INSERT IGNORE INTO `#__hikashop_category` (`category_id`, `category_parent_id`, `category_type`, `category_name`, `category_description`, `category_published`, `category_ordering`, `category_left`, `category_right`, `category_depth`, `category_namekey`) VALUES (1, 0, 'root', 'ROOT', '', 0, 0, 1, 22, 0, 'root'),(2, 1, 'product', 'product category', '', 1, 1, 2, 3, 1, 'product'),(3, 1, 'tax', 'taxation category', '', 1, 2, 4, 7, 1, 'tax');
Afterwards you might need to perform a "rebuild tree" via the HikaShop category listing toolbar.
But if you have purge your hikashop_category table ; I'm afraid that you might have other side effects.