Book Library API

A book library API created using an Express.js app connected via Sequelize to a PostgreSQL database in a Docker container.

Table of contents

• Introduction
• Concepts covered
• Setup & getting started
• API end points
• Models

Introduction

Following on from the music library project (https://github.com/cocomarine/music-library), this project involves creating an Express API that stores information about readers, books, genres and authors. Users can create accounts ('readers') and list books ('books') with their genre ('genres') and author ('authors') information for browsing books. When a book is loaned or returned by a user, the book record is updated by adding or removing the user's ID ('ReaderId').

Concepts covered

• Interpreting user stories and translating into app features
• Creating a web server using Express
• Handling HTTP requests and responses and errors
• Creating API using CRUD (Create, Read, Update and Delete) operations on databases
• Routing, middleware and controller functions
• Database synchronisation, manipuation and validation using Sequelize, a promise-based Node.js ORM (Object-Relational Mapping) tool
• Establishing complex relationships between database tables
• Creating test and development PostgreSQL databases in a Docker container
• Interacting with database using node-postgres, a collection of node.js modules
• Use of helpers and refractoring to make code DRY
• Using Postman to manage API requests
• Integration testing using Mocha, Chai and SuperTest
• Use of Dotenv to store sensitive information
• Use of Nodemon to automatically restart the node application when code changes
• Use of Swagger to generate API documentation

Setup & getting started

1. Start by running postgres in a Docker container.

docker run --name postgres -p 5432:5432 -e POSTGRES_PASSWORD=password -d postgres

2. Make sure pgAdmin and Postman are installed.

3. Run pgAdmin and add new server with the following credentials to connect to the container-run postgres.

   • hostname/address: localhost or the ip address of your postgres container
   • user: postgres
   • password: password

4. Create a fork of this repo. Then clone the repo and install project dependencies.

git clone git@github.com:[your-github-username]/book-library-api # to clone your copy of the repo
npm install # to download dependencies defined in the package.json file

5. Create a .env file in the root of your project. This contains environment variables that Dotenv loads into process.env in the create-database.js file.

    PGPASSWORD=password
    PGDATABASE=book_library_dev
    PGUSER=postgres
    PGHOST=localhost
    PGPORT=5433

6. Also, create a .env.test file to be used for creating test database by copying the same environment variables as .env but with different database name such as 'book_library_test'.

7. Add .env and .env.test to .gitignore to prevent your credentials from commited to Github.

8. To test or run the app, run the following commands.

npm test  # to test the codes
npm start # to start the app at http://localhost:4000

9. Use Postman and pgAdmin to check if the CRUD operations are working. You can also access API documentation at http://localhost:4000/api-docs .

---

API end points

Book

POST /books (add a new book)

Parameters and body content

Parameters	Body content, required	Optional
None	title [string], ISBN [string], AuthorId [integer], GenreId [integer]	ReaderId [integer]

Responses

code	description
201	successful operation
400	content element empty, null or not unique

GET /books (find all the books)

Parameters and body content

Parameters	Body content
None	None

Responses

code	description
200	successful operation
404	books not found

GET /books/{id} (find a book by ID)

Parameters and body content

Parameters	Body content
bookId	None

Responses

code	description
200	successful operation
404	book not found

PATCH /books/{id} (update a book by ID)

Parameters and body content

Parameters	Body content
bookId	title [string], ISBN [string], AuthorId [integer], GenreId [integer] or ReaderId [integer]

Responses

code	description
200	successful operation
404	book not found

DELETE /books/{id} (delete a book by ID)

Parameters and body content

Parameters	Body content
bookId	None

Responses

code	description
204	successful operation
404	book not found

Reader

POST /readers (add a new reader)

Parameters and body content

Parameters	Body content
None	name [string,], email [string, email format], password [string, more than 8 characters]

Responses

code	description
201	successful operation
400	content element empty, null, not unique, not right format or not right length

GET /readers (find all the readers)

Parameters and body content

Parameters	Body content
None	None

Responses

code	description
200	successful operation
404	readers not found

GET /readers/{id} (find a reader by ID)

Parameters and body content

Parameters	Body content
readerId	None

Responses

code	description
200	successful operation
404	reader not found

PATCH /readers/{id} (update a reader by ID)

Parameters and body content

Parameters	Body content
readerId	name [string,], email [string, email format] or password [string, more than 8 characters]

Responses

code	description
200	successful operation
404	reader not found

DELETE /readers/{id} (delete a reader by ID)

Parameters and body content

Parameters	Body content
readerId	None

Responses

code	description
204	successful operation
404	reader not found

Author

POST /authors (add a new author)

Parameters and body content

Parameters	Body content
None	author[string]

Responses

code	description
201	successful operation
400	content element empty, null or not unique

GET /authors (find all the authors)

Parameters and body content

Parameters	Body content
None	None

Responses

code	description
200	successful operation
404	authors not found

GET /authors/{id} (find an author by ID)

Parameters and body content

Parameters	Body content
authorId	None

Responses

code	description
200	successful operation
404	author not found

PATCH /authors/{id} (update an author by ID)

Parameters and body content

Parameters	Body content
authorId	author [string]

Responses

code	description
200	successful operation
404	author not found

DELETE /authors/{id} (delete an author by ID)

Parameters and body content

Parameters	Body content
authorId	None

Responses

code	description
204	successful operation
404	author not found

Genre

POST /genres (add a new genre)

Parameters and body content

Parameters	Body content
None	genre[string]

Responses

code	description
201	successful operation
400	content element empty, null or not unique

GET /genres (find all the genres)

Parameters and body content

Parameters	Body content
None	None

Responses

code	description
200	successful operation
404	genres not found

GET /genres/{id} (find a genre by ID)

Parameters and body content

Parameters	Body content
genreId	None

Responses

code	description
200	successful operation
404	genre not found

PATCH /genres/{id} (update a genre by ID)

Parameters and body content

Parameters	Body content
genreId	author [string]

Responses

code	description
200	successful operation
404	genre not found

DELETE /genres/{id} (delete a genre by ID)

Parameters and body content

Parameters	Body content
genreId	None

Responses

code	description
204	successful operation
404	genre not found

---

Models

Books

column	data type
id	integer (PK)
title	string
ReaderId	integer (FK)
GenreId	integer (FK)
AuthorID	integer (FK)
Reader
Genre
Author

Readers

column	data type
id	integer (PK)
name	string
email	string
password	string
Books

Authors

column	data type
id	integer (PK)
author	string
Books

Genres

column	data type
id	integer (PK)
genre	string
Books

---

Author

👤 HJ Kang

• GitHub @cocomarine
• LinkedIn @hj-kang07