Essential SQLAlchemy introduces a high-level open-source code library that makes it easier for Python programmers to access relational databases such as Oracle, DB2, MySQL, PostgreSQL, and SQLite. SQLAlchemy has become increasingly popular since its release, but it still lacks good offline documentation. This practical book fills the gap, and because a developer wrote it, you get an objective look at SQLAlchemy's tools rather than an advocate's description of all the cool features. SQLAlchemy includes both a database server-independent SQL expression language and an object-relational mapper (ORM) that lets you map "plain old Python objects" (POPOs) to database tables without substantially changing your existing Python code. Essential SQLAlchemy demonstrates how to use the library to create a simple database application, walks you through simple queries, and explains how to use SQLAlchemy to connect to multiple databases simultaneously with the same Metadata.