class
Allows programmers to programmatically define a schema in a portable DSL. This means you can define tables, indexes, etc. without using SQL directly, so your applications can more easily support multiple databases.
Usage:
ActiveRecord::Schema.define do create_table :authors do |t| t.string :name, :null => false end add_index :authors, :name, :unique create_table :posts do |t| t.integer :author_id, :null => false t.string :subject t.text :body t.boolean :private, :default => false end add_index :posts, :author_id end
ActiveRecord::Schema is only supported by database adapters that also support migrations, the two features being very similar.