sql_values retrieves SQL values using Active Record query interface but without instantiation of AR-objects.

Assuming you've got a class:

class Player < ActiveRecord::Base
  validates_presence_of :name
  scope :best, order('rating desc')
end

You can now retrieve values:

Player.values(:name)              # => ["boffy", "pitibo", "macovsky"]
Player.best.values(:rating)       # => [30, 25, 10]

There's also a shorthand ids for values(:id):

Player.where("rating>?", 10).ids  # => [1, 3]
Player.ids(:league_id)            # => [5, 3, 4]

And last but not the least, hashes:

Player.hashes(%w{id name})        # => [{"id" => 1, "name" => "boffy"}, {"id" => 2, "name" => "pitibo"}, {"id" => 3, "name" => "macovsky"}]

That's all folks!