CustomEntity / workshop-scylladb

CarePet

Description

CarePet is a web application that allows users to monitor their pets' health and well-being. It is a full-stack application that uses NestJS for the backend, Svelte for the frontend, and ScyllaDB for the database.

Your task is to set up the database and implement the queries that the backend needs to perform to work properly. You will be given a Docker Compose file that will start the backend, frontend, and database for you.

Installation

Requirements

• Docker
• Docker Compose
• Node.js >= 16.0.0
• NPM
• CQL Shell

Clone the repository

$ git clone https://github.com/CustomEntity/workshop-scylladb.git
$ cd workshop-scylladb

Install dependencies

$ cd backend
$ npm install

$ cd ..

$ cd frontend
$ npm install

Run everything

Run the following command to start the database:

$ docker-compose up

Run the following command to start the backend:

$ cd backend
$ npm run start

Run the following command to start the frontend:

$ cd frontend
$ npm run dev

Tasks

Task 1: Connect to the database using the CQL shell

After starting the Docker Compose file, you should be able to connect to the database using the CQL shell.

Task 2: Create the keyspace

The keyspace is the top-level container for all data in ScyllaDB. It is similar to a database in other databases. You have to create a keyspace called carepet with a replication factor of 1 and a simple strategy.

Task 3: Create the tables

You have to create the following tables: owner, pet, sensor, measurement.

For the measurement table, you have have to use TimeWindowCompactionStrategy compaction strategy.

We will use the following schema:

owner table:

Column name	Type
owner_id	UUID
address	text
name	text
PRIMARY KEY	owner_id

pet table:

Column name	Type
owner_id	UUID
pet_id	UUID
chip_id	text
species	text
breed	text
color	text
gender	text
age	int
weight	float
address	text
name	text
PRIMARY KEY	(owner_id, pet_id)

sensor table:

Column name	Type
pet_id	UUID
sensor_id	UUID
PRIMARY KEY	(pet_id, sensor_id)

measurement table:

Column name	Type
sensor_id	UUID
ts	timestamp
value	float
PRIMARY KEY	(sensor_id, ts)
Compaction	TimeWindowCompactionStrategy

Task 4: Populate the tables

You have to populate the database using the npm run populate command in the backend directory.

Task 5: Implement the queries

You have to implement the queries in the backend/src/sensor/sensor.service.ts, backend/src/pet/pet.service.ts and backend/src/owner/owner.service.ts files.