Using ORMs with YugaByte DB

This repository has examples showing build a simple REST API server using ORMs on top of YugaByte DB (using the YSQL API). The scenario modelled is that of a simple online e-commerce store. It consists of the following.

• The users of the ecommerce site are stored in the users table.
• The products table contains a list of products the ecommerce 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.

Step 1. Install YugaByte DB

You should first install YugaByte DB, which is a distributed SQL database compatible with the PostgreSQL language.

Step 2. Bring up the REST API server

The same REST APIs are implemented using various ORMs. Each of these is present in one of the sub-directories in this repo. For example, to start the REST API server using Spring, simply go to the appropriate directory and follow the instructions there.

By default, the REST API server listens on localhost port 8080.

Step 3. Create a user

You can create a user named John Smith and email [email protected] as follows:

$ curl --data '{ "firstName" : "John", "lastName" : "Smith", "email" : "[email protected]" }' \
       -v -X POST -H 'Content-Type:application/json' http://localhost:8080/users

This will return the inserted record as a JSON document:

{
  "userId": "1",
  "firstName": "John",
  "lastName": "Smith",
  "email": "[email protected]"
}

You can connect to YugaByte DB using psql and select these records:

postgres=# select * from users;
 user_id | first_name | last_name |  user_email
---------+------------+-----------+---------------
       1 | John       | Smith     | [email protected](1 row)

Step 4. List all users

You can list the current set of users by running the following:

$ curl http://localhost:8080/users

You should see the following output:

{
  "content": [
    {
      "userId":"1",
      "email":"[email protected]",
      "firstName":"John",
      "lastName":"Smith"
    }
  ],
  ...
}

Step 5. Create a product

You can create a product listing as follows:

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

You should see the following return value:

{
  "productId": "1",
  "productName": "Notebook",
  "description": "200 page, hardbound, blank notebook",
  "price": 7.5}

Step 6. List all products

You can do this as follows:

$ curl http://localhost:8080/products

You should see an output as follows:

{
  "content":[
    {
      "productId": "1",
      "productName": "Notebook","description":"200 page, hardbound, blank notebook",
      "price": 7.5
    }
  ],
  ...
}

Step 7. Create an order

Creating an order involves a user id ordering a particular product, this can be achieved as follows:

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

You should see the following return value:

TBD

Note that you can check out multiple products in one order. As an example, the following POST payload makes one user (id=1) checkout two products (id=1 and id=2) by creating the following payload:

{ "userId": "1", "products": [ { "productId": 1, "units": 2 }, { "productId": 2, "units": 4 } ] }