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Build a NodeJS application

Prerequisites

This tutorial assumes that you have:

installed YugabyteDB and created a universe with YSQL enabled. If not, please follow these steps in the Quick Start guide.

Clone the orm-examples repository

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

This repository has a node.js example that implements a simple 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 of the e-commerce site are stored in the users table.
The products table contains a list of products the e-commerce site sells.
The 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 source for the above application can be found in the repo. There are a number of options that can be customized in the properties file located at config/config.json.

Build the application

$ cd ./node/sequelize/

npm install

Run the application

Bring the NodeJS 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@yb.com" }' \
   -v -X POST -H 'Content-Type:application/json' http://localhost:8080/users

$ curl --data '{ "firstName" : "Tom", "lastName" : "Stewart", "email" : "tstewart@yb.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 the YSQL shell

$ ./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@yb.com"
    },
    {
      "userId": 1,
      "firstName": "John",
      "lastName": "Smith",
      "email": "jsmith@yb.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@yb.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@yb.com"
      },
      "userId": null,
      "orderTotal": 15,
      "products": []
    }
  ],
  ...
}

Explore the source

As highlighted earlier, the source for the above application can be found in the orm-examples repository.