public function update(Category $category)
 {
     if ($this->find($category->getId())) {
         $catId = $category->getId();
         $userId = $category->getUser()->getId();
         $superCat = $category->getParentCategory()->getId();
         $subCat = $category->getSubCategory();
         $sql = "UPDATE " . $this->TABLE_NAME . " SET\n                    userId='{$userId}',superCategory='{$superCat}',subCategory='{$subCat}'\n                    WHERE id='{$catId}'";
         if (mysql_query($sql, $this->connection)) {
             return true;
         } else {
             return false;
         }
     } else {
         return false;
     }
 }