Chen diagram

ER in Chen notation: entities as boxes, relationships as diamonds, attributes as ovals.

The code

new ChenDiagram({
  title: 'Blog (Chen notation)',
  entities: [
    { name: 'User', attributes: [{ name: 'id', key: true }, { name: 'email' }] },
    { name: 'Post', attributes: [{ name: 'id', key: true }, { name: 'title' }] },
  ],
  relationships: [
    { name: 'writes', from: 'User', to: 'Post', fromCardinality: '1', toCardinality: 'N' },
  ],
}).generate()

What it produces

Generated by running the snippet above — this is the generator's real output,
rebuilt by scripts/build-diagram-examples.mjs, not a picture of it.

Chen notation is more common in data-modelling and academic contexts than crow’s foot; the information is the same.

Saving it

generate() returns the SVG as a string; save(path) writes it straight to
disk.

diagram.save('docs/schema.svg');

Diagram generators — every generator and its options

Models — the definitions these are drawn from

Modified at 2026-10-04 00:40:16

Diagram generators