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ER Diagram Maker

Describe your database entities, tables, or data model and AI builds an ER diagram — tables, columns, primary keys, and relationships.

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Map out the database schema for a SaaS app

Here's an ER diagram for a typical SaaS app. Users join Organizations via a Membership table (with roles). Each Org owns Projects and has one Subscription tied to a Stripe billing record.

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Templates made with this tool

Real prompts and the maps that came back. Open one to see the whole board and remix the prompt.

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Hospital Management System ER Diagram

Create an ER diagram for a hospital management system with Patient, Doctor, Appointment, Department, and Medical Record entities

Hospital Database Design

Library Management System ER Diagram

Create an ER diagram for a library management system

Library Database Design

School Management System ER Diagram

Create an ER diagram for a school management system with Student, Teacher, Course, Enrollment, and Grade entities

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Prompts to start from

Click one to fill the box above. Edit anything before you send.

How to draft an ER diagram

No template to fill in and no drawing. You talk; the canvas keeps up.

Database schema for a SaaS app with users, orgs, projects...

brief.pdflecture-3.pptx
01

Describe entities and rules

Name the things being stored and how they relate in the application.

02

Specify identifiers and cardinality

Provide keys, important attributes, and whether each relationship is optional or required.

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03

Walk through sample records

Check that the model can represent real cases without duplicate or impossible relationships.

A visual model of stored relationships

An entity-relationship diagram shows entities, their attributes, and the relationships between them. At a relational design level, it can also identify tables, primary keys, and foreign keys.

Review a data model before implementation

Use it to discuss requirements or explain an existing schema. The SaaS example links users and organizations through memberships and includes projects and subscriptions.

Make the business rules visible

  1. Choose the modeling level. Distinguish a conceptual entity model from a table-level schema.
  2. Give entities stable identifiers. Names alone may not uniquely identify records.
  3. State minimum and maximum cardinality. Optional and mandatory relationships are different constraints.
  4. Resolve many-to-many relationships deliberately. A relational schema usually represents them with an association table.
  5. Test realistic edge cases. Check repeated memberships, empty collections, and historical records where relevant.

Sketch and revise the model

MyMap turns your entities and rules into a diagram for discussion. Ask to add a relationship or revise cardinality; the visual does not itself create tables or enforce constraints.

Export and share

PNG and PDF

Whole map or one frame. PDF and clean PNG on Pro.

Slides

Ask for slides from this map and present frame by frame.

Share a link

A read-only link for anyone; they can copy it to their own canvas.

Keep editing

Every map stays on your canvas; come back and ask for more.

Common questions

Does generating a diagram create a database?

No. The diagram is a design artifact. Database implementation requires separate schema definitions and migrations.

Can it show many-to-many relationships?

Describe the relationship and your modeling level. For a relational schema, request an association entity with the relevant foreign keys.

Should I include every column?

Include enough detail for the review. A high-level discussion may need only entities and relationships; implementation planning may require keys and important constraints.

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ER Diagram Maker

Free to start. No credit card required.

✦ Free to start · No credit card required · PDF, docs & images supported