Simple all words named_scope

post.rb

  # Matches posts containing all words in the body.
  named_scope :search, lambda { |q|
    if connection.adapter_name == 'MySQL'
      q = q.split(/\W/).map{|q| "[[:<:]]#{Regexp.escape(q)}[[:>:]]"}
      {:conditions => [(['posts.body REGEXP ?'] * q.size).join(" AND "), *q]}
    else
      raise NotImplementedError
    end
  }