ORM – object relational mapping

sf – ORM session factory

Module sf defines SessionFactory class which is central point for your ORM mapping and SQL database access providing connections to database.

dao – ORM data access object support

Provides DAO support.

Base Dao class provides access to Dao.session() and py:meth:Dao.connection properties.

That means that inside any DAO object subclassed from Dao you can access current (thread-bound) SqlAlchemy session simply by accessing Dao.session() and direct connection to database by accessing Dao.connection().

Much more interesting is EntityDao class which is inteded to be used as a base DAO class for your summer.domain.Entity.