MyMapSaaS App Database Schema
An ER diagram for a typical SaaS application — users, organizations, memberships, projects, and subscriptions with relationships mapped out.
Preview
“Map out the database schema for a SaaS app”
About the framework
Entity Relationship Diagram for SaaS Database Design
This template applies the ER diagram framework to the most common database architecture question SaaS founders and engineers face: how do users, organizations, memberships, projects, and subscriptions relate to each other? Getting these relationships wrong early means painful migrations later.
The five entities represent the canonical SaaS data model. USER and ORGANIZATION are connected through a MEMBERSHIP junction table that carries the user's role — this enables multi-tenancy with granular access control. PROJECT belongs to an organization, not a user directly, which is the right pattern for team collaboration. SUBSCRIPTION links to ORGANIZATION and captures the Stripe plan ID, enabling per-org billing.
ERDs are the most efficient tool for communicating database design in team reviews, architecture decision records, and onboarding documentation. A developer joining your team can read this diagram in seconds and understand the data model without reading any code. Use this template as your starting schema and ask the AI to add entities for your specific domain — invitations, audit logs, file attachments, notifications — and it will generate the correct cardinality and foreign key relationships.
What's included
What you get
- Mermaid ER diagram with 5 entities
- USER, ORGANIZATION, MEMBERSHIP, PROJECT, SUBSCRIPTION
- Foreign key relationships and cardinality
- Role-based membership model
- Stripe subscription integration pattern
SaaS App Database Schema
Frequently asked questions
Common questions
Can I add new entities like Invitations or Audit Logs to this schema?
Yes. Describe the new entity and its relationships — 'Add an INVITATION entity that belongs to an ORGANIZATION and references a USER when accepted.' The AI will add the correct entity with attributes, foreign keys, and cardinality notation.
How does this template handle multi-tenancy?
Multi-tenancy is modeled through the MEMBERSHIP junction table, which connects USER and ORGANIZATION with a role attribute. This means a user can belong to multiple organizations with different roles, which is the standard pattern for B2B SaaS products.
Can I use this diagram for a non-SaaS app?
Yes. The USER-ORGANIZATION-MEMBERSHIP pattern applies to any multi-user system. You can rename entities to fit your domain — for example, replacing ORGANIZATION with TEAM or WORKSPACE — and the structural logic remains the same.
What's the difference between an ER diagram and a class diagram for database design?
ER diagrams focus on data relationships and cardinality (one-to-many, many-to-many) and are most useful for database design conversations. Class diagrams show object methods and inheritance and are better for OOP design. For SaaS schema discussions, ER diagrams are the clearer choice.
SaaS App Database Schema
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