Active Record Search For Rails 3, 4

search.rb

##
# A simple search method
def self.search text
  columns = [:name, :roll_no, :address, :city, :pin, :ph]
  words = text.downcase.split(/\s+/)
  query_array_2 = []
  for word in words
        query_array = []
  	for column in columns
  	    query_array << "lower(#{column}) like '%#{word}%'"
  	end
  	query_array_2 << query_array.join(' or ')
  end
  query = query_array_2.collect{|e| "(#{e})"}.join(' and ')
  self.where query
end