Question

In Django, you fully describe your models in models.py. In Rails with ActiveRecord, you describe part of a model in in the /models directory, and part of it in migrations. Then ActiveRecord introspects model properties from the existing database tables.

But I find migrations, columns, and tables to be a headache.

How can I do like Django — just declare all model properties instead of introspecting them from the database tables?

And for extra credit, explain where and why this would be a bad idea. 🙂

Answer 1

If you hate on Migrations, try going NoSQL. No migrations!

So you’d just add properties to your document when you need them. In your code, handle the fact that they may not exist and bam!

I took the following model definition (notice you don’t inherit form activerecord) from a blog about tekpub Also recommend the Herding Code podcast

class Production

  include MongoMapper::Document

  key :title, String, :required => true
  key :slug, String, :unique => true, :required => true, :index => true
  key :description, String
  key :notes, String
  key :price, BigDecimal, :numeric => true
  key :released_at, Date, :default => Date.today
  key :default_height, String, :default => '600'
  key :default_width, String, :default => '1000'
  key :quotes, String

  #royalty info
  key :producers, String

  timestamps!
end