Entity relation diagrams generator
ERAlchemy generates Entity Relation (ER) diagram (like the one below) from databases or from SQLAlchemy models.
Example
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.
Usage from Command Line
From a database
$ eralchemy -i sqlite:///relative/path/to/db.db -o erd_from_sqlite.pdf
The database is specified as a SQLAlchemy database url.
From 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
From a Postgresql DB to a markdown file excluding tables named temp and audit
$ eralchemy -i 'postgresql+psycopg2://username:password@hostname:5432/databasename' -o filtered.er --exclude-tables temp audit
From a Postgresql DB to a markdown file excluding columns named created_at and updated_at from all tables
$ eralchemy -i 'postgresql+psycopg2://username:password@hostname:5432/databasename' -o filtered.er --exclude-columns created_at updated_at
From a Postgresql DB to a markdown file for the schema schema
$ eralchemy -i 'postgresql+psycopg2://username:password@hostname:5432/databasename' -s schema
Usage 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')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