django-er-mermaid 0.1.0

Generate Mermaid ER diagrams and data dictionaries from Django models

django-er-mermaid

Generate Mermaid ER diagrams and data dictionaries from Django models.

Features

• Mermaid ER Diagram: Generate ER diagrams in Mermaid syntax with help_text annotations
• Data Dictionary: Auto-generate comprehensive data dictionary tables
• Deprecation Warnings: Detect deprecated patterns like ForeignKey(unique=True) and unique_together
• Flexible Output: Write to file or stdout

Installation

pip install django-er-mermaid

Add django_er_mermaid to your INSTALLED_APPS:

INSTALLED_APPS = [
    'django_er_mermaid',
    # ... your other apps
]

Usage

Basic Usage

# Generate ER diagram to docs/er-diagram.md (default)
python manage.py generate_er

# Specify output file
python manage.py generate_er -o output.md

# Print to stdout
python manage.py generate_er --to-stdout

Target Specific Apps

# Single app
python manage.py generate_er -a myapp

# Multiple apps
python manage.py generate_er -a app1,app2,app3

Deprecation Warnings

# Include warnings in markdown output
python manage.py generate_er -w

# Include warnings in Japanese
python manage.py generate_er -w -j

Detects the following deprecated patterns:

• ForeignKey(unique=True) � Use OneToOneField instead
• unique_together � Use UniqueConstraint instead

Output Example

ER Diagram (Mermaid)

erDiagram
    User {
        bigint id PK
        varchar username "Username for login"
        varchar email "Email address"
    }
    Profile {
        bigint id PK
        bigint user_id FK
        text bio "User biography"
    }
    User ||--|| Profile : "user"

Data Dictionary

Field	Type	PK	FK	Null	Unique	Description
id	bigint	
username	varchar					Username for login
email	varchar					Email address

Options

Option	Short	Description
--apps	-a	Target apps (comma-separated). Default: all project apps
--output	-o	Output file path. Default: docs/er-diagram.md
--to-stdout		Print to stdout instead of file
--include-warnings	-w	Include deprecation warnings in markdown
--japanese	-j	Output warnings in Japanese (requires -w)

Requirements

• Python >= 3.13
• Django >= 5.0

License

MIT License - see LICENSE for details.

Credits

This project was inspired by django-erd-generator by Andryo Marzuki.