Example SQLAlchemy integration with Plone

buildout.cfg

[buildout]
...

[instance]
...
eggs=
   ...
   z3c.saconfig

zcml-additional =
    ...
    <configure xmlns="http://namespaces.zope.org/zope"
              xmlns:db="http://namespaces.zope.org/db">
       <include package="z3c.saconfig" file="meta.zcml" />
       <db:engine name="my_engine_name"
                  url="mysql://david:password@localhost/my_db_name"
                  setup="my.example.prepare_model.prepare"
                  />
       <db:session name="session" engine="my_engine_name" />
   </configure>

prepare_model.py

def prepare(engine):
    # ``Base`` is a declarative_base object used for ORM classes.
    from my.example import Base

    # Need to import models so Base.metadata is aware of their existence 
    import my.example.models

    # Binds the SQLAlchemy engine to the models' metadata so they can be accessed
    Base.metadata.create_all(engine)