drizzle-erd

name	drizzle-erd
description	Use when needing to visualize database schema, generate ERD diagrams from Drizzle ORM schemas, or understand table relationships

Drizzle ERD Generator

Generate Mermaid ERD diagrams from Drizzle ORM schema files.

When to Use

• Database schema visualization needed
• Understanding table relationships
• Documentation for DB structure
• PR review of schema changes

Process

1. Find schema files - Locate Drizzle table definitions (usually schema.ts or tables.ts)
2. Parse tables - Extract table names, columns, types, and constraints
3. Identify relations - Find .references() calls and relations definitions
4. Generate Mermaid - Output ERD in Mermaid syntax

Mermaid ERD Syntax

erDiagram
    TABLE_NAME {
        type column_name PK "Primary Key"
        type column_name FK "Foreign Key"
        type column_name UK "Unique"
        type column_name "nullable"
    }

    TABLE_A ||--o{ TABLE_B : "has many"
    TABLE_A ||--|| TABLE_C : "has one"
    TABLE_A }o--|| TABLE_D : "belongs to"

Relationship Notation

Symbol	Meaning
||	Exactly one
o|	Zero or one
}o	Zero or many
}|	One or many

Type Mapping

Drizzle	Mermaid
text()	string
integer()	int
real()	float
blob()	blob
boolean mode	boolean

Output Template

erDiagram
    %% Master Tables

    %% Transaction Tables

    %% Snapshot Tables

    %% Relations

Example

From Drizzle:

export const users = sqliteTable("users", {
  id: integer("id").primaryKey(),
  name: text("name").notNull(),
  email: text("email").unique(),
});

export const posts = sqliteTable("posts", {
  id: integer("id").primaryKey(),
  userId: integer("user_id").references(() => users.id),
  title: text("title").notNull(),
});

To Mermaid:

erDiagram
    users {
        int id PK
        string name
        string email UK
    }

    posts {
        int id PK
        int user_id FK
        string title
    }

    users ||--o{ posts : "has many"

Quick Reference

Column Markers

• PK - primaryKey()
• FK - .references()
• UK - .unique()
• Add "nullable" comment if no .notNull()

Grouping

Group related tables with Mermaid comments:

%% === Master Tables ===
%% === Transaction Tables ===