A good analysis of Rail’s implementation of Active Record. His measure is that it’s the “Visual basic of Object Relation Mapping,” and he sums it up nicely with:

Given that Ruby fans like the idea of domain specific languages, which let you work in a super high level language customized to the problem domain, it’s surprising that Rails groupthink is that SQL is bad. It’s actually a very high level language, and allows a well written database to do some pretty amazing optimization on the fly because it provides a strong layer of abstraction between what you requested and how the storage engine provides it.

I think that if Rails switched from their Ruby-based ActiveRecord to something based in SQL, that it would be a damned tempting framework. But as it stands, I’m not sure I want to wrestle with ActiveRecord to do what I can do in SQL quickly and clearly already.

Here’s some learnin’ on ActiveRecord Associations. They’re the construct you use to inflict foreign references on your ActiveRecord tables.

Ruport is a Ruby reporting library that can hook into ActiveRecord, CSV, or SQL/DBI. It has a simple formatting language, can produce PDFs and graphs, and even does some code generation to make things easy.

All about Rails ActiveRecord associations (an a forum example). A useful set of diagrams and keywords showing how to associate things in Rails migrations.

Raaum clearly documents some of Rails ActiveRecord database conventions. And some migrations notes in the Rails wiki.