子程序很像一段小型的程序，由可选的声明部分，
执行控制部分和可选的异常控制部分组成。

?

PROCEDURE award_bonus(emp_id NUMBER) IS
bonus REAL;
comm_missing EXCEPTION;
BEGIN -- executable part starts here
SELECT comm * 0.15
INTO bonus
FROM emp
WHERE empno = emp_id;
IF bonus IS NULL THEN
RAISE comm_missing;
ELSE
UPDATE payroll
SET pay = pay + bonus
WHERE empno = emp_id;
END IF;
EXCEPTION -- exception-handling part starts here
WHEN comm_missing THEN
...

??? EXCEPTION
??? --log
??? WHEN OTHERS THEN
????? v_ErrorCode := SQLCODE;
????? v_ErrorText := SUBSTR(SQLERRM, 1, 2000);
????? insert into t_l4_log
??????? (sid,
???????? TABLENAME,
???????? START_TIME,
???????? END_TIME,
???????? LOG_INFO)
????? values
??????? (t_l4_log_seq.nextval,
???????? 't_l4_pdt_specific',
???????? start_date,
???????? sysdate,
???????? v_ErrorCode || '::' || v_ErrorText||org_code_error||atnam_error||ATWRT_error);
????? --log?
END award_bonus;