Versioning and auditing extension for SQLAlchemy.
- Creates versions for inserts, deletes and updates
- Does not store updates which don't change anything
- Supports alembic migrations
- Can revert objects data as well as all object relations at given transaction even if the object was deleted
- Transactions can be queried afterwards using SQLAlchemy query syntax
- Query for changed records at given transaction
- Temporal relationship reflection. Version object's relationship show the parent objects relationships as they where in that point in time.
- Supports native versioning for PostgreSQL database (trigger based versioning)
pip install SQLAlchemy-Continuum
In order to make your models versioned you need two things:
- Call make_versioned() before your models are defined.
- Add __versioned__ to all models you wish to add versioning to
from sqlalchemy_continuum import make_versioned
make_versioned(user_cls=None)
class Article(Base):
__versioned__ = {}
__tablename__ = 'article'
id = sa.Column(sa.Integer, primary_key=True, autoincrement=True)
name = sa.Column(sa.Unicode(255))
content = sa.Column(sa.UnicodeText)
article = Article(name='Some article', content='Some content')
session.add(article)
session.commit()
# article has now one version stored in database
article.versions[0].name
# 'Some article'
article.name = 'Updated name'
session.commit()
article.versions[1].name
# 'Updated name'
# lets revert back to first version
article.versions[0].revert()
article.name
# 'Some article'For completeness, below is a working example.
from sqlalchemy_continuum import make_versioned
from sqlalchemy import Column, Integer, Unicode, UnicodeText, create_engine
from sqlalchemy.orm import create_session, configure_mappers, declarative_base
make_versioned(user_cls=None)
Base = declarative_base()
class Article(Base):
__versioned__ = {}
__tablename__ = 'article'
id = Column(Integer, primary_key=True, autoincrement=True)
name = Column(Unicode(255))
content = Column(UnicodeText)
configure_mappers()
engine = create_engine('sqlite://')
Base.metadata.create_all(engine)
session = create_session(bind=engine, autocommit=False)
article = Article(name=u'Some article', content=u'Some content')
session.add(article)
session.commit()
article.versions[0].name
article.name = u'Updated name'
session.commit()
article.versions[1].name
article.versions[0].revert()
article.name- http://en.wikipedia.org/wiki/Slowly_changing_dimension
- http://en.wikipedia.org/wiki/Change_data_capture
- http://en.wikipedia.org/wiki/Anchor_Modeling
- http://en.wikipedia.org/wiki/Shadow_table
- https://wiki.postgresql.org/wiki/Audit_trigger
- https://wiki.postgresql.org/wiki/Audit_trigger_91plus
- http://kosalads.blogspot.fi/2014/06/implement-audit-functionality-in.html
- https://github.com/2ndQuadrant/pgaudit