--異常處理---------------------------------------------------------//
--預定義異常
--NO_DATA_FOUND 沒有數據滿足查詢要求
--ZERO_DIVIDE 算術錯誤,如試圖用0去除一個數
--INVALID_NUMBER 在要求數據的地方使用了非數據
--NOT_LOGGED_ON 沒有連接上Oracle
--TOO_MANY_ROWS SELECT INTO 返回多行記錄
--VALUE_ERROR 遇到算術的、轉換的、截去的或約束錯誤
--CURSOR_ALREADY_OPEN 試圖打開一個已經打開的遊標
--DUP_VAL_ON_INDEX 試圖插入一個已經存在的唯一約束值
--LOGIN_DENIED 要求進入系統的請求被拒絕
--TIMEOUT_ON_RESOURCE 等待的系統時間已經超時
--OTHERS 其它異常
--NO_DATA_FOUND 異常-----------------------------------------------//
--%TYPE是指定義一個變量和數據庫中某個表的某個字段的數據類型一樣
DECLARE
v_name emp.ename%TYPE;
BEGIN
SELECT ename INTO v_name FROM emp WHERE empno='1234'; --異常發生,empno 中沒有1234
DBMS_OUTPUT.PUT_LINE('Name is : ' || v_name);
EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('No Data Found');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--ZERO_DIVIDE 異常-------------------------------------------------//
BEGIN
DBMS_OUTPUT.PUT_LINE(5/0); --異常發生,不能被0除
EXCEPTION
WHEN ZERO_DIVIDE THEN
DBMS_OUTPUT.PUT_LINE('Can not divide zero');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--TOO_MANY_ROWS 異常-----------------------------------------------//
DECLARE
no emp.empno%TYPE;
name emp.ename%TYPE;
dept emp.deptno%TYPE;
BEGIN
SELECT empno,ename,deptno INTO no,name,dept FROM emp WHERE empno = 7369;
DBMS_OUTPUT.PUT_LINE('員工號 :' || no);
DBMS_OUTPUT.PUT_LINE('員工名 :' || name);
DBMS_OUTPUT.PUT_LINE('部門號 :' || dept);
EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('7369僱員不存在'); --未找到數據
WHEN TOO_MANY_ROWS THEN
DBMS_OUTPUT.PUT_LINE('有多個學員號是7369'); --返回多行
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--DUP_VAL_ON_INDEX 異常--------------------------------------------//
BEGIN
INSERT INTO emp
VALUES('7788','LaoZhao','Soft','7689','03-12月-81','2600','0','20');
EXCEPTION
WHEN DUP_VAL_ON_INDEX THEN
DBMS_OUTPUT.PUT_LINE('違反了PRIMARY KEY約束:7788僱員已經存在');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
-------------------------------------------------------------------//
--如果員工7788的工資小於3000,則更新爲3000,如未找到該僱員,則利用異常處理打印相應信息
DECLARE
salary emp.sal%TYPE;
BEGIN
SELECT sal INTO salary FROM emp WHERE empno='7788';
IF salary < 3000 THEN
UPDATE emp SET sal = '3000' WHERE empno = '7788';
DBMS_OUTPUT.PUT_LINE('記錄已更新');
ELSE
DBMS_OUTPUT.PUT_LINE('IF 條件不成立');
END IF;
EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('7788僱員不存在');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--用戶自定義異常---------------------------------------------------//
--001
DECLARE
--v_num1 NUMBER:=5;
v_num1 NUMBER:=0;
--v_num2 NUMBER:=0;
v_num2 NUMBER:=5;
MyException EXCEPTION;
BEGIN
DBMS_OUTPUT.PUT_LINE(v_num1/v_num2);
RAISE MyException; --引發自定義異常
DBMS_OUTPUT.PUT_LINE('OK'); --此句永遠不會執行,因爲發生異常後程序將直接跳到EXCEPTION段
EXCEPTION
WHEN MyException THEN
DBMS_OUTPUT.PUT_LINE('Cannot Divide Zero');
--WHEN ZERO_DIVIDE THEN
-- DBMS_OUTPUT.PUT_LINE('Can not Divide Zero');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--002
DECLARE
id score.id%TYPE;
java score.java%TYPE;
MyException EXCEPTION;
BEGIN
SELECT id,java INTO id,java FROM score WHERE id = 4;
IF java < 0 OR java > 100 THEN
RAISE MyException;
ELSE
DBMS_OUTPUT.PUT_LINE('OK');
END IF;
EXCEPTION
WHEN MyException THEN
UPDATE score SET java=0 WHERE id = 4;
DBMS_OUTPUT.PUT_LINE('分數不能大於100或小於0,現已經清0');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--003
