Data Modeling

Data Representations

Imagine you’ve been hired by a library to design their digital system. A library lends physical books to members. This system as one feature, and we want to build a data representation of this system.

What are the objects?

All objects have attributes, and optionally actions.

Entirely subjective, one example of objects here are members, books, and the library itself. Objects become tables. Columns must’t contain collections. (if there is a many <-> many relationship, create a new table)

Member

Attributes:

name: string
member_id: string

Actions:

Can borrow a book
Can return a book

Book

book_id: string
title: string
author: string
available: Boolean

Loan

loan_id: string
member_id: string
book_id: string
date_borrowed: Date
date_due: Date
date_returned: Optional(Date)