Oracle 遊標使用全解

這個文檔幾乎包含了oracle遊標使用的方方面面，所有經過了測試。

-- 聲明遊標；CURSOR cursor_name IS select_statement

--For 循環遊標
--（1）定義遊標
--（2）定義遊標變量
--（3）使用for循環來使用這個遊標
declare
       --類型定義
       cursor c_job
       is
       select empno,ename,job,sal
       from emp
       where job='MANAGER';
       --定義一個遊標變量v_cinfo c_emp%ROWTYPE ，該類型爲遊標c_emp中的一行數據類型
       c_row c_job%rowtype;
begin
       for c_row in c_job loop
           dbms_output.put_line(c_row.empno||'-'||c_row.ename||'-'||c_row.job||'-'||c_row.sal);
       end loop;
end;


--Fetch遊標
--使用的時候必需要明確的打開和關閉

declare 
       --類型定義
       cursor c_job
       is
       select empno,ename,job,sal
       from emp
       where job='MANAGER';
       --定義一個遊標變量
       c_row c_job%rowtype;
begin
       open c_job;
         loop
           --提取一行數據到c_row
           fetch c_job into c_row;
           --判讀是否提取到值，沒取到值就退出
           --取到值c_job%notfound 是false 
           --取不到值c_job%notfound 是true
           exit when c_job%notfound;
            dbms_output.put_line(c_row.empno||'-'||c_row.ename||'-'||c_row.job||'-'||c_row.sal);
         end loop;
       --關閉遊標
      close c_job;
end;

--1：任意執行一個update操做，用隱式遊標sql的屬性%found,%notfound,%rowcount,%isopen觀察update語句的執行狀況。
       begin
         update emp set ENAME='ALEARK' WHERE EMPNO=7469;
         if sql%isopen then
            dbms_output.put_line('Openging');
         else
            dbms_output.put_line('closing');
         end if;
         if sql%found then
            dbms_output.put_line('遊標指向了有效行');--判斷遊標是否指向有效行
         else
            dbms_output.put_line('Sorry');
         end if;
         if sql%notfound then
            dbms_output.put_line('Also Sorry');
         else
            dbms_output.put_line('Haha');
         end if;
         dbms_output.put_line(sql%rowcount);
         exception 
           when no_data_found then
              dbms_output.put_line('Sorry No data');
           when too_many_rows then
              dbms_output.put_line('Too Many rows');
         end;
declare
       empNumber emp.EMPNO%TYPE;
       empName emp.ENAME%TYPE;
       begin
         if sql%isopen then
            dbms_output.put_line('Cursor is opinging');
         else
            dbms_output.put_line('Cursor is Close');
         end if;
         if sql%notfound then
            dbms_output.put_line('No Value');
         else
            dbms_output.put_line(empNumber);
         end if;
         dbms_output.put_line(sql%rowcount);
         dbms_output.put_line('-------------');
                 
         select EMPNO,ENAME into  empNumber,empName from emp where EMPNO=7499;
         dbms_output.put_line(sql%rowcount);
                 
         if sql%isopen then
            dbms_output.put_line('Cursor is opinging');
         else
            dbms_output.put_line('Cursor is Closing');
         end if;
         if sql%notfound then
            dbms_output.put_line('No Value');
         else
            dbms_output.put_line(empNumber);
         end if;
         exception 
            when no_data_found then
                 dbms_output.put_line('No Value');
            when too_many_rows then
                 dbms_output.put_line('too many rows');
         end;
                   
                 
       
--2,使用遊標和loop循環來顯示全部部門的名稱
--遊標聲明
declare 
       cursor csr_dept
       is
       --select語句
       select DNAME
       from Depth;
       --指定行指針,這句話應該是指定和csr_dept行類型相同的變量
       row_dept csr_dept%rowtype;
begin
       --for循環
       for row_dept in csr_dept loop
           dbms_output.put_line('部門名稱:'||row_dept.DNAME);
       end loop;
end;


--3,使用遊標和while循環來顯示全部部門的的地理位置（用%found屬性）
declare
       --遊標聲明
       cursor csr_TestWhile
       is
       --select語句
       select  LOC
       from Depth;
       --指定行指針
       row_loc csr_TestWhile%rowtype;
begin
  --打開遊標
       open csr_TestWhile;
       --給第一行喂數據
       fetch csr_TestWhile into row_loc;
       --測試是否有數據，並執行循環
         while csr_TestWhile%found loop
           dbms_output.put_line('部門地點：'||row_loc.LOC);
           --給下一行喂數據
           fetch csr_TestWhile into row_loc;
         end loop;
       close csr_TestWhile;
end; 
select * from emp


