postgresql7.1 insert into ec_subsubcategories (subcategory_id, subsubcategory_id, subsubcategory_name, sort_key, last_modified, last_modifying_user, modified_ip_address) values (:subcategory_id, :subsubcategory_id, :subsubcategory_name, (:prev_sort_key + :next_sort_key)/2, current_timestamp, :user_id,:address)