CREATE OR REPLACE FUNCTION WBAR_TEST_1 RETURN NUMBER IS
  LN_TMP NUMBER;
BEGIN
  LN_TMP := SOME_SEQUENCE.NEXTVAL;
  RETURN LN_TMP;
END WBAR_TEST_1;

和

CREATE OR REPLACE FUNCTION WBAR_TEST_2 RETURN NUMBER IS
  LN_TMP NUMBER;
BEGIN
  SELECT SOME_SEQUENCE.NEXTVAL INTO LN_TMP FROM DUAL;
  RETURN LN_TMP;
END WBAR_TEST_2;

我认为第二种方法仅用于历史目的.