--4,接收用戶輸入的部門編號，用for循環和遊標，打印出此部門的全部僱員的全部信息(使用循環遊標)
--CURSOR cursor_name[(parameter[,parameter],...)] IS select_statement;
--定義參數的語法以下:Parameter_name [IN] data_type[{:=|DEFAULT} value]  

declare 
      CURSOR 
      c_dept(p_deptNo number)
      is
      select * from emp where emp.depno=p_deptNo;
      r_emp emp%rowtype;
begin
        for r_emp in c_dept(20) loop
            dbms_output.put_line('員工號：'||r_emp.EMPNO||'員工名：'||r_emp.ENAME||'工資：'||r_emp.SAL);
        end loop;
end;
select * from emp   
--5：向遊標傳遞一個工種，顯示此工種的全部僱員的全部信息(使用參數遊標)
declare 
       cursor
       c_job(p_job nvarchar2)
       is 
       select * from emp where JOB=p_job;
       r_job emp%rowtype;
begin 
       for r_job in c_job('CLERK') loop
           dbms_output.put_line('員工號'||r_job.EMPNO||' '||'員工姓名'||r_job.ENAME);
        end loop;
end;
SELECT * FROM EMP

--6：用更新遊標來爲僱員加佣金：(用if實現,建立一個與emp表一摸同樣的emp1表，對emp1表進行修改操做),並將更新先後的數據輸出出來 
--http://zheng12tian.iteye.com/blog/815770 

    create table emp1 as select * from emp;
        
declare
        cursor
        csr_Update
        is
        select * from  emp1 for update OF SAL;
        empInfo csr_Update%rowtype;
        saleInfo  emp1.SAL%TYPE;
begin
    FOR empInfo IN csr_Update LOOP
      if empInfo.SAL<1500 THEN
         saleInfo:=empInfo.SAL*1.2;
      elsif empInfo.SAL<2000 THEN
         saleInfo:=empInfo.SAL*1.5;
      elsif empInfo.SAL<3000 THEN
         saleInfo:=empInfo.SAL*2;
      end if;
      UPDATE emp1 SET SAL=saleInfo WHERE CURRENT OF csr_Update;
     END LOOP;
END;

--7:編寫一個PL/SQL程序塊，對名字以‘A’或‘S’開始的全部僱員按他們的基本薪水(sal)的10%給他們加薪(對emp1表進行修改操做)
declare 
     cursor
      csr_AddSal
     is
      select * from emp1 where ENAME LIKE 'A%' OR ENAME LIKE 'S%' for update OF SAL;
      r_AddSal csr_AddSal%rowtype;
      saleInfo  emp1.SAL%TYPE;
begin
      for r_AddSal in csr_AddSal loop
          dbms_output.put_line(r_AddSal.ENAME||'原來的工資:'||r_AddSal.SAL);
          saleInfo:=r_AddSal.SAL*1.1;
          UPDATE emp1 SET SAL=saleInfo WHERE CURRENT OF csr_AddSal;
      end loop;
end;
--8：編寫一個PL/SQL程序塊，對全部的salesman增長佣金(comm)500
declare
      cursor
          csr_AddComm(p_job nvarchar2)
      is
          select * from emp1 where   JOB=p_job FOR UPDATE OF COMM;
      r_AddComm  emp1%rowtype;
      commInfo emp1.comm%type;
begin
    for r_AddComm in csr_AddComm('SALESMAN') LOOP
        commInfo:=r_AddComm.COMM+500;
         UPDATE EMP1 SET COMM=commInfo where CURRENT OF csr_AddComm;
    END LOOP;
END;

--9：編寫一個PL/SQL程序塊，以提高2個資格最老的職員爲MANAGER（工做時間越長，資格越老）
--（提示：能夠定義一個變量做爲計數器控制遊標只提取兩條數據；也能夠在聲明遊標的時候把僱員中資格最老的兩我的查出來放到遊標中。）
declare
    cursor crs_testComput
    is
    select * from emp1 order by HIREDATE asc;
    --計數器
    top_two number:=2;
    r_testComput crs_testComput%rowtype;
begin
    open crs_testComput;
       FETCH crs_testComput INTO r_testComput;
          while top_two>0 loop
             dbms_output.put_line('員工姓名：'||r_testComput.ENAME||' 工做時間：'||r_testComput.HIREDATE);
             --計速器減一
             top_two:=top_two-1;
             FETCH crs_testComput INTO r_testComput;
           end loop;
     close crs_testComput;
end;
    

