gistfile1.rb

class Person < ActiveRecord::Base
  
  # Everything in here are methods on the Person object.
  class << self
    def find_by_name (name)
      # implement it
    end
  end
  
  # Assume the table has a name and address column.
  
  def name= (name)
    # @name is an instance field that AR doesn't know about.
    # AR doesn't persist instance variables. It only persists 
    # fields that are in the database and stored in its attributes
    # hash.
    @name = name
  end
  
  def some_method
    name = "Mark" # This defines a method variable named 'name'
    this.name = "Mark" # This calls the name= methods on the instance self.
  end
  
  
  def some_other_method
    some_condition ? "mark" : 'ryan'
  end
  
  def the_other_method
    name = some_other_method.capitalize
  end
end


p = Person.new
p.name = 'Ryan'
p.address = 'New York'
p.save # This does not write Ryan into the name field, it does write 'New York' into the address column.