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