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

Example for NewsMeme

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

$ brew install eralchemy

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.

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

The database is specified as a SQLAlchemy database url.

$ 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

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

$ eralchemy -i 'postgresql+psycopg2://username:password@hostname:5432/databasename' -o filtered.er --exclude-columns created_at updated_at

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

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')

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

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.

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