Want to see NoER in action?
Watch the demo on YouTube for a complete overview of its features.
NoER brings conceptual modelling back into the design of MongoDB databases. Starting from an ER diagram, it guides every translation step and generates a JSON Schema ready to deploy.
NoER keeps the steps of classic database design separate: the conceptual schema comes first, its translation into documents follows. Each translation choice is made explicitly and recorded in the design, so it can be revisited later.
NoER is built on ERd, a version of the Entity-Relationship model adapted to document databases. It has three parts:
| Part | What it does |
|---|---|
| Conceptual modelling | A graphical editor for entities, relationships and attributes in the ERd model, with error checking and guidance. |
| Translation assistant | Maps each entity to a collection and each relationship to a MongoDB design pattern, with three levels of guidance. |
| JSON Schema generator | Produces a MongoDB-compatible validator for db.createCollection or MongoDB Atlas. |
Who it is for
- Students learning document database design. NoER is used in the Master’s course in Computer Engineering at Politecnico di Torino, where students with a relational background are introduced to NoSQL modelling.
- ER designers moving to MongoDB, who want to approach document databases from solid conceptual foundations.
- MongoDB developers who want ready-to-use JSON Schema validators.
Design principles
- Guided, not automatic. NoER suggests; the designer decides. Automated actions never override domain knowledge or design intent.
- Only valid options. Each tool appears only when it applies to the selected element, and explains why it is disabled.
- Inspect every step. The collections take shape on screen during translation, before the schema is generated.
- Zero data loss. Every change is saved automatically in the browser, and undo and redo enable navigation back and forth through the design actions.
NoER runs in the browser at nosql.designerdb.io, with no installation.