先执行:ruby script/generatemigration add_change_flag_to_users change_flag:Boolean

生成时间序列文件:db/migrate/20131016034104_add_changeflag_to_users.rb

内容:

class AddchangeflagToUsers< ActiveRecord::Migration

def self.up

add_column :users, :change_flag, :boolean

end


def self.down

remove_column :users, :change_flag

end

end


手动写入 default =>true 设置change_flag默认值1

class AddchangeflagToUsers< ActiveRecord::Migration

def self.up

add_column :users, :change_flag, :boolean, default=> true

end


def self.down

remove_column :users, :change_flag

end

end


执行 rake db:migrate