Draw a PostgreSQL schema in Mermaid

Generate Mermaid erDiagram syntax from a real 13-table schema, with declared cardinality and primary and foreign key labels.

Open the editor Inspect real output

target: Mermaid ER
access: Pro export
source specimen: 4 of 13 tables · seed/schema.json

Trellis exports a schema drafted on its canvas using PostgreSQL types. This page does not claim to parse a PostgreSQL dump or a live database.

01 / relationship run

The useful unit is the path between entities

This excerpt follows an author to an article, then to its revisions and comments. Entity blocks and matching edge lines come from one exporter run.

account||--o{article||--o{comment

actual exporter output4 of 13 tables · account, article, article_revision, comment

erDiagram
  %% Mermaid ER generated from the schema canvas
  account {
    string id PK
    string email
    string display_name
    string status
    string password_hash
    string created_at
    string updated_at
  }
  article {
    string id PK
    string author_id FK
    string title
    string slug
    string body
    string[] labels
    string search_vector
    string published_at
    string created_at
    string updated_at
  }
  article_revision {
    string article_id FK
    number revision
    string title
    string body
    string edited_by FK
    string edited_at
  }
  comment {
    string id PK
    string article_id FK
    string author_id FK
    string parent_id FK
    string body
    string created_at
    string deleted_at
  }
  account ||--o{ article : author_id
  article ||--o{ article_revision : article_id
  account ||--o{ article_revision : edited_by
  article ||--o{ comment : article_id
  account ||--o{ comment : author_id
  comment ||--o{ comment : parent_id

02 / cardinality limit

One documented edge case

All 14 relations in this seed resolve to single-column target keys, so the current Mermaid output emits no caveat line. The source still defines the boundary.

A relation whose target has a composite primary key cannot be represented by this exporter; it is emitted as a Mermaid comment instead.

source / src/lib/exporters/mermaid.ts