DBML ER Diagrams

Obsidian plugin that renders ```dbml code blocks as interactive entity-relationship diagrams, with orthogonal, dbdiagram.io-style routing (right-angle lines), crow's-foot notation (crow's foot / bar) and direct editing on the canvas.

• Plugin ID: dbml-erd
• Name: DBML ER Diagrams
• Author: Wilmar Rojas Avendaño · License: MIT
• Minimum Obsidian version: 1.6.0 · Works on desktop and mobile.

What it does

You write a ```dbml block with your tables and relationships and the plugin draws it as an SVG ERD, with automatic layout, cardinality markers and interactive editing. Every change you make from the diagram (rename, move, color, cardinality, delete…) is written back into the note's own dbml block — the block is the single source of truth.

Render and layout

• Renders dbml / DBML blocks to an SVG ERD.
• Automatic layout with elkjs (elk.layered) that minimizes crossings.
• Orthogonal (90°) routing in dbdiagram.io style, with rounded corners; lines re-route live as you move tables.
• Layout cache by structure: saving the layout does not recompute the layout nor cause flicker.
• Theme integrated with Obsidian variables (automatic light/dark).

Notation

• One symbol per endpoint for cardinality: crow's foot on the "many" side; on the "one" side, a bar (│) if the FK is not null, or a circle (○) if it is nullable.
• PK (🔑) and FK (🔗) icons, NN badge for not null columns.
• Per-table header color (text adjusts to white or dark depending on the background).

Work areas (table groups)

• Each DBML TableGroup is drawn as an area: a box with a colored header bar and a light background that wraps its tables. The layout keeps the tables of an area together.
• Drag the header bar to move the whole area with all its tables; the area grows or shrinks as you drag one of its tables.
• Click ▾ / ▸ to collapse or expand an area. A collapsed area shows its name and table count; relationships to its tables connect to the collapsed box (merged when several go to the same column), and relationships inside the area are hidden.
• The collapsed state is saved in the block and restored when you reopen the note.
• Areas can be created, renamed, recolored and removed from the diagram, and tables moved between them (see Interactive editing). Dragging a table never changes its area.

Canvas navigation

• Pan (drag the empty space), zoom (mouse wheel), + / − / ⊡ (fit) buttons.
• Resizable canvas (width and height).
• Table positions, zoom/pan and canvas size are persisted inside the block and restored when you reopen the note.

Interactive editing (from the diagram)

Everything is saved back to the dbml block:

• New table (table button in the toolbar): asks for a name and creates the table, with an id primary key, in the middle of the view.
• Table header (click the node header) → menu:
  • Rename table… (also updates references).
  • Pick color… / Remove color.
  • Move to area… (searchable list of areas, plus "New area…") / Remove from "area".
  • Delete table… (with confirmation dialog; removes the table and the relationships that reference it).
• Area header (click the area bar, or a collapsed area) → menu:
  • Rename area… / Pick color… / Remove color.
  • New table in this area…
  • Remove area… (with confirmation; its tables are kept).
• Creating tables and changing areas keep every table where it is: the current positions are saved in the same edit, so nothing jumps.
• Column row (click a column) → menu:
  • Rename column… (updates table.col references).
  • Change type…
• Connection / relationship (click the line):
  • First click: selects it and shows the route vertices.
  • Second click: menu with the relationship type (cardinality) — One to many, Many to one, One to one, Many to many (the current one is checked) —, "Reset route" (if hand-edited) and "Deselect".
• Route vertices (with the connection selected):
  • Add: tap/drag the + handle in the middle of a segment.
  • Move: drag a vertex (the line re-orthogonalizes itself to 90°).
  • Delete: right-click on a vertex → "Delete vertex"; if it was the last one, the route returns to automatic mode.

Language

The interface (menus, dialogs and notices) is available in English (default) and Spanish. Switch it under Settings → Community plugins → DBML ER Diagrams → Language.

