Update:
下面是一个来自ruby on rails api的例子:
class AddSystemSettings < ActiveRecord::Migration
# create the table
def self.up
create_table :system_settings do |t|
t.string :name
t.string :label
t.text :value
t.string :type
t.integer :position
end
# populate the table
SystemSetting.create :name => "notice", :label => "Use notice?", :value => 1
end
def self.down
drop_table :system_settings
end
end