SQLAlchemy

Introduction

SQLAlchemy is the Python SQL toolkit and Object Relational Mapper that gives application developers the full power and flexibility of SQL.

Overview

PyAMF 0.4 and newer includes an adapter for decoding/encoding objects managed by SQLAlchemy. The adapter is enabled by default, and SQLAlchemy managed objects are transparently encoded/decoded by the adapter.

To use the adapter, make sure any SQLAlchemy managed classes are mapped before assigning an AMF alias for the class.

# MUST COME FIRST
sqlalchemy.orm.mapper(MappedClass, mapped_table)

# MUST COME LATER
pyamf.register_class(MappedClass, 'mapped_class_alias')

The adapter adds 2 additional attributes to all encoded objects that are managed by SQLAlchemy.

• sa_key – An Array of values that make up the primary key of the

  encoded object (analogous to mapper.primary_key_from_instance(obj) in Python)

• sa_lazy – An Array of attribute names that have not yet been

  loaded from the database

The additional information contained in these attributes can be used to lazy load attributes in the client.

Third party packages

PyAMF also provides support for the excellent Elixir library, a thin wrapper, which provides the ability to create simple Python classes that map directly to relational database tables (this pattern is often referred to as the Active Record design pattern)

Useful Resources

Addressbook

Demonstrates the use of SQLAlchemy and Flex.

http://api.pyamf.org/0.5.1/toc-pyamf.adapters._sqlalchemy_orm-module.html

API documentation.