cs.sqlalchemy-utils 20190517

Assorted utility functions to support working with SQLAlchemy.

Assorted utility functions to support working with SQLAlchemy.

Function auto_session(func)

Decorator to run a function in a session is not presupplied.

Class ORM

A convenience base class for an ORM class.

This defines a .Base attribute which is a new DeclarativeBase and provides various Session related convenience methods.

Subclasses must define their own .Session factory in their own __init__, for example:

self.Session = sessionmaker(bind=engine)

Function orm_auto_session(method)

Decorator to run a method in a session derived from self.orm if a session is not presupplied. Intended to assist classes with a .orm attribute.

Function with_session(func, *a, orm=None, session=None, **kw)

Call func(*a,session=session,**kw), creating a session if required.

This is the inner mechanism of @auto_session and ORM.auto_session_method.

Parameters:

• func: the function to call
• a: the positional parameters
• orm: optional ORM class with a .session() context manager method
• session: optional existing ORM session

One of orm or session must be not None; if session is None then one is made from orm.session() and used as a context manager. The session is also passed to func as the keyword parameter session to support nested calls.