find_by_sample.rb

class ActiveRecord::Base
	def self.find_by_sample(sample)
		columns	= self.columns.reject {|column| %w(id created_at updated_at).include?(column.name) }
		cond_str, cond_val = [], []
		columns.each do |column|
			value = sample.send(column.name)
			next if value.nil?
			cond_str << "#{column.name}=?"
			cond_val << value
		end
		self.all(:conditions=>[cond_str.join(" and "),*cond_val])
	end
end