undefined method `gsub' for nil:NilClass

Je suis newvbie en ruby on rails.. je vais avoir des problèmes avec gsub.. j'ai à chaque fois que je vais à la liste de mon magasin de page il est dit "undefined method `gsub' for nil:NilClass"..

ici est mycode :

def self.search(search_val, page = 1)
    @search_val = search_val.gsub("'", "\\\\'")
    search_query = "store_id LIKE '%#{ @search_val }%' OR english_name LIKE '%#{ @search_val }%' OR chinese_name LIKE '%#{ @search_val }%'"
select("jos_store.id, store_id, english_name, chinese_name, store_manager, delivery_area,year, week").joins("LEFT OUTER JOIN (SELECT id as store_replenishment, store, MAX(stock_movement) AS stock_movement FROM jos_store_replenishment GROUP BY store) AS replenishment ON replenishment.store = jos_store.id").joins("LEFT OUTER JOIN jos_stock_movement ON jos_stock_movement.id = replenishment.stock_movement").where(search_query).order("year DESC, week DESC").paginate :page => page, :per_page => 15  
  end

merci d'avance

InformationsquelleAutor Lian | 2012-07-16