7 ER Diagram Examples For Database Modeling from Mermaid AI
• 6 mins
Studying a batch of well-made ER diagram examples is a great way to familiarize yourself with the diagram syntax and draw inspiration for creating your own.
Lucky for you, you’ve come to the right place.
Entity relationship (ER) diagrams are a cornerstone of database design. ER diagrams provide a blueprint for how you model your database, and allow you to communicate this design across functions within your organization.
These days, nearly every industry and profession is dealing with high volumes of data. And if you’re training AI models, clean database design is a must. That means ER diagrams are becoming increasingly important in many areas of the workplace.
Mermaid Chart, the text-based diagramming and workflow management platform, is an easy tool that anyone — technical or not — can use to create ER diagrams. Plus, with the help of Mermaid AI, users can leverage a ChatGPT-like functionality to get started and fine-tune their ER diagrams.
If you haven’t already, it only takes a few seconds to sign up for a free Mermaid Chart account; just enter your email and get started on our Free tier!
Let’s discuss the importance of this diagram type and then explore seven real ER diagram examples that our team generated using Mermaid AI. These examples are interactive; click on any of them to immediately jump into the Mermaid Chart editor using the example as a template!
What is an ER Diagram used for?
An ER diagram is a visual representation that illustrates the structure of a database. Typically, ER diagrams showcase the entities within a system, the relationships between those entities, and how the data flows within the system.
Entity relationship diagrams are especially useful in the conceptual design phase of database development; they help articulate and visualize the data requirements and relationships. ER diagrams are prevalent in the world of AI development, given that efficient databases are crucial for the storage and retrieval of data by AI algorithms.
Those interested in the syntax of ER diagrams can check out the Mermaid docs site for a deeper dive.
7 ER diagram examples from Mermaid AI
Let’s explore some entity relationship diagram examples created with Mermaid AI. We tried to showcase a wide range of use cases and industries where ER diagrams can be effective.
Looking for some pointers on how to use Mermaid AI on your own? Check out our blog on building ER diagrams with Mermaid AI.
1. E-Commerce – Edit Diagram Here
Prompt: Create an ER diagram that maps the payment flow of an e-commerce platform.
This entity relationship diagram example models the relationships between customers, their orders, the items contained in their orders, and the payments. As you read the diagram, you’ll see that:
- CUSTOMERS may place multiple ORDERS.
- Each ORDER may include multiple ITEMS.
- Each ITEM within an order is associated with a PRODUCT.
- ORDERS are associated with a PAYMENT.
- CUSTOMERS can make multiple PAYMENTS for their ORDERS.
Within each entity, you’ll see various data points, such as product code, price per unit, and payment ID.
Pro Tip: Click on “More details” in the Mermaid AI chat to learn about the entities and attributes within the AI-generated diagram.
2. Social Media – Edit Diagram Here
Prompt: Create an ER diagram that showcases how entities interact within a social media platform.
Here, you’ll see we’ve designed an ER diagram that documents a social media platform. The key entities are users, posts, comments, likes, and friend requests.
Users can create multiple posts, comments, likes, and send/recieve multiple friend requests. Posts (created by users) can receive multiple likes and comments. Both comments and likes are written by users and associated with specific posts. Friend requests are sent and received between users, with attributes tracking who sent the request, its status, and its timestamp.
3. Healthcare – Edit Diagram Here
Prompt: Create an ER diagram for a healthcare clinic and the data it collects from patients.
This ER diagram example illustrates a healthcare system. A clinic might use something similar to boost productivity and patient retention rates and ensure data integrity.
The core aspects of patient data management within a healthcare clinic are captured. Within the diagram, you can discover how patients interact with doctors through appointments, how treatments and prescriptions are given, and how medical records are maintained. Various data attributes are tracked in what can become a complex interaction.
4. Hospitality – Edit Diagram Here
Prompt: Please create an ER diagram for a hotel management system
Here we have an entity relationship diagram example for a hotel management system. A database like this could help hotel staff track which rooms are open, which rooms have been cleaned, and keep track of customer payment information.
Within the diagram, you can decipher the following:
- CUSTOMERS can create multiple RESERVATIONS.
- ROOMS may be booked by multiple RESERVATIONS, but not simultaneously.
- Each RESERVATION can be paid for by multiple PAYMENTS.
- EMPLOYEES are responsible for cleaning the ROOMS.
- RESERVATIONS can make requests, which leads to the delivery of SERVICES.
5. Supply Chain – Edit Diagram Here
Prompt: Please create a ER diagram showing a supply chain database
Modeling a supply chain database means explaining relationships between suppliers, products, shipments, orders, customers, warehouses, and more. Each supply (offered by a supplier) includes multiple products. Multiple supplies fill stock in a warehouse.
6. Inventory Management – Edit Diagram Here
Prompt: Map out an inventory management system with an ER diagram
This ER diagram example is similar to the supply chain diagram. An inventory management system includes warehouses, suppliers, customers, and the various data points and interactions between them.
7. Project Management – Edit Diagram Here
Prompt: Illustrate a project management database using an ER diagram
Most of us are probably familiar with project management tools such as Jira, Asana and ClickUp. Before building out the framework of these tools, it can be helpful to map out the workflow and attributes associated with each step of the process. In the example above:
- A DEPARTMENT would contain multiple EMPLOYEES.
- An EMPLOYEE may spend time on multiple ASSIGNMENTS.
- A PROJECT might have multiple ASSIGNMENTS and consist of multiple TASKS.
- A TASK is made up of SUBTASKS.
- An ASSIGNMENT links an employee to a project
By the way – you can check out Mermaid Chart’s Confluence plugin to create and edit diagrams directly within Confluence.
Get started with Mermaid Chart to build your ER diagrams!
Ready to create your own ER diagram examples? Mermaid Chart offers a user-friendly platform that simplifies the creation process. Here’s how to get started:
- Create your free account: Sign up with your email to join our Free tier.
- Start a new diagram: Open up a new diagram and click on “ER Diagram” from the Templates menu in the editor.
- Edit, tweak, and automate: Use our simple code editor (or message Mermaid AI) to fine-tune your diagram to fit your needs.
We wish you luck in creating effective ER diagrams that enhance your database design and AI development efforts!