--10：編寫一個PL/SQL程序塊，對全部僱員按他們的基本薪水(sal)的20%爲他們加薪，
--若是增長的薪水大於300就取消加薪(對emp1表進行修改操做，並將更新先後的數據輸出出來) 
declare
    cursor
        crs_UpadateSal
    is
        select * from emp1 for update of SAL;
        r_UpdateSal crs_UpadateSal%rowtype;
        salAdd emp1.sal%type;
        salInfo emp1.sal%type;
begin
        for r_UpdateSal in crs_UpadateSal loop
           salAdd:= r_UpdateSal.SAL*0.2;
           if salAdd>300 then
              salInfo:=r_UpdateSal.SAL;
              dbms_output.put_line(r_UpdateSal.ENAME||':  加薪失敗。'||'薪水維持在：'||r_UpdateSal.SAL);
           else 
              salInfo:=r_UpdateSal.SAL+salAdd;
              dbms_output.put_line(r_UpdateSal.ENAME||':  加薪成功.'||'薪水變爲：'||salInfo);
           end if;
           update emp1 set SAL=salInfo where current of crs_UpadateSal;
        end loop;
end;
     
--11:將每位員工工做了多少年零多少月零多少天輸出出來   
--近似
  --CEIL(n)函數：取大於等於數值n的最小整數
  --FLOOR(n)函數：取小於等於數值n的最大整數
  --truc的用法 http://publish.it168.com/2005/1028/20051028034101.shtml
declare
  cursor
   crs_WorkDay
   is
       select ENAME,HIREDATE, trunc(months_between(sysdate, hiredate) / 12) AS SPANDYEARS,
       trunc(mod(months_between(sysdate, hiredate), 12)) AS months,
       trunc(mod(mod(sysdate - hiredate, 365), 12)) as days
       from emp1;
  r_WorkDay crs_WorkDay%rowtype;
begin
    for r_WorkDay in crs_WorkDay loop
        dbms_output.put_line(r_WorkDay.ENAME||'已經工做了'||r_WorkDay.SPANDYEARS||'年,零'||r_WorkDay.months||'月,零'||r_WorkDay.days||'天');
    end loop;
end;
  
--12:輸入部門編號，按照下列加薪比例執行(用CASE實現，建立一個emp1表，修改emp1表的數據),並將更新先後的數據輸出出來
--  deptno  raise(%)
--  10      5%
--  20      10%
--  30      15%
--  40      20%
--  加薪比例以現有的sal爲標準
--CASE expr WHEN comparison_expr THEN return_expr
--[, WHEN comparison_expr THEN return_expr]... [ELSE else_expr] END
declare
     cursor
          crs_caseTest
          is
          select * from emp1 for update of SAL;
          r_caseTest crs_caseTest%rowtype;
          salInfo emp1.sal%type;
     begin
         for r_caseTest in crs_caseTest loop
         case 
           when r_caseTest.DEPNO=10
           THEN salInfo:=r_caseTest.SAL*1.05;
           when r_caseTest.DEPNO=20
           THEN salInfo:=r_caseTest.SAL*1.1;
           when r_caseTest.DEPNO=30
           THEN salInfo:=r_caseTest.SAL*1.15;
           when r_caseTest.DEPNO=40
           THEN salInfo:=r_caseTest.SAL*1.2;
         end case;
         update emp1 set SAL=salInfo where current of crs_caseTest;
         end loop;
end;

