sqlalchemy_continuum_versioned_model_setup_and_history_tracking.py

1from sqlalchemy import create_engine, Column, Integer, Unicode
2from sqlalchemy.orm import sessionmaker, declarative_base
3from sqlalchemy_continuum import make_versioned
4
5
6# 1. Call make_versioned() before defining any models
7make_versioned(user_cls=None)
8
9Base = declarative_base()
10
11# 2. Add __versioned__ to models you wish to track
12class Article(Base):
13    __versioned__ = {}
14    __tablename__ = 'article'
15
16    id = Column(Integer, primary_key=True, autoincrement=True)
17    name = Column(Unicode(255))
18    content = Column(Unicode(255))
19
20# 3. Standard SQLAlchemy setup
21engine = create_engine('sqlite:///')
22Base.metadata.create_all(engine)
23Session = sessionmaker(bind=engine)
24session = Session()
25
26# 4. Usage: Create a new record
27article = Article(name='First article', content='Some content')
28session.add(article)
29session.commit()
30
31# 5. Usage: Update the record to create a new version
32article.name = 'Updated article'
33session.commit()
34
35# 6. Accessing history
36print(article.versions[0].name)  # 'First article'
37print(article.versions[1].name)  # 'Updated article'