Alias for column names in Rails

In my database has column names such as 'delete' or 'listen-control' and so on. These cannot be changed, so I would like to alias the names so as to avoid problems in my application.

I found [the following code][1] but it is outdated (05 Aug 2005) and doesn't work with Rails 3:

module Legacy
def self.append_features(base)
super
base.extend(ClassMethods)
end
module ClassMethods
def alias_column(options)
options.each do |new_name, old_name|
self.send(:define_method, new_name) { self.send(old_name) }
self.send(:define_method, "#{new_name}=") { |value| self.send("#{old_name}=", value) }
end
end
end
end

ActiveRecord::Base.class_eval do
include Legacy
end

How can I alias the column names? Is it possible?

[1]:

[To see links please register here]

As Jaime said, those names might cause problems.

In that case, use some sensible names. Your GUI should never dictate how your columns are named.

Suggestions: `is_deleted` or `deleted_at`, `listen_control`

Then, change your view accordingly, that's way easier than fighting ActiveRecord and your database.

Aliasing method names won't solve your problem. As I mentioned in my comment above, you can't have dashes in ruby method or variable names, because ruby will interpret them as a "minus". so:

object.listen-control

will be interpreted by ruby as:

object.listen - control

and will fail. The code snippet you found might be failing because of ruby 1.9, not rails 3. Ruby 1.9 doesn't let you call `.send` on protected or private methods anymore, like 1.8 used to.

That being said, I do understand there are times when old database column names don't look very nice, and you want to clean them up. Create a folder in your lib folder called "bellmyer". Then create a file called "create_alias.rb", and add this:

module Bellmyer
module CreateAlias
def self.included(base)
base.extend CreateAliasMethods
end

module CreateAliasMethods
def create_alias old_name, new_name
define_method new_name.to_s do
self.read_attribute old_name.to_s
end

define_method new_name.to_s + "=" do |value|
self.write_attribute old_name.to_s, value
end
end
end
end
end

Now in your model that needs aliasing, you can do this:

class User < ActiveRecord::Base
include Bellmyer::CreateAlias
create_alias 'name-this', 'name_this'
end

And it will alias properly. It's using the `read_attribute` and `write_attribute` methods of ActiveRecord to access those table columns without calling them as ruby methods.

Declare this in your model.

alias_attribute :new_column_name, :column_name_in_db