--13:對每位員工的薪水進行判斷，若是該員工薪水高於其所在部門的平均薪水，則將其薪水減50元，輸出更新先後的薪水，員工姓名，所在部門編號。
--AVG([distinct|all] expr) over (analytic_clause)
---做用：
--按照analytic_clause中的規則求分組平均值。
  --分析函數語法:
  --FUNCTION_NAME(<argument>,<argument>...)
  --OVER
  --(<Partition-Clause><Order-by-Clause><Windowing Clause>)
     --PARTITION子句
     --按照表達式分區(就是分組),若是省略了分區子句,則所有的結果集被看做是一個單一的組
     select * from emp1
DECLARE
     CURSOR 
     crs_testAvg
     IS
     select EMPNO,ENAME,JOB,SAL,DEPNO,AVG(SAL) OVER (PARTITION BY DEPNO ) AS DEP_AVG
     FROM EMP1 for update of SAL;
     r_testAvg crs_testAvg%rowtype;
     salInfo emp1.sal%type;
     begin
     for r_testAvg in crs_testAvg loop
       if r_testAvg.SAL>r_testAvg.DEP_AVG then
          salInfo:=r_testAvg.SAL-50;
       end if;
       update emp1 set SAL=salInfo where current of crs_testAvg;
     end loop;
end;

 

===========================================================================

另外，下面再附加一個我在項目中編寫使用的一個PL/SQL程序塊中使用遊標的例子：

declare

  --cursor v_possvcfmv Is       select * from ttg_pos_svcfmv_mike order by id;

cursor v_possvcfmv Is
        SELECT m.id,m.status,m.PRODUCTID,decode(c.servicetermid ,null,0,c.servicetermid) servicetermid, b.parano,m.tp,m.icv,b.paracode,
        m.l3direct,m.l3indirect,m.l2direct,m.l2indirect,m.l1indirect,m.privateprice
        FROM ttg_pos_svcfmv_mike m
        LEFT OUTER JOIN  (SELECT * FROM ttg_dictionary WHERE paraid = 75)b ON m.OFFERINGTYPE=b.paracode 
        LEFT   OUTER JOIN TTG_SERVICE_POSMAP c ON     m.productid = c.productid  AND    b.parano = c.OFFERINGID
        where m.status='1' and m.id in (2616,2617)
        order by m.id ;

s_row v_possvcfmv%rowtype;
begin

      open v_possvcfmv;
           fetch v_possvcfmv into s_row;
           while v_possvcfmv%found loop
               
               /*
               SPA_POSSVCFMV(s_row.productid , s_row.servicetermid , s_row.parano , 
               s_row.tp, s_row.icv , s_row.paracode ,'','', 
               s_row.l3direct ,'1', s_row.l3indirect ,'1',s_row.l2direct ,'1' , s_row.l2indirect  ,'1' , s_row.l1indirect  ,'1' , s_row.privateprice  ,'1' ,
               '','','','999999999');

               update ttg_pos_svcfmv_mike set status='1' where id=s_row.id;
*/

               a_jack_Test('SPA_POSSVCFMV(' || s_row.productid || ',' || s_row.servicetermid || ',''' || s_row.parano || ''',' || 
               s_row.tp || ',' || s_row.icv || ',''' || s_row.paracode || ''','''','''',' || 
               s_row.l3direct || ',''1'',' || s_row.l3indirect || ',''1'',' || s_row.l2direct || ',''1'',' || s_row.l2indirect || ',''1'',' || s_row.l1indirect || ',''1'',' || s_row.privateprice || ',''1''' ||
               ','''','''','''',''999999999'')'
               );
               dbms_output.put_line('SPA_POSSVCFMV(' || s_row.productid || ',' || s_row.servicetermid || ',''' || s_row.parano || ''',' || 
               s_row.tp || ',' || s_row.icv || ',''' || s_row.paracode || ''','''','''',' || 
               s_row.l3direct || ',''1'',' || s_row.l3indirect || ',''1'',' || s_row.l2direct || ',''1'',' || s_row.l2indirect || ',''1'',' || s_row.l1indirect || ',''1'',' || s_row.privateprice || ',''1''' ||
               ','''','''','''',''999999999'')'
               );
               
               
           fetch v_possvcfmv into s_row;
           end loop;
      close v_possvcfmv;
   
      --commit;

     Exception
       When Others Then
       rollback;
     end;

end;

其中  a_jack_Test 是一個存儲過程，只是加了個時間戳，存儲過程以下：

create or replace procedure a_jack_Test(v_username in nvarchar2)
as
v_time varchar2(50);
begin
  v_time:=to_char(systimestamp,'yyyy-mm-dd hh24:mi:ss.ff4');
  dbms_output.put_line('[' || v_time || '] ---- ' || v_username);
end;

 

出處：http://www.cnblogs.com/sc-xx/archive/2011/12/03/2275084.html