oracle 觸發器方式實現行ＩＤ自增加

CREATE OR REPLACE TRIGGER autoInsertSeq_stock_info_dayly
  BEFORE INSERT
  on test_table
  for each row
DECLARE
next_data_id NUMBER;
BEGIN
SELECT seq_sa_data.NEXTVAL
INTO next_data_id
FROM DUAL;
:NEW.id :=next_data_id;
END;