ActiveRecord::Schema

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.column :name, :string, :null => false
    end

    add_index :authors, :name, :unique

    create_table :posts do |t|
      t.column :author_id, :integer, :null => false
      t.column :subject, :string
      t.column :body, :text
      t.column :private, :boolean, :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.