Solucion de problema

usr/local/rvm/gems/ruby-1.9.2-p320/gems/sqlite_magic-0.0.3/lib/sqlite_magic.rb:91:in `block in save_data': Data has nil value for unique key. Unique keys are ["id"]. Offending data: {"name"=>"Malacates", "url"=>"/index.php/malacates.html?page=shop.browse&category_id=1"}  (SqliteMagic::DatabaseError)
	from /usr/local/rvm/gems/ruby-1.9.2-p320/gems/sqlite_magic-0.0.3/lib/sqlite_magic.rb:88:in `each'
	from /usr/local/rvm/gems/ruby-1.9.2-p320/gems/sqlite_magic-0.0.3/lib/sqlite_magic.rb:88:in `save_data'
	from /usr/local/rvm/gems/ruby-1.9.2-p320/gems/scraperwiki-3.0.1/lib/scraperwiki.rb:89:in `save_sqlite'
	from /repo/scraper.rb:43:in `block in <main>'
	from /usr/local/rvm/gems/ruby-1.9.2-p320/gems/nokogiri-1.5.0/lib/nokogiri/xml/node_set.rb:239:in `block in each'
	from /usr/local/rvm/gems/ruby-1.9.2-p320/gems/nokogiri-1.5.0/lib/nokogiri/xml/node_set.rb:238:in `upto'
	from /usr/local/rvm/gems/ruby-1.9.2-p320/gems/nokogiri-1.5.0/lib/nokogiri/xml/node_set.rb:238:in `each'
	from /repo/scraper.rb:37:in `<main>'