Usage

Insert a code block with the dbml language:

```dbml
// height: 600

Table contract {
  contract_id   int          [pk]
  contract_name varchar(120) [not null]
  client_id     int          [not null]
  status        varchar(20)
}

Table client {
  client_id int          [pk]
  name      varchar(100) [not null]
}

Ref: contract.client_id > client.client_id
```

Supported syntax

• Table name { ... } (keyword in any case, and the short form name { ... }).
• Columns: name type [pk, not null, note: '...', ref: > other.col], one per line.
• Relationships: a Ref: a.col > b.col line (optionally named, Ref fk_name: ...), the long form Ref { a.col > b.col }, inline ref: > b.col, or the direct form a.col <> b.col.
• Cardinality operators: > (many→one), < (one→many), <> (many↔many), - (one↔one).
• Per-table header color: Table name [headercolor: #2E7D32] { ... }.
• Work areas: TableGroup name [color: #2E7D32] { table1 table2 }, one table name per line. A table belongs to the first area that lists it; names that don't match a table are ignored.
• Table and column notes (Note: '...', note: '...') are accepted and kept in the block, but not drawn in the diagram.
• Optional // height: N directive (canvas height in px).
• // and /* ... */ comments.
• indexes { }, enum, Project and sticky Note blocks are accepted and ignored.

TableGroup sales [color: #2E7D32] {
  client
  contract
}

A deliberate subset of DBML, enough for controlled schemas. It does not yet include enums or composite keys.

Layout annotations (managed by the plugin)

The plugin stores the visual state as comments inside the block; you don't need to edit them by hand:

• // @pos <table> <x> <y> — position of a moved table.
• // @view <x> <y> <zoom> — pan and zoom.
• // @size <w> <h> — canvas size.
• // @edge <from> <fromCol> <to> <toCol> <x1> <y1> … — vertices of a hand-edited route.
• // @group <area> collapsed — a collapsed work area.

Generate the DBML automatically (sql-to-dbml skill)

So you don't have to write the DBML by hand there is a Claude Code skill, sql-to-dbml, that converts SQL CREATE TABLE scripts (ANSI, SQL Server, PostgreSQL or MySQL) — or tables you define during the conversation — into DBML compatible with this plugin (it degrades to what the plugin draws, never emitting syntax it can't understand).

• Repository: https://github.com/wrojasa/skill-sql-to-dbml
• Typical triggers: "convert this CREATE TABLE to dbml", "generate the dbml for these tables", "build the ERD in dbml", "add this table to the dbml", "update the dbml with…".

Paste the resulting block into a note inside ```dbml and the plugin renders it.

Installation

Manual

1. Download main.js, manifest.json and styles.css from the latest release.
2. Copy the three files to <vault>/.obsidian/plugins/dbml-erd/.
3. Enable the plugin under Settings → Community plugins.

Development

npm install
npm run dev     # build with inline sourcemaps
npm run build   # minified production build
npm test        # parser, block mutators, work areas and layout tests

Code structure:

• src/main.ts — plugin, block rendering and the Diagram class (SVG, interaction, persistence).
• src/parser.ts — DBML parser (subset) and block mutators (rename, types, cardinality, delete).
• src/layout.ts — layout with elkjs and geometry constants.
• src/areas.ts — work areas (table groups) without DOM: boxes, cardinality marks and edges to collapsed areas.
• src/edits.ts — structural block edits without DOM (create tables and areas, edit areas, move tables between areas, pin positions).
• src/i18n.ts — interface strings (English/Spanish) and the t() lookup.
• test/ — tests with Node's built-in runner; npm test bundles the modules with esbuild first.
• styles.css — styles integrated with Obsidian's theme variables.

Release

Releases are produced with GitHub Actions (.github/workflows/release.yml). To publish a new version: bump version in manifest.json and package.json, add the entry to versions.json and CHANGELOG.md, create a tag with that exact number (no v prefix) and push it:

# use the exact number from the manifest, without the v prefix
git tag 0.1.19
git push origin 0.1.19

The workflow compiles and attaches main.js, manifest.json and styles.css to the release.

License

MIT © 2026 Wilmar Rojas Avendaño