Entity relation diagrams generator

ERAlchemy generates Entity Relation (ER) diagram (like the one below) from databases or from SQLAlchemy models.

Example

Example for NewsMeme

Quick Start

Install on a mac

The simplest way to install eralchemy on OSX is by using Homebrew

$ brew install eralchemy

Install

To install ERAlchemy, just do:

$ pip install eralchemy

ERAlchemy requires GraphViz to generate the graphs and Python. Both are available for Windows, Mac and Linux.

Use from the command line and a database

$ eralchemy -i sqlite:///relative/path/to/db.db -o erd_from_sqlite.pdf

The database is specified as a SQLAlchemy database url.

Use from the command line and a markdown file.

$ curl 'https://raw.githubusercontent.com/Alexis-benoist/eralchemy/master/example/newsmeme.er' > markdown_file.er
$ eralchemy -i 'markdown_file.er' -o erd_from_markdown_file.pdf

Use from python

from eralchemy import render_er
## Draw from SQLAlchemy base
render_er(Base, 'erd_from_sqlalchemy.png')

## Draw from database
render_er("sqlite:///relative/path/to/db.db", 'erd_from_sqlite.png')

Use from the command line with a Postgresql database to a markdown file excluding tables named temp and audit

$ eralchemy -i 'postgresql+psycopg2://username:password@hostname:5432/databasename' -o filtered.er -x temp audit

Use from the command line with a Postgresql database to a markdown file for the schema schema

$ eralchemy -i 'postgresql+psycopg2://username:password@hostname:5432/databasename' -s schema

Architecture

Thanks to it's modular architecture, it can be connected to other ORMs/ODMs/OGMs/O*Ms.

Contribute

Every feedback is welcome on the GitHub issues.

To run the tests, use : $ py.test. Some tests require a local postgres database with a schema named test in a database named test all owned by a user named postgres with a password of postgres.

All tested PR are welcome.

Notes

ERAlchemy was inspired by erd, though it is able to render the ER diagram directly from the database and not just only from the ER markup language.

Released under an Apache License 2.0

Creator: Alexis Benoist @Alexis_Benoist