devblog/db/migrate/20141211131858_create_comments.rb

class CreateComments < ActiveRecord::Migration
  def change
    create_table :comments do |t|
      t.integer :article_id
      t.string :title
      t.text :content
      t.float :rate
      t.integer :created_by
      t.integer :updated_by

      t.timestamps
    end
  end
end