oracle 3

--[3]// Oracle PL/SQL 編程
-------------------------------------------------------------------------------------//
--創建錯誤信息表
CREATE TABLE ErrInfo
(
    ErrCode NUMBER(4) NOT NULL,
    ErrWord VARCHAR2(20) NOT NULL,
    ErrDate VARCHAR2(20) NOT NULL
);

--IF...ELSIF...ELSE...END IF;--------------------------------------//
DECLARE
    var1 NUMBER:=8;
BEGIN
    IF var1=1 THEN
        DBMS_OUTPUT.PUT_LINE('This NUMBER is ' || var1);
    ELSIF var1=2 THEN
        DBMS_OUTPUT.PUT_LINE('This NUMBER is ' || var1);
    ELSE
        DBMS_OUTPUT.PUT_LINE('Unknown the number');
    END IF;
END;
/
--CASE variable WHEN expression1 THEN value1;ELSE...END CASE;------//
--%ROWTYPE是指定義一個變量和數據庫中某個表的一條記錄數據類型一樣，它指向該表的某一條記錄
DECLARE
    rec emp%ROWTYPE;
BEGIN
    SELECT  * INTO rec FROM emp WHERE ename='SCOTT';
    CASE  rec.sal
    WHEN 3000 THEN
        DBMS_OUTPUT.PUT_LINE('More than 3000');
    WHEN  2000 THEN
        DBMS_OUTPUT.PUT_LINE('More than 2000');
    ELSE
        DBMS_OUTPUT.PUT_LINE('Less than 2000');
    END CASE ;
END;
/
--LOOP...expression...EXIT WHEN expression...END LOOP--------------//
DECLARE
    var1 NUMBER:=1;
BEGIN
    LOOP
        DBMS_OUTPUT.PUT_LINE(var1);
        var1:=var1+1;
        EXIT WHEN var1=11;  --退出條件
    END LOOP;
END;
/
--WHILE...condition...LOOP...sentence...END LOOP;------------------//
DECLARE
    var1 NUMBER:=10;
BEGIN
    WHILE var1>=1  --退出條件
    LOOP
        DBMS_OUTPUT.PUT_LINE(var1);
        var1:=var1-1;
    END LOOP;
END;
/
--FOR...variable IN 1...10 LOOP...END LOOP;------------------------//
DECLARE

BEGIN
    FOR i IN 1..10 LOOP  --此條語句如變爲 FOR i IN REVERSE 1..10 LOOP ，輸出將爲降序
        DBMS_OUTPUT.PUT_LINE(i);
    END LOOP;
END;
/

--GOTO Label...;...;<<Label>>...;----------------------------------//
BEGIN
    GOTO a;  --程序將在一開始跳到標籤a
    FOR i IN 1..10 LOOP
        DBMS_OUTPUT.PUT_LINE(i);
        IF i=5 THEN
            GOTO a;
        END IF;
    END LOOP;
    <<a>>
    DBMS_OUTPUT.PUT_LINE('This is new line');
END;
/
--嵌套實現9*9乘法表------------------------------------------------//
DECLARE
    i NUMBER:=0;
BEGIN
    WHILE i<9
    LOOP
        i:=i+1;
        DECLARE
            j NUMBER:=0;
        BEGIN
            WHILE j<i
            LOOP
                j:=j+1;
                DBMS_OUTPUT.PUT(j || '*' || i || '=' || i*j || ' ');
            END LOOP;
        END;
    DBMS_OUTPUT.PUT_LINE('');
    END LOOP;
END;
/

--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//