rails generate add column to table

this is something i keep forgetting so up it goes :)

http://api.rubyonrails.org/classes/ActiveRecord/Migration.html

rails generate migration add_fieldname_to_tablename fieldname:string

This will generate the file timestamp_add_fieldname_to_tablename, which will look like this:

class AddFieldnameToTablename < ActiveRecord::Migration
  def up
    add_column :tablenames, :fieldname, :string
  end

  def down
    remove_column :tablenames, :fieldname
  end
end