data-modeling-basics.md

description
An introduction to data modeling and modeling terminology common to relational and graph databases.

Data Modeling Basics

The importance of data modeling

The correct organization of data and the correct definition of the underlying database model or schema are critical to a business. TerminusDB organizes data in an object structure to facilitate modeling a business and the real world generally.

Modeling an organization

Using a small organization as an example, use the steps below to model and define a schema for the organization and its elements - team, project, task, and employee.

Data modeling steps

Step 1. Identify the elements of the organization

Step 2. Identify the properties of each element

Step 3. Identify the relationships between elements

Element relationship modeling

For relational and graph databases, an entity or element relationship model is a good way of implementing these steps. This helps to identify the components of the schema - its elements, properties, and relationships.

Diagram: An element relationship model

Step 1. Identify the elements of the organization

{% hint style="info" %} Elements are similar to entities in relational database terminology. {% endhint %}

Table: Elements of an organization

Element	Description
organization	The main organization.
team	The teams within the organization.
employee	The employee assigned to task.
project	The projects that a team creates.
task	The tasks of the project.

Step 2. Identify the properties of each element

{% hint style="info" %} Properties are similar to attributes in relational database terminology. A property is an item of data describing the element. {% endhint %}

Table: The properties of elements

Element	Properties
organization	name, desc, start-date
team	name, desc, start-date
employee	name, date-of-birth, start-date, role
project	name, start-date, end-date, desc, status
task	name, start-date, end-date, desc, status

Step 3. Identify the relationships between elements

{% hint style="info" %} Relationships are the same in graph and relational database terminology. Relationships define the associations or interactions between elements. {% endhint %}

Table: The relationship between elements

Element	Element	Relationship (phrasal verb)	Relationship description
organization	team	consists-of	An organization consists of teams
team	project	collaborates-on	A team collaborates-on projects
project	task	divided-into	A project is divided-into tasks
task	employee	assigned-to	A task is assigned-to an employee