TypeORM to Draw.io ER Diagram Generator

A powerful CLI tool that automatically generates Draw.io Entity-Relationship (ER) diagrams from TypeORM entity definitions in TypeScript. Transform your database schema code into visual diagrams with just one command.

Features

• 🚀 Automatic ER Diagram Generation: Converts TypeORM entities to Draw.io compatible XML format
• 🔍 Smart Relationship Detection: Automatically identifies and visualizes relationships between entities
• 📊 Complete Field Mapping: Includes all entity fields with type information and constraints
• 🎨 Professional Diagrams: Generates clean, organized diagrams with proper ER notation
• 📁 Batch Processing: Process multiple entity files at once using glob patterns
• 🛠️ TypeScript Native: Full support for TypeScript decorators and type annotations
• ⚡ Modern Node.js: Built with Node.js 22+ features for optimal performance

Prerequisites

• Node.js 22.0.0 or higher
• npm or yarn package manager
• TypeScript 5.7 or higher (for project compilation)

Installation

Global Installation

npm install -g @chelproc/typeorm-to-drawio

Local Installation

Install as a development dependency in your project:

npm install --save-dev @chelproc/typeorm-to-drawio

From Source

Clone the repository and install dependencies:

git clone https://github.com/chelproc/typeorm-to-drawio.git
cd typeorm-to-drawio
npm install
npm run build

Usage

Basic Usage

After global installation, generate a diagram from your TypeORM entities:

typeorm-to-drawio path/to/entities/*.ts

Or use with npx (without global installation):

npx @chelproc/typeorm-to-drawio path/to/entities/*.ts

Command Line Options

Options:
  -o, --output <file>  Output file path (default: entities.drawio)
  -v, --verbose        Enable verbose output
  -h, --help           Show help message

Examples

Process a single entity file:

typeorm-to-drawio models/User.ts

Process multiple entity files:

typeorm-to-drawio models/User.ts models/Post.ts -o diagram.drawio

Process all entities in a directory:

typeorm-to-drawio models/*.ts -o output/er-diagram.drawio

With verbose output:

typeorm-to-drawio models/**/*.entity.ts -v

Using npx (without global installation):

npx @chelproc/typeorm-to-drawio models/**/*.ts -o diagram.drawio

Supported TypeORM Decorators

The tool recognizes and processes the following TypeORM decorators:

Entity Decorators

• @Entity() - Marks a class as a database entity

Column Decorators

• @PrimaryGeneratedColumn() - Primary key with auto-generation
• @PrimaryColumn() - Primary key column
• @Column() - Regular column with type and options
• @CreateDateColumn() - Auto-generated creation timestamp
• @UpdateDateColumn() - Auto-generated update timestamp

Relationship Decorators

• @ManyToOne() - Many-to-one relationships
• @OneToMany() - One-to-many relationships
• @OneToOne() - One-to-one relationships
• @ManyToMany() - Many-to-many relationships
• @JoinColumn() - Specifies join column for relationships
• @JoinTable() - Specifies join table for many-to-many relationships

Example

Input (TypeORM Entity)

@Entity()
export class User {
  @PrimaryGeneratedColumn("uuid")
  id: string;

  @Column()
  name: string;

  @Column({ unique: true })
  email: string;

  @OneToMany(() => Post, (post) => post.author)
  posts: Post[];

  @ManyToOne(() => Organization, (org) => org.users)
  organization: Organization;
}

Output (Draw.io Diagram)

The tool generates a Draw.io compatible XML file that renders as a professional ER diagram with:

• Entity boxes with field listings
• Primary keys marked with [PK]
• Relationship lines with proper cardinality notation (1:1, 1:N, N:N)
• Optional/nullable fields marked with "?"
• Type information for each field

Project Structure

typeorm-to-drawio/
├── src/
│   ├── main.ts                 # CLI entry point
│   ├── parser.ts               # TypeScript AST parser
│   ├── entity-extractor.ts     # Entity and field extraction
│   ├── relationship-analyzer.ts # Relationship analysis
│   ├── drawio-generator.ts     # Draw.io XML generation
│   └── types.ts                # TypeScript type definitions
├── package.json
├── tsconfig.json
└── README.md