DECLARE
v_date emp.hiredate%TYPE;
MyException EXCEPTION;
BEGIN
INSERT INTO emp(empno,hiredate)
VALUES(1111,TO_DATE('2010-12-25','yyyy-mm-dd'));
COMMIT;
SELECT hiredate INTO v_date FROM emp WHERE empno=1111;
IF v_date > SYSDATE THEN
RAISE MyException;
END IF;
DBMS_OUTPUT.PUT_LINE('執行完畢');
EXCEPTION
WHEN MyException THEN
DBMS_OUTPUT.PUT_LINE('僱用日期不能大於當前日期');
--raise_application_error(-20002,'僱用日期不能大於當前日期');
UPDATE emp SET hiredate = SYSDATE WHERE empno = 1111;
DBMS_OUTPUT.PUT_LINE('日期已更新爲當前日期');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--將定義好的異常與標準的ORACLE錯誤聯繫起來-------------------------//
--001
DECLARE
MyException EXCEPTION;
PRAGMA EXCEPTION_INIT(MyException,-00001); --關聯語句
BEGIN
INSERT INTO emp(empno) VALUES(1234); --發生異常,企圖插入有Check約束的重複值
COMMIT; --插入後提交
DBMS_OUTPUT.PUT_LINE('插入正常');
EXCEPTION
WHEN MyException THEN
DBMS_OUTPUT.PUT_LINE('ORA-00001: 違反了唯一約束');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--002
CREATE TABLE a
(
id INT NOT NULL,
name VARCHAR2(20) NOT NULL
);
DECLARE
MyException EXCEPTION;
PRAGMA EXCEPTION_INIT(MyException,-1400); --關聯語句
BEGIN
INSERT INTO a(id) VALUES(1); --發生異常,違反了NOT NULL約束
EXCEPTION
WHEN MyException THEN
DBMS_OUTPUT.PUT_LINE('錯誤代號:-1400');
DBMS_OUTPUT.PUT_LINE('錯誤描述:違反了NOT NULL約束');
DBMS_OUTPUT.PUT_LINE('錯誤發生時間:' ||
TO_CHAR(SYSDATE,'yyyy-mm-dd hh24:mi:ss'));
INSERT INTO errinfo
VALUES('-1400','違反了 NOT NULL約束',TO_CHAR(SYSDATE,'yyyy-mm-dd hh24:mi:ss'));
DBMS_OUTPUT.PUT_LINE('已經將錯誤記錄在ErrInfo表');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--003
DECLARE
MyException EXCEPTION;
salary emp.sal%TYPE;
BEGIN
SELECT sal INTO salary FROM emp WHERE empno = '7788';
IF salary > 2000 THEN
RAISE MyException;
END IF;
EXCEPTION
WHEN MyException THEN
RAISE_APPLICATION_ERROR(-20001,'RAISE_APPLICATION_ERROR異常發生',FALSE); --TRUE
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--課後練習---------------------------------------------------------//
--001
DECLARE
gz emp.sal%TYPE;
MyExc EXCEPTION;
BEGIN
SELECT sal INTO gz FROM emp WHERE ename='SCOTT';
DBMS_OUTPUT.PUT_LINE('原工資 : ' || gz);
IF gz < 2000 THEN
RAISE MyExc;
ELSE
DBMS_OUTPUT.PUT_LINE('工資無需更新');
END IF;
EXCEPTION
WHEN MyExc THEN
UPDATE emp SET sal = 3000 WHERE ename='SCOTT';
DBMS_OUTPUT.PUT_LINE('記錄已經更新');
SELECT sal INTO gz FROM emp WHERE ename='SCOTT';
DBMS_OUTPUT.PUT_LINE('更新後工資 : ' || gz);
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--002
DECLARE
lo salgrade.losal%TYPE;
hi salgrade.hisal%TYPE;
MyExc EXCEPTION;
BEGIN
INSERT INTO salgrade VALUES(6,2600,2400);
COMMIT;
SELECT losal,hisal INTO lo,hi FROM salgrade WHERE grade = 6;
IF lo > hi THEN
RAISE MyExc;
ELSE
DBMS_OUTPUT.PUT_LINE('記錄已經插入');
END IF;
EXCEPTION
WHEN MyExc THEN
--刪除插入的記錄並打印相應信息
delete salgrade WHERE grade = 6;
DBMS_OUTPUT.PUT_LINE('記錄插入失敗 LOSAL 必須小於 HISAL');
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('Unknown Error');
END;
/
--附註-------------------------------------------------------------//
--如需在PL\SQL中進行值輸入,
DECLARE
num LONG;
BEGIN
num := '&num';
DBMS_OUTPUT.PUT_LINE('Input value is : ' || num);
END;
/
--注意:如果要使你在DBMS_OUTPUT.PUT_LINE(...)中顯示的語句得以顯示,則必須顯示的調用
SET SERVEROUTPUT ON;
----------------------------------------------------------------------------------End//
本文來自:http://javato.iteye.com/blog/78060