at config/config.json.

Build the application

$ cd ./node/sequelize/

npm install

Specifying SSL configuration

This configuration can be used while connecting to a YB Managed cluster or a local YB cluster with SSL enabled.

Use the configuration in the following way in the models/index.js file when you create the sequelize object:

sequelize = new Sequelize("<db_name>", "<user_name>","<password>" , {
    dialect: 'postgres',
    port: 5433,
    host: "<host_name>",
    dialectOptions: {
        ssl: {
            rejectUnauthorized: true,
            ca: fs.readFileSync('<path_to_root_crt>').toString(),
        }
    }
  });

Run the application

Start the Node.js API server at http://localhost:8080 with DEBUG logs on.

$ DEBUG=sequelize:* npm start

Send requests to the application

Create 2 users.

$ curl --data '{ "firstName" : "John", "lastName" : "Smith", "email" : "jsmith@example.com" }' \
   -v -X POST -H 'Content-Type:application/json' http://localhost:8080/users

$ curl --data '{ "firstName" : "Tom", "lastName" : "Stewart", "email" : "tstewart@example.com" }' \
   -v -X POST -H 'Content-Type:application/json' http://localhost:8080/users

Create 2 products.

$ curl \
  --data '{ "productName": "Notebook", "description": "200 page notebook", "price": 7.50 }' \
  -v -X POST -H 'Content-Type:application/json' http://localhost:8080/products

$ curl \
  --data '{ "productName": "Pencil", "description": "Mechanical pencil", "price": 2.50 }' \
  -v -X POST -H 'Content-Type:application/json' http://localhost:8080/products

Create 2 orders.

$ curl \
  --data '{ "userId": "2", "products": [ { "productId": 1, "units": 2 } ] }' \
  -v -X POST -H 'Content-Type:application/json' http://localhost:8080/orders

$ curl \
  --data '{ "userId": "2", "products": [ { "productId": 1, "units": 2 }, { "productId": 2, "units": 4 } ] }' \
  -v -X POST -H 'Content-Type:application/json' http://localhost:8080/orders

Query results

Using ysqlsh

$ ./bin/ysqlsh

ysqlsh (11.2)
Type "help" for help.

yugabyte=#

yugabyte=# SELECT count(*) FROM users;

 count
-------
     2
(1 row)

yugabyte=# SELECT count(*) FROM products;

 count
-------
     2
(1 row)

yugabyte=# SELECT count(*) FROM orders;

 count
-------
     2
(1 row)

Using the REST API

$ curl http://localhost:8080/users

{
  "content": [
    {
      "userId": 2,
      "firstName": "Tom",
      "lastName": "Stewart",
      "email": "tstewart@example.com"
    },
    {
      "userId": 1,
      "firstName": "John",
      "lastName": "Smith",
      "email": "jsmith@example.com"
    }
  ],
  ...
}

$ curl http://localhost:8080/products

{
  "content": [
    {
      "productId": 2,
      "productName": "Pencil",
      "description": "Mechanical pencil",
      "price": 2.5
    },
    {
      "productId": 1,
      "productName": "Notebook",
      "description": "200 page notebook",
      "price": 7.5
    }
  ],
  ...
}

$ curl http://localhost:8080/orders

{
  "content": [
    {
      "orderTime": "2019-05-10T04:26:54.590+0000",
      "orderId": "999ae272-f2f4-46a1-bede-5ab765bb27fe",
      "user": {
        "userId": 2,
        "firstName": "Tom",
        "lastName": "Stewart",
        "email": "tstewart@example.com"
      },
      "userId": null,
      "orderTotal": 25,
      "products": []
    },
    {
      "orderTime": "2019-05-10T04:26:48.074+0000",
      "orderId": "1598c8d4-1857-4725-a9ab-14deb089ab4e",
      "user": {
        "userId": 2,
        "firstName": "Tom",
        "lastName": "Stewart",
        "email": "tstewart@example.com"
      },
      "userId": null,
      "orderTotal": 15,
      "products": []
    }
  ],
  ...
}

Explore the source

The application source is in the orm-examples repository.